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Lishan Zhu
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's Individual Contribution Page
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Spring 2016 Contributions
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am advising the fluoride and public relations teams, and working as part of the High Rate Sedimentation - Plate Settlers team this semester. Sedimentation is the process that requires the largest plane view area in a water treatment plant, and this is due to the necessary slow upflow velocity to allow particles to fall down. In hopes of overcoming that obstacle, the two high rate sedimentation teams this semester are looking at ways of concentrating the floc blanket to permit this higher upflow velocity. The team I am a part of this semester will focus on using plate settlers in the floc blanket to concentrate floc particles.
Fall 2015 Contributions
I am advising the ram pump and StaRS Theory teams, and working as part of the EStaRS team this semester. The EStaRS filter currently has orifices in the inlet manifolds, which has not previously been tested in a full scale filter. This semester, we are looking to fine tune the filter for backwashing and verify that orifices are an effective method of fabrication. If all goes well, we plan on modeling head loss through the sand bed at various turbidities of influent water.
Spring 2014 Contributions
This semester, my team members and I are working on the Low Flow Stacked Rapid Sand filter (LFSRSF). One of the main challenges this semester is adding the piping, entrance, and exit tanks and making the system water-tight.
Fall 2013 Contributions
I joined the low flow stacked rapid sand filter team this semester, and was part of the sub-sub team that worked on fabricating a new 12 inch diameter filter from PVC pipe. This design will be the representative of the dimensions of sand filters currently being tested in India.
Spring 2013 Contributions
I joined the foam filtration team this semester, and this semester we plan to redesign the foam filter using two 4 inch PVC pipes filled with foam. One will serve as the rough filter, which will have foam with a lower pore density. The other will be the finishing filter, which has a finer pore foam so water that leaves the rough filter can enter the fine filter. We also need to find a way to build a new stand for the two filters that are made of 80/20 aluminum since that is not a viable choice to use in Honduras
In the fall semester, I have joined the 12in. subteam that is responsible for creating the new filter along with my teammates Sarah Sinclair and Chenxi Wen. This semester, we have designed a created a filter column that can be used to test and make improvements on a design that was used in India.
A large challenge we faced with designing the filter was how the slotted manifolds, inflow, and outflow tubing would be installed with the constraint of only being able to reach arm's length. This created the solution of cutting the main filter column into two pieces, but we then needed a plan to securely join the two halves of the filter column with a leak-proof seal. By the end of the semester, we successfully devised a system that involves joining the two columns with a Fernco gasket, surrounded by shim stock for support, and tightened together with two hose clamps. This method of construction will join both the filter column in the middle and attach the PVC sheet caps to the top and bottom of the filter column.
The next step the team took to complete the new filter was deciding what kind and size of PVC piping would be optimal for the filter we were about to build. When we were designing the connection between the inlet tank and inlet piping, our subteam realized using flexible clear PVC piping would eradicate the problem of the complex geometry involved with connecting rigid PVC pipes from the inlet to outlet tanks. After consulting Professor Weber-Shirk and Julia Morris of the design team about the existing stacked rapid sand filter Mathcad file, my team and I decided that a 1 in. inner diameter flexible PVC tubing would be best for the intended design.
A non-leaking entrance and exit tank have preliminarily been designed using a 6 in. PVC pipe with PVC sheet caps to form the bottom of the "tank." The team is still working to test the water containing abilities of the system. The final design of the inlet and outlet tanks and the effluent waste pipes will be tackled by next semester's Low Flow Stacked Rapid San Filter team. Also, the manifold calculations and method of installing the slotted manifolds will also be designed by next semester's team.