Trends in the Different Grades of Precipitation over South China during 1960–2010 and the Possible Link with Anthropogenic Aerosols

Using observed daily precipitation data to classify five levels of rainy days by strength in South China （SC）,with an emphasis on the Pearl River Delta （PRD） region,the spatiotemporal variation of different grades of precipitation during the period 1960-2010 was analyzed and the possible link with anthropogenic aerosols examined.Statistical analysis showed that drizzle and small precipitation has significantly decreased,whereas medium to heavy precipitation has increased slightly over the past 50 years （although not statistically significant）.Further data analysis suggested that the decline in drizzle and small precipitation probably has a strong link to increased concentrations of anthropogenic aerosols produced by large-scale human activities related to the rapid socioeconomic development of the PRD region.These aerosols may also have led to the obvious decreasing trend in horizontal visibility and sunshine duration in SC,which is statistically significant according to the t-test.

Source analysis and risk evaluation of heavy metal in the river sediment of polymetallic mining area:Taking the Tonglüshan skarn type Cu-Fe-Au deposit as an example,Hubei section of the Yangtze River Basin,China

In this paper,25 sampling points of overlying deposits in Tonglushan mining area,Daye City,Hubei Province,China were tested for heavy metal content to explore pollution characteristics,pollution sources and ecological risks of heavy metals in sediments.A geo-accumulation index method was used to evaluate the degree of heavy metal pollution in the sediment.The mean sediment quality guideline quotient was used for evaluating the ecological risk level of heavy metal in the sediment.And a method of correlation analysis,clustering analysis,and principal component analysis was used for preliminary analysis on the source of heavy metal in the sediment.It was indicated that there was extremely heavy metal pollution in the sediment,among which Cd was extremely polluted,Cu strongly contaminated,Zn,As,and Hg moderately contaminated,and Pb,Cr,and Ni were slightly contaminated.It was also indicated by the mean sediment quality guideline-quotient result that there was a high ecological risk of heavy metals in the sediment,and 64%of the sample sites had extremely high hidden biotoxic effects.For distribution,the contamination of branches was worse than that of the main channel of Daye Dagang,and the deposition of each heavy metal was mainly influenced by the distance from this sample site to the sewage draining exit of a tailings pond.The source analysis showed that the heavy metals in the sediment come from pollution discharging of mining and beneficiation companies,tailings ponds,smelting companies,and transport vehicles.In the study area,due to the influence of heavy metal discharging from these sources,the ecotoxicity of heavy metals in the sediment was extremely high,and Cd was the most toxic pollutant.The research figured out the key restoration area and elements for ecological restoration in the sediment of the Tonglüshan mining area,which could be referenced by monitoring and governance of heavy metal pollution in the sediment of the polymetallic mining area.

Crumb Rubber Modified Bitumen in Open Graded Wearing Course of Flexible Pavement

Rapid road infrastructure development due to an increasing demand of car users resulted in an increase in paved areas including road sites and suppression of green spaces. An integrated solution that can support a country’s economic development without compromising water pollution is becoming inevitable. Recycling tyres in the form of crumb rubber tyres and mixing it into bituminous paving mixture can increase the recycling rate and minimize cost of incineration process. In dry mixing process, five (5) different variations of Open Graded Wearing (OGW) course road samples were made to make up 1.15 kg in each sample. Each OGW mix contained 4% - 6% bitumen Pen 60/ 70 and fixed 1% of crumb rubber tyres, making the percentage of crumb rubber tyres 14% - 20% of bituminous samples. Bitumen Pen 60/70 mixed with 20% crumb rubber tyres content met the PG 76 bitumen properties. Physical properties of OGW made from crumb rubber modified bitumen (CRMB) were better than standard bitumen only. In a separate water leachate test using ICP-OES equipment, heavy metal leachate of Cu(II), Pb(II), Zn(II) and Cd(II) were present in all OGW CRMB samples at increasing surrounding water temperature from 25℃ to 60℃. However all the heavy metal concentration was very low below the allowable limit of trade effluent standards into water course.

