1 00:00:08,000 --> 00:00:12,720 Think of a substance with a sight and smell that disgusts us. 2 00:00:16,800 --> 00:00:19,360 Something we're hard-wired to avoid. 3 00:00:24,600 --> 00:00:29,480 But look beyond our disgust and we might see it's a substance 4 00:00:29,480 --> 00:00:34,440 with amazing potential to be the ultimate renewable resource, 5 00:00:34,440 --> 00:00:40,000 capable of solving some of humanity's greatest challenges. 6 00:00:40,000 --> 00:00:43,240 Its gases have the potential to generate power. 7 00:00:45,240 --> 00:00:49,240 It's full of nutrients that are essential to agriculture. 8 00:00:50,880 --> 00:00:56,320 And it contains medical secrets that could transform health care. 9 00:00:56,320 --> 00:01:00,640 I'm talking about human waste, about sewage. 10 00:01:00,640 --> 00:01:02,320 I'm Dr George McGavin. 11 00:01:02,320 --> 00:01:04,880 With exclusive access to one of Europe's 12 00:01:04,880 --> 00:01:06,800 most advanced sewage works, 13 00:01:06,800 --> 00:01:11,400 I'm setting out to prove that poo could be priceless. 14 00:01:11,400 --> 00:01:13,920 It's black gold, isn't it, really? 15 00:01:13,920 --> 00:01:18,400 Uncovering how a revolution in the science of human waste 16 00:01:18,400 --> 00:01:20,760 could transform our lives. 17 00:01:20,760 --> 00:01:24,120 So you could supply gas to 28,000 homes. 18 00:01:24,120 --> 00:01:26,840 Bold enough to join me on this quest 19 00:01:26,840 --> 00:01:29,880 is materials scientist Dr Zoe Laughlin. 20 00:01:29,880 --> 00:01:32,960 It doesn't smell in any way disgusting. 21 00:01:32,960 --> 00:01:37,200 I want to get up close and personal with what we flush away... 22 00:01:37,200 --> 00:01:41,280 It's just like a horror hatch into raw sewage. It's not pleasant. 23 00:01:41,280 --> 00:01:45,320 ..to get to grips with exactly what's in it... Oh! 24 00:01:45,320 --> 00:01:50,040 ..and discover the mind-boggling microbiology being used to clean it. 25 00:01:51,400 --> 00:01:53,800 Oh! Wow! It's massive! 26 00:01:53,800 --> 00:01:55,120 Look at it. 27 00:01:55,120 --> 00:01:58,040 With a pop up lab based at this sewage works, 28 00:01:58,040 --> 00:02:01,760 we're even going to search for new life in sewage 29 00:02:01,760 --> 00:02:04,520 that could have amazing medical properties. 30 00:02:04,520 --> 00:02:08,000 You have discovered a biological entity 31 00:02:08,000 --> 00:02:10,560 which is potentially a life-saver. 32 00:02:10,560 --> 00:02:12,360 Every new one that we find is another patient 33 00:02:12,360 --> 00:02:14,000 that we can potentially treat. 34 00:02:14,000 --> 00:02:18,240 Join us on an incredible journey into a hidden world 35 00:02:18,240 --> 00:02:21,080 where we face up to our faeces 36 00:02:21,080 --> 00:02:24,320 and uncover the secret science of sewage. 37 00:02:32,040 --> 00:02:35,280 Pretty much all of us will flush something down the toilet 38 00:02:35,280 --> 00:02:37,280 several times a day. 39 00:02:38,960 --> 00:02:41,560 Our developed world affords us the luxury 40 00:02:41,560 --> 00:02:45,040 of never having to think about it again. 41 00:02:45,040 --> 00:02:49,600 A cistern full of water carries the unmentionable "it" away 42 00:02:49,600 --> 00:02:52,280 into a hidden network of pipes. 43 00:02:52,280 --> 00:02:54,360 But where is "away"? 44 00:02:55,800 --> 00:02:57,720 What we flush has to go somewhere. 45 00:02:59,480 --> 00:03:01,960 And that somewhere is a place like this. 46 00:03:03,560 --> 00:03:08,360 This is Minworth Sewage Works on the eastern outskirts of Birmingham. 47 00:03:12,960 --> 00:03:16,480 Run by Severn Trent Water, it's one of the biggest in the country, 48 00:03:16,480 --> 00:03:21,120 a square kilometre of pipes and pools dedicated to processing 49 00:03:21,120 --> 00:03:24,840 the waste water of Birmingham and the Black Country. 50 00:03:24,840 --> 00:03:27,200 Every day, it's on the receiving end 51 00:03:27,200 --> 00:03:31,280 of 1.7 million people's faecal matter. 52 00:03:34,880 --> 00:03:38,200 This massive treatment plant is the ideal place 53 00:03:38,200 --> 00:03:42,320 to investigate how stripping resources out of sewage 54 00:03:42,320 --> 00:03:47,240 can turn it back into water clean enough to return to the environment. 55 00:03:52,640 --> 00:03:56,760 We're going to take you through each stage of the process, beginning 56 00:03:56,760 --> 00:04:01,000 at the point where the raw sewage arrives on site - the inflow. 57 00:04:05,280 --> 00:04:07,200 Which is where I find Zoe. 58 00:04:08,960 --> 00:04:12,120 Zoe, I'm feeling rather overwhelmed now. 59 00:04:12,120 --> 00:04:17,880 Our job is to persuade people that this is a valuable resource. 60 00:04:17,880 --> 00:04:21,760 It's absolutely disgusting, but I can't take my eyes off it. 61 00:04:21,760 --> 00:04:24,440 It gives a whole new meaning to Poohsticks! 62 00:04:24,440 --> 00:04:26,880 HE GUFFAWS 63 00:04:26,880 --> 00:04:32,800 At peak flow, this is 12, nearly 12,500 litres a second. 64 00:04:32,800 --> 00:04:34,520 That's a billion litres a day. 65 00:04:37,360 --> 00:04:41,680 But it hasn't rained for days, so this is just normal toilet 66 00:04:41,680 --> 00:04:44,920 flushing... It's regular... ..and drains on the roads, yeah. 67 00:04:44,920 --> 00:04:46,800 Regular sewage. Regular sewage. 68 00:04:46,800 --> 00:04:49,040 This isn't a storm flow. 69 00:04:49,040 --> 00:04:51,000 I mean, this is just humanity. 70 00:04:51,000 --> 00:04:54,600 This is just the waste product of a large number of people. 71 00:04:54,600 --> 00:04:56,120 That's all it is. 72 00:04:58,320 --> 00:05:01,640 But when we say raw sewage, what do we mean? 73 00:05:01,640 --> 00:05:04,240 What does it actually comprise of? 74 00:05:04,240 --> 00:05:08,240 Perhaps what few of us realise is that sewage plants 75 00:05:08,240 --> 00:05:11,880 don't just deal with human waste, it's all the water we use. 76 00:05:11,880 --> 00:05:15,600 Anything that goes down the sink, from the dishwasher, the washing 77 00:05:15,600 --> 00:05:17,800 machine, the shower, the bath, 78 00:05:17,800 --> 00:05:21,040 anything that ends up in the drains, all of it. 79 00:05:24,760 --> 00:05:28,960 So what's in this disgusting torrent that's a resource? 80 00:05:30,200 --> 00:05:33,240 And what things shouldn't be in there at all? 81 00:05:35,800 --> 00:05:39,720 To find out, Zoe's set up a demonstration at our pop-up lab 82 00:05:39,720 --> 00:05:41,760 to deconstruct sewage. 83 00:05:44,200 --> 00:05:46,120 What I've got here, George, 84 00:05:46,120 --> 00:05:49,480 is a tank that can hold up to 140 litres of water. 85 00:05:49,480 --> 00:05:54,360 Now, that's the volume of how much one person uses every day. 86 00:05:54,360 --> 00:05:57,120 And send it to the sewage treatment plant. 87 00:05:57,120 --> 00:05:59,440 And we send it full of muck. 88 00:05:59,440 --> 00:06:03,080 And what I'm going to do to it is add in all of the things 89 00:06:03,080 --> 00:06:06,160 that we put down the drain over the course of a day. 90 00:06:06,160 --> 00:06:10,040 30% of household water is used for flushing toilets. 91 00:06:10,040 --> 00:06:12,240 So that's where we'll start. 92 00:06:12,240 --> 00:06:14,600 This is two litres of urine. 93 00:06:14,600 --> 00:06:18,600 This is what an average adult would produce... All righty. 94 00:06:18,600 --> 00:06:21,400 ..you know, in a day, if you're well hydrated. Yeah, all right. 95 00:06:21,400 --> 00:06:23,560 In this instance, this is apple juice. 96 00:06:23,560 --> 00:06:29,080 And that contains lots of nitrogen, uric acid, urea, creatinine, 97 00:06:29,080 --> 00:06:31,760 all those things that are very rich in nitrogen 98 00:06:31,760 --> 00:06:33,760 which you have to get out of your system. 99 00:06:33,760 --> 00:06:36,480 Time for a poo. Time for a poo. Time for a poo. 100 00:06:36,480 --> 00:06:41,880 The average adult produces one poo a day of 250g in mass. 101 00:06:41,880 --> 00:06:43,320 Ha! 102 00:06:43,320 --> 00:06:46,640 This is soya bean paste, which is an industry standard 103 00:06:46,640 --> 00:06:48,800 for simulating turds in a toilet. 104 00:06:48,800 --> 00:06:52,640 So I'm going to put in... 250g. ..250g. 105 00:06:52,640 --> 00:06:55,960 231. Not bad. Not bad. Not bad. 106 00:06:55,960 --> 00:06:59,240 In fact, this is quite wet, which isn't far off 107 00:06:59,240 --> 00:07:02,800 what a real poo would be like, because 75% is water. 108 00:07:02,800 --> 00:07:05,400 And then, of the stuff that's not water, 109 00:07:05,400 --> 00:07:09,320 you've got half of that just as biomass, really. 110 00:07:09,320 --> 00:07:14,120 So, bacteria and... And protein. ..protein, fat. 111 00:07:14,120 --> 00:07:17,000 If you've got too much fat in your diet, you'll get the floater. 112 00:07:18,680 --> 00:07:22,120 The protein and biomass in poo equals potential energy, 113 00:07:22,120 --> 00:07:26,320 but as a possible resource, it's now massively diluted. 114 00:07:28,040 --> 00:07:30,640 This amount of poo and pee in this much water 115 00:07:30,640 --> 00:07:34,680 means that human waste makes up less than 2% of raw sewage. 116 00:07:36,160 --> 00:07:39,360 There's something marginally convincingly gross about it, 117 00:07:39,360 --> 00:07:41,280 now it's in the water especially. 118 00:07:41,280 --> 00:07:43,840 But we also add around 25g of toilet paper. 119 00:07:43,840 --> 00:07:47,920 The school of wrap it round the hand, which is bad for the plumbing, 120 00:07:47,920 --> 00:07:50,120 but it is a natural way in which people go. 121 00:07:50,120 --> 00:07:52,400 An average person uses 50 sheets a day. 122 00:07:52,400 --> 00:07:54,840 This is predominantly cellulose. 123 00:07:54,840 --> 00:07:59,680 So this is a natural fibre which will break down pretty easily. 