Team:SDSZ China/Hp
Team:SDSZ China
Integrated HP timeline:
1.Witnessing and documenting a change.Team captain witnessing the river in front of her house in her hometown gradually polluted because of nearby villagers draining waste water of mariculture on the upstream.
- Impact: Realized that fecal pollution might be the cause of water pollution, and formed the idea of starting a project to detect this kind of pollution.
2.Visit Xiaobeihe village to gain a better view of water treatment and detectionVisited Xiaobeihe village to gain a closer look at local water treatment process and detection method on chemically polluted water body in order to gain inspiration and advices on the project.
- Impact：Found out that current detection protocols do not include concentrations of bio-residues as bacteria and bacteriophages. Realized that secondary pollution might exist because of introducing feces to the treatment pool, and decided that a more conspicuous reaction should take place in the detection system because of the color of contaminated water body——revised project design and added the part of PPO.
3.Visit a water treatment factory in BeijingVisited a water treatment factory in Zhaoquanying, consulted about detailed water detection and treatment processes of fecal polluted water body and government policies on corresponding criteria.
-Impact: Understood the current detection policies and criteria specific to fecal water pollution, confirmed that no precise and specific detection methods were applied to measure the bacteriophage concentration in the polluted water sample.
4.Second visit to Xiaobeihe and the factory- Impact: took water samples from the water treatment department in Xiaobeihe and factory, applied them as samples to be tested by our detection system. Reported our detection result to the factory and the department, offered some advice on detection methods.
5.After iGEM- Plans: We hope to be able to finish the optimization of our project of adding 2-PE sequences to our plasmid to further control false negative responses, and to research more on Psp system that might be a prefect solution of the false positive reactions of our design.
A Visit to Xingzhi Experimental Primary School
In order to expand our project’s influence and raise public awareness of molecular and cellular biology as well as water pollution situation in China, our team members visited Xingzhi Experimental Primary School and taught a biology lesson there.
Due to lack of well-trained teachers and educational facilities, the kids there had little science education. Thus, rather than teaching them knowledge, it’s more important to trigger their curiosity in life science and attention on social and natural environment. We devised experiments including observing onion’s scaly epithelial cells and making cell models out of clay, combined with vivid explanations and analogies to induce the children’s interest and better convey the knowledge.
Walking through a run-down playground, opening a ramshackle wooden door, we stepped into a narrow classroom with pungent smell of moist soil and leftovers of lunch. 40 children stared up at us attentively.
When observing the cells, the kids lined up voluntarily, and operated the microscope carefully under our guidance. We have prepared temporary slides of onion cells beforehand, and thus more time is left during the class for kids to observe and try out our microscope. We asked the children to draw what they see on the blackboard, and most of them were able to identify the structure of hexagon cell wall of onion’s epithelial cells and cell nucleus under the lens and draw the basic structures on the blackboard. During our explanation of the concept of cell and cell structure, some children in the last row even stood up to see the blackboard clearly. As it was time to make the clay models of cell, the kids volunteered ardently to help us distribute the clay, and perfectly incorporated all the knowledge they learned into the models they made：different colors of clay indicated cell membrane, cell nucleus and cytoplasm.
In the end, we briefly introduced the condition of China’s water pollution to the kids and explained our project’s purpose in a simple way that they can understand. When hearing the serious state of water pollution and our team’s goal to contribute some to the detection of fecal polluted water, a girl on the back rows raised her hand and told us that she also wished to help protect the environment. We were deeply touched and listed some basic tips for everyone to follow in daily life to reduce the burden of environment. The children were eager to memorize the tips and their wish to study and become responsible citizens were what we did not imagine.
The children’s maturity and intelligence were quite impressive. We were glad to see the children having fun and enjoying some exploration of science in this short lesson, and hopefully, some of them would continue to explore the field of biology in the future. Before we left, we listed some websites and educational WeChat accounts on the blackboard for the kids to explore science on their own, since we wish their interests induced by our lecture can last and proceed to benefit them in the future——they are the future of China, so are the future of the environment around us.
A Visit to Sewage Treatment Plant in Xiaobeihe
Xiaobeihe, a small town located in the Northeastern China, and also one of our teammates’ hometown, is named after a river that runs across the town. The river irrigated crops and raised local residents generation after generation. But as local sock industry sprung up years ago, 208 sock factories bourgeoned in the village, producing tons of sewage polluted with dye. The river was clear no more, so was our teammate’s hometown in her dream.
Thanks to the local government’s effort, a sewage treatment plant was built in the town. To get a holistic understanding of local water pollution and corresponding detection and treating methods, our team members visited the plant, hoping to gain some useful information of water pollution detection that may inspire and instruct our experiment.
