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Vermi-composting processes of sludge from anaerobic baffled reactor and kitchen wastes | |
Author | Senevirathna, S. T. M. L. D. |
Call Number | AIT Thesis no.EV-07-50 |
Subject(s) | Vermicomposting |
Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Envirornnental Engineering and Management |
Publisher | Asian Institute of Technology |
Abstract | In the first phase of the experiment, the qualities of vermicompost were analyzed. The results were compared with the compost quality standards stipulated by the Environment Protection Agency of United State, EU Biowaste Directive and Ohio Environmental Protection Agency. Both sludge and kitchen waste vermicomposts were analyzed for the quality parameters of pH, Total Organic Carbon, Total Nitrogen, Total Phosphorus, Heavy Metals ( Cd, Cu, Pb, Cr, Zn, Mn, Ni) moisture content and Volatile Solids. It was found that the both vermicomposts are rich in nutrients of Nitrogen and Phosphorus. All heavy metal concentrations of kitchen waste vermicomposting is within the standards. Zinc and Copper concentration of sludge vermicompost are beyond the limit stipulated by EU and US EPA, but it does not exceed the limit stipulated by Ohio EPA. The second phase of the experiment was basically concentrated on the optimization of conditions for sludge vermicomposting. Sludge feeding rate and the moisture content of sludge were optimized and it was concluded that the optimum moisture content of the sludge is 90% and the optimum daily feeding rate of sludge (with 94% moisture content) is equal to the weight of worm biomass in the reactor. The third phase of the experiment was to develop a lab scale model for vermicomposting the sludge. The results of phase 1, phase 2 and the up-flow concept were used to construct this model. The advantages of this concept are high performance, easy collection of compost and long nun without cleaning. Worms were also produced as a by-product. Forty percent of the total solid enter the reactor was converted in to the worm biomass and it was -calculated that there is a daily yield of two percent. This reactor was used to calculate the sludge volume reduction by vermicomposting process and it was determined that there is a fifty percent of volume reduction |
Year | 2007 |
Type | Thesis |
School | School of Environment, Resources, and Development (SERD) |
Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
Academic Program/FoS | Environmental Engineering and Management (EV) |
Chairperson(s) | Thammarat Koottatep |
Examination Committee(s) | Chongrak Polprasert;Chettiyappan Visvanathan |
Scholarship Donor(s) | The President's Fund, Sri Lanka - AIT fellowship |
Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2007 |