Food crisis and water pollution will become one of the greatest challenges by 2050. Thankfully, fishery gives us relative sustainable resource to meet the ever-growing demand. With capture fishery remaining static, aquaculture has been responsible for the rapid growth and it reaches half of world total production of aquatic animals.
Successful aquaculture needs good water quality, especially the nitrate concentration should be under control. If the nitrate concentration is too high, the fish will easily get sick and even die. To lower the nitrate level , the easiest and cheapest way for fish farmers is replacing the dirty water by groundwater. Obviously, there exists two problems.
First, groundwater sustains the buildings’ foundation. Over pumping groundwater leads to the ‘’Stratum Subsidence’’ and also results in ‘’Seawater Intrusion’’ and follows by ‘’Soil Salinization’’----This phenomenon is quite familiar in Tainan, where contributes to 1/4 of total value of aquaculture production in Taiwan
Second, the farmers rarely treat the huge amount of waste water for economic purpose. They directly pour untreated water into the river, which leads to algae overgrowing, blocking the sunshine and destroying water ecosystem.
Sensing Device & Sensing Bacteria
Sensing device of "NO problem" is a boat equipped with servomotor and control module. It is designed to contain a pH meter, a thermometer and a nitrate sensor. See more detail
Nitrate sensor is a device with reactor and laser. The reactor contains genetically modified E. coli and will emit different fluorescence intensity when dealing with various concentration of nitrate in water. By determining the fluorescence level and cross-referring with data lines which we've constructed in advance, we can accurately calculate the concentration of nitrate in water. Additionally, pH meter and thermometer allow us to obtain basic information of water. After determining those characteristics of water, combining with GPS data we will upload them to a server and transfer those data to our App. By using smartphone, the users can easily get the information about their fish pond immediately. They can make the appropriate solution before it is too late to regulate the water quality. For the sake of mobility and portability, we construct this device into a boat, which can move around to collect data and is convenient to carry.
Regulation Device & Bacteria
After testing the abnormal data, our boat will notify the fishfarmers through app, and they can turn on the regulation system, which can change nitrate to glutamine in four critical steps.
First, nitrate is transformed into nitrite by NaR cluster, which exists in E. coli originally. Second, nitrite reductase (NiR) changes nitrite into ammonium. Third, glutamate dehydrogenase (GDH) turns ammonium into glutamate. Last step, glutamine synthetase (GS) catalyzes glutamate into glutamine. We put all these genes into E. coli.
We did a lot of experiments to construct and test the function of our bricks. All of the laboratory tests get good results, which means our team successfully convert nitrate waste into useful substance. See more detail
To solve nitrate problem, our sensing boat collects samples and identify its location by GPS system. The sensing data will be sent to the server through Wi-Fi and be analyzed immediately and push to the cloud through the internet. If the level of nitrate is higher than expected, our regulation box can turn on automatically, pump out the water and remove 99% of the nitrate in it.
In this way, we regulate the nitrate concentration to make fish alive instead of using large amounts of water, which avoids over pumping groundwater and follow-up ecological crisis. We used micro-organism to change all the problems into "NO problem "