Steady and transient state performance of a biotrickling filter treating hydrogen sulfide and nitrate
Research output: Other conference contribution › Paper, poster or abstract › Scientific
|Publication status||Published - 4 Nov 2018|
|Event||The 11th Annual International Conference on Challenges in Environmental Science and Engineering - Bangkok, Thailand|
Duration: 4 Nov 2018 → 8 Nov 2018
|Conference||The 11th Annual International Conference on Challenges in Environmental Science and Engineering|
|Period||4/11/18 → 8/11/18|
The simultaneously treatment of hydrogen sulfide (H2S) containing waste gas and nitrate (NO3-) containing wastewater was tested in a biotrickling filter (BTF) under anoxic conditions (Fig. 1). During long-term operation, the anoxic BTF showed a maximum H2S elimination capacity (EC) of 13.5 g S m-3 h-1 (99% of removal efficiency) for inlet H2S loads < 14.5 g S m-3 h-1 (500 ppmv) and a N/S ratio of ~1.7, respectively. The effect of organic carbon addition, in the form of acetate, on the performance of the anoxic BTF was also evaluated. The results showed that organic carbon addition is beneficial for the simultaneous removal of H2S and NO3-, as it increased the NO3- removal efficiency via mixotrophic denitrification and provides CO2 as the endogenous carbon source to the autotrophic bacteria. Microbial community analysis results confirmed that acetate addition stimulated the growth of heterotrophic bacteria in the BTF biofilm. The anoxic BTF was subjected to several types of transient conditions such as variations in gas and trickling liquid flow rates, intermittent NO3- supply and H2S shock loads, in order to evaluate the impact of such changes on the performance of the reactor. Interestingly, despite applying four successive H2S shock loads, the anoxic BTF fully recovered the H2S removal efficiency (~100%) within 40 h after resuming normal operation. These good results proved that the anoxic BTF is a resilient and robust biofilm system for treating H2S under anoxic conditions.