A preliminary study on the feasibility of using fly ash in removing mud turbidity and liming in fish ponds | |
| Author | Vonn Vinary |
| Call Number | AIT Thesis no. AS-99-14 |
| Subject(s) | Fish ponds Fly ash |
| Note | A thesis submitted in partial fulfillment of the requirement for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AS-99-14 |
| Abstract | Two experiments were conducted at the Asian Institute of Technology, Thailand, from April to July 1999 to investigate the feasibility of using fly ash in removing mud turbidity and liming material in aquaculture. The first experiment was carried out in 2-L plastic containers for one week to determine the appropriate dosage of fly ash in mud turbidity removal. There were eleven treatments with different dosages of fly ash, ranging from 0 to 2000 mg/L with three replications each. The second experiment was conducted in twelve 5-m2 concrete tanks for two weeks to assess the response of fly ash at the appropriate dosage (1600 mg/L) determined in the first experiment to fertilization by comparing treatments 1 and 2, and to determine the liming effectiveness of fly ash by comparing treatments 1, 3 and 4. The four treatments were: (1) control; (2) application of fly ash at a rate of 1600 mg/L; (3) application of slaked lime at a rate of 50 mg/L; ( 4) application of fly ash at a rate of 66 mg/L, which was equivalent to the rate of slaked lime in terms of neutralizing value and efficiency rating. All tanks were fertilized with urea and TSP at rates of 28 kg N and 7 kg P/ha/week. Fly ash was effective in removing mud turbidity. The appropriate dosage of fly ash was determined as 1600 mg/L. Dosages below 600 mg/L did not cause significant reduction in turbidity. The neutralizing value of fly ash was estimated as 78%, which was smaller than that (135%) of slaked lime. However, the efficiency rating of fly ash was 96.9%, which was much higher than that (74.5%) of slaked lime. Fly ash at an application rate of 66 mg/L resulted in similar levels of pH and alkalinity as slaked lime at a rate of 50 mg/L. One unit of slaked lime can neutralize as much as acid as 1.33 units of fly ash, by considering both neutralizing value and efficiency rating. Chlorophyll a concentrations in the water treated by fly ash were higher than those in the water treated by slaked lime, although there were no significant differences. This indicated that the response of fly ash to fertilization was at least not less than that of slaked lime. Values of all measured water quality parameters in the water treated by fly ash were similar to those in the water treated by slaked lime. All those values were within the acceptable ranges for fish culture. Compared with commonly used coagulants and liming materials, fly ash is less effective in both removing mud turbidity and liming. However, economically fly ash costs much less than them, therefore, fly ash may have a great potential to be used in aquaculture. |
| Year | 1999 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AS-99-14 |
| 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) | Yi, Yang; |
| Examination Committee(s) | Lin, C. Kwei;Yakupitiyage, Amararatne; |
| Scholarship Donor(s) | Swedish International Development Co-operation Agency (Sida); |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1999 |