Treatment of wastewater from water based paint industries using submerged attached growth reactor

• Biodegradation of toxic compounds from waterbased paint industry was evaluated.
• General mixed substrate biodegradation model was evaluated.
• Model incorporates inhibition factor and interaction between compounds.
• Biodegradation of compounds from waterbased paint industry by SAGR was evaluated.
• Performance of SAGR was evaluated at different OLR and air flow rates.

Pollutants generated from water based paint industries contain mixture of toxic organic solvents. The present study dealt with individual and simultaneous degradation of ethylene glycol, propylene glycol and isobutanol from water based paint industry in batch and continuous mode. Biodegradation of toxic organic solvents under aerobic condition using acclimatized microbial consortia was evaluated in a batch system independently. Haldane biokinetic model stimulated the biodegradation kinetics of single substrate system satisfactorily. The biodegradation kinetics of mixed substrate was stimulated using the biokinetic parameters from single-substrate biodegradation studies. Competitive inhibition model performed well among the various models used for multi-substrate systems. Further models were statistically evaluated using the modified efficiency of coefficient (E). Performance of submerged attached bioreactor at different air flow and organic loading rates, on the removal efficiency was evaluated continuously. It is found that at an organic loading rate of 0.89 kg COD/m3/d, the maximum removal efficiency of 97% was achieved. Studies indicated that the removal efficiency was greatly depending on organic loading rate (OLR) and pollutant nature. Overall, experimental results demonstrated that the submerged attached growth reactor used in present study is found to be viable and efficient treatment system for the wastewater from water based paint industries.