緑藻セネデスムスを用いた養魚廃棄物中の栄養塩除去

抄録

In order to determine algal growth in aquacultural wastewater and the effect of the addition of digested aquacultural solid waste, 7-days culture experiment using the green alga Scenedesmus quadricauda was conducted at a constant temperature of 25°C under continuous light and aeration. Media treatments used in the experiment were derived from diluted wastewater and solid waste that was digested with concentrated sulfuric acid and hydrogen peroxide at 440°C. Treatments included diluted wastewater (WW), diluted wastewater with solid waste which had undergone digestion (WW/SW), and diluted wastewater with sulfuric acid and hydrogen peroxide (WW/SA/HP) as a control. Algal growth occurred in all media treatments examined although low growth and nitrogen removal was recorded in WW and WW/SA/HP. Final readings in WW and WW/SA/HP for phosphorus were not detected. These results indicated that two treatments without containing solid waste were insufficient phosphorus as a nutrient for the algal growth. In contrast, growth of S. quadricauda in WW/SW was higher than in the other two treatments and was comparable to algal growth observed in synthetic medium. The final readings in WW/SW for nitrogen, phosphorous, potassium, iron, manganese, zinc and copper were reduced by over 70% when compared to the initial readings. It is clear from these findings that the addition of digested solid waste resulted in superior nitrogen removal from aquacultural wastewater by S. quadricauda.