Treatment of second cheese whey effluents using a Choricystis ‐based system with simultaneous lipid production

BACKROUND Recently the utilization of microalgae for biological nutrient and organic load removal from industrial wastewater streams has been of great research interest. This present research aimed to develop a biological (algal) second cheese whey wastewater ( SCWW ) treatment system able to generate renewable energy in the form of biodiesel while simultaneously removing polluting nutrients and chemical oxygen demand ( COD ). RESULTS Aerobically‐treated SCWW was diluted in water (dilution factor from 0.05 to 0.35) and evaluated as a substrate for Choricystis ‐like algal growth under photoheterotrophic conditions. Specifically, the algal culture was studied under non‐aseptic conditions for its ability to remove COD , nitrogen, and phosphorous from SCWW and to produce biodiesel. At the end of treatment the pollutant load of COD , TN and PO 4 3 − was reduced by up to 92.3%, 97.3%, and 99.7%, respectively. The lipid content of the algal biomass ranged from 9.2 to 13.4%, which corresponds with an oil production of 60.8–119.5 mg L −1 . The proportions of saturated and mono‐unsaturated fatty acids in the lipids produced reached 79%, thus making the system suitable for biodiesel production. CONCLUSIONS A well‐adapted Choricystis ‐like consortium could be efficiently used to treat SCWW while the biomass produced may be harnessed as a source of biodiesel. © 2015 Society of Chemical Industry