为分析农田土壤中重金属的来源,在研究了受体模型和主成分分析模型基础上,运用矩阵分解和插值方法分析土壤中重金属含量及污染来源.通过实验仿真得到农田重金属含量及空间分布特征,经分析发现,受人为因素影响,重金属含量有明显变化.仿真结果表明:所提方法能较好地解决农田土壤重金属含量及污染源确定问题.

为了解沧州市郊采暖期大气颗粒物中重金属粒径分布和健康风险,于2018年11—12月使用分级撞击式采样器采集大气颗粒物样品(粒径符合总悬浮颗粒物(TSP)标准),采用电感耦合等离子体发射光谱(ICP-OES)测定Fe、Cu、Mn、Pb和Zn含量,利用富集因子法和美国环境保护署推荐的健康风险评价模型,分析重金属主要来源并对其经呼吸途径的人体健康风险进行评价.结果表明,Fe、Cu、M n主要分布在粗粒子中,Zn和Pb主要分布在细粒子中.Fe为粗粒子单峰型,Cu和M n为粗粒子峰值大于细粒子峰值双峰型,Pb和Zn为细粒子峰值大于粗粒子峰值双峰型.细粒子中M n、Cu、Zn和Pb富集因子高于粗粒子,且Pb和Zn在细粒子中富集因子均高于100,发生高度富集;Zn、Pb、Mn和Cu富集因子峰值位于>0.43～1.10μm.TSP和PM9.0中Mn对成人和儿童均存在非致癌风险,PM2.1中Mn对成人和儿童的非致癌风险可以忽略;Pb对成人和儿童的致癌风险均可以忽略;Mn和Pb健康风险峰值均位于>1.10～2.10μm,健康风险评价时应考虑粒径对人群健康风险的影响.

基于2017年沧州市降水观测数据(pH值、电导率和水溶性离子浓度)及PM2.5和PM10质量浓度数据,分析了大气降水化学组成特征,并从降水总量、降水强度和降水时长3个角度探讨了不同类型降水对PM2.5和PM10的清除作用.结果表明:采样期间降水pH值变化范围为5.75～8.61,降水量加权均值为6.63,降水未发生酸化.电导率变化范围为10.79～361μs·cm-1,降水量加权均值为75.26μs·cm-1.降水离子总浓度变化范围为95.82～2519.19μeq·L-1,降雨量加权均值为785.36μeq·L-1.Ca2+和NH+4是降水中主要阳离子,分别占阳离子总浓度的66.49％和13.63％.SO2-4和NO-3是降水中主要阴离子,分别占阴离子总量的63.49％和25.45％.降水对大气颗粒物有一定清除作用,降水日PM2.5和PM10质量浓度分别比非降水日降低34.41％和47.30％.降水对PM2.5和PM10清除效率随着降水总量、降水时长的增加而呈现增加趋势.同等降水条件下,降水对PM2.5的清除效果要优于PM10.

The heavy metals in atmospheric fine particles are of great concern to human health. To understand the pollution characteristics and health risks of heavy metals in particulate matter with an aerodynamic equivalent diameter ≤2.5 μm (PM2.5) during winter in the suburb of Cangzhou, PM2.5 samples were collected with an intelligent medium-flow atmospheric particulate matter sampler from January to February 2019. The Fe, Cu, Mn, Pb and Zn contents in PM2.5 were determined via inductively coupled plasma optical emission spectrometry (ICP-OES). The sources and health risks of heavy metals in PM2.5 were analysed via the enrichment factor (EF) method and the United States Environmental Protection Agency (US EPA) health risk assessment model. The results showed that the average PM2.5 concentration in the suburb of Cangzhou reached 71.6 μg/m3, ranging from 23.7 to 169.5 μg/m3. The exceeding standard rate was 29.4% during the sampling period. The PM2.5 concentration during the nighttime was higher than that during the daytime. The heavy metal concentrations in PM2.5 decreased in the order of Fe > Mn > Zn > Cu > Pb, and the Fe, Mn, Pb and Zn concentrations decreased in the order of clean days the daytime. EF analysis revealed that Zn, Pb and Cu were significantly enriched, and Pb was highly enriched on heavy pollution days with increasing pollution degree. The enrichment level of heavy metals during the nighttime was higher than that during the daytime. Health risk assessment demonstrated that Mn posed non-carcinogenic risks to both adults and children, following the sequence of clean days . The study revealed that the pollution levels of heavy metals in PM2.5 in the suburb of Cangzhou were low, and Pb and Mn in PM2.5 posed certain health risks to the population.

