Phycoremediation and biogas potential of native algal isolates from soil and wastewater

The present study is a novel attempt to integrate phycoremediation and biogas production from algal biomass. Algal isolates, sp. 1 and sp. 2, obtained from wastewater and soil were evaluated for phycoremediation potential and mass production. The estimated yield was 58.4 sp. 1 and 54.75 sp. 2 tons ha−1 y−1. The algal isolates reduced COD by >70% and NH3-N by 100% in unsterile drain wastewater. Higher productivities of sp. 1 (1.05 g L−1) and sp. 2 (0.95 g L−1) grown in wastewater compared to that grown in nutrient media (0.89 g L−1 for sp. 1 and 0.85 g L−1 for sp. 2) indicate the potential of algal isolates in biogas production through low cost mass cultivation. Biogas yield of 0.401–0.487 m3 kg−1 VS added with 52–54.9% (v/v) methane content was obtained for algal isolates. These results indicate the possibilities of developing an integrated process for phycoremediation and biogas production using algal isolates.