Trends in Graded Precipitation in China from 1961 to 2000

Daily precipitation rates observed at 576 stations in China from 1961 to 2000 were classified into six grades of intensity, including trace （no amount）, slight （≤ 1 mm d^-1）, small, large, heavy, and very heavy. The last four grades together constitute the so called effective precipitation （〉 1 mm d^-1）. The spatial distribution and temporal trend of the graded precipitation days are examined. A decreasing trend in trace precipitation days is observed for the whole of China, except at several sites in the south of the middle section of the Yangtze River, while a decreasing trend in slight precipitation days only appears in eastern China. The decreasing trend and interannual variability of trace precipitation days is consistent with the warming trend and corresponding temperature variability in China for the same period, indicating a possible role played by increased surface air temperature in cloud formation processes. For the effective precipitation days, a decreasing trend is observed along the Yellow River valley and for the middle reaches of the Yangtze River and Southwest China, while an increasing trend is found for Xinjiang, the eastern Tibetan Plateau, Northeast China and Southeast China. The decreasing trend of effective precipitation days for the middle- lower Yellow River valley and the increasing trend for the lower Yangtze River valley are most likely linked to anomalous monsoon circulation in East China. The most important contributor to the trend in effective precipitation depends upon the region concerned.

淮河流域地表水污染与癌症的空间关联

目的揭示淮河流域关键污染物的空间聚集模式,并基于污染分级进一步量化非消化道癌症风险和癌症负担,为淮河流域水污染的深化治理提供靶目标和数据支持。方法选取淮河流域2021年地表水质及2019年肿瘤登记年报的7种癌症发病数据,采用随机森林-SHapley加性解释分析筛选关键污染物,基于空间分析划分污染分级,并计算其癌症风险和人群归因分数。结果筛选出5个关键污染物,分别为总磷、总氮、化学需氧量、5日生化需氧量及砷,并将其联合效应划分为3个污染分级,结果显示与低污染地区相比,高污染地区的5种癌症发病风险显著增加,包括肺癌(RR=1.26,95%CI=1.06~1.50)、乳腺癌(女性)(RR=1.46,95%CI=1.21~1.77)、胰腺癌(RR=1.46,95%CI=1.06~2.01)、脑癌(RR=1.44,95%CI=1.05~1.98)和胆囊癌(RR=1.60,95%CI=1.03~2.50),且人群归因分数几乎均超过5%。结论地表水污染的潜在癌症风险和负担不容忽视,唯有各行业密切合作,通过进一步制定政策法规、加强环境治理和进行公众健康干预,才能从根本上应对这一挑战。

An novel identification method of the environmental risk sources for surfacewater pollution accidents in chemical industrial parks

The chemical industry is a major source of various pollution accidents. Improving the management level of risk sources for pollution accidents has become an urgentdemand for most industrialized countries. In pollution accidents, the released chemicals harm the receptors to some extentdepending on their sensitivity or susceptibility. Therefore, identifying the potential risk sources from such a large number of chemical enterprises has become pressingly urgent. Based on the simulation of thewhole accident process, a novel and expandable identification method for risk sources causingwater pollution accidents is presented. The newlydeveloped approach, by analyzing and stimulating thewhole process of a pollution accident between sources and receptors, can be applied to identify risk sources, especially on the nationwide scale. Three major types of losses, such as social, economic and ecological losses,were normalized, analyzed and used for overall consequence modeling. A specific case study area, located in a chemical industry park （CIP） along the Yangtze River in Jiangsu Province, China,was selected to test the potential of the identification method. The results showed that therewere four risk sources for pollution accidents in this CIP. Aniline leakage in the HS Chemical Plantwould lead to the most serious impact on the surroundingwater environment. This potential accidentwould severelydamage the ecosystem up to3.8 kmdownstream of Yangtze River, and lead to pollution over adistance stretching to 73.7 kmdownstream. The proposed method is easily extended to the nationwide identification of potential risk sources.

