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基于RuO2-IrO2/Ti形稳电极和Fe0牺牲电极实现电氧化-电絮凝(EO-EC)一体化处理含Tl (I)废水,并与单一的电絮凝(EC)进行比较,探讨了EO-EC处理含Tl废水的机理.结果表明,相较于单一EC,EO-EC (1:1)组合技术适应于宽pH (4-10)以及电流密度范围(5-20mA/cm2)下含Tl废水高效处理,且不易发生钝化;活性氯以及氧化还原电位在Tl (I)间接氧化Tl (III)过程中扮演重要角色,沉淀分析表明生成的Tl (OH)3(s)与絮体Fe (OH)3(am)共沉淀,纤铁矿位点可吸附残留Tl (I).EO-EC一体化技术可满足实际含Tl废水达标处理(<2µg/L)且具有经济可行性. 相似文献
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de Guzman NP Hendley P Gustafson DI van Wesenbeeck I Klein AJ Fuhrman JD Travis K Simmons ND Teskey WE Durham RB 《Journal of environmental quality》2005,34(3):793-803
The Acetochlor Registration Partnership (ARP) conducted a 7-yr ground water monitoring program at a total of 175 sites in seven states: Illinois, Indiana, Iowa, Kansas, Minnesota, Nebraska, and Wisconsin. While acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)-acetamide] was the primary focus, the analytical methods also quantified alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)-acetamide], atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)-acetamide], and two classes of soil degradates for acetochlor, alachlor, and metolachlor. Ground water samples were collected monthly for five years and quarterly for two additional years. All samples were analyzed for the presence of parent herbicides, and degradates were monitored during the last three years. Parent acetochlor was detected above 0.1 microg L(-1) in three or more samples at just seven sites. Alachlor and metolachlor were also rarely detected, but atrazine was detected in 36% of all samples analyzed. Even more widespread were the tertiary amide sulfonic acid (ethanesulfonic acid, ESA) degradates of acetochlor, alachlor, and metolachlor, which were detected at 81, 76, and 106 sites, respectively. The other class of monitored soil degradates (oxanilic acid, OXA) was detected less frequently, at 26, 16, and 63 sites for acetochlor OXA, alachlor OXA, and metolachlor OXA, respectively. The geographic distribution of detections did not follow the pattern originally expected when the study began. Rather than being a function primarily of soil texture, the detection of these herbicides in shallow ground water was related to site-specific factors associated with local topography, the occurrence of surface water drainage features, irrigation practices, and the vertical positioning of the well screen. 相似文献
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海外耕地保护的社会化扶持对策及其启示 总被引:2,自引:0,他引:2
由于耕地为公众提供了大量的、具有强烈外部性的非生产性功能,很多国家都把耕地保护作为一个公共目标,并通过社会化扶持手段来得到实施.中国作为一个人多地少,人均耕地占有量低的国家,耕地保护任务更加突出,虽然"切实保护耕地"成为我国的一个基本国策,提出要执行"世界上最严格的耕地保护",并制定了耕地总量动态平衡、土地用途管制等一系列耕地保护政策,但耕地保护整体效果却不窖乐观,其中一个原因就是没有形成全社会共同保护耕地的氛围.本文对当今世界耕地保护社会化扶持的政策依据及实践手段进行综合与分析,并结合我国耕地保护的形势,提出了我国耕地保护社会化扶持的一系列对策措施,包括加快耕地产权制度建设,明确耕地保护的责任主体;重视耕地的非生产功能,提高全社会的耕地保护意识;采用综合优惠措施,激励农户的耕地保护行为;完善城镇发展规划,严格控制城镇对耕地的侵占;延长农产晶产业链,增加农业产业的经济收入. 相似文献
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为了探明红树林湿地表层沉积物环境因子对多环芳烃分布的影响,野外采集了汕头红树林湿地表层沉积物样品,实验室内有机溶剂提取、氧化铝硅胶柱净化和气质联用分析了沉积物多环芳烃的质量分数、CHN元素仪分析了沉积物有机碳和黑碳的质量分数、激光粒度仪分析了沉积物的粒级组成,研究了沉积物有机碳、黑碳和粒度等各环境因子与多环芳烃的相关性.结果表明:有机碳与2~3环、4环和总多环芳烃的质量分数显著相关(P<0.05),表明表层沉积物有机碳的质量分数对PAHs的分布产生了显著的影响;黑碳与2~3环、4环、5~6环和总多环芳烃的质量分数显著相关(P<0.01),表明表层沉积物黑碳的质量分数对PAHs的分布产生了显著的影响;粘粒与2~3环多环芳烃的质量分数显著相关(P<0.05),与4环、5~6环和总多环芳烃的质量分数显著相关(P<0.01),表明表层沉积物粘粒的质量分数对PAHs的分布也产生了显著的影响;多元线性逐步回归分析显示,各回归方程黑碳的偏回归系数值都是最大,沉积物黑碳的质量分数对多环芳烃的质量分数贡献最大,表明黑碳是多环芳烃分布的主要影响因素. 相似文献
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进行了氨法脱碳过程中吸收剂中CO2负载量对CO2脱除率影响的实验研究.结果发现,CO2脱除率随着负载量的增大而显著减小,高负载量(≥0.4)时,增加吸收液中总氨质量分数(吸收液中所有包含氨分子和铵离子的物质,并统一换算成NH3的质量分数)并不能有效地提高CO2的脱除率.同时,分别对有机和无机添加剂进行筛选,选取哌嗪(PZ)和十二水磷酸钠(Na3PO4·12H2O)对吸收剂中高CO2负载鼍条件下的氨水溶液进行改性.实验结果表明,当哌嗪(PZ)浓度与总氨浓度之比为0.08,在吸收荆中CO2负载量为0.4、0.5和0.6的条件下,CO2脱除率可分别提高29.4%、31.0%和21.7%;当Na3PO4·12H2O浓度与总氨浓度之比为0.10,在吸收剂中CO2负载量为0.4、0.5和0.6的条件下,CO2脱除率可分别提高11.0%、11.7%和17.1%. 相似文献
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