城市内河蓝藻复苏和生长规律研究

主要探讨城市化对城市内河蓝藻复苏和生长的影响。这些影响包括河流中营养物的升高、高等水生植物的灭绝、河水所受光照强度的变化以及由河水滞流带来的水体复氧效率降低对内河中蓝藻爆发条件的影响。通过实验我们发现金鱼藻与水网藻的存在可以在一定程度上抑制蓝藻的生长,金鱼藻的效果比水网藻更明显。适宜的光照是蓝藻大量生长的条件。对水体进行曝气复氧可以抑制蓝藻的生长。     

Observations of atmospheric pollutants at Lhasa during 2014–2015: Pollution status and the influence of meteorological factors

Atmospheric pollutants including SO₂, NO₂, CO, O₃ and inhalable particulate matter (PM_2.5 and PM₁₀) were monitored continuously from March 2014 to February 2015 to investigate characteristics of air pollution at Lhasa, Tibetan Plateau. Species exhibited similar seasonal variations except O₃, with the peaks in winter but low valleys in summer. The maximum O₃ concentration was observed in spring, followed by summer, autumn, and winter. The positive correlation between O₃ and PM₁₀ in spring indicated similar sources of them, and was assumed to be turbulent transport. Temperature was the dominant meteorological factor for most species in spring. High temperature accelerates O₃ photochemistry, and favors air disturbance which is conductive to dust resuspension in spring. Relative humidity (RH) and atmospheric pressure were the main meteorological factors in summer. RH showed negative correlations with species, while atmospheric pressure posed opposite situation. Wind speed (WS) was the dominant meteorological factor in autumn, the negative correlations between WS and species indicated diffusion by wind. Most species showed non-significant correlations with meteorological factors in winter, indicating the dependence of pollution on source emission rather than restriction by meteorology. Pollution weather character indicated that emissions were from biomass burning and dust suspension, and meteorological factors also played an important role. Air stream injection from the stratosphere was observed during O₃ pollution period. Air parcels from Southwest Asia were observed during air pollution period in winter. An enhancement in air pollutants such as O₃ would be expected in the future, more attention should be given to countermeasures for prevention of air pollution in the future.     

基于能源碳排放预测的中国东部地区达峰策略制定

中国东部的11个省市是中国经济最发达的地区,其碳排放量约占全国碳排放量的1/2.随着气候变化的加剧和国际社会的关注,中国政府制定了区域差异化的达峰目标,因此,预测该地区碳排放对于评估中国能否实现达峰目标具有重要意义.本文基于中国东部11省市1997-2017年的面板数据,采用STIRPAT模型来预测不同情景下的碳排放趋...     

Yearly variation in characteristics and health risk of polycyclic aromatic hydrocarbons and nitro-PAHs in urban shanghai from 2010–2018

This study encompassed the regular observation of nine polycyclic aromatic hydrocarbons (PAHs) and three nitro-PAHs (NPAHs) in particulate matter (PM) in Shanghai in summer and winter from 2010 to 2018. The results showed that the mean concentrations of ?PAHs in summer decreased by 24.7% in 2013 and 18.1% in 2017 but increased by 10.2% in 2015 compared to the data in 2010. However, the mean concentrations of ?PAHs in winter decreased by 39.7% from 2010 (12.8 ± 4.55 ng/m³) to 2018 (7.72 ± 3.33 ng/m³), and the mean concentrations of 1-nitropyrene in winter decreased by 79.0% from 2010 (42.3 ± 16.1 pg/m³) to 2018 (8.90 ± 2.09 pg/m³). Correlation analysis with meteorological conditions revealed that the PAH and NPAH concentrations were both influenced by ambient temperature. The diagnostic ratios of PAHs and factor analysis showed that they were mainly affected by traffic emissions with some coal and/or biomass combustion. The ratio of 2-nitrofluoranthene to 2-nitropyrene was near 10, which indicated that the OH radical-initiated reaction was the main pathway leading to their secondary formation. Moreover, backward trajectories revealed different air mass routes in each sampling period, indicating a high possibility of source effects from the northern area in winter in addition to local and surrounding influences. Meanwhile, the mean total benzo[a]pyrene-equivalent concentrations in Shanghai in winter decreased by 50.8% from 2010 (1860 ± 645 pg/m³) to 2018 (916 ± 363 pg/m³). These results indicated the positive effects of the various policies and regulations issued by Chinese authorities.     

兴化市大气环境现状及防治对策研究

兴化市的大气环境面临着十分严峻的形势.在分析兴化市大气环境现状的基础上,总结出兴化市大气主要污染物的种类,它们主要是细颗粒物、可吸入颗粒物、二氧化氮、一氧化碳、臭氧、二氧化硫;这些大气污染源主要包括能源消耗、工业废气、机动车尾气、生活及农业废气,这些废气对环境带来了严重的干扰,并且有针对性的提出了控制大气污染的对策建议.具体措施包括优化能源结构、整治污染源、治理机动车和扬尘污染、加强秸秆禁烧工作,达到防治与综合利用的并举.     

