污泥热干化过程恶臭污染物的排放特性研究

Study on emission characteristics of odor pollutants during sludge drying

针对污泥热干化过程中恶臭气体的排放特性,以氨气、硫化氢和苯系物等作为污泥干化过程中恶臭污染的表征物质,研究了干化温度和含水率等因素对氨气、硫化氢和苯系物释放量的影响。结果表明,氨气和硫化氢的释放量均随干化温度的升高而增大,且存在释放量突增温度,分别在120℃和140℃以上;对于苯系物,在140℃以前其释放量随干化温度的增加而增大,之后,释放量随干化温度的增加而减小,其中以甲苯的释放量表现最为显著。在80℃~160℃的干化温度范围内,污泥的五种苯系物释放总量在0.0291~1.4766mg/m^3之间。污泥含水率在25%~80%的范围时,氨的释放量随含水率的减少而明显升高,而在污泥高温干化过度后,硫化氢的释放急剧增加。

We studied the characteristics of the odor gases release from sludge thermal drying process, and chose ammonia, hydrogen sulfide and BTEX as the most odors. The effect of drying temperature and moisture content on the emission of ammonia, hydrogen sulfide and BTEX in sludge drying process was researched exper- imentally. The results showed that the release of ammonia and hydrogen sulfide increased with a rise in drying temperature, and the release increased evidently in the vicinity of 120℃ and 140℃. The BTEX emission rate increases significantly when the drying a temperature reaches 140℃, after the release of BTEX decreased with a rise in drying temperature, of which the toluene emission rate is most significant. The total release of BTEX from sewage sludge ranges from 0.0291- 1. 4766mg/m^3 at temperature between 80℃ and 160℃. The release of ammonia increased evidently when the moisture content between 25% and 80%. The release of hydrogen sulfide increased sharply when the high -temperature sludge drying excessive.