Ecological planning for land use and ruraldevelopment of Taojiang County

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Microbial kinetic analysis of three different types of EBNR process

The disadvantages of developed biological nutrient removal (BNR) processes (additional energy for liquid circulation and addition of external carbon substrate for denitrification in anoxic zones) were improved by reconfiguring the process into (1) an anaerobic zone followed by multiple stages of aerobic-anoxic zones (TNCU3 process) or (2) anaerobic, oxic, anoxic, oxic zones in sequence (TNCU2 process). These two pilot plants were operated at a recycling sludge ratio of 0.5 without internal recycle of nitrified supernatant. The sludge retention time was maintained at 10 d. The main objective of this study is to analyze the kinetics of different microorganisms in these two processes and A2O process by using the Activated Sludge Model No. 2d. The effective removal efficiency of carbon, total phosphorus and total nitrogen at 87-98%, 92-100% and 63-80%, respectively, were achieved in the testing runs. According to model simulations, the microbial kinetics in the TNCU3 and TNCU2 processes would be affected by different operations. When the step feeding strategy was adopted, the HRT was longer due to the less influent flowrate in the front stages and the microbes would grow in quantities by about 6% in the aerobic reactors. In the followed anoxic reactors, the microbes would decrease in quantities by about 12% due to the dilution effect. The dilution effects in TNCU3 and TNCU2 processes did not take place in A2O process because the recycling mixed liquid from the aerobic reactor to the anoxic reactor still contained particulate components. The XH, XPAO, and XAUT concentrations in the effluent of the last tank were lower when the step-feeding mode was adopted. The TNCU3 and TNCU2 processes could be operated efficiently without nitrified liquid circulation and addition of external carbon substrate for denitrification.     

城市生态系统的格局和过程

城市生态系统是人类活动影响下的复合生态系统。人为的开发利用活动和局地的生物物理条件形成了城市特有的景观格局。城市发展改变了自然的生物栖息环境,从根本上改变了生态系统的结构、过程、功能,以及所提供的各种服务。这种改变最终又会影响人类自身的健康生存。文章综述了国内外有关城市景观格局和和重要生态过程之间相互作用机制的研究进展。通过研究发现,在大尺度上,净初级生产力是衡量城市发展对区域物流、能流影响的有效指标;在小尺度上,城市物流、能流过程和城市内部的景观结构、格局有很强的相关性。城市发展显著的改变了自然的栖息地及生物生长过程,本地植被种类减少,外来种增加,外来种的数量和人口数量有显著的相关性;而城市动物群落主要由一些小型哺乳动物、无脊椎动物、鸟类、两栖爬行类动物组成,其中,鸟类是研究城市化过程的有效指示物种。城市生态系统特有的景观格局及生态等过程显著的改了局部区域的微气候和水文过程,城市气温增加,风速降低,云、雾量增加,地表径流增加,流速加大,污染负荷增强等。因此,控制人类活动,优化土地利用的结构和空间格局,是改善城市生态系统结构和过程,保证可持续发展的基本出发点。但是,目前有关城市-格局-过程之间的影响机制还不十分清楚,尤其是定量研究较少。因此,结合传统的城市生态学,景观生态学的理论和其他相关学科领域的发展,为深入分析城市格局-过程之间的关系提供了重要的研究前景。     

森林生态系统的水文调节功能及生态学机制研究进展

森林水文调节功能是森林所实现的重要服务功能之一,可是由于森林资源被无节制的开采利用,导致人们不断遭受森林破环所带来的洪旱灾害。因此关于森林生态水文功能研究已成为生态学和水文学的研究重点之一。近年来,国内外对森林水文调节过程及其生态学机制进行了广泛深入的研究,所以文章从森林的水文过程出发,对林冠截留、树干流、凋落物层截留、林地水分涵养和蒸发蒸腾及其影响因子的国内外研究现状进行了归纳分析,研究认为林地各冠层均能够截留降雨,降低雨水动能,从而减少地表径流的产生和对地表的冲击;凋落物层能蓄留水分、抑制蒸散、减缓地表径流;而树干流改变降雨水平空间格局,影响水分入渗以及土壤水源涵养。森林结构复杂,明显改变了降雨分配过程,而森林水文过程及调节功能又受到森林结构的制约,因此定量定性探讨森林生态系统的结构、过程与水文调节功能之间关系,是未来森林生态水文功能研究的重点。     

