Biological treatment of pulp and paper industry effluent by oleaginous yeast integrated with production of biodiesel as sustainable transportation fuel

Abstract

Worldwide pulp and paper industry is recognized as a serious threat due to the discharge of various toxic contents present in its effluent to the surrounding environment. To combat this challenge, the role of oleaginous yeast to utilize the pulp and paper industry effluent for the integrated toxic contents removal and sustainable biodiesel production were undertaken. Oleaginous yeast Rhodosporidium kratochvilovae HIMPA1 was used as a model organism for its unique ability to utilize pulp and paper industry effluent as a culture medium and accumulate high quantity of triacylglycerol or neutral lipids as large size lipid droplets of 4.56 ± 0.24 μm within its cellular compartment. The maximum cell dry weight (13.87 g/L) with total lipid yield of 8.56 g/L was obtained after 144 h of cultivation. Data showed significant reduction in effluent toxic components i.e. color, 89%; lignin, 94.27%; phenol, 99.60%; biochemical oxygen demand, 77.36%; total dissolved solids, 84.59%; and chemical oxygen demand, 94.22%. Fatty acid methyl esters profile revealed high quantity of long chain monounsaturated fatty acids (45.43%) and polyunsaturated fatty acids (15.91%) that improves biodiesel quality under low temperature condition in terms of low cold filter plugging point along with good oxidative stability and cetane number as per American Society for Testing and Materials D6751-02 and European Committee for Standardization - EN14214 guidelines.