大力推进城市资源循环利用基地建设——以北京市朝阳区资源循环利用产业基地为例

资源循环利用基地的建设是破解城市固体废弃物“邻避效应”的创新道路,有助于新型城市功能区的建设,是推进资源循环利用的主要方式。以北京市朝阳区资源循环利用产业基地为例,研究其基地建设的优势基础及制约因素,通过探索基地建设模式,分析了基地建设的总体思路和重要举措,以期为其他地区资源循环利用基地建设提供经验。     

土壤污染风险规制中的行政裁量研究

我国土壤污染风险规制在专家遴选标准、建设用地和农用地污染风险管控要求,以及风险管控措施等方面存在不同程度的行政裁量。社会理性和科学理性的缺失形成了土壤污染风险行政裁量困局。土壤污染信息制度中“适时公开”的规定使得公众缺乏必要污染信息,弱化其参与程度,导致对行政决定合法性的质疑。此外,土壤污染风险管控标准中专家遴选标准和论证规则的欠缺导致土壤污染风险规制科学理性的缺失。为此,需要建构关照事实和规范的协商式行政裁量模式,强调公众的实质性参与以弥合技术理性和公众理性的鸿沟。同时,在程序上确定专家遴选标准和风险管控标准的论证规则以保证土壤污染风险管控的科学性和客观性。在不妨碍行政裁量权灵活性和能动性的前提下,规范行政裁量权的行使,控制行政裁量权的滥用。     

区域主体功能实现与自然资源利用的定量关系研究

主体功能区划通过主体功能划分的方式将开发和保护结合,自然资源开发利用复杂化过程中资源利用与目标实现之间亟需实现基本的定量核算关系。本文从自然资源可持续利用角度,试图探讨建立初步的主体功能核算关系,通过核算框架进行生产、生活、生态主体功能概算与比较。以京津冀主体功能区与水资源为例,对所设立的核算关系进行了验证与应用,并构造绝对与相对量指标量化京津冀主体功能量、功能水资源投入量与效率,进行了异空间尺度与异质性功能的比较,为以主体功能实现最大化为目标的资源优化配置提供量化工具。结果显示:①利用生态服务价值测算的当量因子法与水足迹测算的投入产出法,刻画了水资源对于地区主体功能的支撑作用。②利用功能总量与单位功能水资源投入量指标完成了异质性功能在异质性空间上规模、结构、相应水资源效率的比较。基于算例结果得到以下结论:①本文构建的自然资源-主体功能核算关系框架能够有效衔接主体功能规划,定量核算能有效反映与评价资源对区域功能目标、经济开发活动的支撑作用。②区域资源配置存在相对功能实现的效率差异,可根据资源投入与功能产出之间的关系引导实现功能最大化目标的资源配置。合理、有效的量化手段能够推进主体功能制度的落实,也有助于当前中国空间规划体系编制与落实的实际指导效果。     

Point Sampling Digital Imagery with ‘Samplepoint’

Measuring percent occurrence of objects from digital images can save time and expense relative to conventional field measurements. However, the accuracy of image analysis had, until now, not reached the level of the best conventional field measurements. Additionally, most image-analysis software programs require advanced user training to successfully analyze images. Here we present a new software program, ‘SamplePoint,’ that provides the user a single-pixel sample point and the ability to view and identify the pixel context. We found SamplePoint to allow accuracy comparable with the most accurate field-methods for ground-cover measurements. Expert use of the program requires minimal training and its ease of use allows rapid measurements from image data. We recommend SamplePoint for calibrating the threshold-detection level of image-analysis software or for making direct measurements of percent occurrence from digital images.     

Estimation of Land Use Specific Runoff and Pollutant Concentration for Tapi River Basin in India

Non-point source (NPS) pollution is the result of various land use practices such as agriculture, sites of construction and waste disposal, urban development and so on. The control of NPS pollution is possible by regular monitoring and assessment on watershed basis to educate people for implementing well-known structural and non-structural measures. Recent trend is to use GIS based modelling tool for assessment of rainfall-runoff and non-point loading. The approach requires generation and analysis of basin wide data on various features of land and estimates of Event Mean Concentrations (EMCs) of pollutants in the runoff. In the present paper, basin wide data in different districts of Tapi basin has been analysed for land use distribution; fertilizer application; low, medium and high-density habitation; and annual rainfall. Coefficients of runoff have been estimated considering pervious and impervious area for different land use types, and compared with the reported values for Indian conditions. The estimated mean annual runoff flow indicated that two districts Jalgaon and Dhule contribute maximum runoff to the Tapi River. Estimates of EMCs for BOD and nutrients (N and P) in the runoff from various districts are useful in GIS-based modelling study for NPS pollution assessment.     

