Simultaneous methanethiol and dimethyl sulfide removal in a single-stage biotrickling filter packed with polyurethane foam: Performance, parameters and microbial community analysis.

Abstract

The bio-treatment of methanethiol (MT) and dimethyl sulfide (DMS), the most common sulfur compounds in odorous gas, is difficult due to the inhibition of DMS degradation by MT. This article investigated the treatment of MT and DMS odorous gas using a single-stage biotrickling filter (BTF) packed with polyurethane foam cubes that were inoculated with activated sludge from a sewage treatment plant operating an anaerobic/aerobic/oxic (AAO) process. The BTF system lasted for 161 days (with 9 days to startup) under an empty gas residence time of 39s. The elimination capacities for MT and DMS were 85.2g/m3/h (removal efficiency=96.6%) and 6.4g/m3/h (removal efficiency=95.0%), respectively, and the maximal elimination capacities of MT and DMS were 119.7g/m3/h and 7.3g/m3/h, respectively. The optimal parameters were as follows: empty bed retention time, 39s; pH, 6.1; recirculation medium flow rate, ≥1.2m3/m2/h; temperature, 29-36°C; and SO42- concentration, < 2.0g-SO42-/L. Microbial community analysis revealed that spatial differentiation between MT-degrading bacteria and DMS-degrading bacteria enable the single-stage BTF can simultaneously remove MT and DMS. The activated sludge of AAO process can be used as the inoculation sludge to treating MT and DMS gas, which provides an important reference for the industrial application of treating odorous gas containing MT and DMS.