Environmental pressure, land utilization, and economic feasibility have resulted in the development of alternatives to treatment fish farm wastewater. We examined the influence of two water treatment systems—a constr...Environmental pressure, land utilization, and economic feasibility have resulted in the development of alternatives to treatment fish farm wastewater. We examined the influence of two water treatment systems—a constructed wetland (CW) and a soil filter system (SF)—on the constitution of the phytoplankton community analyzed through the functional grouping of species and nutrients removal of aquaculture farm. The CW provided high removal efficiency: 82.9% for ammonia, 87.0% for nitrate, 96.9% for nitrite, 85.5% for total phosphorus, 88.5% for SRP and 71.6% for BOD. Removal efficiency of SF was lower than CW, removing 82.1% of ammonia, 7.2% of total phosphorus, 45.9% of SRP and 39.4% of nitrite, but was satisfactory. The functional group F, made up of Chlorophyceae Dictyosphaerium pulchellum and Kirchneriella lunaris, was the most representative in both systems, followed by functional group P and constituted by Zygnemaphyceae Melosira sp. The number of functional groups decreased in the outlet of the two treatment systems, where S1, H1 and W1, characteristic of eutrophic environment, were retained. Data show that CW and the SF system are potentially applicable to the fish farm wastewater treatment and ensure an improvement in water quality.展开更多
A seven-month research evaluated the management effect on the water quality and sediment of seven fish ponds. Water and sediment were collected at nine sample sites: seven in the fish ponds;one in inlet water and anot...A seven-month research evaluated the management effect on the water quality and sediment of seven fish ponds. Water and sediment were collected at nine sample sites: seven in the fish ponds;one in inlet water and another in the fish farm’s effluent. The soil samples were analyzed for macro- and micro-nutrients and the water samples were analyzed for physical and chemical parameters. Management and local climate conditions affected nutrient seasonality in the sediment and featured high concentrations of Al, Ca, Cu, K, Mg, C, Na, Zn and OM at the effluent with low pH, ranging between 4.4 and 6.5. Sudden decrease of DO (less than 3 mg/L) during the rainy season, with a 180 mmrainfall, and a TSS increase (approximately 10 mg/L) were reported. Use of organic manure in fish pond V6 caused higher rates of ammonia (over 1 mg/L). Due to the sediment’s acid pH (less than 4.8) and Al at 0.92 mg/L at the effluent, great care was required in the fish farm. Maintenance and procedures management in the fish farm under analysis should be given more attention since high levels of Al, Fe and acid pH and low levels of potassium and phosphorus in the sediment may produce unfavorable conditions in the water column, and may ultimately have an impact on fish.展开更多
基金the“Coordination for the Improvement of Higher Level Personnel”(Capes)for scholarship and“Sao Paulo Research Foundation”(Fa-pesp)financial support(10/50478-6).
文摘Environmental pressure, land utilization, and economic feasibility have resulted in the development of alternatives to treatment fish farm wastewater. We examined the influence of two water treatment systems—a constructed wetland (CW) and a soil filter system (SF)—on the constitution of the phytoplankton community analyzed through the functional grouping of species and nutrients removal of aquaculture farm. The CW provided high removal efficiency: 82.9% for ammonia, 87.0% for nitrate, 96.9% for nitrite, 85.5% for total phosphorus, 88.5% for SRP and 71.6% for BOD. Removal efficiency of SF was lower than CW, removing 82.1% of ammonia, 7.2% of total phosphorus, 45.9% of SRP and 39.4% of nitrite, but was satisfactory. The functional group F, made up of Chlorophyceae Dictyosphaerium pulchellum and Kirchneriella lunaris, was the most representative in both systems, followed by functional group P and constituted by Zygnemaphyceae Melosira sp. The number of functional groups decreased in the outlet of the two treatment systems, where S1, H1 and W1, characteristic of eutrophic environment, were retained. Data show that CW and the SF system are potentially applicable to the fish farm wastewater treatment and ensure an improvement in water quality.
文摘A seven-month research evaluated the management effect on the water quality and sediment of seven fish ponds. Water and sediment were collected at nine sample sites: seven in the fish ponds;one in inlet water and another in the fish farm’s effluent. The soil samples were analyzed for macro- and micro-nutrients and the water samples were analyzed for physical and chemical parameters. Management and local climate conditions affected nutrient seasonality in the sediment and featured high concentrations of Al, Ca, Cu, K, Mg, C, Na, Zn and OM at the effluent with low pH, ranging between 4.4 and 6.5. Sudden decrease of DO (less than 3 mg/L) during the rainy season, with a 180 mmrainfall, and a TSS increase (approximately 10 mg/L) were reported. Use of organic manure in fish pond V6 caused higher rates of ammonia (over 1 mg/L). Due to the sediment’s acid pH (less than 4.8) and Al at 0.92 mg/L at the effluent, great care was required in the fish farm. Maintenance and procedures management in the fish farm under analysis should be given more attention since high levels of Al, Fe and acid pH and low levels of potassium and phosphorus in the sediment may produce unfavorable conditions in the water column, and may ultimately have an impact on fish.
