Simultaneous removal of chromium and arsenate from contaminated groundwater by ferrous sulfate: Batch uptake behavior

Chromium and/or arsenate removal by Fe(II) as a function of pH, Fe(II) dosage and initial Cr(VI)/As(V) ratio were examined in batch tests. The presence of arsenate reduced the removal e ciency of chromium by Fe(II), while the presence of chromate significantly increased the removal e ciency of arsenate by Fe(II) at pH 6–8. In the absence of arsenate, chromium removal by Fe(II) increased to a maximum with increasing pH from 4 to 7 and then decreased with a further increase in pH. The increment in Fe(II) dosage resulted in an improvement in chromium removal and the improvement was more remarkable under alkaline conditions than that under acidic conditions. Chromium removal by Fe(II) was reduced to a larger extent under neutral and alkaline conditions than that under acidic conditions due to the presence of 10 mol/L arsenate. The presence of 20 mol/L arsenate slightly improved chromium removal by Fe(II) at pH 3.9–5.8, but had detrimental e ects at pH 6.7–9.8. Arsenate removal was improved significantly at pH 4–9 due to the presence of 10 mol/L chromate at Fe(II) dosages of 20–60 mol/L. Elevating the chromate concentration from 10 to 20 mol/L resulted in a further improvement in arsenate removal at pH 4.0–4.6 when Fe(II) was dosed at 30–60 mol/L.     

Behavior toxicity to Caenorhabditis elegans transferred to the progeny after exposure to sulfamethoxazole at environmentally relevant concentrations

Sulfamethoxazole (SMX) is one of the most common detected antibiotics in the environment. In order to study whether SMX can a ect behavior and growth and whether these e ects could be transferred to the progeny, Caenorhabditis elegans was exposed at environmentally relevant concentrations for 24, 48, 72 and 96 hr, respectively. After exposure, the exposed parent generation (P0) was measured for behavior and growth indicators, which were presented as percentage of controls (POC). Then their corresponding unexposed progeny (F1) was separated and measured for the same indicators. The lowest POC for P0 after 96 hr-exposure at 100 mg/L were 37.8%, 12.7%, 45.8% and 70.1% for body bending frequency (BBF), reversal movement (RM), Omega turns (OT) and body length (BL), respectively. And F1 su ered defects with the lowest POC as 55.8%, 24.1%, 48.5% and 60.7% for BBF, RM, OT and BL, respectively. Defects in both P0 and F1 showed a time- and concentration-dependent fashion and behavior indicators showed better sensitivity than growth indicator. The observed e ects on F1 demonstrated the transferable properties of SMX. Defects of SMX at environmental concentrations suggested that it is necessary to perform further systematical studies on its ecological risk in actual conditions.     

污染背后的思考

本期话题:继紫金矿业之后,A股市场再爆污染门。2010年10月21日,中金岭南早盘紧急停牌,这已是其上市以来发生的第二次污染事件,污染源来自公司旗下最大的铅锌冶炼厂--韶关冶炼厂,该厂当日已被广东省政府紧急关停。由于冶炼环节会产生众多的污染源,铅锌行业被看作是重污染行业,而韶关冶炼厂早在2005年就曾发生过镉排放污染事件。有意思的是,在中金岭南2009年年报中可以发现,韶关冶炼厂被评为全国有色冶炼企业"环境优美工厂"、"全国环境保护先进单位"和韶关市"环保明星企业",但这些荣誉都没能阻止韶关冶炼厂再度发生污染事件。——《每日经济新闻》     

福州大学生环境公众参与意愿调查研究——以福州大学城部分高校为例

环境公众参与意愿调查研究是公众环境教育的重要组成部分之一,本文针对福州大学城部分在校大学生的环境知识、意识及行为进行问卷调查,分析得出福州大学生环境公众参与意愿的程度,从而进一步探索如何使大学生环境意识真正内化为自觉环境保护行动,为提高大学生在环境保护公众参与方面提出有意义的对策和建议。     

