title: Biodegradation of dichloromethane along with other VOCs from pharmaceutical wastewater.
abstract: The present study dealt with the interaction of dichloromethane (DCM) with other non-chlorinated organic solvents such as methanol, acetone, toluene, and benzene, which are commonly present in the pharmaceutical wastewater, during biodegradation by mixed bacterial consortium. Non-chlorinated solvents were easily degradable even at an initial concentration of 1,000 mg/L, whereas only 20 mg/L of DCM was degraded when used as sole carbon source. The Monod Inhibition model appears to simulate the single pollutant biodegradation kinetics satisfactorily. In dual substrate systems, low concentrations (100 mg/L) of non-chlorinated solvents did not interfere with the DCM degradation. Non-interaction sum kinetics model was able to simulate the experimental results well in this case. However, high concentrations of non-chlorinated solvents (1,000 mg/L) affected the DCM degradation significantly. There was severe competition between the chlorinated and the non-chlorinated solvents. In this case, competitive inhibition model predicted the experimental results better compared to co-metabolism model. In multiple substrate system also, presence of DCM prolonged the degradation of the other non-chlorinated solvents. However, the presence of non-chlorinated compounds accelerated the degradation of DCM. The results of the present study may be helpful in optimal design of biological systems treating mixed pollutants.
authors.affiliation: Environmental and Water Resources Engineering Division, Department of Civil Engineering, IIT Madras, Chennai, 600 036, India.
authors.forename: V S
authors.initials: VS
authors.lastname: Priya
authors.forename: Ligy
authors.initials: L
authors.lastname: Philip
mesh_terms: D001673:Biodegradation, Environmental; D008752:Methylene Chloride / Q000378:metabolism*; D055549:Volatile Organic Compounds / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D055549:Volatile Organic Compounds; D014874:Water Pollutants, Chemical; D008752:Methylene Chloride