臭氧污染对大气环境、人体健康和农作物均会产生不良影响.本研究基于臭氧生成机理和现有研究成果,提出一套臭氧污染成因分析方法,包括污染总体情况分析、区域传输影响分析、气象条件影响分析、前体物影响分析四项主要内容.应用该方法针对京津冀典型城市——河北省沧州市大气臭氧污染过程开展成因解读.基于常规污染物浓度、气象要素、VOCs在线监测数据等,综合分析了 2021年5月沧州市臭氧污染过程,得出本次污染的4条污染传输路径,影响最大的气象因素是温度和能见度;分析了臭氧前体物NOx和VOCs主要组分的浓度变化及VOCs主要组分的反应活性特征.以期为城市臭氧污染防治和应急管控措施的制定提供方向.

采用CALPUFF模型,评估铸造行业提升改造后对沧州市空气质量的改善效果.以2017年为基准年进行核算,从炉窑改造、 末端治理技术升级、 无组织排放管控三个角度进行情景分析.在执行减排策略下,沧州市铸造行业SO2、NOx、PM2.5、VOCs减排量分别达224.4 t/a、282.1 t/a、5631.9 t/a、245.6 t/a,较现状排放情景减排效率分别为50.95％、41.13％、80.28％、55.74％.模拟结果显示,现状情景下SO2、NOx、PM2.5、VOCs对国控点的年均浓度贡献值分别为0.09μg/m3、0.12μg/m3、1.58μg/m3、0.08μg/m3,优化情景下SO2、NOx、PM2.5、VOCs对国控点的年均浓度贡献值分别为0.05μg/m3、0.08μg/m3、0.40μg/m3、0.04μg/m3,PM2.5浓度下降1.18μg/m3,改善效果显著.

本文提出一种基于气象条件分型的城市大气环境允许排放量测算方法,该方法基于环境空气质量和颗粒物组分数据,对气象条件进行分污染天气类型的二次转化规律研究,并确定不同天气类型下的迁移扩散系数.基于扩散理论,建立了污染物排放强度、不同天气类型迁移扩散系数和目标控制浓度之间的关系,在特定区域排放布局和排放方式基本不变的前提下,测算不同天气类型达空气质量标准下的一次PM2.5,PM10,NOx和SO2的允许排放量.以沧州市为例,结合空气质量从优到严重污染程度将对应气象要素依次划分为7种天气类型,测算7种天气类型达空气质量目标下的主要污染物允许排放量.基于2018年基准年的排放量,在天气类型7最不利气象条件下,沧州市一次PM2.5,PM10,NOx和SO2排放量削减率应分别在82.62％,81.17％,75.05％和74.54％以上,才能达到空气质量标准.结果表明,不利气象条件下大气环境允许排放量很小,需要更大力度减少污染物排放,才能避免发生重污染天气.

采用全自动快速溶剂萃取法(ASE)将养殖场土壤中四环素、氯霉素、氟苯尼考、磺胺二甲基嘧啶、磺胺嘧啶和磺胺甲唑提取出来,建立液相色谱-三重四级杆串联质谱法定性、定量检测的分析方法.取畜禽养殖场土壤样品,风干后粉碎机粉碎,过60目筛网,准确称取15 g上述样品置全自动快速溶剂萃取池中,加20 g硅藻土,以甲醇与乙腈混合溶剂进行提取.提取完毕后,将提取液氮吹至近干,加1.0 mL甲醇溶解残渣,涡旋1 min后,用0.22μm滤膜过滤,上液相色谱-质谱仪定性、定量检测.四环素、氯霉素、氟苯尼考、磺胺二甲基嘧啶、磺胺嘧啶和磺胺甲唑在0.02～8.0μg/mL范围内线性关系良好,相关系数(r)均大于0.995;检测限分别为0.021、0.033、0.046、0.018、0.022和0.010μg/kg;平均回收率在83.9％～104.7％之间;重复性RSD分别为2.80％、3.17％、3.63％、2.27％、4.22％和3.93％(n=6).实验方法具有快速、准确等特点,适用于养殖场土壤等样品的检测,为指导养殖户合理使用药物提供了技术依据.