124 00:08:02,560 --> 00:08:06,680 Another 30% of our water use is from the bathroom sink and shower, 125 00:08:06,680 --> 00:08:09,240 over 40 litres worth. 126 00:08:09,240 --> 00:08:13,920 On average, we each add an estimated 30ml of personal hygiene 127 00:08:13,920 --> 00:08:15,520 products a day. 128 00:08:15,520 --> 00:08:17,360 There's a bit of shower gel. 129 00:08:17,360 --> 00:08:19,600 One. Oh, and I did wash my hair. 130 00:08:19,600 --> 00:08:21,000 Shampoo. 131 00:08:21,000 --> 00:08:23,920 Toothpaste. There we go. 132 00:08:23,920 --> 00:08:25,920 These all contain surfactants, 133 00:08:25,920 --> 00:08:28,120 chemicals that act as foaming agents. 134 00:08:28,120 --> 00:08:31,000 Along with sodium hypochlorite in bleach, 135 00:08:31,000 --> 00:08:33,600 these elements will be diluted and break down. 136 00:08:33,600 --> 00:08:35,840 Around... That'll do. 137 00:08:35,840 --> 00:08:39,880 Water use in the kitchen makes up a further 30% of sewage. 138 00:08:39,880 --> 00:08:42,720 And here we can add up to 50ml of detergents 139 00:08:42,720 --> 00:08:44,360 and cleaning agents. 140 00:08:44,360 --> 00:08:45,520 Oh! 141 00:08:46,920 --> 00:08:51,120 All these products are designed to break down in water, 142 00:08:51,120 --> 00:08:55,160 but not everything that we pour down the sink will dissolve. 143 00:08:55,160 --> 00:08:58,160 Sort of sauces and oils on plates definitely go in. 144 00:08:58,160 --> 00:09:00,040 In particular - fats. 145 00:09:00,040 --> 00:09:02,800 And that's what you shouldn't put down the drain, really. 146 00:09:02,800 --> 00:09:05,560 No, but when it's a liquid state, you can see how people do. 147 00:09:05,560 --> 00:09:06,720 Yeah, yeah. 148 00:09:08,360 --> 00:09:11,200 What we can see here is how crucially 149 00:09:11,200 --> 00:09:15,320 the molecular characteristics of fat prevent it dissolving in water. 150 00:09:16,400 --> 00:09:20,760 And in a sewage pipe, it can congeal, causing fatberg blockages. 151 00:09:22,560 --> 00:09:25,000 Once it sort of hits the sewer system, 152 00:09:25,000 --> 00:09:27,840 the turbulence of the flowing water churns it up. 153 00:09:27,840 --> 00:09:30,640 So to simulate that... 154 00:09:30,640 --> 00:09:33,120 Wow, that is...that is a mixer. ..I get the big blender. 155 00:09:33,120 --> 00:09:35,720 BLENDER WHIRS 156 00:09:38,720 --> 00:09:41,000 So now, it's starting to go browner. 157 00:09:41,000 --> 00:09:44,640 Wow! The turds are definitely being agitated. 158 00:09:44,640 --> 00:09:46,240 That's what I like to hear. Yes. 159 00:09:47,960 --> 00:09:52,200 Right, there we go. I want to compare what we have created, 160 00:09:52,200 --> 00:09:53,880 what you have created, 161 00:09:53,880 --> 00:09:57,720 to a bottle of intake water, 162 00:09:57,720 --> 00:09:59,840 which we got from the plant. 163 00:09:59,840 --> 00:10:03,640 And, you know, it's... Not far off. It's not far off, is it? 164 00:10:03,640 --> 00:10:05,760 At the beginning, this was a valuable resource. 165 00:10:05,760 --> 00:10:07,720 It was clean, safe drinking water. 166 00:10:07,720 --> 00:10:11,120 And now I've just come along and contaminated it and made a problem. 167 00:10:11,120 --> 00:10:15,520 But in that problem are, there's energy, 168 00:10:15,520 --> 00:10:18,760 there's minerals that can be reclaimed. 169 00:10:18,760 --> 00:10:21,520 There's stuff in here that's worth having. 170 00:10:22,520 --> 00:10:25,960 But imagining there's stuff in sewage worth having 171 00:10:25,960 --> 00:10:30,800 goes against every natural instinct we have towards it. 172 00:10:30,800 --> 00:10:32,840 We are disgusted by faeces. 173 00:10:34,080 --> 00:10:36,720 It's a socially evolved behaviour. 174 00:10:36,720 --> 00:10:41,400 Babies will play in it, but we learn that excrement is dirty, 175 00:10:41,400 --> 00:10:43,240 it makes you ill. 176 00:10:43,240 --> 00:10:48,280 Scientifically, we know that sewage teems with harmful bacteria 177 00:10:48,280 --> 00:10:51,320 like salmonella and E.coli. 178 00:10:51,320 --> 00:10:55,240 Even traces of Covid-19 have been detected in it. 179 00:10:56,440 --> 00:10:58,360 We pass it out in our poo. 180 00:10:58,360 --> 00:11:01,320 Our bodies are designed to get rid of it. 181 00:11:01,320 --> 00:11:05,120 But does that mean that all viruses and bacteria in us 182 00:11:05,120 --> 00:11:07,160 and in sewage are bad? 183 00:11:10,640 --> 00:11:14,280 Now, this is where the science of shit gets really fascinating. 184 00:11:14,280 --> 00:11:18,160 The bacteria in our intestines, the gut microbiome or flora, 185 00:11:18,160 --> 00:11:22,200 number not in their millions and billions, but in their trillions. 186 00:11:22,200 --> 00:11:25,880 And science is just beginning to understand it. 187 00:11:25,880 --> 00:11:30,680 The bacteria in our gut are a complex and unexplored universe, 188 00:11:30,680 --> 00:11:33,560 individual to each of us. 189 00:11:33,560 --> 00:11:35,600 Yes, they help us digest our food, 190 00:11:35,600 --> 00:11:38,320 but they also protect us from diseases. 191 00:11:38,320 --> 00:11:41,720 There are particular types of bacteria in our intestines 192 00:11:41,720 --> 00:11:44,080 that kill off harmful pathogens. 193 00:11:46,240 --> 00:11:49,840 But when we get sick, often, conventional health care's 194 00:11:49,840 --> 00:11:53,480 default response is to treat us with antibiotics. 195 00:11:54,960 --> 00:11:59,200 This can kill off all the bacteria in our gut, good and bad, 196 00:11:59,200 --> 00:12:02,080 sometimes leaving us even more vulnerable to disease, 197 00:12:02,080 --> 00:12:04,440 especially superbugs. 198 00:12:06,560 --> 00:12:11,800 Just a tiny sample of poo contains millions of unknown good bacteria 199 00:12:11,800 --> 00:12:15,600 and even viruses capable of fighting off disease. 200 00:12:17,200 --> 00:12:21,160 And this is where sewage has the potential to offer 201 00:12:21,160 --> 00:12:24,400 one of the most counterintuitive resources imaginable. 202 00:12:25,600 --> 00:12:27,000 Medicine. 203 00:12:30,520 --> 00:12:34,520 I'm being joined by a true pioneer of the science of sewage, 204 00:12:34,520 --> 00:12:36,360 Dr Ellie Jameson. 205 00:12:36,360 --> 00:12:41,760 And right now, this world-class scientist is, rather bizarrely, 206 00:12:41,760 --> 00:12:46,760 fishing in sewage for a nanoscopic organism she calls a phage. 207 00:12:46,760 --> 00:12:50,200 So this is where the sewage first comes into... 208 00:12:50,200 --> 00:12:52,440 Oh, I've just got a bit of lumpy stuff in there. 209 00:12:52,440 --> 00:12:54,120 ..into the sewage works. 210 00:12:54,120 --> 00:12:57,600 This is where all the bacteria and the phages are. 211 00:12:57,600 --> 00:13:01,840 This is an enhanced photograph of a phage 212 00:13:01,840 --> 00:13:04,800 taken with a powerful electron microscope. 213 00:13:06,800 --> 00:13:11,040 It's an entity so small, it's measured in nanometres, 214 00:13:11,040 --> 00:13:13,480 a millionth of a millimetre. 215 00:13:13,480 --> 00:13:15,120 What is a phage? 216 00:13:15,120 --> 00:13:18,760 So, it's a virus which only infects bacteria. 217 00:13:18,760 --> 00:13:22,120 So, it can't kill any plants or animals, 218 00:13:22,120 --> 00:13:24,280 but it will kill the bacteria. 219 00:13:24,280 --> 00:13:26,320 Why do you want to work on phages? 220 00:13:26,320 --> 00:13:28,720 What use are they to us? 221 00:13:28,720 --> 00:13:31,800 Well, to us, so I'm interested in bacteriophages 222 00:13:31,800 --> 00:13:33,640 which kill superbugs. 223 00:13:33,640 --> 00:13:36,280 So the superbug that I'm interested in is klebsiella, 224 00:13:36,280 --> 00:13:38,760 and that's becoming more of a problem in hospitals. 225 00:13:38,760 --> 00:13:42,720 It's causing pneumonia infections and causing urinary tract infections 226 00:13:42,720 --> 00:13:46,160 which can go on to cause septic shock as well. 227 00:13:47,320 --> 00:13:51,520 Superbugs like klebsiella and E.coli are bacteria 228 00:13:51,520 --> 00:13:53,720 resistant to antibiotics. 229 00:13:53,720 --> 00:13:57,400 But science has discovered that phages will act against them. 230 00:13:59,200 --> 00:14:01,280 How do they attack a bacterium? 231 00:14:01,280 --> 00:14:04,920 So, first of all, they've got little receptors on the legs, 232 00:14:04,920 --> 00:14:08,360 so these bits which come down, like the lunar lander, 233 00:14:08,360 --> 00:14:10,960 so the bit which would land on the moon first, like the legs, 234 00:14:10,960 --> 00:14:13,040 which recognise the bacteria. Right. 235 00:14:13,040 --> 00:14:15,680 And when they stick to a protein that they recognise, 236 00:14:15,680 --> 00:14:19,560 they bind to that and then they can inject their DNA or RNA 237 00:14:19,560 --> 00:14:21,800 inside that bit. Straight into the bacterium? Yeah. 238 00:14:21,800 --> 00:14:26,080 And that basically takes over the bacterium completely. Yeah. 239 00:14:26,080 --> 00:14:29,480 And that will help us to treat infections that we currently 240 00:14:29,480 --> 00:14:31,520 aren't able to treat. 241 00:14:31,520 --> 00:14:34,960 Yes. So, especially in klebsiella, there's a lot of klebsiella 242 00:14:34,960 --> 00:14:37,000 which pick up antibiotic resistance, 243 00:14:37,000 --> 00:14:40,120 and there's some which are multidrug resistant as well. 244 00:14:40,120 --> 00:14:43,520 So resistant to all the common antibiotics that we use. 245 00:14:43,520 --> 00:14:47,000 So by using bacteriophage, these will kill the bacteria, 246 00:14:47,000 --> 00:14:50,280 but also they'll help our existing antibiotics to work better 247 00:14:50,280 --> 00:14:54,480 so we can use them in combination with antibiotics to cure a patient. 