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951.
尾矿是我国工业三废中数量巨大的固体废弃物,其占用土地,浪费资源,污染环境,存在较大安全隐患。论述我国尾矿的基本现状及治理的必要性,提出尾矿综合利用的目标及保障措施,指出提高尾矿的综合利用率对于推动我国工业的发展具有重大意义。  相似文献   
952.
以气浮—过滤预处理后的污水为处理对象,通过臭氧氧化与Fenton氧化两种方法处理油田含油污水。经实验验证:Fenton在pH为4,H2O2初始浓度为0.08mol/L,Fe2+与H2O2的摩尔比为1:10,H2O2与CODCr的质量比为1:1,反应时间为60min的条件下,去除率达54.3%(CODCr100mg/L),可达到GB8978-1996《污水综合排放标准》二级标准。  相似文献   
953.
已二酸生产副产物——混合二元酸的综合利用   总被引:1,自引:1,他引:0  
采用一水合硫酸氢钠作为催化剂,催化己二酸生产副产物——混合二元酸与甲醇反应合成混合二元酸二甲酯。优化工艺条件为:混合二元酸加入量0.1mol,无水甲醇加入量0.5mol,一水合硫酸氢钠加入量4.0g,环己烷加入量20mL,反应时间1.5h。合成混合二元酸二甲酯的酯化反应收率大于97%。经气相色谱检测,产物中酯的质量分数为98.91%。一水合硫酸氢钠可重复使用3次。  相似文献   
954.
泡沫分离法去除废水中微量钴离子   总被引:1,自引:0,他引:1  
采用泡沫分离法对水中微量钻离子的去除进行了研究,考察了表面活性剂种类及浓度、pH、气流量等因素对钴离子去除率的影响。实验结果表明:当水中钴离子初始质量浓度为10mg/L、采用十二烷基硫酸钠(SLS)做表面活性剂且质量浓度为10mg/L、pH为11.0、气流量为300L/h时,钴离子去除率达97.61%。根据泡沫分离过程与化学反应过程在物理行为上的类似性,引入等效的化学反应常数,对泡沫分离法去除水中钴离子进行了宏观动力学研究。结果表明,该泡沫分离过程可等效为一级反应。  相似文献   
955.
956.
China is confronted with the dual task of developing its national economy and protecting its ecological environment. Since the 1980s, China's policies on environmental protection and sustainable development have experienced five changes: (1) progression from the adoption of environmental protection as a basic state policy to the adoption of sustainable development strategy; (2) changing focus from pollution control to ecological conservation equally; (3) shifting from end-of-pipe treatment to source control; (4) moving from point source treatment to regional environmental governance; and (5) a turn away from administrative management-based approaches and towards a legal means and economic instruments-based approach. Since 1992, China has set down sustainable development as a basic national strategy. However, environmental pollution and ecological degradation in China have continued to be serious problems and have inflicted great damage on the economy and quality of life. The beginning of the 21st century is a critical juncture for China's efforts towards sustaining rapid economic development, intensifying environmental protection efforts, and curbing ecological degradation. As the largest developing country, China's policies on environmental protection and sustainable development will be of primary importance not only for China, but also the world. Realizing a completely well-off society by the year 2020 is seen as a crucial task by the Chinese government and an important goal for China's economic development in the new century, however, attaining it would require a four-fold increase over China's year 2000 GDP. Therefore, speeding up economic development is a major mission during the next two decades and doing so will bring great challenges in controlling depletion of natural resources and environmental pollution. By taking a critical look at the development of Chinese environmental policy, we try to determine how best to coordinate the relationship between the environment and the economy in order to improve quality of life and the sustainability of China's resources and environment. Examples of important measures include: adjustment of economic structure, reform of energy policy, development of environmental industry, pollution prevention and ecological conservation, capacity building, and international cooperation and public participation.  相似文献   
957.
关于发展湖北省循环农业的思考   总被引:1,自引:0,他引:1  
改革开放以来,湖北省农业发展取得了显著成效,但农业生产方式仍以落后、粗放、资源消耗型为主,加之湖北省农业资源短缺且浪费严重,严重制约了农业的可持续发展。面对制约湖北省农业可持续发展的种种问题,农业发展方式的改革与升级成为必然。系统概述了循环农业的兴起及其概念、特点,并根据湖北省的实际情况,阐述了循环农业发展的必要性和可行性,提出了湖北发展循环农业的战略思想和办法措施,以促进湖北循环农业的发展。  相似文献   
958.
对中西方关于农村剩余劳动力转移理论进行了比较,在介绍Lee E S“推拉”模型的基础之上,结合湘西龙山县的具体情况分析了民族地区农村剩余劳动力转移的动因和湘西农村剩余劳动力转移存在的问题,提出了解决的对策,并将“推拉理论”运用到我国民族地区农村剩余劳动力转移的实证分析上。  相似文献   
959.
Lin T  Wen Y  Jiang L  Li J  Yang S  Zhou Q 《Chemosphere》2008,72(1):122-128
To evaluate the treatment capability of subsurface flow constructed wetland (SFCW) and the effect of salinity on the degradation of atrazine, the degradation of atrazine in SFCW was studied. Under the static condition, the degradation of atrazine in SFCW followed first-order kinetics: c=0.09679 exp(-0.0396t) (c, residue concentration, mg l(-1); t, retention time, d), with a half-life of approximately 17.5 days. The atrazine degradation kinetic functions were established for salinities of 1.5, 3.0, 5.0, 10.0 and 15.0 g l(-1), respectively, which appeared to approach first-order kinetics. The effect of salinity on the atrazine treatment efficiency showed an exponential inhibition: lnk=3.204+0.04991 C (k, degradation constant; C, NaCl concentration, mg l(-1)). The attenuation of atrazine in SFCW cannot be a result of hydrolysis or sorption process. It was considered that some bacteria in the wetland system degraded atrazine into deethylatrazine (DEA) and deisopropylatrazine (DIA) and sequentially into CO(2) and H(2)O. Salinity impacted on the growth of bacteria resulting in a switch of the microbial community. With the increase of salinity, Shannon-Wiener Diversity Index in the SFCW system declined. The relationship between atrazine degradation constant (k) and Shannon Index was established as shown in linear phase, y=-0.07286+0.0363x. The positive correlation between them indicated that microbial community played an important role in the atrazine degradation process.  相似文献   
960.
深圳市公路建设对生态环境的影响、治理及对策   总被引:7,自引:0,他引:7  
公路建设曾经给深圳的生态环境造成了较为严重的危害 ,主要有 :严重的水土流失及其派生影响 ,对一些具有观赏价值的自然景观产生破坏 ,影响了部分区域动植物生存环境等。主要对这些环境影响及已进行的治理及其成效进行综述 ,对治理工作的不足及未来对策也进行了探讨。  相似文献   
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