Study on changes of microbial activity and organic matter in landfill leachate polluted aquifer sediment

Batch experiment and column experiment were carried out to research the changing law of organic matter and microbial activity with time and space, combined with the theory of redox zone in pollution plume. The results showed that microorganism could experience the complete growth cycle in the leachate contaminated aquifer. The change of TOC with time was closely related with microbial activity, lagging behind the change of microbial activity, and humus inhibited the growth of microorganism. Microbial activity in the contaminated aquifer decreased with the distance away from pollution source, however, it increased obviously in the iron reduction zone. During the experimental period, TOC had penetrated the soil column, but it decreased in iron reduction zone with the highest degradation efficiency of 9%. This indicated the iron reduction zone in leachate plume played an important role in the spreading and attenuating of pollutants in leachate contaminated aquifer.