廊坊市重污染天气特征及减排效果评估

为了统筹推进空气质量改善和经济发展,生态环境部于2019年7月制定了重污染天气“绩效分级、差异化管控”措施。文章将廊坊市11次预警(4次黄色预警、6次橙色预警和1次红色预警)划分为8次污染过程进行分析。结果显示,8次污染过程PM_(2.5)平均浓度为41.4~129.0μg/m^(3),综合后向轨迹模拟、地面天气型等手段,将污染过程分为4类,包括西南输送类、东南输送类,西北方向输送类以及局地污染过程。其中高压后部、低压前部和弱高压是导致南部区域传输污染过程的主要天气型,均压场、弱高压是导致西北来向和局地污染过程的主要天气型,且西南来向与局地污染过程PM_(2.5)均值与峰值浓度均高于东南来向和西北来向污染过程,说明此两类污染发生时,廊坊市空气质量更差。结合各预警等级污染物减排比例,采用WRF-CMAQ模式对11次预警期间“绩效分级、差异化管控”效果进行评估,发现预警期间PM_(2.5)平均浓度下降了2.6%~5.9%,PM_(2.5)峰值浓度降低了0.7%~7.7%。整体来看,应急措施的实施有效改善了廊坊市空气质量,并起到了“削峰”作用。

环境污染物暴露对儿童免疫系统发育的影响

环境污染物的暴露会导致炎症因子释放和免疫功能受损。本文基于粗放式电子垃圾拆解污染现场,通过检测重金属、有机污染物、大气污染物等环境污染物内、外暴露水平,儿童外周血炎症细胞、细胞因子和接种I类疫苗后血清特异性抗体浓度等免疫相关指标,探讨环境污染物暴露对儿童免疫系统发育的影响及其健康风险。结果发现,粗放式电子垃圾拆解区各类污染物处于较高水平,长期污染物暴露可造成儿童机体呈现慢性低度炎症状态,疫苗接种所产生的特异性抗体滴度较低且与污染物暴露水平负相关,儿童黏膜免疫系统受损,感冒、腹泻等呼吸、消化系统病症的发生频率增加,儿童免疫功能的变化与年龄、性别、营养状况和复合暴露有关。由于机体低度炎症是衰老和慢性疾病的重要因素,也是各类器官系统损伤和疾病发生的主要诱发因素,随着年龄的增长,罹患心血管疾病、糖尿病、神经退行性疾病和自身免疫性疾病等慢性疾病的发病风险不断加大。研究提示,环境污染物暴露可通过干扰儿童期免疫系统的正常发育,增加成年后罹患相关疾病的风险。这些研究可为制定针对性的疫苗接种政策和慢性疾病的早期防控提供科学依据。

2000-2023年京津冀蓝天等级日数遥感研究

利用2000年12月—2023年12月卫星遥感反演的气溶胶光学厚度逐日资料,结合2023年每日中午地面观测蓝天资料,基于气溶胶光学厚度得到的蓝天等级监测指标,分析2000—2023年京津冀地区蓝天日数的时空变化特征及其变化趋势。结果表明:2001—2023年京津冀蓝天日数年平均值分别为144.2 d·a^(-1)、96.3 d·a^(-1)和119.6 d·a^(-1),北京蓝天日数最多,河北次之,天津最少。空间分布上,河北北部年平均蓝天日数最多,河北南部蓝天日数最少。京津冀蓝天日数具有明显季节变化,冬季和秋季蓝天日数最多,春季次之,夏季最少。2001—2023年京津冀蓝天日数年平均值均呈显著增加趋势,每10年分别增加18.1 d、22.3 d和16.3 d,其中2001—2013年无显著趋势变化,2013—2023年呈增加趋势,每10年分别增加26.9 d、46.5 d和36.4 d。

付疃河中下游表层沉积物污染状况评价

为探明付疃河中下游沉积物污染情况,对河底12个采样点表层沉积物中的TN,TP,OM和重金属(Cr,Ni,Cu,Zn,As,Cd,Pb)的含量开展调查,分析其分布特征、来源、污染水平以及健康风险。结果表明,城区段河流以及日照水库出库处TN,TP及OM相对较高,且相应的污染指数均为重度污染,其他区域为轻度~中度污染;除Pb外,其余6种重金属含量均高于东港区土壤背景值;城区段河流以及日照水库出口处重金属含量相对较高,可能受工业、农业及交通等复合因素影响导致;Cd处于轻度污染状态或中等生态危害状态,各类重金属均不存在非致癌健康风险,但存在可接受的致癌风险。

