对当前农村环境保护问题的研究

以农村环境保护问题为研究对象,运用归纳、例证等方法对农村环境问题的危害、产生根源、解决措施进行分析.通过分析环境污染与生态破坏制约农业持续发展、威胁农民生命财产安全、扰乱农村稳定,阐明了农村环境问题的危害,指出农村环境问题是"三农"问题的重要内涵.从滥伐、滥牧、粗放式农业生产、城市污染向农村转移及乡村企业污染加剧等方面剖析了农村环境问题的主要根源.提出了我国农村环境保护的主要措施是加强农村环境政策体系创新、城镇化、发展现代生态农业、推进农业集约化经营、多途径有效控制乡村企业污染等.      

Polychlorinated biphenyls in the atmosphere of Taizhou, a major e-waste dismantling area in China

PM2.5,total suspended particles(TSP) and gas phase samples were collected at two sites of Taizhou,a major e-waste dismantling area in China.Concentrations,seasonal variations,congener profiles,gas-particle partitioning and size distribution of the atmospheric polychlorinated biphenyls(PCBs) were studied to assess the current state of atmospheric PCBs after the phase out of massive historical dismantling of PCBs containing e-wastes.The average 38PCBs concentration in the ambient air(TSP plus gas phase) near the e-waste dismantling area was(12,407 ± 9592) pg/m3 in winter,which was substantially lower than that found one decade ago.However,the atmospheric PCBs level near the e-waste dismantling area was 54 times of the reference urban site,indicating that the impact of the historical dismantling of PCBs containing e-wastes was still significant.Tri-Penta-CBs were dominant homologues,consisting with their dominant global production.Size distribution of particle-bound PCBs showed that higher chlorinated CBs tended to partition more to the fine particles,facilitating its long range air transportation.     

Use of Remote-Trip Cameras for Wildlife Surveys and Evaluating the Effectiveness of Conservation Activities at a Nature Reserve in Sichuan Province,China

Monitoring the effectiveness of management activities within reserves is always a complicated task. When the focus of management activities is mammals, it is difficult to monitor their populations in a way that is rapid, effective, and inexpensive. We report on a mammal survey of a reserve in southwest China using remote-trip cameras. We surveyed 329 locations over 2 field seasons in 2002 and 2003. Sixteen species of mammals were detected with these cameras, with four species documented for the first time. After accounting for variation due to slope, aspect, elevation, and habitat type, the distribution of six species was positively associated with the location of conservation stations and/or patrolling routes. Species of medium-sized mammals are excellent candidates for monitoring programs based on these cameras, due to their relative abundance, sufficient size to be detected by the camera units, and sensitivity to human activity. The distribution of mammals relative to management efforts is a relatively rapid means to assess reserve effectiveness. The repeat use of the cameras as part of a monitoring plan should provide a quantifiable measure of reserve effectiveness.     

Sludge earthworm composting technology by Eisenia fetida

Prior to vermicompost application to the soils, there is a need to determine the heavy metal concentrations in the final vermicomposts. Acute toxicity on Eisenia fetida for copper (Cu) and cadmium (Cd) were conducted by artificial soils tests. The dosage of interest is typically the median lethal concentration (LC₅₀) that will kill 50 % of the population of organisms within the test period. The dry artificial soil is pre-moistened 1 or 2 days before the test by adding deionized water to obtain approximately half of the required final water content of 40–60 % of the maximum water holding capacity. The 14-day LC₅₀ values (95 % confidence interval) for Cu and Cd were 530 (450–624) and 1118 (988–1265) mg kg^?1, respectively. The vermicomposting was designed to evaluate the effects of earthworm activity on heavy metals in sewage sludge. Compared with the sludge before vermicomposting by Eisenia fetida, the results are as follows: (1) water content, the pH value and organic matter content decreased, (2) total nitrogen content increased, total phosphorus content and total potassium content decreased, (3) available nitrogen concentration, available phosphorus content increased, and (4) the total content of five metals (Cu, Ni, Cd, Pb and Zn) decreased, and the bioaccumulation factor shows that vermicomposting can efficiently remove heavy metals. Therefore, it can be concluded that the soil use of sludge of the Wastewater Treatment Plant in Huaibei is feasible.     