为研究沧州市大气细颗粒物污染特征,于2018年秋季采集PM2.5样品,利用电感耦合等离子体发射光谱仪测定Cr,Fe,Cu,Mn,Pb,Ni,Zn等7种金属元素含量,对PM2.5质量浓度和气团输送影响及PM2.5中金属元素污染特征进行分析.结果表明,沧州市秋季PM2.5质量浓度为58.9μg·m-3,低于国家二级标准日均浓度限值(75μg·m-3);9月、10月和11月日变化曲线均呈"双峰单谷"型;PM2.5中Fe和Zn元素含量最高,占比为84.3％,Mn,Ni,Pb含量均低于世界卫生组织参考浓度限值.富集因子分析显示,Cu和Cr表现为中度富集,Zn和Pb表现为高度富集.气团后向轨迹分析显示,西北偏北和西北长距离气团为清洁气团,对污染物的清除作用明显,西北偏西和南部气团为污染气团,造成了细颗粒物质量浓度升高.

在我国城市规模不断扩大的同时,市政工程也在大量施工,而在施工过程中所造成的环境污染问题受到了越来越多人的关注,具有很大的社会效益,如果不能很好地解决施工过程中的环境污染问题,那么市政工程的对外形象就会受到很大的影响.

基于京津冀地区某典型钢铁企业排放清单,建立了超低排放改造前后两种情景,利用AERMOD模型模拟了两种情景下典型钢铁企业排放SO2、NOx和一次PM10对周边大气环境的影响.结果 显示:从排放量来看,钢铁企业的超低排放改造对NOx减排效果更为明显,NOx减排比例达到为56.44％.现状情景下,典型钢铁企业对5个空气质量监测站SO2、NOx和PM10的年均贡献浓度分别为0.11μg/m3、0.34μg/m3和0.20μg/m3.超低排放改造后,典型钢铁企业对5个空气质量监测站SO2、NOx和PM10的年均贡献浓度分别下降0.05μg/m3、0.16μg/m3和0.07μg/m3.

120 main industrial installations were screened based on the emissions inventory of 2016 in Cangzhou City, and the air pollution effect of PM2.5, PM10, SO2, NO2, sulfates, nitrates, and secondary organic aerosol (SOA) was simulated for 2017 autumn-winter season for different levels of pollution using the CALPUFF model after code recompilation. The results showed that the ratios of the modelled and measured concentrations of PM2.5, PM10, SO2, and NO2 were 3.3%, 5.7%, 5.6%, and 2.9%, respectively. The areas most affected by pollution from primary PM10 were the southwest and southeast part of Cangzhou, while sulfate, nitrate, and SOA pollution mainly affected the southeast part. The proportion of SOA in the PM2.5 was around 27.3%, and rose to 29.0% during heavily polluted periods. The aerosols of alkenes, tolune, xylene, and PAH in PM2.5 accouted for 12.1%, 6.0%, 7.0%, and 2.2% of the total aerosols respectively. The result of the simulation of individual enterprises showed that their total contribution to PM2.5 during heavily polluted periods was 3.02 μg·m-3, accounting for 50% of the requirements in the "Three-year Plan" for Cangzhou City (6.00 μg·m-3). The top 5 contributors were 1 Petrochemical industry in Cangzhou (0.41 μg·m-3), 2 Carbon Co. Ltd. (0.29 μg·m-3), 3 Petrochemical industry in Juhai (0.26 μg·m-3), 4 Fertilizer Company (0.23 μg·m-3), 5 Dahua Co. Ltd. (0.19 μg·m-3). These industrial installations were mainly located in Xinhua District, Cangxian, and Bohai New District. This research can provide a scientific ground for production restrictions and limitations and emissions reduction of each industry during heavily polluted periods.

为研究沧州市2014～2017年空气质量特征,利用空气质量指数(AQI)及6项污染物(PM2.5、PM10、SO2、NO2、CO、O3)质量浓度,分析了沧州市环境空气质量状况,并采用空气质量指数和空气污染综合指数对市区环境空气质量进行评价.结果 表明:PM2.5、PM10、SO2、AQI年均值呈现下降趋势,NO2、O3年均值表现为增加趋势;PM2.5、PM10、SO2、NO2和CO季节变化特征相似,均表现为冬季最高,夏季最低,O3呈现相反的变化趋势,表现为夏季最高,冬季最低;以PM2.5和PM10的空气污染综合指数最高,两项指标贡献率之和为59 ％～66％,呈现出以尘污染为主的复合型污染特征;为预防和治理污染,应加快产业结构调整,改善能源结构,加强城市扬尘污染控制,有效应对重物染天气.