[Performance of an innovative polyethylene carrier biotrickling filter treating hydrogen sulphide gas]

Characteristics of double-layer biotrickling filter using high density polythene rasching rings carrier treating waste gas containing hydrogen sulphide was studied. Results showed that biotrickling filter had significant advantages of low pressure drop and even load distribution along the reactor height. When removal efficiency was greater than 90%, gas retention time was 12 s, maximum inlet load was 110 g/(m3 x h), elimination capacity was 84 g/(m3 x h). At steady state, about 37%-55% of hydrogen sulfide load was removed from the lower layer. During long-term operation, pressure drop kept to less than 280 Pa x m(-1), the backwashing period was longer than two months, no biomass accumulation happened in the lower layer, and abnormal increase in pressure drop can be used as a indicator of backwashing. Reactor recovery and restart experimental results showed that removal efficiency recovered to 95% in 1 day after 6 days without H2S, pH dramatic variation of spray liquid had significant adverse impact on biotrickling bed reactor.