248 00:14:54,480 --> 00:14:57,320 So instead of killing off everything in your gut, 249 00:14:57,320 --> 00:15:00,160 like when you have antibiotics, they will just target the thing 250 00:15:00,160 --> 00:15:02,240 which is causing the problem in you 251 00:15:02,240 --> 00:15:04,880 and leave all the other bacteria intact. 252 00:15:04,880 --> 00:15:08,600 Science has known about the existence of bacteriophages 253 00:15:08,600 --> 00:15:11,760 and their therapeutic properties for decades. 254 00:15:11,760 --> 00:15:15,000 But the targeted hunt for them in sewage as an alternative 255 00:15:15,000 --> 00:15:18,800 to antibiotics is a relatively new approach. 256 00:15:18,800 --> 00:15:24,240 This is a churning mass of all sorts of bacteria and viruses, 257 00:15:24,240 --> 00:15:28,600 and out of that soup, you want to extract something 258 00:15:28,600 --> 00:15:31,160 that could be the next wonder drug. 259 00:15:31,160 --> 00:15:33,000 Yeah, that's what we're looking for in here. 260 00:15:33,000 --> 00:15:35,880 There could be loads of things in there that nobody's ever seen before 261 00:15:35,880 --> 00:15:38,760 that could kill the next bacteria which are going to cause problems. 262 00:15:38,760 --> 00:15:41,800 So it's really interesting to find out about these things and get 263 00:15:41,800 --> 00:15:44,840 as many as we can, the different ones to help us to help medicine 264 00:15:44,840 --> 00:15:47,800 and improve the future of medicine. 265 00:15:47,800 --> 00:15:51,440 Ellie's returning to her laboratory for now, 266 00:15:51,440 --> 00:15:55,240 where she'll clean up and analyse her sewage sample for phages. 267 00:15:55,240 --> 00:15:58,640 I'll catch up with her later to see if she's found any 268 00:15:58,640 --> 00:16:01,720 and if they're active against any superbugs. 269 00:16:07,240 --> 00:16:11,880 Meanwhile, Minworth's never-ending torrent of sewage keeps on coming. 270 00:16:13,280 --> 00:16:16,040 And I want to get a closer look at the engineering systems 271 00:16:16,040 --> 00:16:18,200 being used here to process it. 272 00:16:20,240 --> 00:16:24,480 The material science and engineering challenge here is staggering, 273 00:16:24,480 --> 00:16:28,640 bearing in mind that sewage is always flowing and waste water 274 00:16:28,640 --> 00:16:30,640 always needs cleaning. 275 00:16:30,640 --> 00:16:33,800 I want to see where this process begins. 276 00:16:33,800 --> 00:16:36,480 A secret of sewage science 277 00:16:36,480 --> 00:16:38,960 is to always keep the effluent moving. 278 00:16:41,040 --> 00:16:44,160 The architecture of the plant channels the waste water 279 00:16:44,160 --> 00:16:48,360 from where it arrives at the inflow towards stage one of the process, 280 00:16:48,360 --> 00:16:50,640 an area known as the screens. 281 00:16:53,320 --> 00:16:56,560 This set of massive structures are the first point 282 00:16:56,560 --> 00:16:58,640 of sewage filtration. 283 00:16:58,640 --> 00:17:02,640 Keeping the system operational is technician Andy. 284 00:17:02,640 --> 00:17:04,480 Oh, my God. 285 00:17:04,480 --> 00:17:08,240 Andy, what I'm actually... Is this the raw sewage coming in? 286 00:17:08,240 --> 00:17:11,200 Yes, this is, this is the raw sewage coming through these screens. 287 00:17:11,200 --> 00:17:14,200 The flow, everything comes down the drains, through the kitchens, 288 00:17:14,200 --> 00:17:19,720 toilets, comes through here until it hits one of the screens over here. 289 00:17:19,720 --> 00:17:24,480 I can see lumps of brown. Anything that goes down the drain. 290 00:17:26,800 --> 00:17:31,080 Inside the screen structures are angled caterpillar-track-like sieves 291 00:17:31,080 --> 00:17:32,880 constantly rotating. 292 00:17:34,760 --> 00:17:37,360 The sewage flows into the lower part of the track. 293 00:17:38,560 --> 00:17:41,720 Large solid objects like plastics are lifted to the top 294 00:17:41,720 --> 00:17:44,240 and fall into the collection bin below. 295 00:17:47,840 --> 00:17:52,360 But anything liquid or small enough, including poo particles, 296 00:17:52,360 --> 00:17:56,080 pass straight through the 6mm size holes in the sieves. 297 00:17:59,040 --> 00:18:02,800 You'll be amazed how many car wheels come down here, and tyres. 298 00:18:02,800 --> 00:18:04,800 There's a football that we took out this morning. 299 00:18:04,800 --> 00:18:07,000 There's a basketball in one of the ones over there, 300 00:18:07,000 --> 00:18:08,440 which we will get round to later. 301 00:18:12,560 --> 00:18:15,560 I want to take a closer look at the inner workings of these screens. 302 00:18:16,840 --> 00:18:19,280 But as Andy opens the inspection hatch, 303 00:18:19,280 --> 00:18:22,480 the true horror of the sewage system is revealed. 304 00:18:27,800 --> 00:18:29,600 Oh, hell's bells. 305 00:18:29,600 --> 00:18:32,080 Wet wipes. 306 00:18:32,080 --> 00:18:35,480 As you can see, most of this, a lot of these are wipes. 307 00:18:35,480 --> 00:18:38,320 That is... Wet wipe, wet wipe. 308 00:18:38,320 --> 00:18:39,960 A little bit of plastic. 309 00:18:39,960 --> 00:18:42,600 So it's not... The cellulose of toilet paper isn't the problem, 310 00:18:42,600 --> 00:18:46,880 it's the heavy weave and the denseness of the wet wipe. 311 00:18:46,880 --> 00:18:49,920 That's right. It doesn't, it doesn't break up. 312 00:18:49,920 --> 00:18:53,680 It just shreds into smaller pieces, which don't go through the screens, 313 00:18:53,680 --> 00:18:54,760 they end up here. 314 00:18:55,800 --> 00:18:59,440 Wet wipes have only become an issue in the last 20 years. 315 00:18:59,440 --> 00:19:03,560 Now, nearly 15 billion are used in the UK every year 316 00:19:03,560 --> 00:19:08,800 and many get flushed, contributing to 75% of all sewer pipe blockages. 317 00:19:10,640 --> 00:19:13,280 And actually, the closer you look, the more you see, 318 00:19:13,280 --> 00:19:17,640 there's a huge amount of human hair, almost felting it all together. 319 00:19:17,640 --> 00:19:19,160 Wow. 320 00:19:19,160 --> 00:19:22,680 It's just like a horror hatch into raw sewage. 321 00:19:22,680 --> 00:19:25,080 It's not a pleasant... No. ..view, no. 322 00:19:25,080 --> 00:19:27,680 How long have you worked here? 17 years. 323 00:19:27,680 --> 00:19:29,520 Do you feel like you've become used to it? 324 00:19:29,520 --> 00:19:32,240 Is there something...? What's your immune system like? 325 00:19:32,240 --> 00:19:34,520 When you open it up and see a dead rat hanging by its tail, 326 00:19:34,520 --> 00:19:37,440 no, it's still a bit of a shocker. 327 00:19:37,440 --> 00:19:40,640 The sewage passing through the screens 328 00:19:40,640 --> 00:19:43,120 is now a filthy, sieved soup. 329 00:19:43,120 --> 00:19:46,040 With all the elements mixed together, 330 00:19:46,040 --> 00:19:49,440 it's harder than ever to see this as a resource, 331 00:19:49,440 --> 00:19:52,280 especially for generating power with. 332 00:19:53,480 --> 00:19:55,720 And why even go to the effort? 333 00:19:55,720 --> 00:19:58,960 The answer is, we need to. 334 00:19:58,960 --> 00:20:01,440 With fossil fuels unsustainable, 335 00:20:01,440 --> 00:20:06,240 renewable energy sources offers a solution to powering the planet. 336 00:20:06,240 --> 00:20:08,520 Wind and solar can be unpredictable. 337 00:20:10,920 --> 00:20:12,800 But sewage is constant. 338 00:20:14,600 --> 00:20:18,760 In the UK, we produce 11 billion litres of it a day. 339 00:20:18,760 --> 00:20:21,920 The single biggest volume of human waste we produce is urine, 340 00:20:21,920 --> 00:20:26,880 two litres a day each, and it's rich in minerals. 341 00:20:28,200 --> 00:20:31,480 So do these minerals have a value as a resource? 342 00:20:31,480 --> 00:20:34,920 And could we use them more efficiently instead of flushing them 343 00:20:34,920 --> 00:20:37,200 into the sewage mix? 344 00:20:37,200 --> 00:20:41,120 Could there ever be such a thing as pee power? 345 00:20:47,240 --> 00:20:51,560 I've come to Bristol, where an incredible new biotechnology 346 00:20:51,560 --> 00:20:56,440 has been developed, one capable of generating clean energy 347 00:20:56,440 --> 00:21:00,120 from a resource we all produce. 348 00:21:00,120 --> 00:21:02,360 Time for me to spend a penny. 349 00:21:02,360 --> 00:21:06,920 Partly because I need to go, as a gentleman in my vintage often does, 350 00:21:06,920 --> 00:21:10,480 but more importantly because I need to charge my mobile phone. 351 00:21:14,280 --> 00:21:16,720 This is going to power my phone. 352 00:21:20,200 --> 00:21:23,000 I've come to a state of the art research facility 353 00:21:23,000 --> 00:21:27,760 full of mysterious wired up devices and whirring dials. 354 00:21:27,760 --> 00:21:30,840 But centre stage in this lab is a urinal. 355 00:21:30,840 --> 00:21:34,680 Above it is a circuit board and a phone charger. 356 00:21:34,680 --> 00:21:37,440 I'm told all I have to do is to plug my phone in... 357 00:21:37,440 --> 00:21:39,400 Let me stick it in. 358 00:21:39,400 --> 00:21:41,960 ..and pour my pee sample into the urinal. 359 00:21:41,960 --> 00:21:44,400 Honestly, I cannot believe this is going to work. 360 00:21:44,400 --> 00:21:46,800 I mean, it's like one of those things, like, ah! 361 00:21:46,800 --> 00:21:48,440 I have never done this before. 362 00:21:52,200 --> 00:21:54,040 And switch on the current. 363 00:21:55,760 --> 00:21:58,120 Ah, there you are. It's charging. 364 00:21:59,200 --> 00:22:01,040 Wow! 365 00:22:01,040 --> 00:22:05,080 The magic happens round the back in this unlikely looking bank 366 00:22:05,080 --> 00:22:07,640 of battery-like fuel cells. 367 00:22:08,800 --> 00:22:11,800 Its inventor, Professor Ioannis Ieropoulos, 368 00:22:11,800 --> 00:22:14,800 is explaining how these cells work. 369 00:22:14,800 --> 00:22:18,040 This is known as a microbial fuel cell technology. 