邯郸市冬季大气PM2.5中金属元素空间污染特征及生态风险评价

为研究邯郸市大气细颗粒物(PM_(2.5))中金属元素的污染特征,选取城区4个功能区(工业区、工业生活区、教学区和交通区)分别布设采样点位,采集2017年冬季PM_(2.5)样品。采用电感耦合等离子体质谱仪分析样品中11种金属元素(V、Cr、Mn、Fe、Ni、Co、Cu、As、Cd、Ba和Bi)的含量,对其空间污染特征进行比较,并运用主成分分析、聚类分析和绝对主成分得分-多元线性回归模型对金属元素的来源及其贡献率进行模拟计算,对Cr、Ni、Cu、As和Cd的潜在生态风险进行评估。研究结果表明,邯郸市冬季PM_(2.5)污染较为严重,4个功能区的PM_(2.5)日均值远超《环境空气质量标准》(GB 3095—2012)二级标准限值。对金属元素含量的分析表明,教学区大气PM_(2.5)中金属元素质量浓度的总和相对较低,尤其是Fe、Cr、Cd、Mn和Cu的含量均低于其他3个功能区,但是As的含量较高。富集因子计算结果显示,V、Co和Ba在邯郸市的富集系数小、污染程度低,其余金属元素尤其是As、Fe、Cd和Bi的富集系数大、污染程度高。对研究区大气PM_(2.5)金属元素的来源进行解析发现,金属元素的主要来源包括工业生产、自然源、化石燃料的燃烧及交通运输活动。其中,Cr、Mn、Fe、Cu、Cd和Ba主要来自工业活动,V、Co和Bi的主要来源是自然源,Ni和As主要来自化石燃料的燃烧及交通运输活动。潜在生态风险评估发现,邯郸市4个功能区金属元素的总生态风险指数均较高,尤其是As和Cd在各个功能区的潜在生态风险程度为极强,但Cr和Ni的潜在生态风险程度较低。     

人工模拟降雨条件下黄土坡面水-沙-氮磷流失特征

黄土坡沟水沙及养分流失严重,不仅造成土地生产力下降,对水环境也存在潜在威胁.为探索黄绵土坡面水沙氮磷流失相关关系,采用人工模拟降雨试验,研究不同雨强（45、60、75、90、105、120 mm/h）、不同坡度（5°、10°、15°、20°、25°）下黄土裸地水沙氮磷的流失规律.结果表明:①产流量可用坡度的二次多项式表达,确定系数（R2）达0.83以上,产沙量随雨强变化规律不明显,但随坡度增加呈显著增加趋势.②各雨强下,25°与5°坡面的ρ（TN）比值范围为1.63~5.42,波动较大,而ρ（TP）随坡度的增加基本呈增加趋势,但整体数值低于ρ（TN）.③各雨强下ρ（吸附态氮）随降雨历时的延长呈剧烈起伏变化;大雨强（105和120 mm/h）下ρ（吸附态磷）随降雨历时的延长逐渐减少至稳定值,其他雨强下ρ（吸附态磷）随降雨历时的延长呈现波动增加.各雨强与坡度下,ρ（吸附态氮）与ρ（吸附态磷）分别占ρ（TN）、ρ（TP）的60.66%、96.62%,是黄土裸坡氮磷的主要流失形式.④随水沙流失的氮磷中,TN占主要部分,其流失量是TP流失量的1.43~22.46倍,径流量增加时TN流失量显著增加,而产沙量增加时TP流失量显著增加.研究显示,雨强和坡度变化对水沙氮磷流失影响各异,吸附态氮磷是黄土养分流失的主要途径,可为黄土坡耕地水土流失治理提供科学依据.      

绿色低碳会计思维在环境污染控制中的优化作用研究

在环境污染治理项目中,通过会计公允价值的优化建模分析,结合环境污染治理项目的会计核算的描述性统计量分析,实现绿色低碳的会计核算,提高环境污染治理水平,提出基于二元逐步回归分析的环境污染治理项目会计核算模型,分析环境污染治理的会计相关性变量,采用拟线性统计分析方法进行会计公允价值定量分析,结合环境污染治理的支付水平和质量效益水平进行均衡博弈控制,实现绿色低碳会计成本核算。实证数据分析结果表明,回归分析的可靠性较好,促进了环保治理成本优化分配。     

