No abstract

The efficiency of H2S removal by an industrial scale biofilter using a wood‐based mulch at a large publicly owned wastewater treatment plant has been evaluated for over a one‐year time period. The research consisted of developing sampling and analytical methods, validation of experimental methods, and the evaluation of the biofilter's performance. The study showed that removal efficiency strongly depends on the inlet H2S concentration. The elimination capacity increases as inlet loading increases until full elimination is achieved. The H2S removal efficiency was constantly higher than 95% during the one‐year period of this study. The removal efficiency was higher than 99% when the inlet H2S concentration was lower than 100 ppmv, and it dropped sharply when the inlet concentration was higher than 100 ppmv. The removal efficiency dropped from 99% to 95% when the inlet H2S concentration reached about 250 ppmv. At lower H2S concentrations (< 100 ppmv), the elimination capacity equaled the inlet H2S loading. The maximum elimination capacity was determined to be 14 g H2S/m2 hr. The seasonal temperature dependency of H2S production was also investigated based on ambient temperature data. Maximum levels of H2S production corresponded to periods of highest average ambient temperature.