370 00:22:18,040 --> 00:22:21,960 It's using live bacteria that generate electricity. 371 00:22:21,960 --> 00:22:25,480 So what is in my urine? 372 00:22:25,480 --> 00:22:28,240 What is it in there that they can use? 373 00:22:28,240 --> 00:22:31,520 It contains carbon, phosphorus, potassium, 374 00:22:31,520 --> 00:22:34,160 sulphur, magnesium, creatinine. 375 00:22:34,160 --> 00:22:37,000 And these are elements that the microbes will require 376 00:22:37,000 --> 00:22:39,240 to continue living and growing. 377 00:22:39,240 --> 00:22:43,480 The fuel cells' central tube is porous ceramic 378 00:22:43,480 --> 00:22:47,960 that microbes colonise and urine permeates through. 379 00:22:47,960 --> 00:22:53,520 As elements in urine are consumed, electrons generated by the microbes 380 00:22:53,520 --> 00:22:56,480 are picked up by the cells' opposing wire coils. 381 00:22:56,480 --> 00:22:59,960 Where do the microbes...? Because there has to be particular sorts 382 00:22:59,960 --> 00:23:02,800 of microbes, not just any bug will do. 383 00:23:02,800 --> 00:23:04,840 How do you locate them? 384 00:23:04,840 --> 00:23:08,720 There's a plethora of microbes out in the natural environment 385 00:23:08,720 --> 00:23:11,520 and this is exactly what we have been using. 386 00:23:11,520 --> 00:23:15,400 So what we would tend to do is collect a sample from a pond 387 00:23:15,400 --> 00:23:18,440 or a lake, a river sediment, 388 00:23:18,440 --> 00:23:23,120 bring it in the lab and then put it inside this microbial fuel cell, 389 00:23:23,120 --> 00:23:27,160 which is connected to the circuit that's drawing current 390 00:23:27,160 --> 00:23:30,440 and demanding to have electrons flowing through. 391 00:23:31,640 --> 00:23:34,080 Each fuel cell produces 1.5 volts - 392 00:23:34,080 --> 00:23:37,520 but link together in series like batteries, 393 00:23:37,520 --> 00:23:39,560 and you boost the output. 394 00:23:39,560 --> 00:23:43,440 But Ioannis' vision for this amazing technology goes much further 395 00:23:43,440 --> 00:23:45,360 than a phone charger. 396 00:23:45,360 --> 00:23:49,720 He's scaling it up as a unit that can be built into the fabric 397 00:23:49,720 --> 00:23:54,200 of houses and instantly draw on urine to provide electric power. 398 00:23:54,200 --> 00:23:57,840 If you can imagine just taking a standard brick 399 00:23:57,840 --> 00:24:02,320 and converting it by simply integrating microbial fuel cells 400 00:24:02,320 --> 00:24:06,600 and continuously taking the household waste water, 401 00:24:06,600 --> 00:24:11,480 and then we generate electricity we require for charging devices, 402 00:24:11,480 --> 00:24:16,400 lighting up rooms, DC refrigerators would be the future. 403 00:24:17,960 --> 00:24:21,160 But how far in the future are we talking? 404 00:24:21,160 --> 00:24:24,640 Whilst all this kit might look like a prototype, 405 00:24:24,640 --> 00:24:28,600 Ioannis' technology is very close to being rolled out. 406 00:24:28,600 --> 00:24:33,640 The work has been funded by the Bill & Melinda Gates Foundation, 407 00:24:33,640 --> 00:24:36,720 by the UK EPSRC and by the European Commission. 408 00:24:36,720 --> 00:24:42,120 And from those funders, we have got our objectives 409 00:24:42,120 --> 00:24:45,760 which are to deliver the technology 410 00:24:45,760 --> 00:24:49,040 outside of this lab to the society. 411 00:24:50,200 --> 00:24:55,160 For this technology to benefit UK homes, separate unisex urinals 412 00:24:55,160 --> 00:24:59,240 and plumbing add-ons could pipe pee directly to the cells. 413 00:24:59,240 --> 00:25:03,480 In the quest for diverse energy sources sitting alongside 414 00:25:03,480 --> 00:25:06,480 solar and wind, this has incredible potential, 415 00:25:06,480 --> 00:25:09,560 and there's no doubt it's renewable. 416 00:25:09,560 --> 00:25:13,600 If we have microbial fuel cells in the walls, 417 00:25:13,600 --> 00:25:19,080 then we are tapping on a ubiquitous and never-ending fuel. 418 00:25:19,080 --> 00:25:22,720 It's so exciting. The whole thing is so exciting. 419 00:25:22,720 --> 00:25:26,400 It's just, this is what science should be about, especially now. 420 00:25:26,400 --> 00:25:28,920 Oh, my goodness. We need this stuff. 421 00:25:28,920 --> 00:25:30,840 I couldn't agree with you more. 422 00:25:32,000 --> 00:25:34,160 Well, I absolutely love that. 423 00:25:34,160 --> 00:25:36,160 In terms of what we're investigating, 424 00:25:36,160 --> 00:25:38,200 is there any value in our waste, 425 00:25:38,200 --> 00:25:42,520 this is it answered and realised in a way that is truly inspiring. 426 00:25:42,520 --> 00:25:46,440 You can imagine a future when all of us will have microbial fuel cells 427 00:25:46,440 --> 00:25:49,400 built into the fabric of our homes, 428 00:25:49,400 --> 00:25:52,840 generating power from our pee at source. 429 00:25:52,840 --> 00:25:56,480 But, you know, I can't help wondering if generations from now, 430 00:25:56,480 --> 00:25:59,920 our descendants will think we were totally insane 431 00:25:59,920 --> 00:26:02,360 to simply flush our waste away. 432 00:26:05,600 --> 00:26:09,480 Back at Minworth Sewage Works, the waste we've simply flushed away 433 00:26:09,480 --> 00:26:11,080 is in full flow. 434 00:26:11,080 --> 00:26:13,840 Having come through stage one's screens, 435 00:26:13,840 --> 00:26:16,600 where the largest solid materials are taken out, 436 00:26:16,600 --> 00:26:21,040 the main solid elements left are millimetre sized poo particles 437 00:26:21,040 --> 00:26:23,880 and grease from cooking fats. 438 00:26:25,120 --> 00:26:28,760 But how can any of this be isolated and extracted for use 439 00:26:28,760 --> 00:26:31,880 as a resource from such a finely sieved soup? 440 00:26:35,680 --> 00:26:39,480 Now, the sewage is channelled from the stage one screens 441 00:26:39,480 --> 00:26:43,880 into stage two of the treatment process - the settlement tanks. 442 00:26:46,280 --> 00:26:50,400 There are 22 of these massive circular tanks for the second part 443 00:26:50,400 --> 00:26:52,560 of the processing stage, 444 00:26:52,560 --> 00:26:56,080 and I want to find out exactly what's settling in them. 445 00:26:58,440 --> 00:27:01,080 Compared to the gushing torrent at the inflow, 446 00:27:01,080 --> 00:27:03,520 everything's got rather sedate. 447 00:27:04,720 --> 00:27:07,760 Just like Zoe's demonstration earlier showed us, 448 00:27:07,760 --> 00:27:11,880 I can see fat and grease floating on top of the sewage. 449 00:27:13,440 --> 00:27:16,480 But as Minworth's senior technician Phil explains, 450 00:27:16,480 --> 00:27:19,040 the secret science at this stage 451 00:27:19,040 --> 00:27:23,600 exploits how sewage behaves when it's not flowing so fast. 452 00:27:25,040 --> 00:27:29,520 So it's a very simple idea, heavy stuff sinks to the bottom 453 00:27:29,520 --> 00:27:32,760 and then anything that floats is grease or fats. 454 00:27:32,760 --> 00:27:36,600 Yeah, you get the fats on the rise there, you see in the tanks there. 455 00:27:36,600 --> 00:27:39,680 We have scum traps, so they'll just go into a well 456 00:27:39,680 --> 00:27:41,880 and then we'll take that away. 457 00:27:41,880 --> 00:27:44,720 All the grease will naturally sit on the top. 458 00:27:44,720 --> 00:27:47,360 And the scraper hook paddle it down into there. 459 00:27:47,360 --> 00:27:51,480 And that big bar there is just constantly moving. 460 00:27:51,480 --> 00:27:54,480 Yeah, yeah. Fairly slowly. Yeah, very slow. 461 00:27:57,480 --> 00:28:00,560 But it's below the surface of the sewage in these tanks 462 00:28:00,560 --> 00:28:04,600 that the crucial settlement process of this stage is taking place. 463 00:28:07,120 --> 00:28:10,360 Like sediment in wine, gravity takes effect 464 00:28:10,360 --> 00:28:14,600 and millions of broken up poo particles are simply sinking, 465 00:28:14,600 --> 00:28:18,840 forming a sludge in the tank's conical bottom. 466 00:28:18,840 --> 00:28:23,160 The slowly revolving rake arm scrapes the sludge 467 00:28:23,160 --> 00:28:25,360 into a collection tank below. 468 00:28:28,040 --> 00:28:30,640 The now much cleaner sewage water above 469 00:28:30,640 --> 00:28:32,640 filters over the tank's baffle 470 00:28:32,640 --> 00:28:35,800 and is channelled onto the next stage of treatment. 471 00:28:35,800 --> 00:28:38,880 But what happens with that settled sludge 472 00:28:38,880 --> 00:28:42,120 collecting underneath the settlement tank? 473 00:28:42,120 --> 00:28:46,680 I'm going to get a closer look via an inspection well. 474 00:28:47,920 --> 00:28:51,600 OK. You're prepared? Yeah, yeah. Are you ready? I'm ready. 475 00:28:51,600 --> 00:28:55,840 So far, the smell on site hasn't been that overwhelming, 476 00:28:55,840 --> 00:28:59,080 but the settled sludge absolutely stinks. 477 00:29:03,840 --> 00:29:06,280 Stand back. Well, I think I will, yeah. 478 00:29:06,280 --> 00:29:10,520 Now that the poo has been separated out of the sewage, 479 00:29:10,520 --> 00:29:15,160 gases like hydrogen sulphide are more concentrated. 480 00:29:15,160 --> 00:29:20,360 There's a spicy top note of indole and skatole produced by bacteria 481 00:29:20,360 --> 00:29:22,800 that's particularly offensive. 482 00:29:24,280 --> 00:29:27,600 But there's also a gas in here which is odourless, 483 00:29:27,600 --> 00:29:33,280 one that has phenomenal potential as yet another energy resource - 484 00:29:33,280 --> 00:29:35,040 methane. 485 00:29:38,280 --> 00:29:41,520 The crucial thing about methane is it's volatile 486 00:29:41,520 --> 00:29:43,600 and incredibly flammable. 487 00:29:43,600 --> 00:29:46,920 So is there a way we could somehow extract the methane in here 488 00:29:46,920 --> 00:29:49,200 and exploit it as a resource? 