白洋淀喹诺酮类抗生素与微生物群落结构和多样性相关性研究

微生物作为水生态系统中的重要组成部分,其对水环境的能量流动和物质循环等具有重要作用,为研究富营养化湖泊中喹诺酮类抗生素(Quinolones,QNs)对微生物群落结构和微生物多样性的影响,本研究选取白洋淀为研究区,建立了QNs与微生物群落的相关性.结果表明,已测的QNs均有不同程度检出,其中,氟甲喹(Flumequine,FLU)和恶喹草酸(Oxolinic Acid,OXO)检出率较高;就空间分布而言,水体中QNs最大值出现在采蒲台区(433.52 ng·L~(-1)),最小值出现在枣林庄和烧车淀区(20.51 ng·L~(-1));沉积物中QNs最大值出现在端村区(372.72 ng·g~(-1)),最小值出现在藻苲淀区(20.29 ng·g~(-1)).高通量测序结果表明,白洋淀沉积物微生物群落的优势种群为变形菌门和绿弯菌门,平均含量分别为38.62%和19.85%;变形菌门和绿弯菌门占所有微生物的比例在端村区最高(62.31%),藻苲淀区最低(54.62%).多样性指数分析结果表明,枣林庄和烧车淀区和藻苲淀区的微生物多样性指数(Chao1指数、Shannon指数和Simpsoneven指数)最高,而端村区最低.研究表明,受抗生素污染严重的区域通常会使微生物群落丰度下降,与本研究结果基本相符,说明微生物多样性受抗生素污染影响,对研究QNs污染的治理具有重要意义,为未来解决污染问题提供了良好的基础.     

某工矿废弃地重金属污染评价及农田复垦修复建议

以四川某废弃硫磺矿厂区域为研究区,采集78个土壤样本,测定土壤Cd、Cr、Cu、Ni含量及p H值。采用单因子污染指数、内梅罗综合污染指数评价研究区重金属污染程度,采用聚类分析解析污染来源,GIS制图呈现污染空间分布。以土壤环境质量二级标准值为参考,单因子污染指数评价结果显示,重金属样本点位超标率由高到底依次为Cd(84.6%,表层)Cu(53.9%,表层)Ni(51.3%,表层)Cr(32.3%,次表层);内梅罗综合污染指数评价结果表明研究区属于中度污染级别;聚类分析结果表明研究区重金属Cr、Cu、Ni污染来源于矿渣,Cd污染来源尚不明确;GIS制图结果表明污染程度较重的区域主要分布在研究区西南侧。本调查评价旨在为土壤污染治理方案的制定提供参考。     

广东省突发环境事件应急预案体系建设现状分析与对策

环境应急预案体系建设在落实"一案三制"中具有重要作用。本文通过总结广东省突发环境事件应急预案体系的建设情况,梳理分析政府及企业突发环境事件应急预案在工作实践过程中遇到的问题,从顶层设计、功能定位、编制方法、改进机制等方面提出意见和建议,进一步健全环境应急管理体系。     

贵州中部山区煤矸石堆场周边污染水稻土重金属的释放特征

通过对贵州中部山区煤矸石堆场周边污染的水稻土及上覆水进行调查与采样分析,探讨污染水稻土有效态重金属(Cr、Cu、Zn、As、Cd、Hg和Pb)含量的变化及其释放特征。研究结果表明:不同程度污染水稻土中Cd、As和Hg的含量及部分水稻土中的Cu含量超过了土壤环境质量二级标准,随着水稻土污染程度的增加,土壤有效态Cd的含量出现明显的增加,中度污染水稻土和重度污染水稻土有效态Cd的平均含量分别比轻度污染水稻土增加了1.30、2.60倍;在水稻生长期间(6~8月),污染稻田上覆水中均出现Cd的超标,中度污染稻田和重度污染稻田上覆水Cd的平均浓度(三次采样)分别比轻度污染稻田的上覆水高11.3%和27.3%。污染水稻土淹水1~30d期间,上覆水Cd的浓度出现不断地增加,淹水20d后中度及重度污染水稻土上覆水Cd均出现超标。因此,煤矸石堆场周边污染稻田排水的Cd会产生明显的二次污染。     

基于复杂网络理论的北京地铁网络脆弱性评估

以北京市现有地铁线网为研究对象,使用Space L方法构建拓扑网络,为更加符合实际情况,对换乘车站进行了拆分。分析中,综合考虑连通OD对和出行效率两个因素,以运输能力损失作为评估网络脆弱性指标。随后,计算分析了单节点攻击、随机攻击、静态攻击和动态攻击下造成的地铁网络运输能力损失的变化规律,得出动态攻击对地铁网络影响最大。在该攻击方式下,相对基于度的动态攻击,地铁网络对基于介数和基于ER的动态攻击,具有更高的脆弱性。同时攻击介数较大的节点对网络南北方向运输能力影响较大;攻击对出行效率影响较高的节点对网络东西方向运输能力影响较大。因此,在地铁运营过程中,应针对不同站点的节点属性和事故发生情况,采取相关防护措施。