Effect of environmental factors on performance of immobilized consortium system for degradation of carbendazim and 2,4-dichlorophenoxyacetic acid in continuous culture

As a model process for bioaugmentation, a microbial consortium obtained from soil of paddy fields was immobilized on loofa sponge. The immobilized consortium had the ability to degrade carbendazim (methyl-2-benzimidazole carbamate; MBC) and 2,4-dichlorophenoxyacetic acid (2,4-D), which are fungicide and herbicide, respectively, used in paddy fields in large quantities and are often detected from environmental water, during the 2-month operation period using a column type reactor for the continuous treatment of runoff water from paddy fields. For success of bioaugmentation, it is important to investigate the effect of environmental factors on degradation ability for hazardous chemicals. The degradation ability of the immobilized consortium for MBC and 2,4-D was also maintained at various flow rates (the mean residence time of up to 0.1 day), and at low concentrations of MBC, 2,4-D, ammonium, and phosphate estimated condition of runoff water. The degradation ability was also stably maintained up to at least 6 months by simple preservation methods. From these results, valuable information to establish the treatment system for actual environmental conditions was obtained. This study may be useful as a model research for solving problems of pollution by hazardous organic compounds.