489 00:29:49,200 --> 00:29:51,120 And if so, how? 490 00:29:54,160 --> 00:29:58,600 The sludge from the settlement tanks is piped across Minworth 491 00:29:58,600 --> 00:30:03,280 to 16 giant silos called biodigesters. 492 00:30:03,280 --> 00:30:07,960 Acting like pressure cookers, conditions inside the biodigesters 493 00:30:07,960 --> 00:30:12,040 are engineered to force a bacterial reaction in the sludge, 494 00:30:12,040 --> 00:30:14,560 causing methane gas to be released. 495 00:30:15,680 --> 00:30:19,160 Given that this is a hugely hazardous environment, 496 00:30:19,160 --> 00:30:22,160 this is as close as I'm permitted to get. 497 00:30:22,160 --> 00:30:26,200 But explaining the process is sludge scientist Charlotte. 498 00:30:26,200 --> 00:30:30,480 So, Charlotte, that sludge that I had in a container, 499 00:30:30,480 --> 00:30:33,680 thick like emulsion paint, that stuff is heated... 500 00:30:33,680 --> 00:30:37,800 About 40 degrees, which is optimum for the bacteria to work at. 501 00:30:37,800 --> 00:30:39,440 The sludge is fed in. 502 00:30:39,440 --> 00:30:42,480 On this site it's held at about 20 to 30 days in there. 503 00:30:42,480 --> 00:30:44,840 And that's where the fun starts. 504 00:30:46,160 --> 00:30:51,080 Inside the biodigesters, special bacteria are added to the sludge. 505 00:30:51,080 --> 00:30:54,240 The atmosphere inside the digesters is airless 506 00:30:54,240 --> 00:30:58,520 and along with the temperature, that causes the bacteria to start feeding 507 00:30:58,520 --> 00:31:02,560 on the proteins and carbohydrates in the sludge. 508 00:31:02,560 --> 00:31:07,240 In so doing, the bacteria give off a methane-rich biogas 509 00:31:07,240 --> 00:31:11,320 that rises up in the digesters and is piped off. 510 00:31:11,320 --> 00:31:14,560 It's then injected into the National Grid, 511 00:31:14,560 --> 00:31:18,520 supplementing our supply of natural gas we drill for 512 00:31:18,520 --> 00:31:20,720 in the North Sea and import. 513 00:31:22,480 --> 00:31:24,360 How much gas can it produce? 514 00:31:24,360 --> 00:31:26,360 How many homes could it heat? 515 00:31:26,360 --> 00:31:29,400 Well, last week, George, we actually broke our record where we 516 00:31:29,400 --> 00:31:32,840 was able to power 28,000 homes from what we produced in a day. 517 00:31:32,840 --> 00:31:35,080 28...? 28,000 homes. 518 00:31:35,080 --> 00:31:38,920 So you could supply gas to 28,000 homes? That's correct, yes. 519 00:31:38,920 --> 00:31:42,360 So the person frying their bacon and eggs in the morning 520 00:31:42,360 --> 00:31:46,240 might not be aware that what they're cooking with 521 00:31:46,240 --> 00:31:50,520 is a gas flame that has been produced by what they may have 522 00:31:50,520 --> 00:31:53,080 deposited in their toilet a couple of weeks before. 523 00:31:53,080 --> 00:31:55,600 That's correct, yeah. It's the state of the world. 524 00:31:55,600 --> 00:31:57,400 I love it. 525 00:31:59,160 --> 00:32:03,880 Methane from sewage isn't going to supply gas to every home in the UK, 526 00:32:03,880 --> 00:32:08,280 but it can form part of our diverse suite of renewable energy sources 527 00:32:08,280 --> 00:32:12,240 like wind and solar that we need to provide us with power. 528 00:32:13,480 --> 00:32:17,680 But the beauty of methane or biogas is that it'll fuel more 529 00:32:17,680 --> 00:32:20,320 than just central heating and cookers. 530 00:32:21,400 --> 00:32:25,040 And so, Zoe is heading off on a road trip 531 00:32:25,040 --> 00:32:27,880 to investigate what else poo can power. 532 00:32:29,360 --> 00:32:31,360 What if I told you 533 00:32:31,360 --> 00:32:35,960 we could use it to get from 0-60 in under ten seconds? 534 00:32:41,680 --> 00:32:46,560 Meet the Bio-Bug, a converted VW that runs on methane gas 535 00:32:46,560 --> 00:32:49,040 derived from sewage. 536 00:32:49,040 --> 00:32:52,000 Or as I like to call it - the Dung Beetle. 537 00:32:53,600 --> 00:32:57,160 With government targets committing the UK to net zero carbon emissions 538 00:32:57,160 --> 00:33:02,040 by 2050, I'm keen to see if methane gas has potential 539 00:33:02,040 --> 00:33:05,080 to be a cleaner alternative to petrol and diesel. 540 00:33:07,720 --> 00:33:11,240 I'm meeting sustainable transport specialist Francis Marsh, 541 00:33:11,240 --> 00:33:14,600 who promotes poo power as a viable vehicle fuel. 542 00:33:16,640 --> 00:33:19,400 Considering this was powered by methane gas, 543 00:33:19,400 --> 00:33:22,400 it was a pleasure to drive, but how does it actually work? 544 00:33:22,400 --> 00:33:24,960 Well, it all happens round the back here. 545 00:33:24,960 --> 00:33:27,280 We'll pump in the upgraded biomethane 546 00:33:27,280 --> 00:33:30,440 into the rear of the vehicle at 200 bar of pressure. 547 00:33:30,440 --> 00:33:34,120 And then we've got some gas canisters in the boot here. 548 00:33:34,120 --> 00:33:36,760 It's like you're going to go scuba diving. Absolutely. 549 00:33:36,760 --> 00:33:40,520 So these gas cylinders hold enough gas to go about 200 miles. 550 00:33:40,520 --> 00:33:42,640 And then, is it a normal engine? 551 00:33:42,640 --> 00:33:45,080 Well, if you pop the hood, we'll have a look. Hang on. 552 00:33:46,320 --> 00:33:47,520 OK. 553 00:33:51,600 --> 00:33:54,000 Yeah, I mean, this just looks like most car engines I've seen. 554 00:33:54,000 --> 00:33:56,600 Yeah, absolutely. So it's fundamentally exactly the same, 555 00:33:56,600 --> 00:33:58,560 very few parts that have changed. 556 00:33:58,560 --> 00:34:01,760 So we've got the injectors here that are slightly different, 557 00:34:01,760 --> 00:34:04,240 that's a modification, and then the engine management system, 558 00:34:04,240 --> 00:34:06,040 which is also slightly different. 559 00:34:06,040 --> 00:34:08,760 There's a global push towards electric cars, 560 00:34:08,760 --> 00:34:12,520 but battery technology requires vast amounts of lithium, 561 00:34:12,520 --> 00:34:16,800 which is a finite resource, whereas biomethane is infinite. 562 00:34:18,280 --> 00:34:20,200 So does it generate lower emissions? 563 00:34:20,200 --> 00:34:24,720 Absolutely. So 99% less particulate matter being emitted out of 564 00:34:24,720 --> 00:34:29,880 a tailpipe, 90% reduction in carbon dioxide. 565 00:34:29,880 --> 00:34:32,600 And I suppose being able to fuel vehicles 566 00:34:32,600 --> 00:34:35,840 that would traditionally be quite heavy pollutants like buses 567 00:34:35,840 --> 00:34:38,720 and, you know, dustbin lorries. Yeah, exactly. 568 00:34:38,720 --> 00:34:42,560 That would work in built up urban areas where air quality 569 00:34:42,560 --> 00:34:44,480 is traditionally very poor. 570 00:34:44,480 --> 00:34:49,080 You can save probably around about 150 tonnes of CO2 per year 571 00:34:49,080 --> 00:34:51,520 using a heavy goods vehicle on this fuel. 572 00:34:51,520 --> 00:34:55,200 So this is a way in which you could actually tackle the most polluting 573 00:34:55,200 --> 00:34:57,680 type of vehicle and not scrap the whole vehicle, 574 00:34:57,680 --> 00:35:01,680 just convert the engine and run a much cleaner journey. 575 00:35:01,680 --> 00:35:03,280 Yeah, absolutely. 576 00:35:06,160 --> 00:35:10,000 So far at Minworth, we've followed the process through the stage one 577 00:35:10,000 --> 00:35:12,800 screens, where larger solids are filtered out... 578 00:35:14,560 --> 00:35:17,600 ..then on to the stage two settlement tanks, 579 00:35:17,600 --> 00:35:20,280 where chunkier poo particles sink, 580 00:35:20,280 --> 00:35:24,000 a sludge that's piped off for methane gas production. 581 00:35:25,560 --> 00:35:27,920 The water being filtered out of the settlement tanks 582 00:35:27,920 --> 00:35:31,240 is now a lot cleaner than when it first arrived on site. 583 00:35:32,360 --> 00:35:36,600 But the next process has to operate at a microbial level. 584 00:35:39,040 --> 00:35:42,480 The problem is, it's full of minute poo particles, 585 00:35:42,480 --> 00:35:45,760 too small to sink in the primary stage tanks, 586 00:35:45,760 --> 00:35:48,800 as well as the ammonia from our urine. 587 00:35:53,240 --> 00:35:57,120 So how on earth do you remove these microelements from sewage 588 00:35:57,120 --> 00:35:59,760 and make the water safe enough to return to the environment? 589 00:36:01,360 --> 00:36:05,040 Having being channelled from the stage two settlement tanks, 590 00:36:05,040 --> 00:36:08,680 the filtered sewage is now entering stage three of the treatment 591 00:36:08,680 --> 00:36:10,760 process - the activated tanks. 592 00:36:16,040 --> 00:36:22,800 Here in these six gigantic pools, incredible activity is taking place. 593 00:36:22,800 --> 00:36:25,640 Massive green pipes are pumping air into the sewage, 594 00:36:25,640 --> 00:36:29,600 churning it up like a nightmarish Jacuzzi. 595 00:36:29,600 --> 00:36:31,840 It looks alive and it is. 596 00:36:33,880 --> 00:36:38,360 The pumped oxygen gives life to trillions of naturally occurring 597 00:36:38,360 --> 00:36:43,840 microorganisms in the sewage that actually eat the tiny poo particles 598 00:36:43,840 --> 00:36:46,680 and ammonia, cleaning the water. 599 00:36:50,560 --> 00:36:53,800 I'm desperate to see if we can get a look at these tiny life forms 600 00:36:53,800 --> 00:36:56,840 under a microscope back in our pop-up lab. 601 00:36:59,840 --> 00:37:03,120 I come bearing a container of the finest activated sludge, 602 00:37:03,120 --> 00:37:06,720 hopefully bursting with living microorganisms. 603 00:37:06,720 --> 00:37:09,480 Well, I'll be quite interested to see what's actually in this. 604 00:37:09,480 --> 00:37:14,080 I'm taking the tiniest sample from the stage three sewage. 