市政污水与厂区空气中cVMS浓度与排放研究
发布时间：2018-07-26 08:04
【摘要】：环状挥发性甲基硅氧烷(cVMS)因其独特的物理化学性质被广泛添加于化妆品和个人护理品(CPCPs)、电子产品、家具、生物制品等产品当中,其中添加于CPCPs是cVMS的重要应用。含有cVMS的CPCPs在使用过程中约有10%的cVMS会随污水进入市政污水处理厂,污水中的cVMS 一部分通过挥发方式进入大气,部分吸附到污泥中,最后进入天然水体。进入大气中的cVMS通过干湿沉降方式进入到天然水体和陆地环境,对陆地和水生生态环境产生不利影响,因此,对污水处理厂污水及厂区环境空气中cVMS行为的研究具有重要意义,目前,国内对市政污水处理厂中cVMS环境行为的研究较少,市政污水处理工艺和厂区是否封闭等对厂区大气中cVMS浓度的影响及其排放过程并不十分清楚。本文选取大连市具有代表性的8家污水处理厂为研究对象,重点研究了污水(入、出水)中cVMS(D3、D4、D5、D6)的浓度水平及污水浓度随月份变化的规律、厂区空气中cVMS(D4、D5、D6)浓度水平,剖析了污水载入量、气温和风向风速对其浓度变化的影响规律,最后采用简易高斯扩散模型和空气污染物浓度单室模型对8家水厂cVMS的大气排放量进行了估算。结果表明,8家污水处理厂入水D3、D4、D5和D6平均浓度(ng/L)分别为:190.64±61.92,396.61±379.61,2073.31±1714.44,857.90±788.00,D5 浓度分别是D3、D4、D6浓度的11倍,5倍和2.4倍;出水cVMS浓度较低,大部分未检出。大连市污水处理厂入水cVMS平均浓度比国外报道浓度水平低1-2个数量级。入水cVMS浓度趋势为D5D6D4D3,与上海、加拿大相关研究报道CPCPs组分浓度规律相同。8家污水处理厂曝气池附近空气中D4、D5和D6平均浓度(ng/m3)分别为:11645.58±1828.36,3540.43±5771.10,586.70±634.23,其中 D5 约占 cVMS总量的61%。与距离污水处理厂较远的参照点环境空气浓度相比,污水处理厂空气中cVMS浓度高于参照点1-3个数量级,表明污水处理厂是大气中cVMS的重要排放源。采用简易高斯扩散及单室模型对污水处理厂∑cVMS年排放量进行了估算,8家污水厂总排放量为1343.12 kg/yr,其中开放式污水处理厂排放量为1314 kg/yr,封闭式污水处理厂排放量为123 g/yr,封闭式污水处理厂cVMS排放量远低于开放式污水处理厂,这说明封闭式水厂能够极大地减少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 卤61.92396.61 卤379.61 卤379.61 卤2073.31 卤1714.44857.90 卤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 卤1828.36t3540.43 卤5771.10586.70 卤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，
本文编号：2145387
[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 卤61.92396.61 卤379.61 卤379.61 卤2073.31 卤1714.44857.90 卤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 卤1828.36t3540.43 卤5771.10586.70 卤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，
本文编号：2145387
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