Biodegradation of hydrogen sulphide by inoculated Rhodococcus sp.zw11 in a pilot-scale biotrickling filter

Abstract

A strain of autotrophic micro-organism, Rhodococcus sp.zw11, was isolated from pharmaceutical wastewater containing hydrogen sulphide (H2S). The shape, physiological and biochemical characteristics and oxidation capacity of Rhodococcus sp.zw11 were studied, and the effect of inlet concentration and volumetric loading of H2S on the removal efficiency was evaluated by the biotrickling filter inoculated with Rhodococcus sp.zw11. The results suggested that the optimal temperature of Rhodococcus sp.zw11 (aerobic bacilli, short rod and gram-negative) was from 20°C to 28°C and the optimal pH was from 5.5 to 6.5. The criteria necessary for a scale-up design of the biotrickling filter were established, and pressure drops at the start and end of the experiment were investigated. The optimal inlet loading could be noted as 180 g/m3h, corresponding to H2S removal efficiency close to 100%. Furthermore, the inoculated biotrickling filter had good ability to resist shock loading, which was a potential industrialisation method to control H2S emissions.