Effects of operational conditions on the performance of Triethylamine Biofiltration

ABSTRACT

Nitrogen compounds such as triethylamine are odorants generally found in chemical plants and foundries in which cold-box cores are made. In this study, the efficiency of biofiltration of triethylamine [TEA] vapor was evaluated. Experiments were conducted in two 6-L biofilters arranged in three stages and packed with inoculated compost - wood chips [4060v/v] as the filter medium. The seed inoculum was obtained from municipal activated sludge. Tests were made to compare effects of initial temperature [30-/+1°C, biofilter A] and [23-/+2 °C, biofilter B] on the performance of the biofilter. TEA elimination rate pattern was evaluated by changing loading rates [6-138 gm-3h-1 and hydraulic retention times [40-60 s] while operating at constant temperature and humidity at 50-55%. Results showed that organic loading rates [OLR] of up to 114.4 gin-3h-1 [biofilter A] and 90.56 gin-3h-1 [biofilter B] could be handled without any apparent indication of maximum elimination capacity and substrate inhibition. The elimination capacity of biofilters could reach up to 72 gm-311-1[biofilter A] and 613 gm-3h [biofilter B]. When the loading of TEA exceeded the critical values, substrate inhibition occurred and the elimination capacity decreased. However, the requirement of keeping the pressure drop below 4 cm water gauge per meter of bed height to avoid operational problems warranted lower than maximum capacity operation. The optimal OLR values of 90-114 gm3h-1 are suggested for hydraulic retention time value of 48 s and temperature of 30-/+1°C. Under these conditions, elimination capacity of 71-/+3 gm-3h-land removal efficiency of 81-/+14% was achieved