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871.
纳米TiO2/EP光催化降解罗丹明B废水的研究 总被引:2,自引:1,他引:2
通过溶胶-凝胶法制备出可漂浮于水面的膨胀珍珠岩(EP)负载型TiO2,研究其在水中对罗丹明B(RB)的去除效果、吸附降解动力学以及最佳工艺条件,并研究其多次回收再生后的降解效果。结果表明,浸渍3次的负载型TiO2光催化活性最高,回收5次后活性变化很小,降解率下降不到8%;光催化剂用量为0.2 g,20 mL初始浓度为10 mg/L和15mg/L RB溶液光照6 h后降解率分别达98%和74%。在实验浓度范围内,该光催化反应可用一级反应动力学方程描述。 相似文献
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利用湿生铬超富集植物李氏禾构建的三段式波形潜流式人工湿地,研究了湿地系统对Cr(Ⅵ)污染水体的净化效果。结果显示,李氏禾湿地系统对Cr(Ⅵ)污染水体的净化效果明显好于无植物的对照。当进水Cr(Ⅵ)浓度为2.50mg/L时,李氏禾湿地系统出水Cr(Ⅵ)浓度显著低于对照,说明李氏禾在湿地系统净化Cr(Ⅵ)污染水体中发挥了重要的作用。当进水Cr(Ⅵ)浓度超标150倍(7.50mg/L)时,李氏禾湿地系统出水Cr(Ⅵ)浓度仍可达到国家地表水环境质量标准(0.05mg/L),表明李氏禾湿地系统具有很强的Cr(Ⅵ)污染净化能力。沿程Cr(Ⅵ)浓度的变化显示,湿地系统对Cr(Ⅵ)的去除效率随水流方向逐渐降低,Cr(Ⅵ)主要在湿地系统的前两个阶段被去除。 相似文献
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以彩叶草(ColeusblumeiBenth.)为材料,用营养液培养方法,研究了不同浓度硒(se)处理对浓度为1.0mmol·L-1Pb2+胁迫下彩叶草根、叶的形貌变化及其组分形态等变化,从光谱学角度初步探讨了硒对重金属铅毒害的缓解机制。结果表明:铅胁迫下的彩叶草根系c、K、ca含量减少,O、Mg、Al、Si、Fe、Pb含量增加,叶片中的C、Mg、Al、si、K、Ca、Fe含量减少,O、Cl含量增加。铅胁迫下硒处理的彩叶草根元素种类及其元素含量均发生了明显变化;根中晶体情况及其晶相也发生了相应变化。 相似文献
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杨培雷 《中国环境管理干部学院学报》2014,(5):1-4
区域贸易协定框架下的多边环境协议涉及的主要问题可以概括为RTAs的环境条款类型、制度基础与制度选择问题,RTAs环境影响评价问题,RTAs的环境合作问题,RTAs环境标准、环境法实施与争端解决机制问题以及RTAs的公众参与环境保护问题等。贸易与环境问题的结合一直具有争议性,区域贸易协定在文本上达成的环境标准与贸易的结合要得到真正的实施,后续的努力至关重要,这些努力包括环境对话与合作、环境保护资金来源、公众参与等。 相似文献
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液化天然气场站事故定量风险评价方法研究 总被引:1,自引:1,他引:1
液化天然气(LNG)具有低温、易挥发、易燃、易爆的特性,其场站安全问题凸显。研究结合某LNG汽车加注站加注枪或管道LNG溢出的可能性事故,对事故发生概率及后果进行定量分析,其中事故后果的确定采用DEGAD IS和LNGF ire3模型。文章结合相关文献提供的伤害准则数据,得出人员受伤等级和死亡率,进而确定事故造成的个人风险值。与英国、荷兰等国家和机构制定的个人风险标准进行比较,所得的个人风险大大低于标准极限值,同时表明将5kW/m2作为安全距离临界热辐射强度的合理性。 相似文献
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Jigang Xi Shijian Fu Zhendong Cao Jianglan Peng Jing Peng Tingting Dai Lili Cheng 《环境科学学报(英文版)》2013,25(8):1672-1679
The potential risks of perfluorooctane sulfonate (PFOS) are of increasing ecological concern. Swimming performance is linked to the fitness and health of fish. However, the impacts of PFOS on swimming performance remain largely unknown. We investigated the ecotoxicological effects of acute exposure to PFOS on the swimming performance and energy expenditure of juvenile goldfish (Carassius auratus). The fish were exposed to a range of PFOS concentrations (0, 0.5, 2, 8 and 32 mg/L) for 48 hr. The spontaneous swimming activity, fast-start swimming performance, critical swimming speed (Ucrit) and active metabolic rate (AMR) of the goldfish were examined after exposure to PFOS. PFOS exposure resulted in remarkable effects on spontaneous activity. Motion distance was reduced, and the proportion of motionless time increased with increasing concentrations of PFOS. However, no significant alterations in the fast-start performance-related kinematic parameters, such as latency time, maximum linear velocity, maximum linear acceleration or escape distance during the first 120 msec after stimulus, were observed after PFOS exposure. Unexpectedly, although PFOS exposure had marked influences on the swimming oxygen consumption rates and AMR of goldfish, the U crit of the goldfish was not significantly affected by PFOS. This may result in a noteworthy increase in the energetic cost of transport. The overall results indicate that, in contrast to spontaneous activity, underlying swimming capabilities are maintained in goldfish after short-term exposure to PFOS, but energy expenditure during the process of swimming is dramatically aggravated. 相似文献