农村生活污水处理的生物生态组合除臭工艺与机理

Deodorization Process and Mechanism of Combined Biological-Ecological Processes for Rural Domestic Wastewater Treatment

在生物生态组合工艺处理农村生活污水过程中,采用硝化液回流的方式控制臭味可进一步经济地提升农村人居生态环境质量。硫化物是生活污水处理过程中主要致臭物质之一,文章通过小试规模试验对生物生态组合工艺生物单元中硫化物去除及脱氮除碳过程的影响因素和相关机理进行了探究。试验设置了温度、C/N和DO这3个影响因素,结果表明,在较高环境温度下(25℃),缺氧除臭单元内溶解性硫化物去除和脱氮除碳效能最佳;体系中硫化物去除效率随C/N降低而显著提升,当C/N为2∶1时硫化物去除效率最高,在4 h时可达到64.68%,而此时硝酸盐和有机物的去除效率则相对稍低;较高DO水平(质量浓度为1.8~2.0 mg/L)可显著提高体系内硫化物去除效率,有机物去除率也略有提升,脱氮效率则会降低,在5 h时,硫化物、硝酸盐和COD的去除率分别达到98.20%、60.13%和23.97%。

In the process of rural domestic wastewater treatment by combined biological-ecological process, the use of nitrified liquid backflow to control the odor emission can further economically improve the quality of the ecological environment of rural human settlements. Sulfide is one of the main odor-causing substances in the domestic wastewater treatment process. In this paper, the influencing factors and related mechanisms of the sulfide, nitrogen and carbon removal process in the biological-ecological combination process were explored through a small-scale experiment. Three influencing factors of temperature, C/N and dissolved oxygen were set up in the test. The results showed that at a higher ambient temperature(25 ℃), the removal of dissolved sulfide, nitrogen and carbon in the anoxic deodorization unit was the highest. The sulfide removal efficiency increased significantly with the decrease of C/N. When the C/N was 2∶1, the sulfide removal efficiency was the highest, which could reach 64.68% at 4 h, while the removal efficiency of nitrate and organic matter was relatively low. The removal efficiency of sulfide could be significantly improved at higher levels of DO(mass concentration of 1.8~2.0 mg/L), the removal rate of organic matter was also slightly improved, but the denitrification efficiency was reduced, in which condition, the removal rate of sulfide, nitrate and CODreached 98.20%, 60.13% and 23.97%, respectively at 5 h.