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991.
南中国纺织品商业协会安全健康防护用品委员会陈海达秘书长为团长,国内劳保行业内的部分企业组成的的赴欧洲考察团共13人于2009年10月26日从上海出发抵达巴黎,先后途经法国、比利时、荷兰,于11月4日到达德国杜塞尔多夫,参观了2009国际工业安全用品及健康用品展(A+A).  相似文献   
992.
双酚F(bisphenol F, BPF)和双酚AF(bisphenol AF, BPAF)作为双酚A(bisphenol A, BPA)的替代品已被投入生产和使用,然而目前有关BPA替代品毒性的数据还很缺乏。本文从急性毒性和应激响应2个方面比较了BPF、BPAF与BPA对非洲爪蛙蝌蚪的毒性。结果表明,48 h的半致死浓度(LC_(50))顺序为BPF(11.01 mg·L~(-1))>BPA(7.54 mg·L~(-1))>BPAF(2.87 mg·L~(-1));对氧化应激水平的影响BPAF强于BPA,BPF与BPA相近;BPA和BPAF对热休克蛋白基因表达水平有影响,BPF没有影响。本研究提示,BPAF作为BPA的替代品,其毒性强于BPA,而BPF与BPA类似。  相似文献   
993.
• The g-MoS2 coated composites (g-MoS2-BC) were synthesized. • The coated g-MoS2 greatly increased the adsorption ability of biochar. • The synergistic effect was observed for CIP adsorption on g-MoS2-RC700. • The adsorption mechanisms of CIP on g-MoS2-BC were proposed. The g-MoS2 coated biochar (g-MoS2-BC) composites were synthesized by coating original biochar with g-MoS2 nanosheets at 300°C(BC300)/700°C (BC700). The adsorption properties of the g-MoS2-BC composites for ciprofloxacin (CIP) were investigated with an aim to exploit its high efficiency toward soil amendment. The specific surface area and the pore structures of biochar coated g-MoS2 nanosheets were significantly increased. The g-MoS2-BC composites provided more π electrons, which was favorable in enhancing the π-π electron donor-acceptor (EDA) interactions between CIP and biochar. As a result, the g-MoS2-BC composites showed faster adsorption rate and greater adsorption capacity for CIP than the original biochar. The coated g-MoS2 nanosheets contributed more to CIP adsorption on the g-MoS2-BC composites due to their greater CIP adsorption capacity than the original biochar. Moreover, the synergistic effect was observed for CIP adsorption on g-MoS2-BC700, and suppression effect on g-MoS2-BC300. In addition, the adsorption of CIP onto g-MoS2-BC composites also exhibited strong dependence on the solution pH, since it can affect both the adsorbent surface charge and the speciation of contaminants. It was reasonably suggested that the mechanisms of CIP adsorption on g-MoS2-BC composites involved pore-filling effects, π-π EDA interaction, electrostatic interaction, and ion exchange interaction. These results are useful for the modification of biochar in exploiting the novel amendment for contaminated soils.  相似文献   
994.
• Functional groups of AM and EDTA in composite increased removal of Cr(VI) and CR. • Removal process reached equilibrium within 30 min and was minimally affected by pH. • Elimination of Cr(VI) was promoted by coexisting CR. • Adsorption process of CR was less influenced by the presence of Cr(VI). • Mechanisms were electrostatic attraction, surface complexation and anion exchange. We prepared ethylenediaminetetraacetic acid (EDTA)-intercalated MgAl-layered double hydroxide (LDH-EDTA), then grafted acrylamide (AM) to the LDH-EDTA by a cross-linking method to yield a LDH-EDTA-AM composite; we then evaluated its adsorptive ability for Congo red (CR) and hexavalent chromium (Cr(VI)) in single and binary adsorption systems. The adsorption process on LDH-EDTA-AM for CR and Cr(VI) achieved equilibrium quickly, and the removal efficiencies were minimally affected by initial pH. The maximum uptake quantities of CR and Cr(VI) on LDH-EDTA-AM were 632.9 and 48.47 mg/g, respectively. In mixed systems, chromate removal was stimulated by the presence of CR, while the adsorption efficiency of CR was almost not influenced by coexisting Cr(VI). The mechanisms involved electrostatic attraction, surface complexation, and anion exchange for the adsorption of both hazardous pollutants. In the Cr(VI) adsorption process, reduction also took place. The removal efficiencies in real contaminated water were all higher than those in the laboratory solutions.  相似文献   
995.
