达州市城区环境空气质量变化趋势及CMAQ模型预报分析

利用Spearman秩相关系数法、污染日历图、浓度分析法和CMAQ预测模型研究了达州市城区2015—2019年空气质量状况。结果表明:2015—2019年,达州市城区O_3浓度变化趋势为显著上升(P0.05),季度变化明显,8月易发生因O_3超标导致的轻度污染状况;CO年均值变化趋势为显著降低(P0.05);NO_2年均值呈上升趋势,但尚未达到显著水平(P0.05);SO_2、PM_(10)和PM_(2.5)年均值呈下降趋势,但变化趋势不明显(P0.05)。2019年,1月和12月污染最重,PM_(2.5)超标是主因,PM_(10)和PM_(2.5)年均值达标形势严峻,全年一半以上天数的PM_(2.5)浓度超过年均值二级标准限值,PM_(10)也近半;NO_2年均值达标形势严峻,全年212 d超过年均值二级标准限值。CMAQ模型对不同污染指标的预测准确率不同,预测PM_(2.5)浓度、首要污染物和空气质量等级时的准确率不及人工预测,预测AQI时的准确率高于人工预测,更多污染指标的预测比较还有待进一步研究。     

贵阳市城区PM10和PM2.5水溶性离子特征分析

分别于2013年10月和2014年2月、5月、7月在贵阳市城区3个环境空气质量监测国控点位（南明区市监测站、云岩区黔灵公园马鞍山和观山湖区贵阳一中）进行PM₁₀、PM_2.5样品采集，并对10种水溶性离子（SO₄^2-、NO₂^-、NO₃^-、NH₄⁺、Cl^-、F^-、Na⁺、K⁺、Mg²⁺、Ca²⁺）的含量进行了分析。结果表明，研究时段内，贵阳市3个点位PM₁₀、PM_2.5平均质量浓度分别为（64.8±25.5）、（46.6±21.2）μg/m³。其中，云岩区黔灵公园马鞍山点位的颗粒物浓度最低，南明区市监测站点位最高。3个点位PM_2.5平均浓度与PM₁₀平均浓度的比值为0.719，表明贵阳市城区PM₁₀中，PM_2.5占主导地位。水溶性离子分析显示，SO₄^2-、NO₂^-、NO₃^-、NH₄⁺、Cl^-、F^-、Na⁺、K⁺主要分布在PM_2.5中，Mg²⁺、Ca²⁺主要分布在PM₁₀中。3个点位PM₁₀和PM_2.5中的水溶性离子均表现为SO₄^2-、NH₄⁺、Ca²⁺浓度较大，F^-、NO₂^-较小，表明3个点位的污染源总体相同，且水溶性离子占PM₁₀、PM_2.5含量的比例达33.6%~48.1%。贵阳市城区大气中的SO₂转化率在5月、7月、10月较高，2月最低，主要是由于5月、7月、10月的高温、高湿、强辐射环境条件促进了SO₂向SO₄^2-的转化。阴阳离子平衡分析表明，贵阳市城区PM₁₀、PM_2.5呈现出偏碱性的特征。水溶性离子主成分分析表明，贵阳市城区PM₁₀中的水溶性离子主要来源于城市扬尘、生物质燃烧尘、煤烟尘、建筑尘以及二次粒子，PM_2.5中水溶性离子的来源与PM₁₀较为相似。     

蚯蚓粪复配硼钼调理剂对土壤改良和茄子生长的影响作用

土壤质量决定着农产品的质量和农业生产的可持续发展,然而土壤退化成为农业生产的重要限制因素之一,施用土壤调理剂有利于减缓土壤退化的速度。该研究配制土壤调理剂,即蚯蚓粪:草菇渣:蛭石=6:3:1、钼酸钠50 g·kg^-1、硼酸13.3 g·kg^-1,并设5个不同的处理CK、QY-T1、QY-T2、QY-T3、QY-T4,研究该调理剂对土壤理化性质和肥力的影响作用,分析其对茄子硼、钼和生长状况的促进作用。结果表明,该调理剂能提高土壤温度,5 cm、09:00的土壤温度QY-T4较高,但10 cm、14:00的土壤温度QY-T3最高;土壤容重随着施用量的增大而显著降低至1.50 g·cm^-3以下,土壤pH值从CK的4.93提高到QY-T4的5.57、微生物量碳分别比CK高29.9%、36.1%、47.6%和52.2%,有机质分别比CK高10.8%、11.7%、12.5%和7.0%,QY-T2、QY-T3、QY-T4土壤有效硼达到0.35、0.36、0.42mg·kg^-1,QY-T1、QY-T2的有效钼分别为0.107、0.140mg·kg^-1,随着调理剂的增多而增多,但QY-T3、QY-T4分别为0.101、0.092 mg·kg^-1反而随着调理剂的增多而下降,茄子硼、钼含量都随着调理剂的增加而增大,且显著高于对照(P<0.01);总产量比CK分别提高了29%、36%、190%和66%,总个数分别增加了25%、28%、155%和66%,59 d株高和叶片面积分别比CK增高了23%、1.4%、23%、16%和6.8%、11%、9.3%、7.4%,而叶片数量,所有的处理差异不显著,因此推荐该土壤调理剂用量与QY-T3相同,为1.5×10⁴kg·hm^-2。该研究可为土壤调理剂修复土壤退化的应用提供依据。     