605 00:37:14,080 --> 00:37:16,600 That's a nice bit of gunk. 606 00:37:16,600 --> 00:37:20,200 But by magnifying it a few hundred times under a microscope, 607 00:37:20,200 --> 00:37:23,800 hopefully we can see some of these tiny life forms 608 00:37:23,800 --> 00:37:26,080 cleaning the poo particles. 609 00:37:27,440 --> 00:37:30,040 There's things moving about. Oh! Look at that. 610 00:37:30,040 --> 00:37:33,600 There's something going on there. Definitely things moving. 611 00:37:33,600 --> 00:37:35,280 Oh! Look at, look at that. 612 00:37:35,280 --> 00:37:36,880 Look at that microorganism. 613 00:37:36,880 --> 00:37:41,200 It's got, it's got a sort of tail part. That is definitely alive. 614 00:37:43,200 --> 00:37:46,840 Some sort of almost mouthpiece action, I saw there. 615 00:37:46,840 --> 00:37:49,400 Yeah. Whoa! Look at that. Oh, my word. 616 00:37:49,400 --> 00:37:52,880 Look at that! It's got propellers. 617 00:37:52,880 --> 00:37:55,600 That is beautiful. 618 00:37:55,600 --> 00:37:59,000 So that is a single celled organism, 619 00:37:59,000 --> 00:38:03,680 it has a little row of cilia, or hairs, at its front end. 620 00:38:03,680 --> 00:38:08,080 And it's basically gathering bacteria, just sucking, you know, 621 00:38:08,080 --> 00:38:09,760 all the water through it. 622 00:38:09,760 --> 00:38:12,000 So those, almost those propellers, that turbine... 623 00:38:12,000 --> 00:38:14,040 Yeah. That's just hair just drawing the water in. 624 00:38:14,040 --> 00:38:15,800 So it's cleaning the bacteria. 625 00:38:15,800 --> 00:38:19,320 So this activated sludge contains all kinds of bacteria. 626 00:38:19,320 --> 00:38:21,920 I mean, literally gazillions of them. 627 00:38:21,920 --> 00:38:25,960 In just a few millilitres of this activated sludge, 628 00:38:25,960 --> 00:38:29,680 we've accessed a nanoverse of microorganisms 629 00:38:29,680 --> 00:38:35,960 eating up the poo particles and bacteria, and cleaning the sewage. 630 00:38:35,960 --> 00:38:39,720 Oh! He's hoovered up a friend. What he's doing? 631 00:38:39,720 --> 00:38:41,880 No, no, no. It's just... 632 00:38:41,880 --> 00:38:46,760 But that, that's being drawn towards it because of the water stream. 633 00:38:46,760 --> 00:38:49,720 It's sucking air in. That's rather beautiful. 634 00:38:49,720 --> 00:38:51,560 Oh, look at that. Oh! 635 00:38:53,240 --> 00:38:55,840 THEY BOTH GASP Wow! It's massive! 636 00:38:55,840 --> 00:38:57,480 Oh, George. 637 00:38:57,480 --> 00:38:59,720 Oh! Look at it. It's a monster. 638 00:38:59,720 --> 00:39:02,160 Look at the size of that. 639 00:39:02,160 --> 00:39:04,400 Oh, my God. 640 00:39:04,400 --> 00:39:08,040 It's clearly hoovering up... It's almost got a mouthpiece. 641 00:39:08,040 --> 00:39:10,800 Yeah, yeah. Can you see it open up a little bit? 642 00:39:10,800 --> 00:39:13,520 See, this mouthpiece here, I almost want it to... 643 00:39:13,520 --> 00:39:16,000 Go and, eat that bit. Go on, matey, get it. 644 00:39:16,000 --> 00:39:20,320 These tiny aquatic life forms can be found in all freshwater 645 00:39:20,320 --> 00:39:24,040 and even in soil, breaking down organic matter. 646 00:39:24,040 --> 00:39:27,120 But now science, as we're seeing here, 647 00:39:27,120 --> 00:39:31,440 is able to harness them as incredible cleaning biotechnology. 648 00:39:32,600 --> 00:39:35,680 George, can we track down its body? Want to see the whole length of it. 649 00:39:35,680 --> 00:39:38,320 Let's go down to the back end. It's a giant. 650 00:39:38,320 --> 00:39:40,760 Oh, look, and there's the other end. Wow! 651 00:39:40,760 --> 00:39:43,240 There's the other end of it. 652 00:39:43,240 --> 00:39:46,200 And there's its gut, you can see the gut. 653 00:39:46,200 --> 00:39:48,680 Yeah, the tract inside. 654 00:39:48,680 --> 00:39:50,320 It's thrilling. 655 00:39:50,320 --> 00:39:54,720 And there's numerous different species with their own exotic names. 656 00:39:56,000 --> 00:39:57,840 These are called rotifers. 657 00:39:58,880 --> 00:40:04,120 There's naidids and stalked ciliates all hard at work. 658 00:40:05,360 --> 00:40:08,200 But we have to remember that this activity is occurring 659 00:40:08,200 --> 00:40:10,720 in millions of litres of sewage here. 660 00:40:12,080 --> 00:40:15,840 It's bioengineering on a mind-boggling scale. 661 00:40:17,200 --> 00:40:22,640 Incredibly, the microorganisms in the stage three activated tanks 662 00:40:22,640 --> 00:40:25,680 can complete their task of cleaning the sewage 663 00:40:25,680 --> 00:40:27,840 in as little as five hours. 664 00:40:31,960 --> 00:40:35,600 Whilst this process continues, I want to investigate how sewage 665 00:40:35,600 --> 00:40:38,640 could help with one of the biggest challenges we might face 666 00:40:38,640 --> 00:40:40,280 in the future. 667 00:40:42,720 --> 00:40:44,480 The threat to our soil. 668 00:40:46,400 --> 00:40:50,040 In 2020, the United Nations published a report 669 00:40:50,040 --> 00:40:52,320 based on the work of 300 scientists. 670 00:40:53,480 --> 00:40:57,560 It warned that the planet's soil, vital for food production, 671 00:40:57,560 --> 00:41:00,440 is at risk of being degraded by a combination of factors 672 00:41:00,440 --> 00:41:02,600 not yet fully understood, 673 00:41:02,600 --> 00:41:07,080 like climate change, intensive agriculture and deforestation. 674 00:41:08,440 --> 00:41:12,400 But here, sewage might be able to provide yet another resource - 675 00:41:12,400 --> 00:41:14,200 compost. 676 00:41:23,760 --> 00:41:27,200 I've come to the Centre for Alternative Technology in Mid Wales. 677 00:41:28,400 --> 00:41:32,280 A facility that's been developing compost toilets for 30 years. 678 00:41:35,320 --> 00:41:38,920 I'm meeting the centre's microbiologist, Louise Halestrap. 679 00:41:40,400 --> 00:41:42,680 What a great setting, a loo with a view. 680 00:41:42,680 --> 00:41:45,320 It's a space I'd be really happy to spend some time in. 681 00:41:45,320 --> 00:41:48,520 But it is a composting toilet. It is a composting toilet. 682 00:41:48,520 --> 00:41:52,600 The different thing is there's not white porcelain and water. 683 00:41:52,600 --> 00:41:57,080 So instantly, you're confronted with a black dark hole. 684 00:41:57,080 --> 00:41:59,920 Now, that's on purpose, because the other option will be 685 00:41:59,920 --> 00:42:02,880 looking at a pile of loo paper and poo. 686 00:42:02,880 --> 00:42:06,080 You're literally dumping into a void. Yeah. 687 00:42:06,080 --> 00:42:10,280 So then you just use the toilet and go, "Eurgh, no flush." 688 00:42:10,280 --> 00:42:13,160 Instead of water, you add wood shavings. 689 00:42:13,160 --> 00:42:17,760 The carbon in the wood balances with the nitrogen in the waste. 690 00:42:17,760 --> 00:42:20,400 So what's left behind at the business end? 691 00:42:20,400 --> 00:42:22,800 How does this alternative system 692 00:42:22,800 --> 00:42:25,920 offer another means of resource recovery? 693 00:42:25,920 --> 00:42:30,600 The poo and stuff plops down into this half of the chamber, 694 00:42:30,600 --> 00:42:34,120 and then once a year, or once every year and half, 695 00:42:34,120 --> 00:42:37,880 the whole toilet is moved to the other side 696 00:42:37,880 --> 00:42:40,680 and it comes down into this chamber. 697 00:42:40,680 --> 00:42:43,000 So the left is your live shit pile 698 00:42:43,000 --> 00:42:46,440 and the right is last year's... Composting shit pile. 699 00:42:46,440 --> 00:42:48,880 So the idea behind that is hygiene. 700 00:42:48,880 --> 00:42:54,400 So us compost workers who are having to deal with this shit, literally, 701 00:42:54,400 --> 00:42:58,960 are safe from very fresh poo, 702 00:42:58,960 --> 00:43:02,280 which has pathogens in it. 703 00:43:02,280 --> 00:43:06,480 After two years, it becomes stable or benign. 704 00:43:06,480 --> 00:43:07,960 So two years is the thing. 705 00:43:07,960 --> 00:43:11,400 But I know this pile's been sitting there for about three years, 706 00:43:11,400 --> 00:43:14,400 so we can have a look at that, if you want. Please. Yeah, yeah. 707 00:43:15,720 --> 00:43:17,920 In the sealed chamber, it's our friends, 708 00:43:17,920 --> 00:43:21,560 the naturally occurring microorganisms doing the work, 709 00:43:21,560 --> 00:43:25,880 consuming bad bacteria and pathogens in our poo and composting it down. 710 00:43:25,880 --> 00:43:28,680 I'm a microbiologist, I would not be touching this 711 00:43:28,680 --> 00:43:31,080 if I didn't think it was safe. 712 00:43:31,080 --> 00:43:35,200 So that is human waste and sawdust plus three years. 713 00:43:35,200 --> 00:43:38,800 There's not a lot in there. The average human's poo is about 250g. 714 00:43:38,800 --> 00:43:41,480 Dry weight, that's about 50g. 715 00:43:41,480 --> 00:43:43,720 So if you think, during the composting process 716 00:43:43,720 --> 00:43:47,360 the poo's going to be eaten, ingested by microorganisms 717 00:43:47,360 --> 00:43:51,040 and then they're going to give off carbon dioxide and water, 718 00:43:51,040 --> 00:43:54,240 and then eventually it's only 50g dry weight. 719 00:43:54,240 --> 00:43:56,680 So it's about the fifth of the size it was. 720 00:43:56,680 --> 00:43:59,120 Do you want to grab some and have a sniff? Please. 721 00:43:59,120 --> 00:44:02,200 Right, I'm going to get in. Here we go. 722 00:44:06,200 --> 00:44:08,480 It's actually... 723 00:44:11,440 --> 00:44:16,200 I mean, it smells like soil, it doesn't smell in any way disgusting, 724 00:44:16,200 --> 00:44:18,480 but there's definitely a soil-y feeling. 725 00:44:18,480 --> 00:44:21,480 If I squeeze it together, it's slightly damp as well. 726 00:44:21,480 --> 00:44:26,520 All the active volatile nutrients, like the phosphorus and the nitrogen 727 00:44:26,520 --> 00:44:30,400 and carbon, are all in there and they've been stabilised. 