• DPAA sorption data was found to fit the Freundlich equation. Kf was significantly positive correlated with oxalate-extractable Fe2O3. • Ligand exchange was the main mechanism for DPAA sorption on soils. • Bidentate binuclear and monodentate mononuclear DPAA bonds were identified. Diphenylarsinic acid (DPAA) is a phenyl arsenic compound derived from chemical warfare weapons. Macroscopic and microscopic work on DPAA sorption will provide useful information in predicting the partitioning and mobility of DPAA in the soil-water environment. Here, batch experiments and extended X-ray absorption fine structure (EXAFS) spectroscopy were used to investigate the sorption mechanisms of DPAA. The DPAA sorption data from 11 soil types was found to fit the Freundlich equation, and the sorption capacity, Kf, was significantly and positively correlated with oxalate-extractable Fe2O3. The Kf values of eight of the 11 untreated soils (1.51–113.04) significantly decreased upon removal of amorphous metal (hydr)oxides (0.51–13.37). When both amorphous and crystalline metal (hydr)oxides were removed from the untreated soils, the Kf values either decreased or slightly increased (0.65–3.09). Subsequent removal of soil organic matter from these amorphous and crystalline metal (hydr)oxide-depleted samples led to further decreases in Kf to 0.02–1.38, with only one exception (Sulfic Aquic-Orthic Halosols). These findings strongly suggest that ligand exchange reactions with amorphous metal (hydr)oxides contribute most to DPAA sorption on soils. EXAFS data provide further evidence that DPAA primarily formed bidentate binuclear (2C) and monodentate mononuclear (1V) coring-sharing complexes with As-Fe distances of 3.34 and 3.66 Å, respectively, on Fe (hydr)oxides. Comparison of these results with earlier studies suggests that 2C and 1V complexes of DPAA may be favored under low and high surface coverages, respectively, with the formation of 1V bonds possibly conserving the sorption sites or decreasing the steric hindrance derived from phenyl substituents.  相似文献   
996.
应用浮游植物对扎龙自然保护区水质的初步评价   总被引:3,自引:0,他引:3  
通过对扎龙自然保护区水体中浮游植物调查及运用几种评价公式分析,评价结论为:扎龙水体浮游植物由8门60个属组成,数量在19 515×10~2~23 755×10~3个/升之间;水质属中污染型,同一年度污染情况为:8月>6月,北区>南区。  相似文献   
997.
The occurrence, toxicities, and ecological risks of five heavy metals(Pb, Cu, Cd, Zn and Ni) in the sediment of Taihu Lake were investigated in this study. To evaluate the toxicities caused by the heavy metals, the toxicities induced by organic contaminants and ammonia in the sediments were screened out with activated carbon and zeolite. The toxicities of heavy metals in sediments were tested with benthic invertebrates(tubificid and chironomid).The correlations between toxicity of sediment and the sediment quality guidelines(SQGs)derived previously were evaluated. There were significant correlations(p 0.0001) between the observed toxicities and the total risk quotients of the heavy metals based on SQGs,indicating that threshold effect level(TEL) and probable effect level(PEL) were reliable to predict the toxicities of heavy metals in the sediments of Taihu Lake. By contrast, the method based on acid volatile sulfides(AVS) and simultaneously extracted metals(SEM),such as ∑SEM/AVS and ∑SEM-AVS, did not show correlations with the toxicities. Moreover,the predictive ability of SQGs was confirmed by a total predicting accuracy of 77%. Ecological risk assessment based on TELs and PELs showed that the contaminations of Pb, Cu, Cd and Zn in the sediments of Taihu Lake were at relatively low or medium levels. The risks caused by heavy metals in the sediments of northern bay of the lake, which received more wastewater discharge from upper stream, were higher than other area of the lake.  相似文献   
998.
Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carded out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids.Results showed that citdc acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubUization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the pκa values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was not correlated with pκa. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.  相似文献   
999.
随着我国工业的发展,噪声危害的分布范围越来越广,人们接触噪声的机会日益增多。长期接触噪声会对人体多个系统产生不良影响,其中尤以对听觉器官的损害最为突出。本文针对噪声的概念及噪声作业听力防护,分析了噪声对人体健康的影响因素及其主要损害,阐述了预防和控制噪声的个体防护装备,提出了噪声性听力损伤的自身防护早发现早防治措施。  相似文献   
1000.
运用苯系物与甲醛在酸催化下发生显色反应生成树脂状褐色产物的原理,初步研制了一种能够测定空气中低浓度甲醛的检测管。其载体为60~80目的活化硅胶;玻璃管内径为18~20mm;指示粉为硅胶、浓硫酸和二甲苯的混合物。对空气进行测定的采样条件为:采气速度005L/min,采样量3L。经初步试验,该检测管变色长度与甲醛的浓度具有较好的相关性(γ=09941);检测之重现性较好(不同浓度测定的变异系数小于25%);灵敏度较高(最低显色浓度为01mg/m3)。  相似文献   
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