Macroalgae culture to treat anaerobic digestion piggery effluent (ADPE)

Environmental consequences of high productivity piggeries are significant and can result in negative environmental impacts, hence bioremediation techniques (in particular using macroalgae) are therefore of great interest. Here, the growth potential of several freshwater macroalgae in anaerobic digestion piggery effluent (ADPE), their nutrient removal rates and biochemical composition of the biomass were investigated under outdoor climatic conditions. A consortium of two macroalgae, Rhizoclonium sp. and Ulothrix sp. was isolated and could efficiently grow in the ADPE. Maximum ammonium removal rate (30.6±6.50mg NH₄⁺-NL^-1d^-1) was achieved at ADPE concentration equivalent to 248mgNH₄⁺-NL^-1. Mean biomass productivity of 31.1±1.14g ash-free dry weight (AFDW) m^-2d^-1 was achieved. Total carbohydrate and protein contents ranged between 42.8-54.8 and 43.4-45.0% AFDW, respectively, while total lipid content was very low. The study indicates the potential use of this macroalgal consortium for treating ADPE as well as source of animal feed production.