Transient-state biodegradation behavior of a horizontal biotrickling filter in co-treating gaseous H2S and NH3.
A horizontal biotrickling filter (HBTF) was used to inoculate autotrophic sulfide-oxidizing and ammonia-oxidizing microbial consortiums over H2S-exhausted carbon for co-treating H2S and NH3 waste gas in a long-term operation. In this study, several aspects (i.e., pH change, shock loading and starvation) of the dynamic behavior of the HBTF were investigated. The metabolic products of N and S bearing species in recycling liquid and biological activities of the biofilm were analyzed to explain the observed phenomena and further explore the fundamentals behind. In the pH range of 4-8.5, although the removal efficiencies of H2S and NH3 remained 96-98% and 100%, respectively, the metabolic products demonstrated different removal mechanisms and pathways. NH4-N and NO2/NO3-N were dominated at pH < or = 6 and > or = 7, respectively, indicating the differentiated contributions from physical/chemical adsorption and bio-oxidation. Moreover, the HBTF demonstrated a good dynamic stability to withstand shock loadings by recovering immediately to the original. During shock loading, only 15.4% and 17.9% of captured H2S and NH3 was biodegraded, respectively. After 2, 11, and 48 days of starvation, the HBTF system reached a full performance within reasonable re-startup times (2-80 h), possibly due to the consumption of reduced S and N species in biomass or activated carbon thus converted into SO4-S and NO3-N during starvation period. The results helped to understand the fundamental knowledge by revealing the effects of pH and transient loadings linked with individual removal mechanism for H2S and NH3 co-treatment in different conditions.
Jiang
Xia
X
Environmental Engineering Research Center, School of Civil and Environmental Engineering, Nanyang Technological University, Blk N1, 50 Nanyang Avenue, Singapore 639798, Singapore.
Yan
Rong
R
Tay
Joo Hwa
JH
D000397:Air Pollution; D000641:Ammonia / Q000378:metabolism*; D001673:Biodegradation, Environmental; D006862:Hydrogen Sulfide / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration
D000641:Ammonia; D006862:Hydrogen Sulfide