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91.
Ionic liquids are studied intensively for different applications. They tend to be denoted as “green solvents”, largely because of their low vapour pressure. In recent years toxicity and biotoxicity of ionic liquids have also been investigated, which proved that not all of these are “green”. In this paper the use of ionic liquids based on choline chloride and ethylene glycol in electrochemistry is discussed in the context of their use as green solvents. Due to their low toxicity and ready biodegradability, these deep eutectic solvents are promising for the electrodeposition of metals. The influence of the use of these liquids as metal deposition baths on the waste water is investigated. Drag-out was found to be the most influencing parameter on the environmental impact of the process, as it is three times higher compared to classical solutions due to the higher viscosity of the ionic liquid. There are no major changes needed in the rinsing configuration of classic electroplating plants, and ion exchange to remove the metal out of the waste water was not hindered by the presence of the ionic liquid. The formation of by-products during the deposition of metals has to be further investigated and evaluated in consideration of the environmental impact.  相似文献   
92.
试验了玻璃、聚乙烯、聚四氟乙烯等不同材质容器溶出氯离子对环境空气中氯化氢测定的影响,指出测定结果偏高的原因在于采用玻璃气泡吸收管,分析了玻璃材质溶出氯离子的原因,建议采用特制的聚四氟乙烯或聚乙烯吸收管采样。  相似文献   
93.
Schmidt AC  Kutschera K  Mattusch J  Otto M 《Chemosphere》2008,73(11):1781-1787
Phenylated arsenic compounds occur as highly toxic contaminants in former military areas where they were formed as degradation products of chemical warfare agents. Some phenylarsenic compounds such as roxarsone and aminophenylarsonic acids were applied as food additive and veterinary drugs in stock-breeding and therefore pose an environmental risk in agricultural used sites. Very few data exist in the literature concerning uptake and effects of phenylarsenic compounds in plants growing on contaminated soils. In this study, the accumulation, extractability, and metabolization of five different phenylarsenic compounds, phenylarsonic acid, p- and o-aminophenylarsonic acid, phenylarsine oxide, and 3-nitro-4-hydroxyphenylarsonic acid called roxarsone, by the terrestrial plant Tropaeolum majus were investigated. Ion chromatography coupled to inductively coupled plasma mass spectrometry was used to differentiate these arsenic compounds, and inductively coupled plasma atomic emission spectroscopy was used for total arsenic quantification. All compounds considered were taken up by the roots and transferred to stalks, leaves, and flowers. The strongest accumulation was observed for unsubstituted phenylarsonic acid followed by its trivalent analogue phenylarsine oxide that was mostly oxidized in soil whereas the amino- or nitro- and hydroxy-substituted phenylarsonic acids were accumulated to a smaller degree.The highest extraction yield of 90% for ground leaf material was achieved by 0.1 M phosphate buffer, pH 7.7, in a two-step extraction with a total extraction time of 24 h. The extraction of higher amounts of arsenic (50–70% of total arsenic present in leaves depending on arsenic species application) from non-ground intact leaves with deionized water in comparison with the buffer (20–40% of total arsenic) is ascribed to osmotic effects. The arsenic species analysis revealed a cleavage of the amino groups from the phenyl ring for plants treated with aminophenylarsonic acids. A further important metabolic effect consisted in the production of inorganic arsenate and arsenite from the phenylated arsonic acid groups.  相似文献   
94.
张丽君  刘峰 《环境保护科学》1998,24(2):24-25,34
用离子色谱法(简称IC)测定有害工业固体废物浸出液中的氟化物,其测定方法较化学法(离子选择电极法)手续简便、快速、准确.  相似文献   
95.
阚平  卢益 《四川环境》2007,26(3):18-20
在日化工业磷酸盐解析方法的基础上,针对污水中各磷酸盐含量特征,对树脂床高度、淋洗液流速和用量等因素作了选择研究,确定了分离污水中各种磷酸盐及测定其含量的条件和步骤。  相似文献   
96.
Juang RS  Lin SH  Wang TY 《Chemosphere》2003,53(10):1221-1228
Fixed bed removal of equimolar metal ions (Co2+, Ni2+, Mn2+, Sr2+) from aqueous solutions using a strong-acid resin was examined. The solution contained a water-soluble complexing agent including ethylenediaminetetraacetic acid, nitrilotriacetic acid, and citric acid. Experiments were performed under different solution pH and molar concentration ratios of complexing agent to the total metals. It was shown from batch studies that the equilibrium exchange of metals and the resin mainly depended on solution pH, and partly on the type of complexing agent used. A mass transfer model was proposed to describe the breakthrough curves of the resin bed, which contained two parameters (τ and k) estimated from the observed breakthrough data. The calculated breakthrough curves agreed well with the measured ones (standard deviation <6%). In fixed bed tests at low pH (=2), the type of complexing agent had little effect on the breakthrough data. For a given complexing agent, the metal with a larger overall formation constant (Kf) showed a smaller exchange capacity. For a given metal ion, the complexing agent with a larger Kf also revealed a smaller exchange capacity.  相似文献   
97.
采用固相萃取技术富集海水中的666、DDT,并使用气相色谱进行测定。主要包括不同填料(C8、C18、C18-N)、SPE柱规格(500 mg/3 mL、500 mg/6 mL)、洗脱试剂、上样流速、水样pH和洗脱试剂体积6个因素对666、DDT富集效率的影响。最终确定最优条件为:采用500 mg/6 mL C18SPE小柱,调节海水pH=6,上样流速4~5mL/min,10 mL二氯甲烷洗脱。优化后的固相萃取-气相色谱方法测定海水中666、DDT加标10 ng/L回收率为75.7%~110.4%,精密度为1.16%~4.00%,方法检出限为0.19~1.20 ng/L。  相似文献   
98.
建立了用离子色谱法测定工业废气中异丁酸的新方法。废气中异丁酸经淋洗液吸收,0.45μm微孔滤膜过滤后离子色谱法分析,时间定性,峰高定量,其异丁酸回收率为93.5%~104.2%,消采样体积为20L的条件下,异丁酸最低检出质量浓度为0.02mg/m^3。  相似文献   
99.
氧化钙燃烧固硫添加剂的研究   总被引:21,自引:1,他引:21  
在寻找钙基燃烧固硫加剂,并探讨其机理的试验中,研究了碱金属化合物在不同含量,不同温度下对氧化钙固硫率的影响,试验结果表明,一些碱金属化合物能使固硫率增加约10个百分点左右,采用SEM和热天平分析了固硫率提高的原因,提出碱金属化合物提高固硫率的机理在于:低熔点液相共熔物的形成导致CaO微观结构的改变。  相似文献   
100.
We have analysed the sensitivity, specificity, and reliability of biochemical diagnosis based on microvillar membrane enzyme assay and using discriminant analysis in amniotic fluid samples obtained from 54 pregnancies at high risk for cystic fibrosis and 125 normal pregnancies. Our results show that amniotic fluid trehalase, alkaline phosphatase, alkaline phosphatase isoenzymes and gamma-glutamyltransferase enzyme activities measured during 16–20 gestational weeks, in spite of their non-specificity for cystic fibrosis, have a very good predictive value for fetal cystic fibrosis or exclude the possibility of the disease. Overall enzyme activity analysis provided over 90 per cent reliability of the method.  相似文献   
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