Abatement of dimethyl sulfide using anoxic biotrickling filter

Abstract

AbstractBACKGROUNDThis study aimed to use a lab‐scale anoxic biotrickling filter (ABTF) for the bioconversion of dimethyl sulfide (DMS) gas to produce less harmful byproducts, i.e. elemental sulfur and/or sulfate. It examined the exploitation of nitrate as an electron acceptor in the oxidation of malodorous DMS‐containing gas in combination with other parameters: gas/liquid (G/L) ratio (40, 60, 80, 100, 150), empty bed residence time (EBRT) (10, 30, 60, 90, 120 s) and inlet loading (IL) (9, 18, 48, 90 g m−3 h−1).RESULTSThermodynamic analysis and half‐reactions showed that at DMS/NO3− molar yield ratios 0.75 and 0.34, elemental sulfur and sulfate were the main metabolic products respectively. Overall, 58% of the sulfur element in DMS was bioconverted to elemental sulfur. Mass balance calculations revealed high denitrification efficiency, i.e. 52.7% of inlet NO3− was converted to N2. The optimal EBRT was found as 30 s (corresponding to removal efficiency (RE) 89%) for inlet concentration 150 mg m−3 and as 60 s (corresponding to RE 78%) for inlet concentration 1500 mg m−3. However, the maximum elimination capacity (EC) was 70.3 g m−3 h−1 at EBRT 60 s and G/L ratio 80. The relative abundance of bacterial communities was dominated by Proteobacteria (56.1%) and Alphaproteobacteria (27.3%) at phylum and class levels respectively.CONCLUSIONThe study revealed that ABTF has a reliable biodegradation capacity in DMS oxidation under anoxic conditions; however, process improvement on mass transfer enhancement for low waste gas concentrations is still required. © 2019 Society of Chemical Industry