Exploitation of Chlorella Pyrenoidosa's Biomass Energy by Aquiculture Wastewater

Abstract

Biomass energy of microalgea is one of the most potential renewable energy. However, over expensive cost, especially the material cost limited its industrialization. Aquiculture wastewater, which is rich in nitrogen and phosphorus, is a main reason for the eutrophication of the surrounding water and is always a problem for the sustainable development of aquaculture. Although many treatments have been used in the field, the expensive cost limited their wide application. Microalgae can utilize the N and P in the wastewater to grow, so it is feasible to purify the wastewater by the microalgae and produce the biomass energy of microalgae from the wastewater. The present paper studied the growth of Chlorella pyrenoidosa in three aquiculture wastewaters and optimized the cultivating condition. The study showed that Chlorella pyrenoidosa could grow in the wastewater from the culture of Cynoglossus semilaevis. Under the condition of pH5, illumination 5000 LX and original inoculation density 0.01 mg/mL, the microalgae had the best growth. Under the optimal condition, the microalgae could eliminate 75.2% active phosphorus, 100% ammonia nitrogen, 84.1% nitrite nitrogen and 52.8% nitrate nitrogen in the wastewater within 11 days, which suggested that the cultivation of microalgae in aquiculture wastewater is a good method for both the exploitation of microalgae biomass energy and the purification of wastewater.