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污染控制技术及原理

唐静玥,曾立民,胡敏,吕爱华,兰国栋.利用气体-气溶胶在线测量技术研究乌鲁木齐颗粒物水溶性组分与气体污染[J].环境科学学报,2009,29(11):2250-2258

Online measurements of trace gases and particulate water-soluble inorganic ions in Urumqi using a gas-aerosol collector(GAC)

摘要：将气体-气溶胶收集装置与离子色谱联用技术(GAC)应用于冬季重污染地区乌鲁木齐,对当地大气中痕量气体与气溶胶中的水溶性组分进行了为期2周的在线测量,并结合膜采样结果、PM₁₀质量浓度及气溶胶消光系数等数据初步分析了污染物的变化规律与重污染成因.结果表明,GAC测得的氯盐、硝酸盐、硫酸盐与膜采样方法测得的相应组分数值显著正相关,相关系数分别为0.92(p<0.0001)、0.89(p<0.0001)、0.90(p<0.0001).乌鲁木齐大气污染极其严重,氯盐、硫酸盐和二氧化硫浓度都非常高,这在其他地区较为罕见;二氧化硫、氯盐、硝酸盐与硫酸盐分别呈现不同的日变化规律;整个采样期间出现了1次极端污染天气,API值达到500,该日硫转化率(SOR)和氮转化率(NOR)的小时平均值最高达到0.69与0.36,说明二次转化也可能是形成重污染天气的主要原因.高浓度的PM₁₀对能见度影响极大,PM2.5中的氯盐与气溶胶消光系数的相关系数最大,硫酸盐与硝酸盐次之,而硫酸盐、硝酸盐、氯盐这3种盐类对PM₁₀的贡献依次递减.

Abstract：The concentrations of both trace gases and water-soluble inorganic ions in particles were measured in Urumqi using a gas-aerosol collector(GAC)and ion chromatography(IC).The measurements were performed continuously from 15th Jan to 28th Jan 2008 at a time resolution of 30 minutes.Inter-comparison of the results obtained from the GAC-IC system and a filter-based method showed good correlations for chloride,nitrate and sulfate;the correlation coefficients were 0.92,0.89 and 0.90 respectively.Of the three anions,sulfate was the major component in PM2.5,followed by nitrate and chloride.The measured species,SO₂,chloride,nitrate and sulfate showed different diurnal variation patterns,suggesting different sources.A severe pollution episode was observed during the campaign with the hourly average sulfur oxidation rate(SOR)and nitrogen oxidation rate(NOR)up to 0.69 and 0.36,indicating that secondary processes are important in air pollution in Urumqi.The mass concentrations of PM₁₀ showed good correlation with ambient extinction coefficients,while the concentration of chloride in PM2.5 had a nice correlation with ambient extinction coefficients,followed by sulfate and nitrate in PM2.5.