Sediment and Suspended Matter Lead Contamination in the Gulf of Kavala, Greece

Sediment and suspended particulate matter samples from 24 stations in the Gulf of Kavala have been examined for lead contamination. Grain size analysis and organic matter content were also performed. Total – anthropogenic sediment lead concentrations and enrichment factors at stations close to harbors and chemical industries were found higher (up to 209–135μg/g and 4.12 respectively), in relation to concentrations from the rest of the coastal zone. In the above areas, increased suspended particulate lead in the bottom of the water column was also recorded (up to 109μg/g). Total sediment lead concentrations composed of high natural Pb background increased with decreasing grain size, suggesting their association with the fine fractions of the sediments (31.1–66.0% mud presence) and the organic matter content (6–9% higher values). Overall, higher total lead concentrations in the sediments, determined by this work, appear to be significantly different from those reported for the Gulf of Kavala in previous studies and similar to those detected in other highly contaminated eastern Mediterranean coastal areas.     

Fruit Stones from Industrial Waste for the Removal of Lead Ions from Polluted Water

Lead, one of the earliest metals recognized and used by humans, has a long history of beneficial use. However, it is now recognized as toxic and as posing a widespread threat to humans and wildlife. Treatment of lead from polluted water and wastewater has received a great deal of attention. Adsorption is one of the most common technologies for the treatment of lead-polluted water. This technique was evaluated here, with the goal of identifying innovative, low-cost adsorbent. This study presents experiments undertaken to determine the suitable conditions for the use of peach and apricot stones, produced from food industries as solid waste, as adsorbents for the removal of lead from aqueous solution. Chemical stability of adsorbents, effect of pH, adsorbents dose, adsorption time and equilibrium concentration were studied. The results reveal that adsorption of lead ions onto peach stone was stronger than onto apricot stone up to 3.36% at 3 h adsorption time. Suitable equilibrium time for the adsorption was 3–5 h (% Pb adsorption 93% for apricot and 97.64% for peach). The effective adsorption range for pH in the range was 7–8. Application of Langmuir and Freundlich isotherm models show high adsorption maximum and binding energies for using these adsorbents for the removal of lead ions from contaminated water and wastewater.     

沸石在水污染控制中的研究与应用进展

综述了沸石在水污染控制领域的理论研究和应用的进展。     

Integrated Risk Framework for Onsite Wastewater Treatment Systems

Onsite wastewater treatment systems (OWTS) are becoming increasingly important for the treatment and dispersal of effluent in new urbanised developments that are not serviced by centralised wastewater collection and treatment systems. However, the current standards and guidelines adopted by many local authorities for assessing suitable site and soil conditions for OWTS are increasingly coming under scrutiny due to the public health and environmental impacts caused by poorly performing systems, in particular septic tank-soil adsorption systems. In order to achieve sustainable onsite wastewater treatment with minimal impacts on the environment and public health, more appropriate means of assessment are required. This paper highlights an integrated risk based approach for assessing the inherent hazards associated with OWTS in order to manage and mitigate the environmental and public health risks inherent with onsite wastewater treatment. In developing a sound and cohesive integrated risk framework for OWTS, several key issues must be recognised. These include the inclusion of relevant stakeholders throughout framework development, the integration of scientific knowledge, data and analysis with risk assessment and management ideals, and identification of the appropriate performance goals for successful management and mitigation of associated risks. These issues were addressed in the development of the risk framework to provide a generic approach to assessing risk from OWTS. The utilisation of the developed risk framework for achieving more appropriate assessment and management techniques for OWTS is presented in a case study for the Gold Coast region, Queensland State, Australia.     

Effect of Cadmium on Microbial Activity and a Ryegrass Crop in Two Semiarid Soils

Soil pollution with Cd is an environmental problem common in the world, and it is necessary to establish what Cd concentrations in soil could be dangerous to its fertility from toxicity effects and the risk of transference of this element to plants and other organisms of the food chain. In this study, we assessed Cd toxicity on soil microorganisms and plants in two semiarid soils (uncultivated and cultivated). Soil ATP content, dehydrogenase activity, and plant growth were measured in the two soils spiked with concentrations ranging from 3 to 8000 mg Cd/kg soil and incubated for 3 h, 20 days, and 60 days. The Cd concentrations that produced 5%; 10%;, and 50%; inhibition of each of the two soil microbiological parameter studied (ecological dose, ED, values) were calculated using two different mathematical models. Also, the effect of Cd concentration on plant growth of ryegrass (Lolium perenne, L.) was studied in the two soils. The Cd ED values calculated for soil dehydrogenase activity and ATP content were higher in the agricultural soils than in the bare soil. For ATP inhibition, higher ED values were calculated than for dehydrogenase activity inhibition. The average yields of ryegrass were reduced from 5.03 to 3.56 g in abandoned soil and from 4.21 to 1.15 g in agricultural soil with increasing concentrations of Cd in the soil. Plant growth was totally inhibited in abandoned and agricultural soils at Cd concentrations above 2000 and 5000 mg/kg soil, respectively. There was a positive correlation between the concentration of Cd in the plants and the total or DTPA-extractable concentrations of Cd in the soil.