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751.
随着经济的发展,由发展带来的污染问题也愈发的严重,如何治理和监测环境问题显得十分重要。文章旨在研究环境监测在对污染物总量控制上的作用做出分析,指出目前环境监测上存在的不足,提出建议和解决方案,更好的发挥环境监测的作用。 相似文献
752.
通过对生态系统健康评价体系的研究,以沙湖为例进行论证,最终得出沙湖生态系统健康度为0.32,属于不健康,制约沙湖不健康的疾病因子在于:湿地的补水水质差,导致湿地水质污染加重,富营养化现象严重,并且由于人为因素,导致物种多样性逐年下降,以上因素最终导致了沙湖湿地生态系统抗干扰能力下降,湖区湿地健康水平较低,根据对沙湖湿地功能的分析,最终设计出了沙湖湿地生态系统健康恢复技术方案。 相似文献
753.
754.
目前,随着我国农村经济的高速发展,环境问题也日益突出.如仅重视经济的发展而忽略环境污染问题,必将严重导致一个恶性循环发展链,使经济发展的速度受到不良因素的制约.改革开放以来,中国农村经济得到了较快的发展,农村面貌发生了翻天覆地的变化.但在经济迅速发展的同时,农村的生态环境却在迅速的恶化.如何改变农村现有的经济发展模式,寻求高效、稳定、持续的农村发展模式成为当前重要而紧迫的课题.文章就当前农村经济的发展现状与农村环境污染的防治做相关的探讨. 相似文献
755.
756.
以Al2(SO)4和PDMDAAC为原料进行了无机-有机复合絮凝剂的复合实验研制,确定其制备工艺条件,并对油田现场采集的钻井废水作絮凝沉降实验,所研制的PAS-PDMDAAC复合絮凝剂对COD的去除效率可大大提高. 相似文献
757.
An organo-montmorillonite-supported nanoscale zero-valent iron material(M-NZVI) was synthesized to degrade decabromodiphenyl ether(BDE-209). The results showed that nanoscale zero-valent iron had good dispersion on organo-montmorillonite and was present as a core-shell structure with a particle size range of nanoscale iron between 30–90 nm, characterized by XRD, SEM, TEM, XRF, ICP-AES, and XPS. The results of the degradation of BDE-209 by M-NZVI showed that the efficiency of M-NZVI in removing BDE-209 was much higher than that of NZVI. The efficiency of M-NZVI in removing BDE-209 decreased as the pH and the initial dissolved oxygen content of the reaction solution increased, but increased as the proportion of water in the reaction solution increased. 相似文献
758.
Catalytic oxidation is widely used in pollution control technology to remove volatile organic compounds. In this study, Pd/ZSM-5 catalysts with different Pd contents and acidic sites were prepared via the impregnation method. All the catalysts were characterized by means of N2 adsorption- desorption, X-ray fluorescence (XRF), HE temperature programmed reduction (H2-TPR), and NH3 temperature programmed desorption (NH3-TPD). Their catalytic performance was investigated in the oxidation of butyl acetate experiments. The by-products of the reaction were collected in thermal desorption tubes and identified by gas chromatography/mass spectrometry. It was found that the increase of Pd content slightly changed the catalytic activity of butyl acetate oxidation according to the yield of CO2 achieved at 90%, but decreased the cracking by-products, whereas the enhancement of strong acidity over Pd-based catalysts enriched the by-product species. The butyl acetate oxidation process involves a series of reaction steps including protolysis, dehydrogenation, dehydration, cracking, and isomerization. Generally, butyl acetate was cracked to acetic acid and 2- methylpropene and the latter was an intermediate of the other by-products, and the oxidation routes of typical by-products were proposed. Trace amounts of 3-methylpentane, hexane, 2-methylpentane, pentane, and 2-methylbutane originated from iso4merization and protolysis reactions. 相似文献
759.
Jun Bai Xiuhong Yang Ruiying Du Yanmei Chen Shizhong Wang Rongliang Qiu 《环境科学学报(英文版)》2014,26(10):2056-2064
Mechanisms of soil Pb immobilization by Bacillus subtilis DBM, a bacterial strain isolated from a heavy-metal-contaminated soil, were investigated. Adsorption and desorption experiments with living bacterial cells as well as dead cells revealed that both extracellular adsorption and intracellular accumulation were involved in the Pb2+removal from the liquid phase. Of the sequestered Pb(II), 8.5% was held by physical entrapment within the cell wall, 43.3% was held by ion-exchange, 9.7% was complexed with cell surface functional groups or precipitated on the cell surface, and 38.5% was intracellularly accumulated.Complexation of Pb2+with carboxyl, hydroxyl, carbonyl, amido, and phosphate groups was demonstrated by Fourier transform infrared spectroscopic analysis. Precipitates of Pb5(PO4)3OH, Pb5(PO4)3Cl and Pb10(PO4)6(OH)2that formed on the cell surface during the biosorption process were identified by X-ray diffraction analysis. Transmission electron microscopy–energy dispersive spectroscopic analysis confirmed the presence of the Pb(II)precipitates and that Pb(II) could be sequestered both extracellularly and intracellularly.Incubation with B. subtilis DBM significantly decreased the amount of the weak-acid-soluble Pb fraction in a heavy-metal-contaminated soil, resulting in a reduction in Pb bioavailability, but increased the amount of its organic-matter-bound fraction by 71%. The ability of B.subtilis DBM to reduce the bioavailability of soil Pb makes it potentially useful for bacteria-assisted phytostabilization of multi-heavy-metal-contaminated soil. 相似文献
760.
Understanding the efectiveness of national air pollution controls is important for control policy design to improve the future air quality in China. This study evaluated the efectiveness of major national control policies implemented recently in China through a modeling analysis. The sulfur dioxide(SO2) control policy during the 11th Five Year Plan period(2006–2010) had succeeded in reducing the national SO2emission in 2010 by 14% from its 2005 level, which correspondingly reduced ambient SO2and sulfate(SO4 2) concentrations by 13%–15% and 8%–10% respectively over east China. The nitrogen oxides(NOx) control policy during the 12th Five Year Plan period(2011–2015) targets the reduction of the national NOx emission in 2015 by 10% on the basis of 2010. The simulation results suggest that such a reduction in NOx emission will reduce the ambient nitrogen dioxide(NO2), nitrate(NO3), 1-hr maxima ozone(O3) concentrations and total nitrogen deposition by 8%, 3%–14%, 2% and 2%–4%, respectively over east China. The application of new emission standards for power plants will further reduce the NO2, NO3, 1-hr maxima O3concentrations and total nitrogen deposition by 2%–4%, 1%–6%, 0–2% and 1%–2%, respectively. Sensitivity analysis was conducted to evaluate the inter-provincial impacts of emission reduction in Beijing-Tianjin-Hebei and the Yangtze River Delta, which indicated the need to implement joint regional air pollution control. 相似文献