Assessment of the Feasibility of Using Filter Made of Rice Straw for Treating Aquaculture Effluents in Egypt

摘要

Aquaculture production in Egypt is practiced exclusively on polluted drainage water. This results in low productivity of a low quality product. Current aquaculture practices result in additional waste loads to the existing polluted water. The present paper reports the treatment effectiveness of a filter media for treating wastewater arising from aquaculture farms at the field level. First, wastewater entering the farm from is treated to remove hazardous pollutants. Then, a water recycling and filtration system of the pond water is introduced, to purify fish wastes from the pond and to recover nutrients. A pilot study is conducted at experimental fish ponds in the Northern Delta Region. Fish pond material flow analysis model is developed to simulate the impact of the adoption of the proposed approach on the aquaculture industry. The findings of the pilot study are used to extrapolate its effectiveness in reducing waste loads in water and improving water use efficiency in aquaculture farms at broader scale. Results indicated potential improvement in fish quality and productivity and a considerable reduction in pollution loads to the receiving water bodies. The system provides yield increase of about 15% and reduction in pollution loads by about 95%. However, Nitrogenous compounds in the form of Nitrates remain in the effluent; it is less toxic to the environment than Ammonia. To increase the revenue of this approach, the system is recommended to be combined with renewable energy to operate the circulation pumps.