...
Fall 2011 Contributions
This semester, I am conducting conducted research toward the problem of Residuals Management in AguaClara plants.
There are numerous waste streams associated with the operation of our plants, including alum sludge (from the sedimentation, floc, and entrance tanks), dirty backwash water, plant influent/effluent during bypass and treatment failure, chemical precipitates from preparation of our chlorine disinfection solution, and chemical waste from the alum and/or PAC stock tanks.
I 'm researching researched different dewatering and treatment methods to handle the alum sludge, including lagooning, irrigation, and simple dispersal. Preliminary results have indicated problems with each method, so further deliberation is necessary before making any decisions or coding the design specifications.
The CaC03 that precipitates out of the chlorine solution is innocuous, so we will likely be able to add it to the sludge in whatever method we use.
There were too many issues associated with dewatering and treatment processes, most notably due to the lack of a freeze/thaw cycle in Honduras as well as our desire not to create standing bodies of water in which disease-spreading mosquitoes could reproduce.
I proposed that the most feasible option for residuals management is to continue diluting and discharging our waste streams, but to begin protecting the land at the outlet of our disposal pipes. This can be done with rock-lined pipe outlet protection structures, design procedures for which have been programmed into MathcadFor the other chemical waste streams, further research is required before deciding on a disposal plan.