夏季渭河西安段溶解性有机质(DOM)的特征、分布及来源分析

通过紫外吸收光谱,三维荧光光谱结合平行因子分析(EEMs-PARAFAC)方法及主成分分析(PCA),研究了夏季渭河西安段水体中的溶解性有机质(DOM)的组成、来源,及其与水质指标的相关性.在研究区域共检出2种类别5个不同的DOM组分,分别为类腐殖质荧光组分C1、C2、C3、C5和1个类蛋白类荧光组分C4,5个组分具有同源性.对比分析光谱斜率S、SUVA₂₅₄、α355和DOC浓度,上游(S1—S5)和下游(S13—S17)各组分分子量和腐殖化程度接近但来源有所差异,中游(S6—S12、S18—S19)分子量和腐殖化程度最低;研究区域DOM和CDOM浓度值变化基本保持一致.通过三维光谱参数和主成分分析进行DOM源解析,内源贡献率为72.36%,外源贡献率为12.45%,累计方差贡献率为84.81%;污废水排放是组分C1、C4的主要来源,C2、C3、C5则来源于城市景观水体和湿地公园中微生物和浮游动植物的活动产生,TN与外源具有较好的相关性而TP与内源相关性较高.水质指标DO、DOC、COD、TN、TP与DOM组分有较强的相关性.在此基础上建立了多元线性回归方程,一定程度上能够利用荧光组分组成和特征反映渭河夏季的水质状况.     

A new prediction method of industrial atmospheric pollutant emission intensity based on pollutant emission standard quantification

● Established a quantification method of pollutant emission standard. ● Predicted the SO₂ emission intensity of single coking enterprises in China. ● Evaluated the influence of pollutant discharge standard on prediction accuracy. ● Analyzed the SO₂ emissions of Chinese provincial and municipal coking enterprises. Industrial emissions are the main source of atmospheric pollutants in China. Accurate and reasonable prediction of the emission of atmospheric pollutants from single enterprise can determine the exact source of atmospheric pollutants and control atmospheric pollution precisely. Based on China’s coking enterprises in 2020, we proposed a quantitative method for pollutant emission standards and introduced the quantification results of pollutant emission standards (QRPES) into the construction of support vector regression (SVR) and random forest regression (RFR) prediction methods for SO₂ emission of coking enterprises in China. The results show that, affected by the types of coke ovens and regions, China’s current coking enterprises have implemented a total of 21 emission standards, with marked differences. After adding QRPES, it was found that the root mean squared error (RMSE) of SVR and RFR decreased from 0.055 kt/a and 0.059 kt/a to 0.045 kt/a and 0.039 kt/a, and theR² increased from 0.890 and 0.881 to 0.926 and 0.945, respectively. This shows that the QRPES can greatly improve the prediction accuracy, and the SO₂ emissions of each enterprise are highly correlated with the strictness of standards. The predicted result shows that 45% of SO₂ emissions from Chinese coking enterprises are concentrated in Shanxi, Shaanxi and Hebei provinces in central China. The method created in this paper fills in the blank of forecasting method of air pollutant emission intensity of single enterprise and is of great help to the accurate control of air pollutants.     

燃煤电厂大气污染物排放考核时间间隔的建议

新的《火电厂大气污染物排放标准》和新《环境保护法》实施后，燃煤火电企业的依法治企自觉性不断提高，但由于不同的环保管理文件对超标处罚依据和处罚手段不同，造成政府对企业处罚的自由裁量权加大，对企业造成一定的压力与困惑。结合企业实际运行情况对燃煤电厂大气污染物排放考核时间间隔提出建议。     

徐州大气颗粒物污染特征及传输途径分析

利用徐州2015年PM2.5和PM10逐小时质量浓度数据,分析了徐州颗粒物时空变化特征。同时基于HYSPLIT后向轨迹模式,结合GDAS气象数据和空气质量数据,利用轨迹聚类及潜在源分析法研究徐州不同季节气流轨迹对颗粒物浓度的影响及PM2.5和PM10的潜在来源。结果显示,2015年徐州环境空气中PM2.5和PM10的年均值为65和122μg/m3,分别超过国家《环境空气质量标准》(GB 3095—2012)二级标准限值86%和63%。各国控站点ρ(PM2.5)和ρ(PM10)月变化呈现一致的冬季高夏季低的"V"型变化特征,这与气象条件和气流轨迹特征季节性变化有关。秋冬季污染较高时期徐州主要受西北内陆性气团和较为稳定的气象条件影响,而春夏季来自较为干净的东部海洋性气团利于污染扩散。潜在源分析显示,山东、安徽、苏中南、浙西北等地区是影响徐州市PM2.5和PM10的主要潜在源区。各季节潜在源区分布范围有一定差异,冬季时潜在源区分布最广,并有明显向西北方向转移延伸的趋势。     

