Potential of using rice-straw and rice-husk ash as liming materials in aquaculture | |
| Author | Paul, Tapan Kumar |
| Call Number | AIT Thesis no.AQ-03-27 |
| Subject(s) | Fish ponds Pond aquaculture Aquatic liming |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environmnet, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AQ-03-27 |
| Abstract | This study, consisting of four experiments, was conducted at the Asian Institute of Technology, Thailand, from February to July 2003 to assess the feasibility of using iice-straw ash (RSA) and rice-husk ash (RHA) as liming materials for aquaculture. The first experiment was carried out to determine neutralizing values, efficiency ratings, and solubility of RSA and RHA, and total alkalinity, total hardness and pH values in RSA or RHA saturated solutions with quick lime (CaO) serving as a control. The second experiment was conducted in fifty-four 25-L plastic buckets to determine effects of RSA and RHA at different doses on mud turbidity removal and water quality. There were nine doses (treatments) for both RSA and RHA with three replicates each. RSA or RHA was applied at 0, 2,500, 5,000, 7,500, 10,000, 15,000, 17,500 and 20,000 mg/Lin the buckets with the prepared turbid water. The treatments were randomly allocated to experimental buckets. The third experiment was conducted in nineteen 5-m2 outdoor cement tanks to determine effects of RSA and RHA as liming materials on water quality and growth of Nile tilapia ( Oreochromis niloticus). There were six experiments: (Tl) no liming (control); (T2) liming soil by quick lime (CaO); (T3) liming soil by rice-straw ash (RSA); (T4) liming soil by rice-husk ash (RHA); (T5) liming water by rice-straw ash (RSA-water); and (T6) liming water by rice-husk ash (RHA-water). Liming rates for soil were dete1mined based on soil acidity, while liming rates for water were determined based on the weekly measured total alkalinity concentration to maintain total alkalinity at 75 mg/Las CaC03. All tanks were pre-treated using CaO to reduce soil acidity which was too low to be treated by RSA and RHA, fertilized with urea and TSP at the rates of 28 kg N and 7 kg P/ha/week, and stocked with sex-reversed Nile tilapia fingerlings of 10-15 g size at 2 fi sh/m2 • The fourth experiment was conducted in eighteen plastic buckets of 47 cm in diameter and 64 cm in depth to determine effects of rice-straw ash and rice-husk ash as liming materials on water quality. In this experiment, soils at the bottom of the buckets were not pre-treated, and no fish were stocked. The treatments were same as the third experiment. The first experiment showed that the neutralizing values of RSA and RHA were 11.02% and 2.55%, respectively, and efficiency ratings were 30.17% and 33.74%, respectively. Compared to quick lime, the neutralizing values and efficiency ratings were much lower. RSA and RHA could bring total alkalinity concentrations to 227 and 178 mg/L as CaC03, respectively, which were much lower than the increased concentration by quick lime (1,775 mg/Las CaC03). However, total hardness concentration increase caused by quick lime was significantly lower than that by RSA, but significantly higher than that by RHA (P < 0.05). Increase of pH caused by quick lime was significantly higher than that caused by both RSA and RHA (P < 0.05). The second experiment showed that both RSA and RHA were not effective in removing mud turbidity. Final concentrations of total alkalinity were positively linearly correlated with both RSA and RHA doses (Y = 0.0094X + 18.852, r2 = 0.9643, n = 27, P < 0.05; Y = 0.001 lX + 8.6222, r2 = 0.8507, n = 27, P < 0.05; respectively). RSA gave higher concentrations of total alkalinity than RHA at the same doses. Both RSA and RHA raised pH values significantly at all doses, compared to the control, however, RSA had higher ability to increase pH than RHA. Values of ~H increased linearly with increasing doses of both RSA and RHA (Y = 0.000lX + 6.0233, r = 0.6274, n = 27, P < 0.05; Y = 0.00004X + 4.4167, r2 = 0.8716, n = 27, P < 0.05; respectively). The third experiment showed that there were no significant differences for most water quality parameters among all treatments, and growth of Nile tilapia were not significantly different among all treatments (P > 0.05). TP and SRP concenh·ations were significantly higher, compared to other h·eatments, indicating that that RSA and RHA released significant amount of phosphorus to the tank water and could be a cheap source of phosphorus for fish culture. The fourth experiment showed that RSA and RHA could significantly increase pH compared to the control, and could significantly increase total alkalinity compared to both the control and quick lime h·eatment. This experiment confirmed the findings from the third experiment that both RSA and RHA could release significant amount of phosphorus to the water. The present study revealed that both RSA and RHA have potentials to be used as lowcost alternative liming materials and phosphorus sources for aquaculture, especially for rural aquaculture. More research is needed to optimize the doses of both RSA and RHA. |
| Year | 2003 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AQ-03-27 |
| 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 | Aquaculture and Aquatic Resources Management (AQ) |
| Chairperson(s) | Yi, Yang; |
| Examination Committee(s) | Yakupitiyage, Amararatne ;Lin, Chang. Kwei. ; |
| Scholarship Donor(s) | Department For International Development (DFID); |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2003 |