北京市饮用水源水重金属污染物健康风险的初步评价

对北京市城区8个区和郊区10个区、县120个样点的饮用水中Cu, Hg, Cd和As的浓度进行了调查研究,并应用目前美国环保局推荐的健康风险评价模型对北京市各区县饮用水中重金属所引起的健康风险作了初步评价.结果表明,城区8个区和郊区10个区、县重金属的平均浓度范围分别为Cu:0.81～6.96 μg·L^-1,Cd: 0.34～0.82 μg·L^-1,Hg: 0.10～0.74 μg·L^-1,As: 0.19～3.02 μg·L^-1.通过饮水途径所致健康风险中,As在通州区所引起的致癌风险最大(2.0×10^-5·a^-1),Cd在昌平区的致癌风险最大(2.3×10^-6·a^-1), 但均低于国际辐射防护委员会(ICRP)推荐的通过饮水途径最大可接受风险水平(5×10^-5·a^-1);在北京市通过饮水途径引起的非致癌健康风险中,Hg的风险最大,Cu次之,但是两者风险水平均在10-8～10^-9·a^-1,远低于ICRP推荐的最大可接受风险水平.     

区域集镇基准地价体系建立研究

以江苏六合县为例,对区域集镇基准地价体系建立方法进行了探讨。研究结果表明,先对集镇土地进行分等,然后以分等结果为控制对级差收益和市场交易地价进行对比和综合,是建立区域集镇基准地价体系的有效途径     

环境中抗生素的富集、分离和监测

抗生素造成的环境污染日趋严重,在我国形势尤为严峻.其污染的现状及其对策、正逐步成为国际国内研究热点,并引起包括我国在内的各国政府的高度重视.加强对环境中抗生素的富集、分离和监测研究巳迫在眉睫.     

CeO2-La2O3/γ-Al2O3稀土氧化物混合物催化还原SO2的实验研究

在La₂O₃ 中加入变价稀土氧化物CeO₂,组成一种稀土氧化物的混合物,以这种混合物作为CO还原SO₂的催化剂.采用连续流动固定床反应器,在反应气体SO₂和CO按SO₂∶CO = 1∶3,载流气体为N₂,气体流量为1000 mL/min的条件下,实验研究了该催化剂的活化过程以及温度和反应物浓度配比对活化反应的影响,用XRD和XPS对反应前后催化剂进行了表征,分析了相结构的变化.结果表明:CeO₂和La₂O₃ 2种稀土氧化物的混合物,在CO还原SO₂的催化反应中,活化温度比单个的CeO₂或La₂O₃氧化物下降了50℃～100℃,而且具有更高的活性.这可能是CeO₂和La₂O₃氧化物之间存在着某种协同作用所致.     

3种水生植物腐解过程中磷营养物质迁移、转化过程研究

室内模拟沉水植物狐尾藻(Myriophyllum verticillatum L)、浮水植物菱角(Trapa bispinosa Roxb)、挺水植物荷花(Lotus flower)在5.7 g·L~(-1)初始生物量密度下的腐解过程,并探究该过程中磷营养物质迁移、转化规律.结果发现,3种植物腐解速率在第2 d上升至最大值(分别为1.075、1.455、1.16 g·d~(-1))后出现下降-上升-下降的变化规律,并且在整个腐解周期内种间差异性显著(p0.01),造成整个腐解周期内狐尾藻、菱角、荷花3种植物平均磷释放速率分别为0.456、0.670、0.537 mg·g~(-1),且以无机磷酸盐为主;水中释放的磷在底泥吸附及其自身沉降等作用下,明显向底泥迁移转化,水中磷含量下降,最终在试验结束时恢复至初始水平(0.5 mg·L~(-1));该研究可为湖泊水生植被系统的修复或重建提供科学参考.     

基于主成分分析的河流水环境质量评价研究

主成分分析是多元统计分析的一个分支,它能够在保证原始数据信息损失最小的情况下,以少数的综合变量取代原有的多维变量,简化数据结构,客观确定权重,是环境质量综合评价的一种简单易行的方法.基于主成分分析理论,建立了水质综合评价模型,以南淝河为例,选取南淝河五个监测断面的九项监测指标作为评价因子,对南淝河的水环境质量进行综合评价.结果表明,南淝河流域水环境质量总体较差,有机污染物是造成南淝河水质污染的主要原因.