Treatment of toxic wastewater by use of biological processes

Abstract

The present work evaluates the capacity of suspended-growth un-acclimated sludge in treating 2-chorophenol (2-CP) and 2,4,6 – trichlorophenol (2,4,6 – TCP) containing synthetic wastewater in Continuous Flow Reactor (CFR) and in Sequencing Batch Reactor (SBR). In CFR, 2-CP concentrations were 103 and 163 ppm; 2,4,6 – TCP concentrations were 71 and 72 ppm. Under these 2-CP and 2,4,6 –TCP loadings, TSS growth was halted. Also, continuous decrease in nitrification was observed characterized by increasing effluent ammonium and decreasing nitrate production. 2-CP and 2,4,6 – TCP removals were decreasing under all their concentrations. In SBR, 2-CP inlet concentrations were 17 and 51 ppm; 2,4,6 – TCP inlet concentrations were 20 and 26 ppm. TSS demonstrated continued growth under all chlorophenol concentrations. 2-CP 17 and 51 ppm inhibited nitrification process. 2,4,6 – TCP 20 and 26 ppm did not cause nitrification inhibition. 100% removal of all 2-CP and 2,4,6 – TCP feed concentrations was achieved. Aeration in SBR played a significant role removing 43.9 % of Total Carbon (TC) and 39.9% of Total Nitrogen during the 1st day of experiment.