Sulfate reduction behavior in pressure-bearing leachate saturated zone

Attention should be paid to the sulfate reduction behavior in a pressure-bearing leachate saturated zone.In this study,within the relative pressure range of 0–0.6 MPa,the ambient temperature with the highest sulfate reduction rate of 50℃ was selected to explore the difference in sulfate reduction behavior in a pressure-bearing leachate saturated zone.The results showed that the sulfate reduction rate might further increase with an increase in pressure;however,owing to the effect of pressure increase,the generated hydrogen sulfide (H_(2)S) could not be released on time,thereby decreasing its highest concentration by approximately 85%,and the duration extended to about two times that of the atmospheric pressure.Microbial community structure and functional gene abundance analyses showed that the community distribution of sulfate-reducing bacteria was significantly affected by pressure conditions,and there was a negative correlation between disulfide reductase B(dsrB) gene abundance and H_(2)S release rate.Other sulfate reduction processes that do not require disulfide reductase A (dsrA) and dsrB genes may be the key pathways affecting the sulfate reduction rate in the pressure-bearing leachate saturated zone.This study improves the understanding of sulfate reduction in landfills as well as provides a theoretical basis for the operation and management of landfills.