The characteristics and treatments of sludge from plastic-lined ponds for intensive shrimp culture | |
| Author | Premsak Wanuchsoontorn |
| Call Number | AIT Thesis no.AS-97-01 |
| Subject(s) | Shrimp culture Sewage sludge--Characterization Sewage--Purification--Activated sludge process |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AS-97-01 |
| Abstract | Sludge accumulation, removal, characteristics were determined in completely closed circular plastic lined pond for intensive shrimp culture of 108 days. Sludge samples were taken from 3 concentric zones during different periods of culture (40, 80, 95 and 108 days). The study also aimed at evaluating methods for sludge treatments. The study revealed that the sludge accumulation and nutrient concentration were highest (14.91 kg/m2 of total dry sludge solids, 208.55 g/m2 of nitrogen, 62.82 g/m2 of phosphorus) at the center of the pond which needs frequent and proper treatment before disposal. The sludge contained nitrogen, phosphorus and BOD5 at 1.12-2.57%, 0.45-0.66% and 42.1-83.1 g/kg.TS. respectively. The total nitrogen, phosphorus and BOD5 removed sludge was 38. 72 g N, 11.89 g P and 175.31 g per kg. of shrimp produced, respectively. The bacterial composition of the sludge included pathogenic bacteria and anaerobes congregate towards the end of culture cycle with a reduction in aerobes, indicating that the shrimp bottom turned anaerobic towards the end of the culture cycle. Sludge Volume Index (SVI) was determined for all sludge samples taken from three bottom zones and three culture periods and the maximum SVI was 66.5 in the sludge from the center at the end of culture cycle. The sludge decomposition rate was studied by mixing the sludge with different ratio of sand to increase surface area for bacteria growth and it was found that three was a significant effect of sand treatments on the water quality (P<0.05) although not on the sludge characteristics. Sludge was treated with three types of conditioners which optimum dose was decided based on capillary suction test (CST). The conditioned sludge was then dewatered on sand drying beds with four different solid loadings to determine the maximum solid loading rate. It was found that 12 kg/m2 was the most efficient loading for all the conditioners and ferric chloride at 20% of TS sludge yielded highest solid loading rate (2.65 kg/m2.d) thus requiring minimum area for drying. The quality of the filtrate was also analyzed and it was found that the filtrate from the treatment without conditioners was the best. |
| Year | 1997 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AS-97-01 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Aquatic Systems (AS) |
| Chairperson(s) | Lin, Chang Kwei; |
| Examination Committee(s) | Hambrey, John B.;Yakupitiyage, Amararatne; |
| Scholarship Donor(s) | Charoen Pokphand Group of Companies, Thailand; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1997 |