Atmospheric deposition of polybrominated dibenzo-p-dioxins and dibenzofurans in Guangzhou, China: seasonal variations and sources

The atmospheric deposition of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) was investigated at four locations in different suburban and urban functional districts of Guangzhou City. The annual deposition fluxes of total PBDD/Fs (eight 2,3,7,8-substituted tetra- to hexa-BDD/Fs) were in the range of 36-51 (mean 46) pg m(-2) day(-1), and the corresponding TEQ fluxes were estimated to range between 7.9 and 11.3 (mean 10.3) pg I-TEQ m(-2) day(-1), indicating a noticeable pollution level. The deposition fluxes of PBDD/Fs during the wet season were 2-4 times as high as those during the dry season. Both rainfall and temperature positively correlated with PBDD/F deposition fluxes. Ambient gas/particle partition coefficients (K(p)) were predicted with SPARC. It appears seasonal variations of PBDD/F deposition fluxes were influenced by meteorological parameters and the local usage of brominated flame retardants (BFRs). The congener profiles of PBDD/Fs at four locations were similar either spatially or temporally, indicating that the main PBDD/F emission sources were similar to one another. Seasonal variations and congener patterns of PBDD/Fs indicated the possible sources included electronic waste recycling, industrial waste incinerators and products containing BFRs.     

美国环境空气监测数据质量核查工作的经验与启示

国控网城市环境空气自动监测点位的监测事权上收后,对监测数据精密度和准确度的定量化评价已成为考核运维公司工作成果、评估国控网数据质量、编制数据质量报告的迫切需求。为加强中国环境空气数据质量核查体系的建设,总结了美国环境空气监测数据质量核查体系及其相关的技术规范,简要介绍其包含的各类核查项目和主要特点,提出了建设中国环境空气数据质量核查体系的建议。     

东莞市一次空气污染过程成因分析

基于东莞市大气复合污染超级监测站的监测数据,选取2017年12月一次典型空气污染过程,对污染期间气象要素、大气颗粒物组分特征和污染物来源进行综合研究。结果表明,在污染期间,首要污染物为PM_(2.5),日均值为86μg/m3,其主要化学组分依次是OC、NO_3~-和SO_4~(2-),分别占PM_(2.5)的19.7%,16.1%和14.9%;在不利的气象条件下,本地污染排放和外源输入的一次污染物快速生成二次有机物、硝酸盐和硫酸盐,是造成该次空气污染的主要原因; PM_(2.5)污染主要来源为机动车尾气(27.7%)及二次无机源(19.0%)。     

煤矿开采矿山地质环境问题类型和特征探讨

我国煤炭资源赋存丰富且条件复杂,历年开采引发或加剧众多矿山地质环境问题。本文以煤炭资源开发各环节活动及开采形式为基础．分析和探讨了煤矿建设和生产对矿山地质环境的影响,探讨了问题类型及特征,并给出了不同开采形式对矿山地质环境影响的关系,并提出了矿山地质环境问题防治工作进一步开展的几点建议,对我国发展绿色、高效矿山有一定促进作用。     

基于时间序列分析的渐变性水源水质预测研究

针对引黄水库水质渐变性特点,运用时间序列分析理论建立了水质分析模型并对山东省某市某水库的水质变化趋势进行模拟和预测。选取温度、pH、氨氮、浊度、化学耗氧量、亚硝酸盐作为预测变量。水库水质的模拟结果表明除浊度外其余项准确率均达到了80%以上,所建立的水质模型能够合理地反映渐变性水库中水质的动态变化趋势,预测结果较好。     

土壤中OCPs残留特征及健康风险评价——以松花江佳木斯段为例

文章利用索氏提取技术,使用气相色谱-电子捕获检测器(GC-ECD)分析方法测定了佳木斯市松花江沿岸土壤中17种有机氯农药(OCPs)残留情况,并探讨该区土壤中OCPs的残留来源,运用健康评价模型对DDTs和HCHs对人体可能存在的健康风险进行了评价。17种OCPs的回收率为69.6%～112.4%,GC-ECD的仪器检出限为0.006～0.021 0 ng/g,方法检出限为2.05～12.83 pg/g,相对标准偏差为3.21%～11.37%,能够满足OCPs痕量分析的要求。研究结果表明,17种OCPs均有不同程度的检出,浓度较高的组分为滴滴涕(DDTs)、六六六(HCHs)和七氯,∑OCPs浓度为167.27～667.54 ng/g。研究区DDTs、HCHs的来源解析表明,DDTs、HCHs主要来自于早期农药的残留及林丹的使用。利用健康风险评价模型对土壤中HCHs、DDTs所致健康风险的评价结果表明,目前研究区土壤中HCHs、DDTs类污染物对人体健康的风险处于较低水平。     

