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491.
尹戈  范军  黄涛宏 《环境化学》2020,39(5):1448-1450
本文使用岛津HS-10顶空进样器结合GC-2010 Pro气相色谱仪,建立了顶空-气相色谱法测定医用口罩和防护服中环氧乙烷(EO)和2-氯乙醇(ECH)含量的方法.EO和ECH在配制标样浓度范围内标准曲线线性良好,相关系数在0.999以上,仪器检出限分别为0.012 μg·mL-1和0.13 μg·mL-1.以6针平行进样测试考察方法重复性,两个组分的峰面积RSD均小于5.0%.本方法可应用于医用口罩、防护服等医用防护用品中EO和ECH含量的快速定量测定.  相似文献   
492.
    
• CW-Fe allowed a high-performance of NO3-N removal at the COD/N ratio of 0. • Higher COD/N resulted in lower chem-denitrification and higher bio-denitrification. • The application of s-Fe0 contributed to TIN removal in wetland mesocosm. • s-Fe0 changed the main denitrifiers in wetland mesocosm. Sponge iron (s-Fe0) is a porous metal with the potential to be an electron donor for denitrification. This study aims to evaluate the feasibility of using s-Fe0 as the substrate of wetland mesocosms. Here, wetland mesocosms with the addition of s-Fe0 particles (CW-Fe) and a blank control group (CW-CK) were established. The NO3-N reduction property and water quality parameters (pH, DO, and ORP) were examined at three COD/N ratios (0, 5, and 10). Results showed that the NO3-N removal efficiencies were significantly increased by 6.6 to 58.9% in the presence of s-Fe0. NH4+-N was mainly produced by chemical denitrification, and approximately 50% of the NO3-N was reduced to NH4+-N, at the COD/ratio of 0. An increase of the influent COD/N ratio resulted in lower chemical denitrification and higher bio-denitrification. Although chemical denitrification mediated by s-Fe0 led to an accumulation of NH4+-N at COD/N ratios of 0 and 5, the TIN removal efficiencies increased by 4.5%‒12.4%. Moreover, the effluent pH, DO, and ORP values showed a significant negative correlation with total Fe and Fe (II) (P<0.01). High-throughput sequencing analysis indicated that Trichococcus (77.2%) was the most abundant microorganism in the CW-Fe mesocosm, while Thauera, Zoogloea, and Herbaspirillum were the primary denitrifying bacteria. The denitrifiers, Simplicispira, Dechloromonas, and Denitratisoma, were the dominant bacteria for CW-CK. This study provides a valuable method and an improved understanding of NO3-N reduction characteristics of s-Fe0 in a wetland mesocosm.  相似文献   
493.
The concentration of solubilized aluminium in soils and waters increases due to environmental influences. To obtain information on the types of Al species occuring under these conditions, aluminium chloride solutions were prepared in a wide range of concentrations (10?1–10?5 mol·l?1 Al) and basicity (OH/Al=0,5–2,5), respectively, and then structurally characterized using the ferron method. For the freshly prepared solutions, a decrease in the portion of monomeric Al species is observed, with an increasing OH/Al-ratio; the formation of polymeric cations decreases to lower OH/Al-ratios with diminishing concentration. The portion of tridecameric cations (Al13) decreases with diminishing concentration, but so called transition polymers occur in these solutions. The transition polymers are instable under ageing; by inreasing the ageing time, a disproportion of these cations into monomeric and polymeric species can be observed. At extremly low Al concentrations (10?5 mol·l?1 Al), a condensation of the transition polymers into polymeric species occurs, after only a short ageing. The influence of admixtures of Mg2+-and Ca2+-ions, respectively, on the specification of the Al cations are only observed after longer ageing times; in this case, the formation of polymeric Al species is forced. The polymeric Al species therefore, seem to be especially preferred alongside the monomeric ones under biologically relevant concentrations.  相似文献   
494.
In order to reduce environmental pollution and regulatory issues, the adsorption of n-butane from vehicle exhaust is one of the necessary requirements. When active carbon was mixed with different proportions of metal oxides, the adsorption capacity of n-butane was markedly improved. Infrared spectroscopy data provided information on functional groups derived from activated carbon composite metal oxide indicating that one of the best adsorption capacities for n-butane was obtained by mixing 3 g TiO2, 2.7 g CuO, and 2.1 g NaBO3·4H2O with 30 g activated carbon. However, more effective results were obtained by mixing 6 g TiO2, 2.1 g CuO, and 0.9 g NaBO3·4H2O with 30 g activated carbon. Data suggest that these chemical complexes may be effective in lowering n-butane pollution.  相似文献   
495.