Sediments distribution of trace metals in a coastal lagoon (Southern Sardinia,Mediterranean Sea): assessment of contamination and ecological risk

Coastal lagoons are subject to several sources of contaminations. To shade light on the contamination level of the Santa Gilla lagoon (Tyrrhenian Sea) we investigated the spatial distribution of Cr, Ni, Pb, Zn and Hg in sediments and their correlation with grain size and organic matter contents. Moreover, sediment contamination levels and the ecological risk associated with metal concentration were assessed using different abiotic indicators. The lagoon is characterised by low levels of contamination, with exceptions for Pb and Hg, whose distribution reflects the position of an old chlor-alkali plant and that of an airport. These results indicate that the restoration put in place 30 years ago have not reached the expected target and that the presence of the airport deserves further attention. In the outer section of the lagoon, where clam fishery occurs, we observed low levels of contamination suggesting that such artisanal fishery could somehow help mobilising metals. We conclude that the area exposed to Hg pollution, though tentatively restored, still suffers of a potential risk of ecosystem deterioration. We pinpoint that further investigations on the mobility, bioavailability and toxicity of metals are needed to finally address the actual impairment of the Santa Gilla lagoon.     

北京不同污染天气PM_(2.5)和PM_(10)染毒对大鼠生理病理参数的影响

为探讨北京不同污染天气大气可吸入颗粒物PM_(10)和细颗粒物PM_(2.5)污染对雄性大鼠血常规、氧化损伤、炎症反应和肺组织的影响,将64只雄性8周龄Wistar大鼠随机分为8组,分别为2个对照组(空白组和生理盐水组)和6个染毒组(清洁、雾霾及沙尘暴3种不同天气的PM_(10)染毒组和PM_(2.5)染毒组),每组8只。用2015年3月—5月在北京南海子麋鹿苑采集的清洁、雾霾和沙尘暴3种不同天气的PM_(10)和PM_(2.5)制备悬液,分别采用气管滴入PM_(10)和PM_(2.5)悬液作为染毒组,空白对照组不做任何处理,生理盐水对照组采用气管滴注生理盐水。急性染毒24 h后处死大鼠。采集血液测定18个血常规指标,分析肺泡灌洗液(BALF)中转化生长因子-β1(TGF-β1)、乳酸脱氢酶(LDH)、总抗氧化能力(T-AOC)、白介素-6(IL-6)及肿瘤坏死因子-α(TNF-α)的含量,并在高倍显微镜下观察肺组织和气管病理形态变化。同时,对PM_(10)和PM_(2.5)中的水溶性离子、有机碳/元素碳、16种多环芳烃和7种重金属等元素进行了测定,并分析了各组分与大鼠生理病理指标的相关性。结果表明:清洁、沙尘暴天气的PM_(10)和雾霾天气的PM_(2.5)急性染毒导致大鼠白细胞系参数即免疫力显著下降。污染天气颗粒物染毒后大鼠BALF氧化炎症因子的改变表明呼吸系统受到感染:沙尘暴和清洁天的PM_(10)染毒均显著提高了TGF-β1,雾霾PM_(10)染毒后IL-6和LDH有一定程度升高。3种天气颗粒物染毒对肺和气管造成的组织病理伤害各有特点,但PM_(2.5)伤害程度普遍大于PM_(10)。染毒颗粒物粒径大小,其化学成分类别、浓度是造成大鼠血常规指标变化、氧化炎症反应和组织学病变的可能原因。     

Environmental forensic investigation of the air pollution from a cement manufacturing unit

Abstract

Cement manufacturing is a process that results in the emission of significant quantities of suspended particulate matter (SPM) to the ambient air. An environmental forensic investigation was carried out in the surroundings of a major cement manufacturing unit at a place called Coimbatore in the southern Indian state of Tamil Nadu. The investigation was carried out to identify the contribution of the cement manufacturing unit to the SPM concentration of the surrounding air environment. The sampling points’ selection and sample collection were done following the principles outlined in the INTERPOL Manual for Pollution Crime Forensic Investigation. On-site monitoring of the air samples was carried out using Mini Laser Aerosol Spectrometer (GRIMM, Mini-LAS Model 11R). The instrument was capable of measuring particles ranging from 0.25 to 32 µm and classifying them into 31 size channels. The test results at majority of the monitoring locations were well above the limits specified in the National Ambient Air Quality Standards of India. Microscopic studies of the dust samples were carried out for surface texture and particle shape. The spatial distribution of particles was analysed using geographic information system (GIS) for the visual identification of the extent of the pollution by keeping the cement factory as the focal point. The results from the GIS and microscopic analysis established the role of the cement factory in the particulate matter pollution of its surroundings, specifically in the areas North-West of the factory. The successfully adopted procedure can serve as a guideline for the environmental forensic investigation of similar pollution incidences.