Pollution characteristics and health risk assessment of polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons during heating season in Beijing

Polycyclic aromatic hydrocarbons(PAHs) and their nitrated derivatives(NPAHs) attract continuous attention due to their outstanding carcinogenicity and mutagenicity. In order to investigate the diurnal variations, sources, formation mechanism, and health risk assessment of them in heating season, particulate matter(PM) were collected in Beijing urban area from December 26, 2017 to January 17, 2018. PAHs and NPAHs in PM were quantitatively analyzed via gas chromatography-mass spectrometry(GC-MS). ...     

硝化作用对盐碱湿地N2O排放的影响及其环境因子分析

湿地是温室气体氧化亚氮(N_2O)重要的源或汇,盐碱湿地作为湿地的重要组成部分,研究其N_2O排放对于探究盐碱湿地N_2O产生的硝化作用机制及评估其在温室效应中的作用具有重要意义.本文对代表性盐碱湿地——扎龙芦苇沼泽湿地生长季的N_2O释放量及相关环境因子进行了研究.结果表明,生长季N_2O通量呈波动性下降趋势,最大值出现在7月中旬,平均排放通量为(37. 49±15. 75)μg·(m2·h)-1,表现为N_2O的释放"源". N_2O通量与不同深度土层温度存在显著正相关关系(P 0. 05),且上层土温对N_2O排放的影响程度高于深层土;淹水期间N_2O通量与积水深度呈显著负相关关系(P 0. 05);且土壤TOC和TN含量较低,N_2O通量与0～40 cm土层NH+4-N含量呈显著正相关关系(P 0. 05),而与NO-3-N含量没有关系,硝化作用程度要比反硝化强;此外,土壤氨氧化菌活性与0～20 cm土层温度存在极显著正相关关系(P 0. 01),且N_2O通量与氨氧化菌活性也呈极显著的线性正相关关系(P 0. 001),表明盐碱湿地的N_2O释放受硝化作用影响巨大.     

包埋反硝化填料强化二级出水深度脱氮性能研究及中试应用

利用包埋广谱性高效反硝化填料处理城市污水厂二级出水,可有效降低出水总氮(TN)浓度,本研究共分为两部分,D1阶段研究了包埋反硝化填料对污水厂二级出水的适应性、TN去除效果、稳定运行及填料反冲洗的工况条件; D2阶段研究了填料在中试条件下稳定运行1 a脱氮性能的变化,并通过高通量测序和荧光定量分析(q PCR)手段,研究对比了包埋填料运行前后微生物种群的变化规律.通过研究发现,包埋反硝化填料在水温为(24±1)℃、pH为7. 1、HRT为1 h和填充率为10%,投加乙酸钠保证碳源充足的条件下稳定运行7 d,即可适应二级出水水质,实现出水总氮5 mg·L~(-1).通过对比研究不同水力停留时间(HRT)对填料TN去除效果的影响,得出适宜的HRT为30 min,填充率为10%的运行条件,在7. 2 m~3·d~(-1)的进水条件下经过1 a的稳定运行,TN去除率最高可达到90. 42%,出水总氮可稳定在5 mg·L~(-1)以下.通过对比反冲洗效果,确定了反冲洗强度为5. 2 L·(m~2·s)~(-1),周期为每3 d进行一次.高通量测序和荧光实时定量PCR分析结果表明,运行前后填料上反硝化功能菌属的丰度及拷贝数都有了明显增长,这说明细菌在包埋条件下可实现良好的自我生长.     

抚河南昌段重金属空间分布特征及来源分析

为分析抚河南昌段流域水体中重金属空间分布特征及可能来源,2019年08月在抚河南昌段共采集了23个地表水样及8个地下水样,对水体中的重金属V、Mn、Ba、Fe、Sr、Zn及类金属元素As进行了测定.结果表明,水体中不同重金属空间分布特征总体趋势一致,即中下游地区高于上游地区,污染特征空间差异性为中等及以上.地表水中V、Fe、Mn的平均浓度超过《地表水环境质量标准》（GB3838-2002）集中式生活饮用水特定项目标准限值;地下水中类金属元素As平均浓度超过《地下水质量标准》（GBT14848-2017）Ⅲ类水质标准.多元统计分析表明Sr、Ba、Mn可能主要来源于人类生产、生活污染物的排放,Fe、V、Zn可能主要来源于农业渔业及交通污染,类金属元素As主要来源于沿岸及河流底部淤泥及岩石碎屑.     

尿素废水生物处理技术原理与工艺研究进展

尿素废水的处理是当前亟需解决的难题,其中生物处理法因具有工艺流程短,成本低,抗冲击负荷,不产生二次污染等优点,在尿素废水的处理中备受青睐.本文基于尿素生物水解法原理,从机理上深入分析了脲酶的发展历程,酶学结构与水解机制,并对传统生物尿素脱氮法的应用进行了系统梳理.此外,为了更好地理解厌氧氨氧化菌降解尿素的潜能及在实际工程中的应用,本文分别从微生物学和工程应用的角度总结了相关研究结果.最后提出了尿素废水生物处理研究的建议与展望,以期为实际工程应用提供有力的理论基础和技术支持.     

A large-scale outdoor atmospheric simulation smog chamber for studying atmospheric photochemical processes: Characterization and preliminary application

Understanding the formation mechanisms of secondary air pollution is very important for the formulation of air pollution control countermeasures in China. Thus, a large-scale outdoor atmospheric simulation smog chamber was constructed at Chinese Research Academy of Environmental Sciences (the CRAES Chamber), which was designed for simulating the atmospheric photochemical processes under the conditions close to the real atmospheric environment. The chamber consisted of a 56-m³ fluorinated ethylene propylene (FEP) Teflon film reactor, an electrically-driven stainless steel alloy shield, an auxiliary system, and multiple detection instrumentations. By performing a series of characterization experiments, we obtained basic parameters of the CRAES chamber, such as the mixing ability, the background reactivity, and the wall loss rates of gaseous compounds (propene, NO, NO₂, ozone) and aerosols (ammonium sulfate). Oxidation experiments were also performed to study the formation of ozone and secondary organic aerosol (SOA), including α-pinene ozonolysis, propene and 1,3,5-trimethylbenzene photooxidation. Temperature and seed effects on the vapor wall loss and SOA yields were obtained in this work: higher temperature and the presence of seed could reduce the vapor wall loss; SOA yield was found to depend inversely on temperature, and the presence of seed could increase SOA yield. The seed was suggested to be used in the chamber to reduce the interaction between the gas phase and chamber walls. The results above showed that the CRAES chamber was reliable and could meet the demands for investigating tropospheric chemistry.     

承包商安全管理关键人员安全素质能力的提升

以某超大型石油化工集团S下属的油田、炼化、销售等板块企业为试点,研究包括甲方(建设单位)、乙方(承包商、监理)的承包商管理关键岗位人员安全素质管理能力,旨在发现承包商安全管理存在的问题,从而研讨承包商安全管理关键环节的对策,提升相关人员安全素质能力,降低承包商安全事故。     

倡导清洁生产创建绿色作业

文章通过对创建绿色作业队的认识与实践,提出:创建绿色作业必须依靠科技转变方式;整体规划,典型带动;持续改进,重点落实。从而形成创建绿色作业的长效机制。