水分调控下生物炭施入对重金属污染农田土壤Pb、Zn形态的影响

【目的】探究水分调控和生物炭对矿区附近农田土壤的修复效果并提高耕地安全。【方法】以云南某铅锌矿附近农田土壤为研究对象,设置干湿交替(G)、淹水(Y)、自然含水量(Z)3种水分条件和0%(BC0,CK)、2.5%(BC1)、5.0%(BC2)、7.5%(BC3)4种生物炭添加量,通过土壤培养试验,研究不同水分调控措施下施加鸡粪生物炭对重金属污染土壤中Pb、Zn形态的影响。【结果】在3种水分条件下,施加生物炭均能提高土壤pH。生物炭处理土壤中水溶态和交换态Pb、Zn浓度均显著低于对照,降低了Pb、Zn生物有效性。生物炭处理土壤中可氧化态和残渣态Pb质量分数提高,其中ZBC2处理可氧化态和残渣态Pb质量分数最高,分别为64.58%、25.06%;各处理土壤残渣态Zn质量分数依次为干湿交替>淹水>自然含水量。不同水分条件下,施加生物炭显著降低TCLP提取态Pb、Zn质量浓度,且均远低于国际限制标准,其中GBC3处理土壤TCLP提取态Zn浓度最低,为3.45 mg/L。SGET法的Pb、Zn生物可给性平均质量分数小于PBET法和SBET法,其中ZBC3处理Pb、Zn生物可给性质量分数最低,为0.43%、0.27%。【结论】3种水分调控下施加不同量生物炭均可有效钝化土壤重金属Pb、Zn,降低其对土壤环境的危害。自然含水量条件下,施加较高量生物炭(5.0%、7.5%)对土壤重金属Pb钝化效果最佳;干湿交替条件下,施加7.5%生物炭对土壤重金属Zn钝化效果最佳。

连续强对流天气下重污染扩散概率预报研究

为了更好地掌握重污染在特定天气条件下的扩散规律,提出连续强对流天气下重污染扩散概率预报研究。在连续强对流天气下将污染划分为重度污染等级、中度污染等级和轻度污染等级;依据等级分类结果,分析重污染扩散概率预报具体要素,建立重污染扩散概率预报框架,预测在连续强对流天气下,不同污染等级的扩散概率,由此完成重污染扩散概率预报方法研究。实验结果表明,轻度污染类型变化情况明显比中度、重度污染类型更为显著,重污染扩散概率预报结果与实际变化情况相符,表明所提方法具有较高的预报精度。

重污染天气下铸造企业绩效分级研究

每年秋冬季重污染天气频发,各级生态环境部门会适时启动重污染天气应急响应,启动响应后铸造企业开始限停产。为降低重污染天气应急响应对企业正常生产的影响,企业需开展绩效评级创“A”保“B”工作。为进一步帮助铸造企业更好的开展绩效评级工作,从装备水平及生产工艺、污染治理技术、污染物排放限值和无组织控制、监测监控水平、环境管理水平、运输方式及运输监管等方面予以分析,提供可参考的措施方法。

玻纤滤芯过滤效率与压降及油液污染度关系分析

阐释玻纤滤芯过滤效率对设备装置流体系统清洁度水平控制的重要性。通过模拟流体系统实际工况的清洁度水平,在实验室条件下进行玻纤滤芯过滤性能试验验证,并从过滤效率与压降关系、下游油液清洁度水平等维度对验证结果分析论证,提出了过滤器使用周期内各阶段过滤现象的产生机制,确定了过滤效率与压降及污染控制水平的关系。对于滤芯厂家开展系统污染度控制及过滤器设计具有重要意义。