城市环境规划的公定力

行政行为的公定力是行政行为作为国家机关公法行为的内在属性,城市环境规定作为环境规划部门的一种行政行为,当然应该具有公定力。文章重点分析了城市环境规划公定力存在的社会基础:规划瑕疵的不可避免性、规划纠纷的客观必然性和纠纷解决的非合意性;理论基础:"秩序需求说"和城市环境规划公定力对规划相对人、对规划主体及其他行政机关和其他社会组织及公民个人的要求。     

考虑视野范围模糊性的从众疏散模型

为了提高疏散模拟的真实性,针对行人视野范围模糊性的特点,应用膨胀-连通域算法建立一种视野范围动态变化模型,分析不同人员数量、熟悉环境人数占比下从众行为对疏散时间的影响。结果表明：从众行为对疏散时间的影响具有两面性。人数较少情况下,从众行为可减少行人随机移动,减少疏散时间;人数较多但熟悉环境行人占比较少时,盲目从众容易导致行人受群体错误方向影响偏离出口,增加疏散时间。视野范围动态变化模型较固定值模型的从众群体现象特征更明显。     

突发事故情境中内隐记忆驱动的应急决策行为特性分析

为探究突发事故情境中认知心理对应急决策的影响,提高个体应急处置能力,采用认知心理学中加工分离范式,设计再认试验来量化内隐记忆水平。开展应急决策行为模拟试验,测试应急决策的反应时间和行为选择,并通过反应时和准确率来评价其应急决策能力,进一步对比不同内隐记忆水平当事人应急决策行为结果差异,分析内隐记忆驱动下应急决策行为的过程特性及自动化产生机制。结果表明：内隐记忆能够对应急决策的信息感知、认知加工和行为选择过程产生影响;相较于内隐记忆较低的被试群体,内隐记忆较高的被试应急反应速度更快,应急行为选择的准确性更高;当事人在危险感知的启动阶段,通过无意识提取相关记忆,能够快速响应;在认知加工阶段,消耗较少的注意资源,表现出一定程度的自动化行为特征,减少自我损耗,从而增强应急决策情绪状态的稳定性,减少冒险行为。     

大学生校内交通安全素养调查研究

为了解校园安全现状,基于计划行为理论提出校内交通安全素养模型,对大学生校内出行基本信息、态度、主观规范以及知觉行为控制等方面进行问卷调查。结果表明：校内出行方式以步行与自行车为主,路程在10 min以内和10～30 min占比较高;79.97%学生认为校内比校外安全,学生在校内道路倾向于做出不安全行为,导致道路安全性降低;态度、主观规范与知觉行为控制呈显著相关(p<0.01);计划行为理论可用于校内学生交通安全研究。     

隧道彩色路面和侧墙设计对驾驶行为的影响分析

为探究不同隧道环境设计下驾驶绩效以及驾驶员的生、心理变化特性,采用3D Max软件搭建仿真试验场景,选取15名驾驶员开展不同隧道环境设计场景下的驾驶模拟试验,采集驾驶员的生、心理及车辆运行状态数据;选取具有代表性的车辆运行指标和驾驶员状态指标,构建驾驶行为趋势面模型,分析指标之间的相对敏感程度。研究结果表明：路面铺设彩色路面可提示驾驶员适当减速,其中,黄色系渐变彩色路面和纵向减速标线彩色路面的综合效果更佳,更利于安全行车;隧道内设置装饰侧墙可缓解隧道内驾驶员视觉信息单调的现象,考虑到隧道内行车安全和通行效率,建议采用蓝-白装饰侧墙。     

煤炭企业差序格局下员工安全行为路径研究*

为促进煤炭企业员工安全行为,减少生产安全事故,基于差序格局理论、资源保存理论和自我决定理论,构建差序式领导、组织认同、安全动机和员工安全行为的链式中介模型。通过路径检验和Bootstrap方法,对367名煤炭企业基层员工的有效问卷数据进行统计分析,探讨激发员工安全行为的有效路径。研究结果表明:煤炭企业中的差序式领导可正向影响员工安全遵从行为和安全参与行为,且对安全参与行为的促进作用更强;组织认同和安全动机在差序式领导与员工安全遵从行为、安全参与行为的关系中存在独立中介和链式中介作用,且相较于组织认同,安全动机的独立中介作用更强。研究结果可为建立合理的差序标准、采取适度偏私手段提供参考。