城市污水处理厂恶臭挥发性羰基化合物的排放特征

Source Emission Characteristics of Malodorous Volatile Organic Carbonyls from a Municipal Sewage Treatment Plant

选取广州市猎德污水处理厂进行为期4 d的现场采样,采用PFPH衍生化-GC/MS联用技术分析恶臭挥发性羰基化合物的组成特征和含量水平,研究它们的排放特征.结果表明,在该污水处理厂共检测出18种羰基化合物,其中具有恶臭气味的组分包括15种,它们在6个处理车间的浓度范围为0.39～19.92μg·m-3,总浓度均值为(68.66±10.05)μg·m-3.采取归一化方法获得了该类污染源的恶臭挥发性羰基化合物成分谱,并发现了分子标志物为甲醛、乙醛、丙醛、2-丁酮、丁醛和己醛,它们占该成分谱总含量的78.91%,其中己醛含量最高,浓度均值达到11.71μg·m-3.应用恶臭面源源强的计算方法,估算出该污水处理厂恶臭挥发性羰基化合物的年排放总量为2 302.33 kg·a-1,各车间的排放量贡献率由高至低为:生化池>浓缩池>A级曝气池>提升泵房>沉砂池>脱水机房.由于污水处理厂的恶臭污染排放过程较为复杂,因此在一定程度上影响了排放量估算的准确度.

A 4-day field observation was conducted at Liede sewage treatment plant in Guangzhou,using PFPH/GC/MS method to analyse the composition and the concentration of volatile carbonyl compounds,and investigate the source emission characteristics of the pollutants.The results were as follows： 18 carbonyl species were detected,which including 15 malodorous volatile carbonyls with a concentration range from 0.39 μg·m-3 to 19.92 μg·m-3 at six processing units.Mean value of the total malodorous volatile carbonyls was（68.66±10.05） μg·m-3.Normalization data process was used to research the source emission profile for malodorous volatile carbonyls,formaldehyde,acetaldehyde,propionaldehyde,2-butanone,butyraldehyde and hexaldehyde were found to be molecular markers of the source emission with their percentage of total carbonyls up to 78.91%.Hexaldehyde was the most abundant carbonyl species with an average concentration of 11.71 μg·m-3.Using a calculation model of area source emission,it estimated that the total annual emissions of the municipal sewage treatment plant was 2 302.33 kg·a-1,and the contribution ratio of each processing unit was in an order of biochemical reaction basin,concentration basin,grade A aeration,ascending pump room,grit basin,dewatering house.The malodorous emission of sewage treatment plant is affected by many complex factors,so there＇s some uncertainty on the estimate.