Integration of Real Industrial Wastewater Streams to Enhance Chlorella vulgaris Growth: Nutrient Sequestration and Biomass Production

The streams from textile wastewater (TWW) contain numerous nutrients which is suitable for microalgae cultivation. However, direct use of TWW reduces microalgae algae growth and lipid production due to the presence of dyes and other suspended solids which cause hindrance in microalgae cultivation. This problem can be overcome by diluting TWW with freshwater. However, the use of freshwater to treat wastewater is neither sustainable nor economical. The study is based on the hypothesis that mixing two wastewater streams with different characteristics would, first, eliminate the use of freshwater for dilution and, second, increase the biomass production of Chlorella vulgaris. To test the hypothesis, TWW and juice wastewater (JWW) were chosen as the former is enriched with high nutrients and the latter can provide high COD environment for the microalgae to thrive. The results, indeed, demonstrate that a maximum biomass yield of 2.83 +/- 0.04 g L-1 was achieved in 75% TWW diluted with 25% JWW. The highest nitrate and phosphate of 99 +/- 0.19% and 97 & PLUSMN; 1% was also achieved in the 75% TWW. Finally, this study concludes that merging two wastewater streams can not only increase the wastewater treatment process efficiency but also eliminate the need of freshwater to treat wastewater.