污水处理过程中H_2S和NH_3的浓度特性及扩散规律研究

Concentrations and diffusion characteristics of H_2S and NH_3 in sewage treatment process

对污水处理厂七个处理单元中释放的H2S和NH3进行了四个季节的平行采集和分析,并根据臭气强度和浓度的关系,确定臭气等级,同时利用EIAPro A大气环评专业辅助系统对臭气的扩散规律进行了模拟。结果表明,在七个处理单元中,H2S的释放浓度为污泥脱水间>格栅>厌氧池>沉砂池;NH3的释放浓度为污泥脱水间>格栅>沉砂池>厌氧池>二沉池。根据H2S的四季浓度数据:污泥脱水间的H2S在冬季浓度最大,夏季最小;其余处理单元则是夏季的H2S浓度最大,冬季最小。根据韦伯定律,污泥脱水间散发的H2S和NH3产生的臭气强度均超过4级;其余处理单元H2S和NH3产生的臭气强度接近3级。根据扩散模型预测结果,污水处理厂散发出的H2S和NH3的浓度随着离处理单元距离的增加而降低,在1 000 m处H2S和NH3浓度降为100 m处的10%以下。

The H2S and NHa released from seven processing units of a sewage treatment plant were paral- lel collected and analyzed during four seasons. Based on the relationship of odor intensity and concentra- tion, the odor level was determined. The diffusion of odor was simulated by using EIAProA. The results showed that the released concentration of H2S was sludge dewatering 〉 grille 〉 anaerobic pool 〉 grit chamber, and the released concentration of NH3 was sludge dewatering 〉 grille 〉 grit chamber 〉 anaero- bic pool 〉 two pond. According to the seasonal concentrations ,the concentration of H2S was the highest in winter and the lowest in summer in sludge dewatering. However, the concentration of H2S was the low- est in winter and the highest in summer in other processing units. According to weber＇ s law, the stench intensity of HES and NH3 was more than level 4 in the sludge dewatering and close to level 3 in other pro- cessing units. According to the simulation results of the diffusion model, the concentrations of H2S and NH3 from the sewage treatment plant decreased with the increase of distance away from processing unit, the concentrations of H2S and NHa at 1 000 m is less 10% of that at 100 m.