不同颗粒龄的好氧颗粒污泥性能的研究

在SBR反应器中,分别以絮状活性污泥培养的好氧颗粒污泥和直接接种的已稳定运行1 a的好氧颗粒污泥为对象,对2种颗粒龄不同的颗粒污泥的形态、理化特性、对有机物降解能力以及微生物活性进行了比较研究.结果表明,小颗粒龄好氧颗粒的平均湿密度、污泥的比重和表示物理强度的完整系数(IC)分别为1.066 g.cm-3、1.013 g.cm-3和98.7%,各指标均高于大颗粒龄好氧颗粒的1.026 g.cm-3、1.010 g.cm-3和98.4%,两者的平均粒径分别为1.9 mm和2.2 mm.小颗粒龄好氧颗粒和大颗粒龄好氧颗粒的沉降速度分别为0.005～0.032 m.s-1和0.003～0.028 m.s-1,前者的SVI较低,且两体系中好氧颗粒的沉降速度均随粒径的增大而增大.两者对COD、NH4+-N的去除率都保持在90%以上和85%左右,从出水COD浓度、NH4+-N浓度和周期试验来看,小颗粒龄好氧颗粒对COD、NH4+-N的去除效果更好,两者对TP的去除率分别维持在40%～90%和32%～85%,但两者对TN的去除效果相差不大,去除率都在80%左右.同时,小颗粒龄好氧颗粒的异养菌比耗氧速率(SOURH)、亚硝酸菌比耗氧速率(SOURNH4)、硝酸菌比耗氧速率(SOURNO2)分别为26.4、14.8和11.2 mg.(h.g)-1,均大于大颗粒龄好氧颗粒的25.2、14.4和8.4 mg.(h.g)-1.综上所述,好氧颗粒污泥由于颗粒龄的不同会具有明显不同的理化性质,颗粒龄小的好氧颗粒具有更好的有机物降解能力、更高的微生物活性和更好的稳定性.     

Size distribution of chemical elements and their source apportionment in ambient coarse, fine, and ultrafine particles in Shanghai urban summer atmosphere

Ambient coarse particles (diameter 1.8-10 μm), fine particles (diameter 0.1-1.8 μm), and ultrafine particles (diameter < 0.1 μm) in the atmosphere of the city of Shanghai were sampled during the summer of 2008 (from Aug 27 to Sep 08). Microscopic characterization of the particles was investigated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX). Mass concentrations of Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, and Pb in the size-resolved particles were quantified by using synchrotron radiation X-ray fluorescence (SRXRF). Source apportionment of the chemical elements was analyzed by means of an enrichment factor method. Our results showed that the average mass concentrations of coarse particles, fine particles and ultrafine particles in the summer air were 9.38 ± 2.18, 8.82 ± 3.52, and 2.02 ± 0.41 μg/m³, respectively. The mass percentage of the fine particles accounted for 51.47% in the total mass of PM10, indicating that fine particles are the major component in the Shanghai ambient particles. SEM/EDX results showed that the coarse particles were dominated by minerals, fine particles by soot aggregates and fly ashes, and ultrafine particles by soot particles and unidentified particles. SRXRF results demonstrated that crustal elements were mainly distributed in the coarse particles, while heavy metals were in higher proportions in the fine particles. Source apportionment revealed that Si, K, Ca, Fe, Mn, Rb, and Sr were from crustal sources, and S, Cl, Cu, Zn, As, Se, Br, and Pb from anthropogenic sources. Levels of P, V, Cr, and Ni in particles might be contributed from multi-sources, and need further investigation.     

强化混凝去除湘江原水中天然有机物的研究

文章应用强化混凝技术对湘江原水中天然有机物的去除效果进行了研究。通过选择混凝剂、增加混凝剂的用量和降低pH值等措施强化混凝处理湘江水。实验结果表明,选用聚合氯化铝(PAC)作为混凝剂,并控制PAC的投加量为3 10-4 mol.L-1,pH在5 6之间,能有效去除湘江水中的有机物。同时还初步探讨了TOC和UV-254之间的相关性,得出UV-254=0.048 5 TOC-0.073 8。