矿化垃圾反应床出水对植物发芽与幼苗生长的影响

通过测定植物种子萌发率、萌根数、根长、幼根鲜质量、芽长和幼芽鲜质量这6个指标,考察了矿化垃圾反应床出水对大麦和玉米2种植物的毒性。结果表明,垃圾渗滤液经三级矿化垃圾反应床处理后,其出水中的COD、BOD5、NH4+-N和大肠菌数虽然较低,但仍会对植物的生长产生抑制作用;随着处理时间的延长,抑制作用更显著;同时,不同植物对矿化垃圾反应床出水毒性的敏感程度不同,同一植物的不同部位其敏感程度也不同。     

艰氮和限磷对活性污泥合成聚羟基烷酸的影响

聚羟基烷酸（PHA）是微生物在不平衡营养条件下贮存的一种胞内聚合物,限磷和限氮两种方式均有助于活性污泥中的混合菌群合成PHA,研究考察了两种不同方式下活性污泥合成PHA的情况。实验结果表明,当C：N为125时,活性污泥中PHA的合成量达到细胞干重的59％;当c：P为750时,活性污泥积累的最大PHA含量占细胞干重的37％,说明限氮和限磷两种方式对活性污泥合成PHA均有很大影响,且限氮方式更有效。     

自然灾害风险评估国际计划述评Ⅰ——指标体系

自然灾害风险评估是综合灾害风险管理的关键途径。概述了近年来3个重要的自然灾害风险评估国际计划：灾害风险指标计划（Din）、多发区指标计划（Hotspots）和美洲计划（American Programme）的目标与成果。重点介绍了3个国际计划选取的指标：DRI首次开发了2个脆弱性全球指标;Hotspots发展了3个灾害风险指数;美洲计划开发了4个独立的指标体系,用于描述国家级的灾害风险构成要素,同时,提出城市级的风险评估指标。通过比较3个国际计划选择的指标体系的优缺点,提出选择能全面反映脆弱性和风险特征、计算简便的指标是今后灾害风险评估的关键和重点。     

Review and challenges of policies of environmental protection and sustainable development in China

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.     

关于发展湖北省循环农业的思考

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。     

湘西民族地区农村剩余劳动力转移问题探讨——以湘西龙山县劳动力转移情况为例

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。     

Study of atrazine degradation in subsurface flow constructed wetland under different salinity

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.     

A novel pretreatment approach for fast determination of organochlorine pesticides in biotic samples

Recent studies have focused on enantiomeric behaviors of chiral organochlorine pesticides (OCPs) in biotic matrix because they provide insights into the biotransformation processes of chiral OCPs. In the present paper, a double in-line column chromatographic method was developed to effectively remove the lipid impurity in different biotic samples for clean-up of OCPs. After an initial Soxhlet extraction of OCPs from the biotic samples by a mixture of acetone and dichloromethane (DCM), dimethyl sulfoxide (DMSO) was directly added to the extract, and low boiling point solvents (acetone and DCM) were then evaporated. OCPs remained in DMSO were eluted via column 1 filled with silicon gel, and subsequently passed through column 2 packed with 15% deactivated florisil. This novel method was characterized by significant time and solvent savings. The recovery rates of alpha-HCH (hexachlorocyclohexane), beta-HCH, gamma-HCH and delta-HCH were 78.5+/-3.1%, 72.4+/-7.7%, 72+/-4.0% and 70.0+/-8.7%, respectively, and 92.5+/-3.8%, 79.7+/-6.7% and 83.4+/-6.5% for 1,1-dichloro-2-(2-chlorophenyl)-2-(4- chlorophenyl) ethylene (o,p'-DDE), 1,1-dichloro-2-(2-chlorophenyl)-2-(4-chloro phenyl)ethane (o,p'-DDD) and 1,1,1-trichloro-2-(2-chlorophenyl)-2-(4-chlorophenyl) ethane (o,p'-DDT), separately. In addition, the separation efficiencies of the target compounds by both achiral and chiral gas chromatographic columns were satisfactory using the established method. Therefore, the double in-line column chromatography was a useful alternative method for pretreatment of OCPs in different biotic samples.     

α-环糊精接枝壳聚糖纤维的合成及其对对硝基酚的包合吸附与释放

在氰基硼氢化钠存在的弱酸性条件下将6-去氧-6-甲酰基-α-环糊精接枝到壳聚糖纤维上,制备了α-环糊精接枝壳聚糖纤维.测定了不同温度和时间下,α-环糊精接枝壳聚糖纤维对对硝基酚(PNP)的包合吸附与释放性能,及其包合稳定性常数和热力学参数.结果表明,α-环糊精接枝壳聚糖纤维是一种高效的PNP分离剂,对PNP具有良好的分子识别、包合吸附和释放性能,其PNP包合吸附容量可达到2.93 mg/g,318 K时PNP释放度可达到70%左右,并可反复包合吸附与释放;该包合反应为放热反应,分子间的范德华力起主导作用;包合物的稳定性受温度影响较大,低于298 K时较稳定,318 K时PNP释放达到平衡;在同一温度下,PNP释放度随时间的增加而提高.     

已二酸生产副产物——混合二元酸的综合利用

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。