【摘要】：環(huán)狀揮發(fā)性甲基硅氧烷(cVMS)因其獨特的物理化學性質被廣泛添加于化妝品和個人護理品(CPCPs)、電子產品、家具、生物制品等產品當中,其中添加于CPCPs是cVMS的重要應用。含有cVMS的CPCPs在使用過程中約有10%的cVMS會隨污水進入市政污水處理廠,污水中的cVMS 一部分通過揮發(fā)方式進入大氣,部分吸附到污泥中,最后進入天然水體。進入大氣中的cVMS通過干濕沉降方式進入到天然水體和陸地環(huán)境,對陸地和水生生態(tài)環(huán)境產生不利影響,因此,對污水處理廠污水及廠區(qū)環(huán)境空氣中cVMS行為的研究具有重要意義,目前,國內對市政污水處理廠中cVMS環(huán)境行為的研究較少,市政污水處理工藝和廠區(qū)是否封閉等對廠區(qū)大氣中cVMS濃度的影響及其排放過程并不十分清楚。本文選取大連市具有代表性的8家污水處理廠為研究對象,重點研究了污水(入、出水)中cVMS(D3、D4、D5、D6)的濃度水平及污水濃度隨月份變化的規(guī)律、廠區(qū)空氣中cVMS(D4、D5、D6)濃度水平,剖析了污水載入量、氣溫和風向風速對其濃度變化的影響規(guī)律,最后采用簡易高斯擴散模型和空氣污染物濃度單室模型對8家水廠cVMS的大氣排放量進行了估算。結果表明,8家污水處理廠入水D3、D4、D5和D6平均濃度(ng/L)分別為:190.64±61.92,396.61±379.61,2073.31±1714.44,857.90±788.00,D5 濃度分別是D3、D4、D6濃度的11倍,5倍和2.4倍;出水cVMS濃度較低,大部分未檢出。大連市污水處理廠入水cVMS平均濃度比國外報道濃度水平低1-2個數(shù)量級。入水cVMS濃度趨勢為D5D6D4D3,與上海、加拿大相關研究報道CPCPs組分濃度規(guī)律相同。8家污水處理廠曝氣池附近空氣中D4、D5和D6平均濃度(ng/m3)分別為:11645.58±1828.36,3540.43±5771.10,586.70±634.23,其中 D5 約占 cVMS總量的61%。與距離污水處理廠較遠的參照點環(huán)境空氣濃度相比,污水處理廠空氣中cVMS濃度高于參照點1-3個數(shù)量級,表明污水處理廠是大氣中cVMS的重要排放源。采用簡易高斯擴散及單室模型對污水處理廠∑cVMS年排放量進行了估算,8家污水廠總排放量為1343.12 kg/yr,其中開放式污水處理廠排放量為1314 kg/yr,封閉式污水處理廠排放量為123 g/yr,封閉式污水處理廠cVMS排放量遠低于開放式污水處理廠,這說明封閉式水廠能夠極大地減少cVMS的排放。
[Abstract]:Cyclic volatile methyl siloxane (cVMS) is widely used in cosmetics and personal care products such as (CPCPs), electronic products, furniture and biological products because of its unique physical and chemical properties. CPCPs is an important application of cVMS. About 10% of CPCPs containing cVMS will enter municipal sewage treatment plant with sewage, part of cVMS in sewage enters atmosphere by volatilization, part is adsorbed into sludge, and finally into natural water. CVMS entering the atmosphere enters into the natural water body and terrestrial environment by dry and wet deposition, which has adverse effects on the terrestrial and aquatic ecological environment. Therefore, it is of great significance to study the behavior of cVMS in the sewage of sewage treatment plant and the ambient air of the plant. At present, there are few studies on the environmental behavior of cVMS in municipal wastewater treatment plant. The influence of municipal wastewater treatment process and the closure of the plant site on the concentration of cVMS in the atmosphere and its discharge process are not very clear. In this paper, 8 representative wastewater treatment plants in Dalian are selected as the research objects, and the concentration level of cVMS (D3OD4D5D6) and the regularity of the variation of sewage concentration with month in the sewage (D3D4D4D5D6) and the concentration level of cVMS (D4D5D6) in the air of the plant area are studied emphatically. The effects of sewage loading amount, temperature and wind direction and wind speed on the concentration change were analyzed. At last, a simple Gao Si diffusion model and a single chamber model of air pollutant concentration were used to estimate the atmospheric emissions of cVMS in 8 water plants. The results showed that the average concentration (ng/L) of D3, D4, D5 and D6 in eight sewage treatment plants were respectively 1: 190.64 鹵61.92396.61 鹵379.61 鹵379.61 鹵2073.31 鹵1714.44857.90 鹵788.00 D5, 11 times and 2.4 times of that of D3D4D6, respectively, and the concentration of cVMS in effluent was lower, most of them were not detected. The average concentration of cVMS in wastewater treatment plant of Dalian is 1-2 orders of magnitude lower than that reported abroad. The trend of cVMS concentration in water was D5D6D4D3. It was reported that the average concentration (ng/m3) of D4D5 and D6 in the air near the aeration tank of wastewater treatment plants in Shanghai and Canada were respectively 1: 11645.58 鹵1828.36t3540.43 鹵5771.10586.70 鹵634.23, among which D5 accounted for 61th of the total cVMS. Compared with the ambient air concentration at the reference point far away from the sewage treatment plant, the concentration of cVMS in the air of the wastewater treatment plant is higher than that of the reference point by 1-3 orders of magnitude, which indicates that the wastewater treatment plant is an important source of cVMS discharge in the atmosphere. The annual discharge of 鈭，

本文編號：2145387