728 00:44:30,400 --> 00:44:32,880 So they've been locked in to the humus, 729 00:44:32,880 --> 00:44:35,920 which is the kind of brown stuff that soil is. 730 00:44:35,920 --> 00:44:38,960 And they do kind of magical things to the soil. 731 00:44:38,960 --> 00:44:43,640 They release only when the plant needs it. 732 00:44:43,640 --> 00:44:47,280 I mean, basically, fertiliser. It's more of a soil conditioner. 733 00:44:47,280 --> 00:44:50,960 A fertiliser is more like a sports drink for the crops, 734 00:44:50,960 --> 00:44:55,600 whereas soil conditioner is more like a wholefood. 735 00:44:55,600 --> 00:44:58,840 So a nitrogen, phosphorus, potassium, industrial 736 00:44:58,840 --> 00:45:01,520 man-made fertiliser would be kind of fast food, 737 00:45:01,520 --> 00:45:03,920 and then this is good nutrition for life. 738 00:45:03,920 --> 00:45:08,520 Here at the centre, they've applied their compost, or humanure, 739 00:45:08,520 --> 00:45:11,640 to enrich the soil of the apple orchard on site. 740 00:45:13,280 --> 00:45:16,440 They're not growing anything like root vegetables in the compost 741 00:45:16,440 --> 00:45:20,200 as an extra safety precaution, but food like apples growing 742 00:45:20,200 --> 00:45:23,120 above ground rather than in it is deemed OK. 743 00:45:23,120 --> 00:45:26,520 And a bumper crop they produce, too. 744 00:45:26,520 --> 00:45:30,200 I have to say, I find a composting toilet appealing. 745 00:45:30,200 --> 00:45:33,320 It solves two problems with one piece of kit. 746 00:45:33,320 --> 00:45:36,440 Firstly, you save phenomenal amounts of water, 747 00:45:36,440 --> 00:45:40,040 but secondly, you're capturing a critical resource 748 00:45:40,040 --> 00:45:42,320 to nurture plants with. 749 00:45:42,320 --> 00:45:44,360 But can it scale? 750 00:45:52,520 --> 00:45:55,720 Let's face it, putting a composting toilet 751 00:45:55,720 --> 00:45:58,000 in every home isn't practical. 752 00:45:59,200 --> 00:46:03,040 But, although perhaps a slightly stomach churning idea, 753 00:46:03,040 --> 00:46:07,520 if we did it right, using our own excrement to help grow food 754 00:46:07,520 --> 00:46:12,000 is worth considering, especially since the chemical fertilisers 755 00:46:12,000 --> 00:46:16,440 designed to keep soil productive use minerals that the planet 756 00:46:16,440 --> 00:46:20,240 is running out of, and minerals our poo and pee is rich in. 757 00:46:21,280 --> 00:46:25,200 So how can we scale up using our own human waste as compost? 758 00:46:26,680 --> 00:46:29,640 The answer to that lies back at Minworth. 759 00:46:36,840 --> 00:46:38,640 Here at Minworth Sewage Works, 760 00:46:38,640 --> 00:46:42,360 they're extracting every last possible resource from sewage 761 00:46:42,360 --> 00:46:45,280 right up to the very end of the treatment process. 762 00:46:47,720 --> 00:46:52,640 1.7 million people's number twos pass through here every day. 763 00:46:54,040 --> 00:46:56,680 That's potentially a lot of compost. 764 00:46:57,920 --> 00:47:02,520 I'm heading back towards Minworth's massive biodigester gas plant. 765 00:47:04,080 --> 00:47:07,120 You know all that sludge that gets piped there 766 00:47:07,120 --> 00:47:09,960 and turned into methane gas for the grid? 767 00:47:09,960 --> 00:47:14,040 Well, all that poo hasn't just simply evaporated. 768 00:47:14,040 --> 00:47:17,760 They've still got hundreds of tonnes of dried solids left. 769 00:47:18,800 --> 00:47:21,040 And guess what they're going to do with that? 770 00:47:22,680 --> 00:47:25,920 They're turning those dried solids into food for plants 771 00:47:25,920 --> 00:47:27,760 on an epic scale. 772 00:47:30,000 --> 00:47:33,240 To make it safe from pathogens, the sludge goes through an advanced 773 00:47:33,240 --> 00:47:35,920 system called thermal hydrolysis. 774 00:47:37,320 --> 00:47:42,080 It's heated to above 160 degrees and pasteurised. 775 00:47:44,400 --> 00:47:49,160 I'm meeting bioresources manager Simon Farris to find out more. 776 00:47:51,520 --> 00:47:54,160 This is where we're taking the solid material out at the end. 777 00:47:54,160 --> 00:47:57,080 So this is everything that's left after we've extracted as much 778 00:47:57,080 --> 00:47:59,000 of the energy out of it as we possibly can. 779 00:47:59,000 --> 00:48:01,480 So what we've got here is essentially something 780 00:48:01,480 --> 00:48:03,400 that's quite rich in nitrogen, phosphorus 781 00:48:03,400 --> 00:48:06,400 that we can actually take out onto land and use as a soil conditioner 782 00:48:06,400 --> 00:48:09,800 for certain types of crops. This looks absolutely fantastic. 783 00:48:09,800 --> 00:48:11,280 I mean, it's... 784 00:48:12,720 --> 00:48:15,400 It's black gold, isn't it, really? Yeah, essentially. 785 00:48:15,400 --> 00:48:18,320 So loads of stuff that the world is running out of right now 786 00:48:18,320 --> 00:48:21,400 is still containing that. There's a slight ammonia whiff. Not too much. 787 00:48:21,400 --> 00:48:24,120 There's a little bit of an ammonia whiff, but that's some of the 788 00:48:24,120 --> 00:48:26,760 nitrogen that's in there that we can actually use to replenish 789 00:48:26,760 --> 00:48:29,280 some of the soil and condition it in the way that we want to. 790 00:48:29,280 --> 00:48:32,160 I would have no qualms about eating a root vegetable, or a tomato 791 00:48:32,160 --> 00:48:35,760 or whatever that had been grown using this. 792 00:48:35,760 --> 00:48:38,640 Is that a general feeling or does there...? 793 00:48:38,640 --> 00:48:42,520 Are people alarmed about it in any way? 794 00:48:42,520 --> 00:48:45,240 So there's a huge amount of legislation at the moment 795 00:48:45,240 --> 00:48:48,000 that governs what we can and can't take out to land 796 00:48:48,000 --> 00:48:51,200 and it's quite tight. Particularly here in the West Midlands, 797 00:48:51,200 --> 00:48:54,920 we've got zinc from galvanising companies and there are other heavy 798 00:48:54,920 --> 00:48:57,840 metals that come out of industry that come down the sewer to us. 799 00:48:57,840 --> 00:49:00,480 And what we have to do is, we have to make sure that all of those 800 00:49:00,480 --> 00:49:03,440 stay within very tight constraints in a way that we can ensure 801 00:49:03,440 --> 00:49:05,920 how it's used is safe for public consumption. 802 00:49:07,280 --> 00:49:11,000 The end result looks much the same as the compost Zoe had held 803 00:49:11,000 --> 00:49:13,720 in her hand, but it's not as pure. 804 00:49:15,400 --> 00:49:18,360 The reality of our "everything in it" sewage system 805 00:49:18,360 --> 00:49:21,080 means that although it can be applied to farmland, 806 00:49:21,080 --> 00:49:25,760 like this field near Minworth, its use in agriculture is limited, 807 00:49:25,760 --> 00:49:29,720 strictly not for farm to fork produce. 808 00:49:29,720 --> 00:49:34,120 In the UK though it's mainly used to grow crops like this oilseed rape, 809 00:49:34,120 --> 00:49:36,760 which is then turned into animal feed. 810 00:49:38,520 --> 00:49:42,560 But all the nutrients are there in our waste - the nitrogen, 811 00:49:42,560 --> 00:49:48,920 the phosphorus, the vital resources to feed the soil to feed us. 812 00:49:48,920 --> 00:49:53,000 Arguably, we've taken our soil for granted for too long. 813 00:49:53,000 --> 00:49:57,040 But by being more careful about what we send into sewers, 814 00:49:57,040 --> 00:50:00,320 then we could have a renewable resource available 815 00:50:00,320 --> 00:50:04,560 to keep replenishing some of our soil with the nutrients it needs. 816 00:50:10,600 --> 00:50:14,840 Using our own waste for agriculture and energy is one thing, 817 00:50:14,840 --> 00:50:17,480 but can science go even further? 818 00:50:18,680 --> 00:50:24,000 Might sewage be a secret resource for revolutionary health benefits? 819 00:50:24,000 --> 00:50:27,520 Earlier, Dr Ellie Jameson went fishing in the raw sewage 820 00:50:27,520 --> 00:50:32,000 here at Minworth in search of phages, nanoscopic entities 821 00:50:32,000 --> 00:50:37,000 that can kill deadly superbugs like E. Coli and klebsiella. 822 00:50:38,520 --> 00:50:41,160 And I'm keen to see what, if anything, 823 00:50:41,160 --> 00:50:44,840 she's managed to isolate in her sewage sample. 824 00:50:47,680 --> 00:50:52,120 Ellie, I'm very excited. You've been on a phage fishing expedition. 825 00:50:52,120 --> 00:50:55,360 What have you found? Yeah, so, while we've been hunting for phages 826 00:50:55,360 --> 00:50:59,640 we've taken the water from Minworth and we've filtered it 827 00:50:59,640 --> 00:51:02,480 to get out the cells that were in the sewage. 828 00:51:02,480 --> 00:51:04,880 So take out bacteria, any human cells... 829 00:51:04,880 --> 00:51:06,960 Any human cells. ..any debris. 830 00:51:06,960 --> 00:51:10,720 So all it leaves behind? It should just leave behind phages. 831 00:51:10,720 --> 00:51:12,640 Yeah. Viruses. 832 00:51:12,640 --> 00:51:15,240 So, yeah, then we can kind of look at those a bit closer. 833 00:51:15,240 --> 00:51:17,840 So, and when you look at that under the transmission electron 834 00:51:17,840 --> 00:51:20,320 microscope, you can see these phage particles. 835 00:51:20,320 --> 00:51:23,600 So these are some of the phages that we've got from our sewage. 836 00:51:23,600 --> 00:51:27,240 So, have you any idea what these are? Are these new ones? 837 00:51:27,240 --> 00:51:30,080 Yeah, these are new ones that we've never looked at before. 838 00:51:30,080 --> 00:51:33,720 So a result, new phages found in sewage. 839 00:51:35,040 --> 00:51:39,000 But do these ones have the power to act against deadly superbugs 840 00:51:39,000 --> 00:51:42,280 like E.coli and klebsiella? 