Phycoremediation of water of Ellenga beel polluted with paper mill effluent using Chlorella ellipsoidea and Desmodesmus opoliensis.

The present study investigated the phycoremediation efficacy of two freshwater green microalgae Chlorella ellipsoidea and Desmodesmus opoliensis for treatment of water of Ellenga beel, a wetland located in the vicinity of Nagaon paper mill and into which effluents of the paper mill are drained-off. After inoculation of water samples with the two freshwater green microalgae, the culture medium were analyzed for various physicochemical parameters such as pH, electrical conductivity, total dissolved solids, phosphate, nitrate, potassium, chloride, phenol, cyanide, biological oxygen demand, chemical oxygen demand and heavy metals at every seven days interval for a period of 42 days. A reduction of phosphate (85%), sulfate (96%), nitrate (76%) and chloride (48%) was observed after 42 days of incubation in the tested beel water. The micro algal incubation also resulted in decrease of heavy metal such as Pb (54%), Zn (98%), Cr (59%), and Cu (61%). Comparison of Fourier transform infrared spectra of beel water samples (control) with those inoculated with the test micro algal species showed presence of binding sites for certain functional groups like phosphate, amide, carbohydrate and alkyl halides in inoculated samples. D. opoliensis exhibited higher phycoremediation efficiency than C. ellipsoidea in removal of pollutants from the beel water samples. [ABSTRACT FROM AUTHOR]