BOD5 AND COD REMOVAL EFFICIENCY BY Chlorella vulgaris IN WASTEWATER FROM TANNING PROCESSES

Abstract

Microalgae are a very heterogeneous microbial group that provides several applications nowadays, including wastewater treatment. The treatment of wastewater is very important, as it contains pollutants that prevent its reuse. In the present study, the growth potential of the microalga Chlorella vulgaris and its purification capacity in wastewater from tanning processes were evaluated. Ch vulgaris was bioaugmented in a bioreactor, using exponential phase cells of 106 cells/mL. The Ch. vulgaris cells were treated with tanning wastewater for 20 days. BOD₅ and COD parameters were measured daily. The results of the organic load degradation tests confirm that Ch. vulgaris reduces BOD₅ and COD to values below those permitted by the regulations established for the leather manufacturing, tanning and dressing industry. Ch. vulgaris is able to survive the adverse conditions present in wastewater, efficiently removing pollutants present in wastewater from tanning processes.