我国大城市环境铅污染影响因素分析

应用灰色理论，以武汉、兰州、长春、青岛四大城市为空间序列点，取表土、植物和居民头发平均铅含量为参考因素，取单位面积年均燃料油和燃料煤耗量，主要含铅污染物年均排放量，以及某些气象因素为比较因素，进行了多参考因素的优势分析。灰关联度矩阵表明，我国大城市环境铅污染的优势影响因素是燃料油年均耗量、燃料煤年均耗量、平均相对湿度和煤灰年均排放量，其中燃料煤年均耗量是表土平均铅含量的最大影响因素；相对湿度是植物平均铅含量的最大影响因素；燃料油年均耗量是居民发铅平均含量的最大影响因素。可以确认抗爆汽油中的铅对居民健康具潜在危害性。

环境污染事故危险源评级方法研究

将环境污染事故危险源分成空气污染型和水体污染型两大类,并考虑危险源自身特性和周围环境状况两个主要因素对两类危险源分别提出了评级模式,依据危险指数大小将危险源分为特大、重大、较大和一般四级;利用试点调研的63家企业的183个危险源数据,对危险源评级模式进行了参数选定和验证,证明所建议的方法和模式是可行的,可供危险源调研和建立数据库等实际工作应用。

大冶铁山地区河流水体及水系沉积物中重金属元素分布特征

矿产资源的长期勘探、开采和冶炼活动给大冶铁山地区的自然生态环境造成了严重破坏。对该区西港河、东港河河水和水系沉积物中重金属元素分布特征的研究结果表明,该区矿山开采和冶炼活动形成的重金属污染元素主要为Cd、As、Zn;其主要污染源为冶炼厂排放的废水,其次是采矿废弃物堆积渗漏水;重金属元素在河水与水系沉积物中的空间分布特征较相似,但水系沉积物中元素质量分数比河水中的普遍增高,元素变化的剧烈程度加剧。

海水网箱渔场老化风险初探

根据网箱渔场老化的主要特征 ,并参照渔业环境标准 ,半定量地描述海水网箱渔场老化程度和风险大小 ,初步建立了渔场老化风险评价方法。实例分析表明渔场老化程度、风险大小与海水养殖所受污染损害基本一致。

超高压交流线路长串绝缘子的冰闪特性

在覆冰、污秽、积雪、高海拔等因素综合作用下,输电线路绝缘子的绝缘性能将显著降低,因此研究其闪络特性对线路外绝缘配合具有重要意义。在带电覆冰下对超高压线路长串瓷和复合绝缘子进行了冰闪试验研究,考虑了覆冰前染污和均压环(含模拟导线)对冰闪电压的影响。研究表明:在ρSDD=0.1和0.05mg/cm2时,28片XWP2-160绝缘子串的冰闪电压较500kV线路额定运行电压分别约低20.5%和13.1%,在ρSDD=0.025mg/cm2时,约高2.3%;而在ρSDD=0.1和0.05mg/cm2时,FXBW4-500/160绝缘子的冰闪电压较500kV线路额定运行电压分别约低18.7%和12.0%,在ρSDD=0.025mg/cm2时,约高4.3%;在ρSDD和ρNSDD分别为0.1和0.5mg/cm2的重覆冰情况下,不带均压环的冰闪电压比带均压环时约高11.6%。研究结果可给我国线路绝缘子冰闪特性研究和重冰区超高压线路外绝缘配合提供参考。

大冶市城市湖泊表层水体中重金属的分布特征及其来源

以大冶市三个城市湖泊(三里七湖、尹家湖和红星湖)作为研究对象,测定了三个湖泊中22个采样点的pH值、电导率和表层水体中Mn、Ni、Zn、Cu和Cd 5种重金属元素的含量,并运用主成分分析法对表层水体中重金属的分布特征和来源进行了研究。结果表明:三个湖泊表层水体中5种重金属含量之间呈显著相关,可能具有相同的来源;湖泊表层水体中主要重金属的分布可由第一(F1)和第二(F2)两个主成分因子来反映,其贡献率分别为F1(Mn、Ni、Zn、Cd)83.315%、F2(Cu)8.989%,累积标准单位(CCU)与每种重金属含量、F1因子得分系数、电导率呈显著正相关,说明CCU是揭示湖泊重金属污染的有效指标;此外,重金属含量在各湖泊内部采样点间无显著性差异,而在三个湖泊之间则呈显著性差异,其中三里七湖处于重度污染状态。