Removal of high concentrations of NH3 by a combined photoreactor and biotrickling filter system

• Published in: Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering Toxic/hazardous substances & environmental engineering, 2011-12, Vol.46 (14), p.1675-1682
• Main Authors: Wu, Li-Chun, Kuo, Cheng-Lang, Chung, Ying-Chien
• Format: Article
• Language: English
• Subjects: Ammonia; Applied sciences; Atmospheric pollution; Bacillus cereus; biotrickling filter; Exact sciences and technology; General processes of purification and dust removal; General purification processes; photoreactor; Pollution; Prevention and purification methods; Pseudomonas aeruginosa; Stenotrophomonas; TiO; Wastewaters; Water treatment and pollution
• ISSN: 1093-4529; 1532-4117
• DOI: 10.1080/10934529.2011.623948

Average emission levels as high as 800 ppm v NH 3 have often been found during the anaerobic fermentation process. At these levels, NH 3 is regarded as an environmental toxic compound. High concentrations of NH 3 gas are difficult to treat in a single treatment process, suggesting that, in terms of economic cost and treatment performance, a coupled system may be a feasible technological alternative. In the coupled TiO 2 photocatalytic-biological treatment system evaluated here, the optimal gas retention time for NH 3 removal - in terms of removal efficiency and capital cost - was 26 s. High gas temperatures, high NH 3 concentrations, and low oxygen contents were unfavorable conditions for NH 3 removal by the photoreactor. The coupled system successfully removed concentrated NH 3 gas (R % > 97 %) under disrupted and shutdown conditions. The photoreactor component of the system successfully fulfilled its role as a pretreatment process and enhanced the performance of the biotrickling filter at a high inlet NH 3 load (2,277 g-N m −3 day −1 ). Potential ammonia-oxidizing bacteria, including Bacillus cereus, Pseudomonas aeruginosa, and Stenotrophomonas sp., were isolated under the high inlet NH 3 load condition. These microbial strains have a potential as biological agents in the removal of high concentrations of NH 3 in waste gas or wastewater.