Experimental investigation for purification of waste gas containing low concentration toluene in a trickle-bed biofilter

The experiments on purifying waste gas containing low concentration toluene in trickle-bed biofilter with regular ceramic sphere were conducted in present paper. The effects of liquid flow rate, gas flow rate, pH of circulation liquid, and toluene concentration of gas at inlet on the purification efficiency of trickle-bed biofilter were investigated, respectively. The friction characteristics of the trickle-bed biofilter were also measured during experiments. The experimental results revealed that an increase in liquid flux or gas flux results in a lower purification efficiency of trickle-bed biofilter in general. The trickle-bed biofilter possess the highest purification efficiency for the circulation liquid of 7 in pH. The porosity of the packing material in bilfilter is higher at gas outlet than at gas inlet after continuously operating in 50 days. The decrease in the porosity of packing material results in a great increase in the pressure drop of the biofilter due to the growth of biofilm.