Role of water on the H-abstraction from methanol by ClO

The influence of a single water molecule on the reaction mechanism and kinetics of hydrogen abstraction from methanol(CH_3OH) by the ClO radical has been investigated using ab initio calculations. The reaction proceeds through two channels: abstraction of the hydroxyl H-atom and methyl H-atom of CH_3OH by ClO, leading to the formation of CH_3O + HOCl(+H_2O) and CH_2OH + HOCl(+H_2O), respectively. In both cases, pre-and post-reactive complexes were located at the entrance and exit channel on the potential energy surfaces. Results indicate that the formation of CH_2OH + HOCl(+H_2O) is predominant over the formation of CH_3O + HOCl(+H_2O),with ambient rate constants of 3.07 × 10-19 and 3.01 × 10~(-23) cm~3/(molecule·sec), respectively, for the reaction without water. Over the temperature range 216.7–298.2K, the presence of water is seen to effectively lower the rate constants for the most favorable pathways by 4–6 orders of magnitude in both cases. It is therefore concluded that water plays an inhibitive role on the CH_3OH + ClO reaction under tropospheric conditions.     

水库网箱养鱼富营养化生态修复模式研究——以青狮潭水库为例

为有效控制青狮潭水库富营养化的发展,确保库区及饮用水源保护区水质达标,结合库区水质现状及网箱养鱼对富营养化成因分析,本文提出青狮潭水库网箱养鱼富营养化生态修复模式。根据青狮潭水库水环境容量及水域的地理特点,对库区水域进行分类管理,划分网箱养鱼禁止区和控制区,并对出现富营养化的水域进行水生生态修复,为青狮潭水库水环境管理和决策提供科学依据。     

Removal characteristics and kinetic analysis of an aerobic vapor-phase bioreactor for hydrophobic alpha-pinene

Biofiltration is considered an effective method to control volatile organic compounds (VOCs) pollution. This study was conducted to evaluate the potential use of a bacterial biofilter packed with wood chips and peat for the removal of hydrophobic α-pinene. When inoculated with two pure degraders and adapted activated sludge, a removal efficiency (RE) of more than 95% was achieved after a start-up period of 11 days. The maximum elimination capacity (EC) of 50 g/(m³. hr) with RE of 94% was obtained at empty bed retention time (EBRT) of 102 sec. When higher α-pinene concentrations and shorter EBRTs were applied, the REs and ECs decreased significantly due to mass-transfer and biological reaction limitations. As deduced from the experimental results, approximately 74% of α-pinene were completely mineralized by the consortiums and the biomass yield was 0.60 g biomass/g α-pinene. Sequence analysis of the selected bands excised from denaturing gradient gel electrophoresis revealed that the inoculated pure cultures could be present during the whole operation, and others were closely related to bacteria being able to degrade hydrocarbons. The kinetic results demonstrated that the whole biofiltration for α-pinene was diffusion-limit controlled owing to its hydrophobic characteristics. These findings indicated that this bacterial biofiltration is a promising technology for the remediation of hydrophobic industrial waste gases containing α-pinene.     

Distribution and sources of solvent extractable organic compounds in PM2:5 during 2007 Chinese Spring Festival in Beijing

The solvent extractable organic compounds (SEOC), including n-alkanes, polycylic aromatic hydrocarbons, fatty acids, anddicarboxylic acids in PM2.5 during the 2007 Chinese Spring Festival in Beijing, were measured via gas chromatography-massspectrometry for determining the characteristics and sources of these organic pollutants. The concentrations of total n-alkanes, PAHs,and organic acids before Chinese Spring Festival Eve (1025.5, 95.9, and 543.3 ng/m3, respectively) were higher than those after (536.6,58...     

重庆燃煤电厂烟气脱硫石膏综合利用前景分析

随着重庆市烟气脱硫工程的推进,必将产生大量的烟气脱硫副产物——脱硫石膏,这些脱硫石膏如不加以处置,不仅占用大量土地,还可能给环境带来二次污染,处置和利用好脱硫石膏,对重庆市的环境尤其是生态环境保护有着重要意义,而且具有良好的经济效益和社会效益。首先阐述了重庆燃煤电厂脱硫石膏的产生、特性及国内外综合利用现状。结合重庆市实际情况,对脱硫石膏在建筑建材业、农业等领域的应用前景进行了分析,并提出了脱硫石膏综合利用的建议。     

基于响应面法的流化床生物膜反应器运行条件优化

采用自主设计的流化床生物膜反应器(FBBR)处理城市生活污水,主要研究了不同构型填料、填充率和不同进水C/N比下反应器的启动效能,采用响应面法对稳定运行期的有机负荷、曝气量、水力停留时间进行优化,并分析了不同阶段的微生物群落特征.结果表明,启动期间,填充率为40％时,MFD填料上生物量较多,挂膜时间较短,最大生物量为6...