夏季有机生活垃圾堆肥过程恶臭排放特征及健康风险评估

为研究有机生活垃圾在夏季堆肥过程的恶臭污染物分布特征及对堆肥厂职业暴露人员的非致癌和致癌风险水平，以北方某有机生活垃圾堆肥厂为研究对象，利用冷阱富集-气质联用（GC/MS）技术对恶臭气体进行分析.结果表明:①堆肥过程中的恶臭物质以含氧有机物为主，其次是芳香烃，这两类物质分别占总恶臭污染物质量浓度的63.46%±2.65%和15.56%±0.67%.②各单元的主要恶臭贡献物质种类存在差异，卸料单元和粉碎单元主要为乙酸和甲硫醚，占这两个单元总异味活度值的83.07%和85.44%；发酵单元和腐熟单元恶臭贡献的主要物质是乙酸、乙醛、甲硫醚、α-蒎烯、二甲二硫醚、柠檬烯、b-蒎烯和乙醇，占两个单元总异味活度值的96.60%和92.51%.③从人群健康风险来看，腐熟单元HI（非致癌健康风险指数）最高（13.54），其次是发酵单元（7.95）和粉碎单元（5.36），卸料单元最低（4.94），而苯是主要的致癌风险物LCR（终生致癌风险）>10-4].研究显示，有机生活垃圾堆肥厂在夏季产生的恶臭污染物对人群可能产生较大影响，应加强堆肥过程中恶臭污染物的控制，另外加强对职业暴露人群的健康防护以及对恶臭物质的有效处理以减少对人群健康的不利影响. 

Emission Characteristics and Health Risk Assessment of Odorous Pollutants from Organic Fraction of Municipal Solid Waste Compost in Summer

In order to investigate the distribution characteristics of odorous pollutants and assess the non-carcinogenic and carcinogenic exposure risk levels of workers during the composting process of organic fraction of municipal solid waste in summer, cold enrichment-GC/MS was used to analyze the odor components in a full-scale composting plant located in northern China. The results indicated that oxygenated compounds were the main pollutants emitted during composting of organic fraction of municipal solid waste, which accounted for 63.46%±2.65% of the total concentration, followed by aromatic compounds (15.56%±0.67%). However, the types of main malodorous contributors were different in different units. Acetic acid and methyl sulfide were the main odor contributors in tipping unit and crushing unit, which accounted for 83.07% and 85.44% of the total odor activity values. Whereas acetic acid, acetaldehyde, methyl sulfide, α-pinene, dimethyl disulfide, limonene, b-pinene and ethanol were the main odor contributing substance in primary fermentation unit and the maturity unit, which accounted for 96.60% and 92.51% of the total odor activity values, respectively. From the view point of human health risk, the results indicated that the maturity unit had the highest non-carcinogenic health risk to workers (non-carcinogenic health risk index HI=13.54), followed by primary fermentation unit (HI=7.95) and the crushing unit (HI=5.36), while the lowest health risk appeared in the tipping unit (HI=4.94). Benzene was the main pollutants causing carcinogen risk (lifetime cancer risk (LCR)>10-4). In conclusion, the overall potential of non-carcinogenic and carcinogenic risk caused by the odorous pollutants emitted from organic fraction of municipal solid waste were at relatively higher level in summer. Therefore, the production of odorous pollutants should be controlled, the occupational protection should be strengthened, and the odorous pollutants should be efficiently removed to synthetically reduce the adverse health effect on workers.