Simultaneous phytoremediation of tannery effluent and production of fatty acids rich biomass by Chlorella sorokiniana

Tanning is a technique of transforming hides to skins and the production of leather products involves a wide variety of processes that produce substantial amounts of effluents which are frequently discarded into the environment without prior treatment. The phytoremediation potential of the chlorophyte Chlorella sorokiniana was investigated in the present study using tannery effluent. The chlorophyte was grown in tannery effluent for 14 days, and the resulting biomass, dry weight, dissolved oxygen, chemical oxygen demand (COD), biochemical oxygen demands (BOD), Phosphate (PO42 over bar ), nitrate (NO3 over bar ), sulfate (SO42-), Cd, Cr, and Pb concentrations were monitored as well as lipid production. Cell count was highest in Bold Basal Medium (BBM) treatment, producing 159 x 10(6) cells mL(-1) on the eighth day. Chlorella was observed to reduce heavy metals with efficiency > 95% for Cd on day twelve of culture, > 44% for chromium, and > 76% for Pb at the end of the experiment. Chlorella grown in 5% effluent treatment produced the highest dry weight (58.7 mg L-1) on the twelfth day, Basal Bold Medium (Control) treatment produced the highest percentage lipid yield, and the 75% effluent treatment produced the highest fatty acid content (89.98%). PO42 over bar , NO3 over bar , and SO42- levels were lowered significantly in effluent incubated cultures. Though dissolved oxygen was decreased and COD selectively increased, the study results are vital, suggesting the potential use of C. sorokiniana in bioremediating tannery effluent alongside producing high-value products like biomass and fatty acids.

Automated summary

This study investigated the phytoremediation potential of Chlorella sorokiniana in tannery effluent. The results showed that Chlorella efficiently reduced heavy metal contaminants and produced high dry weight and lipid yield.