Off-gas emission response mechanism in aerobic composting of sewage sludge: A review

Abstract

In recent years, sludge output has increased rapidly with the dramatical growth of sewage treatment capacity. As a typical technology to treat organic solid waste, composting combined with land utilization is a wide-used to deal with sewage sludge. However, the off-gas emission, which includes odors and greenhouse gas, still is a ubiquitous problem in the composting industry. In this study, we reviewed the findings about this topic in the last decades. It was summarized that what was the emission mechanism of off gas and which are the key factors during aerobic composting of sewage sludge. The off-gas emission is corresponding to the anaerobic-region distribution in matrix, which is intensively affected by the obstructed gas region in matrix and physicochemical properties of the matrix particle. And some suggestions and prospects for future research are put forward to provide a reference for solving the off-gas emission problem of aerobic composting of sewage sludge in China.