水相催化芳香氯化物脱氯研究

通过把起相转移作用的聚乙二醇（PEG）链，键合到硅胶上，再将聚乙烯吡咯烷酮（PVP）络合双金属Pd-Cu后负载其上，制成一种新型双负载双金属催化剂PVP－PdCl2/SiO2-PEG600,以甲酸钠为氢转移试剂，在水相催水芳香氯化物脱氯，当反应温度80℃左右，n(Pd):n(Cu）=2:1，反应介质pH值11．7左右时，具有较高的催化脱卤活性，催化剂不但易于制备，便于分离，且具有良好的重复使用性能，经重复使用六次，转化率仍在70％以上。     

Occupational exposure assessment of phthalate esters in indoor and outdoor microenvironments

Phthalate esters(PAEs) are widely used as plasticizers in consumer products. PAEs are a group of environmental hormone which disrupts human and animals' endocrine systems. Different occupational groups are exposed to various levels of PAEs. In the present study, four typical occupational groups were chosen, including doctors, college teachers, college students, and drivers who worked in public traffic system. In order to understand the exposure levels to PAEs via inhalation, air samples were collected from multiple microenvironments including indoor and outdoor in Hangzhou to measure the gas and particle concentrations of six PAEs, together with time spent in different microenvironments of these four groups. A comprehensive PAEs exposure model was built to estimate the daily PAEs exposure through inhalation, oral and dermal pathways. The Monte Carlo simulation results show that doctors were exposed to the highest level of PAEs, and consequently had the highest health risk among these four occupational groups. In contrast, college students had the lowest health risk. By setting the exposure level of staying in residences as the baseline, doctors and drivers were two occupations exposed to high PAEs health risk. Di-(2-ethylhexyl) phthalate(DEHP) was the largest contributor among the six phthalates, posing moderate health risk(10-5–10-6) to every occupation. For traffic microenvironments alone, the total exposure levels for different transportation modes were in the descending order of busses, cars, cabs, tubes, motor bikes, and walking.     

宜昌市水环境质量红线划分与空间管控研究

在宜昌市水环境质量红线划分中,对饮用水源保护区划分、水环境功能区划分和流域控制单元划分给予评估,分析在城市水环境质量红线划分上的可取之处,在自然社会综合系统框架下创造性的提出了适应宜昌城市环境总体规划中水环境质量红线划分的原则、技术方法和分级管控措施,提出的原则与适宜的管控措施为宜昌市水环境质量改善、环境公共服务实现与生态城市建设提供了支持,丰富并实践了生态保护红线体系.     

Evaluation of the economic and environmental impact of converting cropland to forest: a case study in Dunhua county, China

The Sloping Land Conversion Program (also known as "Grain for Green" or the Upland Conversion Program) for converting cropland to forest is one of China's most ambitious environmental initiatives, and is one of the world's largest land-conservation programs with a budget of RMB 337 billion (over US$ 40 billion). Although environmental impacts have played a vital role in the general reasoning and argumentation for forest plantations, environmental impact analyses have often received less attention than economic analyses in the planning of plantation forestry projects. The overall goal of this paper is to evaluate the program's environmental impact considering the farmer's interests and the potential social benefits due to carbon sequestration in different scenarios based on household and field survey data in Dunhua County. Our findings are that: (1) in many cases, the program did not give adequate consideration to land productivity and environmental heterogeneity when selecting plots; (2) more than half of the reforestation plots were on flat cropland (slopes of less than 5 degrees ); (3) in five of the eight townships, net incomes on reforested land were substantially above or below previous crop incomes, raising questions about the efficiency of the allocation of compensation to farmers participating in the program; (4) the potential carbon co-benefit increased the NPV of the program by 5954-7009 RMB/ha. In conclusion, we recommend that more attention should be paid to the quality of reforestation programs rather than just their scale and note that consideration of potential carbon sequestration co-benefits enhances the benefits of cropland conversion programs.