Following the lead of a worker, we walked through the complete water treatment facilities. The first step of treatment was filtration. A turbine was running constantly to remove large solid particles in the water. Seeing how dark the color of the polluted water was, we suddenly realized a problem: our initial design, expressing polyphenol oxidase in E.coli. cells and allow it to oxidize polyphenol under phage-rich conditions to observe the color change of the sample from light yellow to red was unfortunately not a perfect solution of phage detection. Apparently, in polluted water filled with dye, this subtle color change is hard to identify. Likewise, fecal polluted water is normally deep brown or dark in color, and the observation of the chromatic reaction could be difficult. This finding led us think of bioluminescence, which can be palpable even in seriously polluted water, and finally led us optimize our project design of expressing firefly luciferase in E.coli. cells.
The second step of treatment was neutralization. Standing on a bridge over the middle of a water treatment pool, what we saw was tons of dark water, slimy and stinky. Workers added urea and livestock feces into the pool, which is a step required for sewage treatment: the acidic chemical as urea and microbes in feces can neutralize the water filled with dye.
After this treatment, the water is drained into a deposit pool. Without any disturbance from outside environment, the water body was given enough time to deposit rather sufficiently and became cleaner as a result.
Next the workers added flocculant like Aluminum Chloride into the water, forcing the smaller pollutant particles aggregate and stick together.
Then the water was put it to another deposit pool again.
This is the end of water treatment in most of the sock factories in Xiaobeihe village. The treated water was so clean that workers even raised goldfish in the final pool. Water samples are collected at regular time period and detected with machine for the nitrogen and ammonium residues in the samples. The data is uploaded to the government for speculation synchronously.
However, our team raised a problem: what if secondary pollution caused by feces during the purification process was induced due to incomplete deposition and filtration (which we even did not observe to exist)? The automatic detection machine cannot cover the concentration of somatic coliphages as well as bacteria in the water sample. Hopefully we can adopt our detection method to the town.
Before we left, we took a bottle of water sample from the final pool and kept it in our lab: we hope to use our reaction system to detect if there is indeed phages remained in the treated water.
A Visit to Recycled-water Treatment Plant in Zhaoquanying
Compared to other places in Beijing, there are many rivers that flow across Zhaoquanying, a small town located in Beijing. Thus, some recycled-water treatment plants were built nearby. Two of our team members went to Zhaoquanying Recycled-water Treatment Plant, which is specialized in water pollution treatment, to find out the current situation of water pollution by doing an interview and sampling the water there.
When we arrived at Zhaoquanying Recycled-water Treatment Plant, the manager of the plant, Mr. Liang showed us around. We were told that the main pollutants in polluted water in the village were sanitary sewage and chemical wasted-water. Noticing the flow diagram on the wall, we could readily understand the procedure of the treatment of sanitary sewage: filtering twice, using acid treatment, separating solid and liquid, sedimenting, filtering and restoring…The contamination was serious with brownish-yellow water and nauseating smell. Besides using naked eye to see and nose to smell, the researchers also employed specialized methods and standards to judge and evaluate the degree of water pollution.
Interview outline:
1. What is the main pollutant of the contaminated water body?
Domestic and countryside waste water seriously polluted by feces; industrial waste water polluted by toxic chemicals. Feature of the polluted water: Dark in color and stinky
2. How is the water treated?
The untreated water sample is first sent to corresponding government detection centers, a detailed report of the pollution status of the sample is then sent back to the factory, so that a suitable treatment solution with correct concentration can be prepared. The final sample of treated water is sent to the government again to gain a final report of the treated water body. The factory’s treatment
3. Are there any measures taken in local areas focused on water pollution:
Pipe network reconstruction is currently being developed, restroom revolution is taken into consideration：providing one small water purifier to every three homes that can roughly purify water on a small scale. The current technology can purify water to IB level, which can be used for irrigation.
4. What are the indicators of water pollution？
COD, nitrogen, ammonia, phosphorous, suspended solids, heavy metals, E.coli. cells, ova of roundworms, etc. There is no current detection methods focused on phages in water that may be an indicator of many other bacteria’s existence.
5. What are the government’s stipulations?
There are 93 criteria on underground water treatment and 106 criteria on domestic water treatment currently in China that should be conformed by related factories.
6. Is the detection and Treatment of water in the factory sustainable?
Yes. Long term labor cost in the factory takes about 60%-70% of the total revenue, and all facilities are updated in 5-8 years’ cycle. A complete update takes place once in 20 years.
7. May you offer any advices for our project?
Be precise about the reaction system, try to prevent secondary pollution.
We learnt that there is indeed a lack of bacteriophage detection method in current water treatment and detection processes, and the workers confirmed us that bioluminescence would be observable in polluted water body and more conspicuous than simply chromatic reactions. This further gave us confidence in continuing our experiment and ensured us the viability of our project in real life.