841 00:51:42,280 --> 00:51:46,320 From that, then I've taken my cultures of E.coli and klebsiella 842 00:51:46,320 --> 00:51:50,640 and I've added some of this filtered sewage into it. 843 00:51:50,640 --> 00:51:53,280 So these are some of the E.coli on its own. Yeah. 844 00:51:53,280 --> 00:51:56,120 And we have found that there are some phages in there so... 845 00:51:56,120 --> 00:51:58,240 Oh! Oh! Show me. So if we hold it up, 846 00:51:58,240 --> 00:52:01,160 there's a few little faint spots, so they're really round spots, 847 00:52:01,160 --> 00:52:03,040 these are where the phage plaques are. 848 00:52:03,040 --> 00:52:06,200 So where the phage have eaten away at that lawn of bacteria. 849 00:52:06,200 --> 00:52:07,880 Oh, yes. 850 00:52:07,880 --> 00:52:10,160 So you know that there was a phage in there 851 00:52:10,160 --> 00:52:12,960 that has killed the bacteria. That's brilliant. 852 00:52:12,960 --> 00:52:16,840 We can't pick up these tiny holes on camera, but under the microscope, 853 00:52:16,840 --> 00:52:20,920 the effect of the phages on the E.coli is dramatic. 854 00:52:20,920 --> 00:52:23,640 So that's a big hole. Yeah. 855 00:52:23,640 --> 00:52:26,280 That's like a lawn of the bacteria round the edge 856 00:52:26,280 --> 00:52:28,560 with just this giant big hole in the middle of it. 857 00:52:28,560 --> 00:52:30,600 Can I just get my head around this? 858 00:52:30,600 --> 00:52:35,680 You have isolated a new sort of phage from the sewage there. 859 00:52:35,680 --> 00:52:39,360 Yeah. And it's active against E.coli. Yeah. 860 00:52:39,360 --> 00:52:41,360 I mean, this is big. 861 00:52:41,360 --> 00:52:44,200 You have discovered a biological entity, 862 00:52:44,200 --> 00:52:46,840 which is potentially a life-saver. 863 00:52:47,920 --> 00:52:49,640 That's a good day's work. 864 00:52:49,640 --> 00:52:51,760 A good day's work! 865 00:52:51,760 --> 00:52:55,440 This is... This is ground-breaking stuff. 866 00:52:55,440 --> 00:52:58,400 Yeah, it is, yeah. Every new one that we find is another patient 867 00:52:58,400 --> 00:53:01,560 that we can potentially treat, so these are really exciting results. 868 00:53:01,560 --> 00:53:05,560 But how long do you think it'll be before this sort of treatment 869 00:53:05,560 --> 00:53:08,200 is available on the NHS? 870 00:53:08,200 --> 00:53:13,280 So on the NHS, well, that involves these big clinical trials, 871 00:53:13,280 --> 00:53:16,960 which often take maybe ten to 15 years to come to fruition. 872 00:53:16,960 --> 00:53:18,560 So there's this big lag. 873 00:53:18,560 --> 00:53:22,360 But what we're hoping is to get some trials set up, 874 00:53:22,360 --> 00:53:26,760 where we can use them in palliative care and that kind of stage. 875 00:53:26,760 --> 00:53:30,760 So there's still work involved to establish if this new phage 876 00:53:30,760 --> 00:53:34,000 is indeed life-saving and becomes mainstream. 877 00:53:34,000 --> 00:53:38,040 But when permission's been given to use phage treatment in the past, 878 00:53:38,040 --> 00:53:40,880 it's had remarkable success. 879 00:53:40,880 --> 00:53:44,600 At Great Ormond Street, where they treated a patient who had cystic 880 00:53:44,600 --> 00:53:49,640 fibrosis, she'd had a double lung transplant and then got a bacterial 881 00:53:49,640 --> 00:53:52,560 infection afterwards... And was obviously very vulnerable. 882 00:53:52,560 --> 00:53:55,720 Very, very sick, very ill, very vulnerable already. 883 00:53:55,720 --> 00:53:58,440 And she had been sent home on palliative care. 884 00:53:58,440 --> 00:54:01,000 That means it's the end. That's the end of life care, yeah, 885 00:54:01,000 --> 00:54:03,040 just make you comfortable. 886 00:54:03,040 --> 00:54:05,760 And then since having phage treatment, 887 00:54:05,760 --> 00:54:08,120 she's actually got back that quality of life 888 00:54:08,120 --> 00:54:10,400 and she's been able to return to school. 889 00:54:10,400 --> 00:54:14,920 I mean, that is just, that's the grail, isn't it? Yeah, yeah. 890 00:54:14,920 --> 00:54:18,480 That's why we're targeting these superbugs - E.coli and klebsiella 891 00:54:18,480 --> 00:54:21,080 are really important superbugs in the hospitals. 892 00:54:21,080 --> 00:54:23,760 So to have something in the arsenal we can actually treat them with 893 00:54:23,760 --> 00:54:25,400 would be amazing. 894 00:54:25,400 --> 00:54:29,040 For me, Ellie's discovery is the most astonishing 895 00:54:29,040 --> 00:54:31,880 of all the resources that sewage has to offer, 896 00:54:31,880 --> 00:54:36,480 completely at odds with our natural reaction to it as a substance 897 00:54:36,480 --> 00:54:39,320 that's quite simply disgusting. 898 00:54:39,320 --> 00:54:41,760 But of course, it does need cleaning, 899 00:54:41,760 --> 00:54:44,920 and now Minworth's sewage is reaching the end of its journey 900 00:54:44,920 --> 00:54:46,680 through the plant. 901 00:54:50,840 --> 00:54:55,040 The microorganism in the stage three activated tanks have nearly 902 00:54:55,040 --> 00:54:58,880 completed the job of eating the poo particles, bacteria and ammonia 903 00:54:58,880 --> 00:55:00,800 in the sewage. 904 00:55:00,800 --> 00:55:04,600 And senior technician Phil is getting Zoe a sample 905 00:55:04,600 --> 00:55:08,680 to see the results of this extraordinary bioengineered 906 00:55:08,680 --> 00:55:12,880 cleaning process before it goes on to the final stage. 907 00:55:12,880 --> 00:55:16,960 That should settle now. Right, let's have a closer look. 908 00:55:18,400 --> 00:55:20,880 That's amazing. In just that short amount of time, 909 00:55:20,880 --> 00:55:25,800 stuff is settling, and you can see these little micro currents. 910 00:55:25,800 --> 00:55:29,280 It's as if something's...dissolved. 911 00:55:29,280 --> 00:55:31,400 Look at that. 912 00:55:31,400 --> 00:55:35,080 We want a clear water at the top and the solids at the bottom. 913 00:55:35,080 --> 00:55:37,920 Because actually at the moment this has been very agitated. 914 00:55:37,920 --> 00:55:40,120 So it's not going to look as clear as it really is. 915 00:55:40,120 --> 00:55:42,800 No, no, it'll have a lot more time to settle in there. 916 00:55:42,800 --> 00:55:45,400 We're picking it up, we're moving it about. 917 00:55:45,400 --> 00:55:49,160 You take a final effluent sample and you'll see the clearness of it. 918 00:55:49,160 --> 00:55:51,600 it looks like you've just bought it from the supermarket 919 00:55:51,600 --> 00:55:53,400 or out your tap. 920 00:55:53,400 --> 00:55:56,240 It's amazing how powerful microorganisms are 921 00:55:56,240 --> 00:56:00,240 at just breaking things down and treating things as food 922 00:56:00,240 --> 00:56:03,120 and naturally cleaning our water. 923 00:56:04,720 --> 00:56:08,520 The sludgy solids at the bottom, full of microorganisms, 924 00:56:08,520 --> 00:56:12,120 are introduced back into the activated tanks, 925 00:56:12,120 --> 00:56:14,680 whilst the clearing water at the top 926 00:56:14,680 --> 00:56:17,120 is channelled to Minworth's final tanks. 927 00:56:20,120 --> 00:56:24,040 After a last stage of settlement, the water being filtered off 928 00:56:24,040 --> 00:56:25,440 looks like this. 929 00:56:25,440 --> 00:56:29,880 Clear and deemed safe enough to return to the environment. 930 00:56:31,320 --> 00:56:33,960 Incredibly, it's piped out of the site 931 00:56:33,960 --> 00:56:38,640 and dilutes into the nearby River Tame, then joins the Trent, 932 00:56:38,640 --> 00:56:41,880 the UK's third longest river. 933 00:56:46,760 --> 00:56:49,680 Well, Zoe, was that fun? ZOE CHUCKLES 934 00:56:49,680 --> 00:56:54,160 Enlightening. What it has done is totally changed my view 935 00:56:54,160 --> 00:56:56,520 of a sewage works. 936 00:56:56,520 --> 00:56:59,680 You know, I mean, it is an incredible entity. 937 00:56:59,680 --> 00:57:03,960 Completely. The sheer volume of liquid and solids 938 00:57:03,960 --> 00:57:06,080 that arrive here every second, 939 00:57:06,080 --> 00:57:09,960 thousands of litres of the stuff turn up here continuously. 940 00:57:09,960 --> 00:57:14,160 It's a machine for dealing with this tsunami of stuff. 941 00:57:14,160 --> 00:57:17,560 To go from kind of mechanical engineering in the screens, 942 00:57:17,560 --> 00:57:20,480 churning through and taking out the rag, 943 00:57:20,480 --> 00:57:23,320 to then the bioengineering on that microscopic scale 944 00:57:23,320 --> 00:57:27,040 and seeing the world inside that activated slurry. 945 00:57:27,040 --> 00:57:30,840 And you realise that's an incredible ecosystem that's alive. 946 00:57:30,840 --> 00:57:35,360 We saw it. All those little animals, I mean, literally, 947 00:57:35,360 --> 00:57:37,240 gazillions of them. 948 00:57:37,240 --> 00:57:39,600 I mean, they're working for us incredibly hard. 949 00:57:39,600 --> 00:57:43,160 It's cutting edge stuff, actually, what they're doing here. 950 00:57:44,680 --> 00:57:47,320 What this investigation has revealed is 951 00:57:47,320 --> 00:57:50,920 that a sewage plant like this, using the very latest biotechnology, 952 00:57:50,920 --> 00:57:55,840 can be a secret gold mine of fuel, of vital soil conditioners 953 00:57:55,840 --> 00:57:59,520 and even of life-saving new treatments. 954 00:57:59,520 --> 00:58:02,520 We might not be the stage of going for a number two 955 00:58:02,520 --> 00:58:05,800 and filling up the family car with it yet, 956 00:58:05,800 --> 00:58:09,440 but in this brave new world, the secret science of sewage 957 00:58:09,440 --> 00:58:11,880 is only just getting started. 958 00:58:16,720 --> 00:58:19,000 How do microbes affect our health? 959 00:58:19,000 --> 00:58:26,840 To explore the science of what lives in us and on us, go to... 960 00:58:26,840 --> 00:58:30,480 ..and follow the links to the Open University.