Articles · Open Access Policy
Abstract
Nitrogen and phosphorus found in aquaculture wastewater have been cited to be a source of eutrophication and ecologically detrimental. The current study seeks to analyze the effectiveness of constructed wetland systems in removing these nutrients and the suitability of constructed wetlands for small-scale aquaculture wastewater treatment. Quantitative secondary data analysis based on experimental results from pilot-scale constructed wetlands with Salicornia bigelovii for marine aquaculture effluents at low, medium, and high total ammonia nitrogen loadings was performed. The removal efficiencies of ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, and phosphate phosphorus have been analyzed to observe the specific response of nutrients to treatments. It was found that the removal efficiency of ammonia nitrogen has reduced from 58.51% at low loading to 26.21% at high loading. The removal efficiency of nitrite nitrogen has reduced from 96.07% to 27.93%, showing a decrease of 68.14 percentage points. The removal efficiency of nitrate nitrogen has reduced from 52.03% to 29.69%, while that of phosphate phosphorus has been observed to be very limited, i.e., between 1.87% and 8.20%. It can be inferred that with an increase in nutrient loading, nitrogen treatment efficiency decreases significantly, especially for nitrite. Constructed wetlands are a sustainable method of wastewater treatment; however, better hydraulic design, vegetation, substrate, and additional phosphorus removal are required.