High efficient treatment of citric acid effluent by Chlorella vulgaris and potential biomass utilization

• DOI: 10.1016/j.biortech.2012.08.074
• Publication Date: 2012-08-31T21:31:54Z
• Authors: Changling Li; Hailin Yang; Xiaole Xia; Yuji Li; Luping Chen; Meng Zhang; Ling Zhang; Wu Wang
• Keywords: Chlorella vulgaris

The efficiency of treating citric acid effluent by green algae Chlorella was investigated. With the highest growth rate, Chlorella vulgaris C9-JN2010 that could efficiently remove nutrients in the citric acid effluent was selected for scale-up batch experiments under the optimal conditions, where its maximum biomass was 1.04 g l(-1) and removal efficiencies of nutrients (nitrogen, phosphorus, total organic carbon, chemical oxygen demand and biochemical oxygen demand) were above 90.0%. Algal lipid and protein contents were around 340.0 and 500.0 mg · g(-1) of the harvested biomass, respectively. Proportions of polyunsaturated fatty acids in the lipids and eight kinds of essential amino acids in algal protein were 74.0% and 40.0%, respectively. Three major fatty acids were hexadecanoic acid, eicosapentaenoic acid and docosadienoic acid. This specific effluent treatment process could be proposed as a dual-beneficial approach, which converts nutrients in the high strength citric acid effluent into profitable byproducts and reduces the contaminations.