Hydrogen sulphide removal from air by biotrickling filter using open-pore polyurethane foam as a carrier

Abstract

A study was conducted on H2S removal in a biotrickling filter packed with open-pore polyurethane foam. Thiobacillus denitrificans was used as inoculum and a mixed culture population was developed during the process. The inhibitory effect of sulphate concentration (1.8-16.8 g L-1), pH (6.9-8.6), trickling liquid velocity (TLV, 9.1-22.8 m h(-1)), H2S inlet concentration (20-157 ppmv) and the empty bed residence time (EBRT, 9-57 s) on the H2S removal efficiency (RE) were thoroughly investigated. An increase in pH from 6.9 to 8.5 led to a corresponding increase in H2S removal. In addition, an inhibitory effect of sulphate concentration was observed from 16.8 g L-1 and the maximum elimination capacity was found to be 22 gS m(-3) h(-1) (RE 98%). The RE was constant (98.8 +/- 0.30%) for EBRT >= 16 s, but a decrease in the EBRT from 16 to 9s led to a corresponding decrease in RE from 98.2 to 89.6% for a TLV of 9.1 m h(-1) and from 97.9 to 94.9% for a TLV of 22.8 m h(-1) (inlet load of 11.0 +/- 0.2 gS m(-3) h(-1)). The sulphur oxidation capacity in the biotrickling filter was not diminished by the presence of other bacteria. (C) 2014 Elsevier B.V. All rights reserved.