Investigation of the effects of humic acid and H2O2 on the photocatalytic degradation of atrazine assisted by microwave

A solution of atrazine in a TiO₂ suspension, an endocrine disruptor in natural water, was tentatively treated by microwave-assisted photocatalytic technique. The effects of mannitol, oxygen, humic acid, and hydrogen dioxide on the photodegradation rate were explored. The results could be deduced as follows: the photocatalytic degradation of atrazine fits the pseudo-first-order kinetic well with k = 0.0328 s⁻¹, and ·OH was identified as the dominant reactant. Photodegradation of atrazine was hindered in the presence of humic acid, and the retardation effect increased as the concentration of humic acid increased. H₂O₂ displayed a significant negative influence on atrazine photocatalysis efficiency. Based on intermediates identified with gas chromatography-mass spectrometry (GC-MS) and Liquid chromatography-mass spectrometry (LC-MS/MS) techniques, the main degradation routes of atrazine are proposed.     

Phytoplankton community from Lake Taihu, China, has dissimilar responses to inorganic and organic nutrients

To evaluate the response of phytoplankton from Lake Taihu to di erent types of nutrients, the phytoplankton responses were measured after adding inorganic nitrogen (N) and phosphorus (P) or decomposed algal scum (Microcystis spp.) into the lake water. Both types of nutrients promoted an increase in phytoplankton biomass as determined by chlorophyll a and algal wet weight. The addition of decomposed algal scum resulted in a significantly greater phytoplankton response than the addition of inorganic N and P alone. The dissolved inorganic N and P in the inorganic nutrient treatment were found not limit phytoplankton growth. The higher algal biomass obtained in the treatment with decomposed algal scum indicated the importance of other organic nutrients besides N and P such as trace elements, as well as the importance of the form of N since the levels of ammonia nitrogen (NH4 +-N) from the decomposed algal treatment were actually higher than that of the inorganic N and P addition. Microcystis spp. (Cyanobacteria), Scenedesmus spp. (Chlorophyta) and Synechocystis spp. (Cyanobacteria) were the dominant taxa in the control, inorganic N and P treatment, and the decomposed algal scum treatment, respectively. Microcystis never bloomed in response to both types of nutrient additions indicating that the bloom propagation is not solely related to nutrient additions, but may be related to the absence of selective grazing from zooplankton.     

太阳能热水器的安全隐患及防范措施

针对屋顶太阳能热水器的安全隐患、产生原因进行了分析,提出相应的防护措施,避免设备、人员受到危害。     

陆上油气田钻井作业HSE视频教材开发

陆上石油天然气钻井是一个多工种、多工序、立体交叉、连续作业的系统工程。在钻井施工的各个阶段和各个环节中,特殊作业繁多,安令管理难度大,事故发生率相对较高,存在着不同程度、形式各异的风险,是石油行业中的一个高危作业。其中最易发生的事故有：机械伤害、物体打击、起重伤害、高处坠落、触电、中毒等人身伤害事故,特别是一旦发生井喷失控和火灾爆炸事故,将严重危及人民群众的生命安全．     

珠江口和大鹏湾海豚体内石油烃含量

为了积累海豚污染基础资料,保护海洋濒危动物,本文用荧光分光光度法测定了珠江口及其附近海域5头海豚(3个种)体内的总石油烃(TPHs)含量。结果表明,不同组织中TPHs含量与脂肪多少显著正相关(r=0.746~0.989,P0.02),在腹部皮肤和额隆中占优势,在肝脏、心脏、肾脏、肌肉中比在肺、肠和胃组织中略高。海豚TPHs含量为鱼类、虾类的2.2~3.2倍,海豚脂肪可将海水中的石油烃浓缩103~104倍。     

质量控制档案在环境监测日常工作中的作用探讨

随着环境监测机构实验室认可这项工作的深入开展,作为质量管理体系文件化直接产物的质量档案工作被推向了质量管理体系运行和认证的前沿,结合实验室资质评审工作,阐述了环境监测机构建立与管理质量控制档案的重要性：介绍了环境监测机构质量控制档案收集的内容和范围;论述了质量控制档案在环境监测机构质量体系运行、实验室认可、实验室内质量考核、实验室分析工作中的重要作用。     

Ag/TiO_2对邻硝基氯苯废水的催化氧化降解

以自制的Ag/TiO2为催化剂,过碳酸钠(SPC)作氧化剂催化氧化降解邻硝基氯苯(oCNB),考察了催化剂种类、催化剂用量、SPC用量、底物浓度、反应温度及添加无机盐对降解反应的影响。实验结果表明:当催化剂用量1.57×10-6mol、底物浓度6.35×10-4mol/L、SPC用量3.18×10-3mol、温度40℃时,降解率可达到约94%。添加碱金属与碱土金属的卤化物对反应有促进作用,降解率可达99%,因此,利用本方法可以有效降解废水中的邻硝基氯苯。根据实验结果对过碳酸钠氧化邻硝基氯苯的机理进行了推测。     

全球汞污染回顾与分析

回顾全球所经历的主要汞污染事件,引述国外科研工作者对全球汞污染与汞排放的调查和研究成果,重点介绍金矿开采对环境的污染与危害,揭示造成亚马逊流域汞污染的深层根源。分析今后全球防止汞污染的主要措施：一是主要工业化国家将进一步研究和改善工业领域相关行业的工艺技术水平,趋向无汞产品和无汞工艺,以减少自身的汞污染与排放;其二,发达国家陆续立法禁止汞的自由贸易和出口。发达国家对汞的出口限制将促使发展中国家相关行业（特别是小金矿）采取汞的替代工艺,从而减少全球性汞污染与排放。     

海洋生态文明视角下的厦门海岸带综合管理初探

海洋是人类生存和发展的重要空间,人类的发展将越来越多地依赖海洋资源。然而由于人类无节制地开发海岸、海洋资源和无管制的经济行为,海岸和海洋的生态功能在过去的几十年里遭到了严重的威胁。因此构建海洋生态文明,以海洋生态环境的良性循环促进海洋经济发展,最终保证海洋经济与生态环境和谐发展将具有十分突出的战略意义。文章从海洋生态文明的视角回顾分析了厦门海岸带综合管理十多年的成效,并在此基础上探讨了改善厦门海岸带综合管理促进厦门海洋生态文明建设的几点设想。     

某工业区近十年酸雨污染特征简析

根据某工业区1998年-2007年的降水监测资料,利用统计方法对该地区的酸雨污染变化规律、化学组成进行分析,结果表明：该工业区近十年来酸雨频率逐年上升,酸雨污染日趋严重,目前已成为重酸雨区;化学组成的分析表明该工业区的酸雨逐步由硫酸型转化为硫酸型和硝酸型并重;该工业区降水酸度与Cl^-、NO3^-、SO4^2-的灰色关联度最大,说明该工业区受海洋、交通以及工业排放的影响较大,海洋源、交通源、工业源对该工业区降水的酸度有重要影响。