尾砂库溃坝对大环江沉积物中重金属的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
为研究2001年特大洪水导致的北山铅锌矿尾砂库溃坝对大环江沉积物中重金属含量的影响及其潜在的生态风险,沿大环江自北向南设置了21个样点,共采集沉积物样品77个;分别采用SQG(沉积物质量基准)、PLC(污染负荷指数)和Hankson潜在生态风险指数法,对尾砂库下方大环江沉积物表层及剖面中As、Pb、Cd、Cu和Zn 5种重金属进行了分析和评价. 结果表明:大环江沉积物剖面pH平均值在2.09~7.51之间,其中38.1%的采样点土壤pH低于环江县背景值上限;表层(0~25 cm)沉积物中w(As)、w(Pb)、w(Cd)、w(Cu)和w(Zn)的平均值分别是环江谷地土壤平均值的3.2、20.0、59.2、2.1、17.0倍. 沉积物剖面的重金属质量分数分布主要有自上而下先降后升或先升后降2类规律,w(As)与w(Pb)、w(Cu),w(Pb)与w(Cu)、w(Zn),w(Cd)与w(Zn)均呈显著相关. 根据SQG法评估结果,大环江沉积物剖面首层(0~22 cm)w(As)、w(Pb)、w(Cd)和w(Zn)已对水域生物产生严重影响;大环江流域的PLI为2.57,属于极强污染;以环江县土壤背景值为参比值的Hankson潜在生态风险指数分析结果显示,大环江表层沉积物呈现强~极强的生态风险,5种重金属的污染程度为Cd>Pb>As>Zn>Cu. 尾砂库溃坝导致大环江沉积物中重金属质量分数陡然升高且难以恢复.   相似文献   
496.
Environmental Science and Pollution Research - The low carbon-to-nitrogen (C/N) ratio in wastewater will inhibit pollutant removal, and more seriously, it will cause an increment of nitrous oxide...  相似文献   
497.
A deltamethrin-imprinted polymer (MIP1) was prepared using bis(-6-O-butanediacid monoester)-β-cyclodextrin (BBA-β-CD) as the functional monomer and toluene 2,4-diisocyanate (TDI) as the cross-linker. In comparison to the molecularly imprinted polymer where β-CD was applied as the functional monomer (MIP2), MIP1 showed a higher specific binding capacity (ΔCP) and an improved imprinting factor (IF) for deltamethrin. The selective recognition experiments demonstrated that compared to MIP2, MIP1 could better recognize its template over other substrates that had similar chemical structures. The solid phase extraction (SPE) of deltamethrin using MIP1 as the adsorbent was further investigated. The recoveries of the molecularly imprinted solid phase extraction (MISPE) column for deltamethrin were 83.2–93.4% with relative standard deviations (RSD) of 2.03–6.19%. The method has been successfully applied to the enrichment of trace deltamethrin from real water samples.  相似文献   
498.
499.
In samples with 1,009, 7,723, 7,618, 7,618, 1,004 and 1,009 number, oleic acid were found as 62.0, 77.0, 74.84, 71.55, 54.52 and 62.30 %, respectively. In other samples, oleic acid content was determined between 17.43 % (1,589) and 34.86 % (1,298). Linoleic acid content of seed oils ranged from 6.52 % (7,727) to 57.29 % (1,501). In addition, linolenic acid content was found between 0.22 % (7,618) and 46.91 % (1,589). Palmitic acid content of samples changed between 2.03 % (7,727) and 19.81 % (1,298). Capric acid was found at high level in 1,009 (8.53 %), 7,727 (37.31 %) and 1,004 (8.28 %) samples. Caproic acid was found in only 7,727 (3.38 %).  相似文献   
500.
污染损失与环境效益分析   总被引:8,自引:0,他引:8  
污染损失是在某一污染状况下,环境资源使用者因环境污染所遭受的经济损失,包括损害费用和防护费用。污染损失不只与环境质量有关,也与环境资源使用量有关。以水污染为例,通过江苏某区水污损失估算结果,经回归分析,评价了该区“七五”期间水环境投入的效益。  相似文献   
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