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氢化物发生一原子荧光光谱法测定气田废水中的痕量砷 总被引:2,自引:0,他引:2
采用氢化物发生-原子荧光光谱法测气田废水中的痕量砷。方法有取样量少,操作简单、灵敏度高、准确度高、重现性好等优点。砷的测定线性范围为1~200ng/mL,方法的检出限为0.0453ng/mL,相对标准偏差小于等于1.6%,加标回收率在96.0%~97.7%范围内。测定密码标样与气田废水中的痕量砷,获得了满意的结果。 相似文献
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以4年生蒙古栎(Quercus mongolica) 幼树为实验材料,分别于2007,2008年6~9月采用开顶箱法,研究了高浓度CO2和O3及复合作用对蒙古栎叶片光合量变化和生长的影响.结果表明,高浓度O3处理下蒙古栎叶片日光合总量降低, 单叶鲜重、干重和单叶面积均有所下降,对蒙古栎叶片生长产生抑制.高浓度CO2处理下,蒙古栎叶片干、鲜重和单叶面积均高于对照,其中2007年差异显著,日光合总量总体高于对照.2种气体复合作用处理下,蒙古栎日光合总量、单叶鲜重、单叶干重、单叶面积均低于对照,且高于O3单独处理,说明高浓度CO2可以通过减缓O3对植物光合的抑制,进而减少O3伤害,缓解生长抑制. 相似文献
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北京农业循环经济发展评价研究 总被引:11,自引:0,他引:11
借鉴行为-压力-效果-冲击-反应(BPEIR)概念模型及特尔菲法构建区域农业循环经济发展评价指标体系,并通过层次分析法,对1991年至2005年北京市农业循环经济发展水平进行综合评价。分析结果表明:从1991年-2005年北京市农业循环经济在总体上呈上升趋势,年均增长速度为2.44%。其障碍因素呈现出从90年初期的社会经济因素和资源循环利用为主,90年后期资源减量投入为主,而到21世纪主要以资源减量投入、资源循环利用和资源环境安全为主的变化趋势。根据评价结果,为提高北京市农业循环经济发展水平,提出相关建议。 相似文献
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渤海近岸海域污染已是约环渤海地区社会经济的发展。本文对配合天津市主要污染物总量控制,对天津市陆源主要污染物允许排海量的功能区划原则,水环境主要污染物,总量,主要污染物允许排海量的数学模型,陆源主要污染物允许排海量的计算依据等进行了阐述,同时对主要排污口主要污染物允许排海量及其消减量进行了计算。 相似文献
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广东省典型电子工业企业挥发性有机物排放特征研究 总被引:10,自引:4,他引:10
针对广东省电子工业进行调研与监测,分别选取了手机、相机及笔记本电脑3类典型产品的代表性企业为研究对象,利用活性炭管采样,样品经溶剂解吸后采用GC/MS分析,获得了排气筒及车间废气的VOCs含量水平及组分特征,并利用监测计算法、排放因子法及物料衡算法3种方式计算了各企业的VOCs排放量.结果表明:喷涂车间VOCs浓度范围为43.01~322.34 mg·m~(-3),调漆、供漆车间VOCs浓度范围为103~172.714 mg·m~(-3);车间中VOCs物种为8~10种,不同产品类型VOCs物种不同,但含氧VOCs的比例均超过50%.排气筒的VOCs浓度范围为48.01~155.38 mg·m~(-3),且不同产品排气筒的VOCs物种均比车间成分简单.3种方式计算的VOCs排放量不同,其中,物料衡算法计算结果最大,监测计算法计算结果最小.3类产品喷涂车间非致癌风险危害商值(HQ)在3.44×10-3~7.17之间,总危害商值之和(HI)分别为2.22×10-2、1.97及7.27. 相似文献
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The changes promoted by treatment of a highly polluted soil with sulphuric acid or calcium hydroxide for changing its pH value are studied by controlling physical properties (particle size, TGA and DTA curves), evolution of metal species (exchangeable, as carbonates, related to Fe‐Mn oxides, linked to organic matter and residual) and metal uptake by plant cultures. Metal contents were determined, after wet digestion with HF—HNO3—HC1O4 when necessary, by AAS (Ca, Mg, Cu, Pb, Mn, Fe, Zn) or emission (Na, K). The treatment of soil with successive amounts of sulphuric leads to changes in particle size, hydration properties and exothermic peak for organic matter combustion. Very small changes were, however, detected in the alkaline treatment of soil. Soil treatments do not have practical influence on speciation of some metals (Na, K, Mg, Pb, Mn, Fe), but the intensity of the acid treatment leads to both an increase in the Cu extraction and a decrease in the Ca solubilization, probably through gypsum formation. In the case of zinc a maximum solubility in the middle of the range of acid treatment was observed. The comparison among extractants shows solubilities high for two pollutants (Pb, Cu), associated mainly to Fe—Mn oxides and organic matter, and low for two macrocomponents (Fe, K). The rest of metals, basically present in soil as carbonates or oxides, have intermediate extractions. Pot cultures weights depended mainly on both the treatment of soil (poor development in the more acid sample and drainage difficulties in the rest of acid treatments) and the situation (very low weights in laboratory runs as compared with outside), but the irrigation with water or a diluted sulphuric acid solution (at pH = 4.0) did not produce significant weight changes. Tendencies to increase plant pollution were observed for smaller soil pH, acid irrigation and probably for outside cultures, due to uptake by leaves. 相似文献