Modeling of H2S Dispersion in Brazil with Aermod: Case Study of Water Resource Recovery Facility In South of Brazil

Abstract Water Resource Recovery Facility (WRRF) can be source of odorous gases. We analyzed the emission and dispersion of hydrogen sulfide gas (H2S), odor indicator, produced during the anaerobic treatment of wastewaters, using WATER9 and AERMOD models for two distinct events: August 2013 and February-March 2014. Data from two WRRF in Brazil were used to feed the model and a statistical data validation was performed, followed by an evaluation of model results regarding H2S emission and dispersion. Daily peak events and averages over the two periods were calculated. Results show a good performance from the model in comparison to the observations. Moreover, odor plumes typically reached 2-4 km from their sources and they may be strongly affected by atmospheric stability/instability conditions in the events analyzed and, in general, only the residences at the vicinity of WRRF were affected by the pollutant odor. Finally, the methodology presented showed to be feasible and realistic for purposes of WRRF planning and management.摘要：水资源回收设施（Water Resource Recovery Facility, WRRF）可成为恶臭气体的排放源。本研究针对废水厌氧处理过程中产生的硫化氢气体（H2S，恶臭指示物）的排放与扩散过程展开分析，采用WATER9与AERMOD模型，覆盖2013年8月及2014年2月至3月两个独立事件。研究使用巴西两座水资源回收设施的数据集作为模型输入，开展了统计数据验证，并针对硫化氢排放与扩散的模型结果进行评估。研究计算了两个时段内的每日峰值事件与平均浓度。结果表明，与观测数据相比，模型表现优异。此外，恶臭羽流通常可扩散至距排放源2至4公里的范围，其扩散效果在本次分析的事件中极易受大气稳定/不稳定条件影响；总体而言，仅水资源回收设施周边的居民区会受到该恶臭污染物的影响。最后，本研究提出的方法在水资源回收设施的规划与管理场景中具备可行性与现实适用性。