垃圾填埋场和室内环境中异味活度系数测定与应用研究

Municipal solid waste landfills and indoor spaces are potential sources of offensive odors that can create annoyance in urban areas. A large number of odor compounds have been identified including alcohols, aldehydes, amines, esters, ethers, hydrocarbons, ketones, nitrogen-containing compounds, aromatic compounds, terpenes and sulfur containing compounds. The odor activity value is the ratio of concentration and odor threshold, and it is used to infer how a component can contribute to the overall character. However, using odor activity values to quantify odorant's intensity presents some limitation because it does not take into account interaction between components in a mixture and difference of odor types. In this proposal, the interaction between the strongest component and other main components is emphasized, and a parameter named odor activity coefficient is given in the first time. The odor activity coefficient is defined as odor activitys ratio of two odor compounds when their relative inensity keep to be equal. The odor activity coefficients of pollutants in different intensities will be tested while the strongest component is selected as the reference. The factors including odor types, references, intensity levels and functional groups will be dicussed to simplified its determination and application. The odor activity and power law model will be modified with odor activity coefficient and component contributing to the overall intensity can be measured. In addition, the relationship between concentration detected by gas chromatography and overall intensity tested by olfactometry will be investigated after modifying odor activity. It can quantitatively reveal the odor interaction and difference of odor types, and predict the odor character in real mixture. The research achievements of odor activity coefficient may promote the progress of odor evaluation.

在垃圾填埋场和室内等人们广泛关注的异味环境中，利用异味活度评价不同组分贡献时，异味间相互作用和类型差异会产生严重影响。本课题在现有定性评价模型基础上，首次提出异味活度系数概念，重点考察异味强度最大组分与其它主要组分间的二元相互作用和类型差异。以异味强度最大组分为基准，目标物与其混合后相对强度相等时计算异味活度比值，测定典型目标污染物在不同强度下的异味活度系数。通过研究异味活度系数影响因素和变化规律探讨简化途径，修正异味活度和幂律模型，从而准确界定不同污染物对总异味强度的贡献，提高利用污染物的化学浓度（仪器测定法）预测总异味强度（感官测定法）的精度。该课题的完成可实现实际环境中主要二元相互作用和异味差异的定量化描述，为准确评价垃圾填埋场和室内环境混合物产生的异味效应，以及实现异味控制提供强支撑，是既有重要学术意义又有应用推广价值的创新性研究，可进一步推动我国在异味研究领域的进步。

近年来，垃圾填埋场、垃圾处理厂等典型环境的异味污染问题日益引起人们的关注和投诉。本项目在现有的异味活度值评价方法基础上，提出异味活度值系数方法准确评价混合物中组分间相互作用等关键因素对异味活度值的影响。针对垃圾填埋场、垃圾处理厂和室内空气等人们广泛关注的典型环境，实际采集并分析异味污染气体样品分析其时空分布特征，测定了51种典型组分的异味阈值计算其异味活度值；提出当量异味浓度方法研究Weber-Fechner斜率对异味浓度预测模型准确性的影响；进一步通过测定组分的异味活度值系数定量评价混合物组分间主要二元相互作用的类型和程度，修正异味活度值，准确评价异味贡献并提高预测异味浓度、异味强度准确度。研究结果表明，在选取异味活度值最大组分硫化氢作为参比物质时，三甲胺、柠檬烯、乙苯、苯乙烯等组分的异味活度值系数随异味强度增加而增大，在混合物中受到了5.57 - 17.64倍（以三甲胺为例）协同作用；氨的异味活度值系数维持0.95，表明在其在混合物中受累加作用；苯酚的异味活度值系数从0.56减至0.15，表明其受到了1.78 - 6.70 倍拮抗作用。硫化氢是垃圾处理厂气体样品中异味贡献最大组分，平均异味贡献达66.4±15.8%。相比传统仅考虑了化学浓度和异味阈值的异味活度值方法，本研究提出的异味活度值系数方法在异味活度值方法基础上进一步考虑了Weber-Fechner斜率和异味相互作用因素，对垃圾处理厂等典型环境异味污染物异味浓度预测结果准确度提高了10倍（80.0±5.7%），异味强度预测值与实测值比值在82%-107%之间，基本实现了基于仪器法测定化学浓度预测感官法测定的异味浓度、异味强度的目标。