Degradation of fecal sludge by using earthworm based-wetlands | |
| Author | Zin Myo Thet |
| Call Number | AIT Thesis no.EV-13-35 |
| Subject(s) | Earthworms Sewage sludge |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-13-35 |
| Abstract | Raw FS from onsite sanitation have high amount of pollutants and improper disposal can cause the serious environmental problem such as health impacts, water pollution and air pollution. On the other hand, the sludge of FS are enrich in nutrients like nitrogen (N), phosphorus (P) and Potassium (K) that can be reuse as fertilizer. In the research, we constructed nine VFCW units and designed to use EWs, cattails plant and with low cost substrata as gravel and sand for treatment. VFCWs were operated by intermittent feeding of FS at a frequency of once a two week and took the effluent after a week of loading. There were highest in the effluent treatment of CW-EP reactor than CW-P and the CW-E (no plant). The CW-EP have highest removal of TS and SS, the average removal efficiency of all units are in the range of 89~90.7% and 91.1~93%. The TKN and NH3 average removal for all units have in the range of 76% to 97 %. The COD average removal efficiency have 96 % to 97.5 %. The average removal efficiency of TP is 87%to 94.12 %. The CW-E reactor have highest nutrient content of vermicomposting FS than CW-EP and CW-P reactor. The total Phosphorus content at the sludge of in CW-E achieved the highest in the phosphorus content of sludge in the range 11.3mg/g to 15.7mg/g, CW-EP have phosphorus at 10.4mg/g~ 11.4mg/g and the TP content of CW-P have 9.7mg/g at the end experiments period. There were dramatic increase of Total Nitrogen in CW-EP among all of VFCWs in the range of 27 % ~35 % of inflation, CW-E is in the range of 12% ~ 18% the nitrogen content of CW-P have 12% increment at the end of composting periods. After finished the experiments for 70days, accumulated sludge layer in the bed of CWs were measured to compare the sludge reduction efficiency. The sludge reduction efficiency of observed are CWs +cattails plants (no worm) only have 35 % reduction of total TS. Comparing the CWs between the different CW-EP (worm densities +cattails plant ) and CW-P ( cattails plant ) and CW-E (only worm CWs) , the CW with EWs have high degradation rates than no worm CWs. The CW-E with EWs have different worm weight have degradation of sludge in the range of 53.5%~86.% reduction. CW-EP has the sludge reduction rate of 46%~76%. of totals mass balance. The weights of EWs for each CW at the end of the experiment are as follow. The increase of weight of EWs in each VFCWs were measured and CW-EP1 which have (75.4 g of worm initial weight increase to 124 g ) at 70 days composting period, CW-EP2 have (150g initial worm weight gained to 328g ) of final weight gain ,CW-EP3(131 g to 18g) of worm weight and CW-EP4 have (263g to 470g) of EWs, CW-E1 got worm weight (75.4 g to 186g), CW-E2 (150g to 374g) of worm and CW-E3 (131.9 to 295g ) EWs, CW-E4 Have (263 g to 561 g ) of EWs at the end of the experiments period. The study demonstrated that CW-EP reactor the highest efficiency in the effluent treatment performance than CW-P and the CW-E reactor. The CW-E reactor have highest nutrient content of vermicomposting FS than CW-EP and CW-P reactor. The FS treatment by EWs produces high nutrient rich sludge that can promote agriculture industry. |
| Year | 2013 |
| 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 (EV) |
| Chairperson(s) | Thammarat Koottatep; |
| Examination Committee(s) | Annachhatre, Ajit P.;Shipin, Oleg V.; |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2013 |