Influence of metal oxides on PCDD/Fs formation from pentachlorophenol

Chlorophenols (ClPhs) are considered as important precursors for PCDD/Fs formation. The influences of series of metal oxides including MgO, Al2O3, CaO, BaO, TiO2, V2O5, MnO2, Fe2O3, Co3O4, CuO, Ag2O, ZnO, HgO, SnO, PbO, La2O3, CeO2, and Eu2O3 on PCDD/Fs formation from pentachlorophenol (PCP) were investigated in a laboratory-scale reactor. The results indicated that most of the above metal oxides have obvious suppressing effects on the total amount of PCDD/Fs formation from precursor PCP except for CuO, ZnO, MnO2, TiO2 and Co3O4 with promotion effects at 280 degrees C for 2 h. Although MgO, Al2O3, Fe2O3, PbO, La2O3 and Eu2O3 could reduce the amount of octachlorinated dibenzo-p-dioxin (OCDD), they promote the formation of more toxic 1,2,3,4,6,7,8-HpCDD at the same time. The total suppressing efficiencies of several metal oxides including CaO, BaO, PbO, Ag2O, HgO and SnO which have lower Z/r (charge to radius ratio) <2 are all over 90%. The theories of generalized acid-base and atomic parameter (Z/r) were used to speculate the effecting mechanisms. The factors including time and temperature on suppressing efficiencies of CaO, BaO and PbO have also been studied in the present paper. The results showed that the total suppressing efficiencies of CaO, BaO and PbO increase with the increase of heated time and temperature.     

焚烧法处理环己酮生产中的皂化液

用环已烷氧化生产环已酮的生产过程中会产生大量的皂化液 ,它含有大量的有害物质 ,是一种难处理的高污染有机废水。某石化厂在借鉴造纸行业的黑液焚烧技术的基础上 ,采用焚烧法来处理皂化液 ,并得到副产蒸气和回收了碳酸钠 ,实现了皂化液的无害化与资源化 ,具有良好的社会效益、环境效益和经济效益 ,每处理 1t皂化液可盈利 10 0～ 2 0 0元     

中国南方某城市自来水厂处理工艺对多环芳烃的去除效果研究

讨论了中国南方某城市自来水厂饮用水中的多环芳烃残留规律以及现有净水工艺对多环芳烃的去除效果。研究结果表明,该自来水厂饮用水中检出多环芳烃以2~4环芳烃为主,强致癌性高环数多环芳烃均在检出限以下,且多环芳烃总量未超出中国供水行业标准(2000年)的相关限值。各处理工艺段中,砂滤过程对多环芳烃的去除效果最好,相较于原水对多环芳烃总量的去除率可达64%。     

玻纤布上胶车间有机溶剂废气净化处理

介绍了工厂有机溶剂废气处理方案和设计及实际运行效果,具有简单经济、净化彻底的特点.     

Effect of bound residues of metsulfuron-methyl in soil on rice growth

A pot experiment was conducted to appraise the hazards of bound residues of metsulfuron-methyl in soil at six levels (0, 0.050, 0.089, 0.158, 0.281, and 0.500 mg kg(-1)) to the growth of four rice varieties (Xiushui 63, Eryou 810, Liangyoupeijiu, and Zhenong 952). The morphological characteristics of rice roots like root number, total length, surface area of rice roots, and rice biomass were determined. The results showed that the bound residues of metsulfuron-methyl in soil impacted the growth of rice. Root number, total length of roots, surface area of roots, and biomass were restrained by bound residues of metsulfuron-methyl in soil. The inhibition rate of root growth increased from 69.46-81.32% to 85.18-95.97% with the increasing of levels of bound residues of metsulfuron-methyl from 0.05 mg kg(-1) to 0.50 mg kg(-1). The number of rice roots could be taken as a sensitive index to screen the rice varieties endurable to bound residues of metsulfuron-methyl in soil and to predict the potential hazards of bound residues of metsulfuron-methyl in soil to rice. The level of bound residues of metsulfuron-methyl in soil causing the root numbers decreased by 50% (IC50) followed the order of Xiushui 63 < Eryou 810 < Liangyoupeijiu < Zhenong 952.     

新生态二氧化锰对水中三价砷去除作用的研究

研究了新生态MnO2对水中As(Ⅲ)的去除效果。结果表明:新生态MnO2对As(Ⅲ)去除率高,作用速度快,作用过程符合二级动力学方程;pH=6.5时吸附等温线符合Langmuir和Frundlich方程;pH<7时,As(Ⅲ)的去除率均达80%以上,受pH和初始浓度影响较小,且与H3AsO3的pKa无关的非特性吸附;阴离子与As(Ⅲ)有吸附竞争作用,阳离子的加入可使As(Ⅲ)的去除率接近100%。     

电磁辐射与电磁防护

本文讨论了电气进程带来的电磁辐射污染及其防护问题。从电磁辐射的来源、作用人群、对人体的影响方式阐述了电磁辐射防护的必要性。介绍了电磁辐射暴露限值标准、电磁辐射防护原理、防护装备标准及产品现状。提出了现有电磁辐射暴露限值标准及防护装备产品标准的不足,指出现阶段应进行的进一步工作：考虑非致热效应对人体的影响,完善统一电磁辐射暴露限值标准;增加电磁辐射防护装备标准覆盖面,以利加强监管,进一步规范产品市场。     

Impacts of the Rising Opportunity Cost of Farm Labor on Agricultural Land Use Structure: Theory and Empirical Evidences

Abstract

Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics is formulated drawn on Low’s model. Under the theoretical framework, the impact of the rising opportunity cost of on-farm on cropping structure is deduced in theory. And then, using statistic and survey data, taking mountain area of southern Ningxia as an example, the theoretical assumes are verified. The results show that the rise of opportunity cost of farm labor leads to less diversified cropping structure.     

Identifying resource and environmental carrying capacity in the Yangtze River Economic Belt,China: the perspectives of spatial differences and sustainable development

Environment, Development and Sustainability - The resource and environmental carrying capacity (RECC) is an important foundation and support for a city or region, and determines the direction of...     

卫星遥感技术在管理长江流域水资源方面的应用研究

详细讨论了卫星遥感技术在长江流域水资源管理方面的应用问题，提出了两种实用的方法：①卫星遥感技术在灌溉水资源管理方面的应用；②长江流域地下水、地表水资源估算。进一步分析了两种方法的特点，介绍了卫星遥感技术的优点及用途，建议在长江流域水资源管理中加以利用。