Spring 2014 contributions
We are the Arsenic team. We will focus on how to measure the small amount of Arsenic in waste and drinking water, and how to remove the Arsenic in water. The team will learn how to use GFAA, and run the batch and continuous flow experiment. From the continuous flow experiment, the team will analyze many factors might affect the Arsenic in water .Being the material coordinator, I mainly work on ordering materials, keeping track of and organizing materials purchased before. First of all, I reviewed the papers about Arsenic removal techinique, the method used is media filtration.After reading several papers, I selected one which is most related to the one we are going to analyze, pick up the main points and wrote a summary of it. Basically from this paper, we can know the efficiency of sand filtraiton method, this is done by using coagulant to remove Arsenic, and we also generally know the conditions such pH, temperature, how they affect the Arsenic removal.Then, we started to design the sand column. We decided the size of the column, put in the sand, and attached to the steel working place. Next, we find the pumps, the necessary tubes with different diameters, the connectors which are fit and also the bottles to store both the solutions and wastes. When all the things are prepared, we put them together and set up the filtration system. Some properties of the system should be measured, such as I found out the porosity of the sand we use. And also, the concentrations and pH condition which the coagulant comes up precipitation should be known, I use different concentration of coagulant solution, mix well, to find which concentration is the best for precipitation. And also, I measured the flow rate of one pump when running in diffferent pump rate, build up the calibration curve for it. Then, there are two things we need to figure out, one is the best way coat the sand with coagulant and another is taking the least of all the materials and liquids. When the sand filtration system is ready, we test the flow rate and also the backwash rate. There is a manometer I build up on the wall, it has the units of length, and use to measure the headloss due to the sand column. To make sure the coagulant is coming into the sand, we use the headloss to detect it, the increasing of the headloss height might be an indication of the coagulant mixed with sand. I measure the headloss height with different pump rate, and also with different coagulant concentrations, collect data and draw graphs, to see how they are related. In next step, we prepare the solutions which are in the exact concentrations used for the experiments, both the Arsenic and coagulant solution. To analyze the coagulant remove the Arsenic, we run both the pre-treatment and co-treatment methods. After we determine the procedure carefully, we are ready to run the Arsenic solution. We collect the samples at different times, and use the GFAAS to measure the concentration of Arsenic in the effluent solution, to analyze how the coagulant remove the Arsenic. In general, the cogulant really has a good efficiency to remove the Arsenic in water. Media filtration method is an useful and significant method to remove the harmful contaminant elements in water, which already or should be widely used in water treatment process.
2014 Fall Turbulent Tube Flocculator
This semester, we are the Turbulent Tube Flocculator team. Before we use the flocculator to run the real experiments tests, we are going to modifying some parts of the flocculator. We will design and build a frame which can support the tube settler at 60 degree, also design a adjustable effluent elevation to make the elevation can be changed appropriate at a specific flow rate. The PID turbidity controller needs additional tuning. At the same time, we need to remove the air bubble in the effluent, check the capture velocity in the settler. Without using the PACl solution, decide a test which run 12 hours. Then, we can start the real test, using different turbidity, chemical dose and capture velocity.