畜禽养殖污水生态处理及资源化利用方式的探讨

论述了畜禽养殖场污水的排放特征,并提出污水治理对策。同时阐述了不同类型人工湿地系统用于污水生态处理的优势,并对人工湿地应用畜禽养殖污水资源化的可行性进行分析介绍。     

人工湿地的发展概况和面临的问题

人工湿地是近年来发展的一种新型污水处理技术。主要介绍了人工湿地的几种主要构建类型:表面流型人工湿地、潜流型人工湿地、垂直流型人工湿地和复合垂直流人工湿地,并分别指出它们的优缺点。同时简要阐述了人工湿地去除污染物质的机理。     

人工湿地组合工艺在风景区污水处理中的应用

文章从污水生态处理、中水回用以及污水处理与景观建设相结合等几方面,详细介绍了人工湿地组合工艺这一领先技术在风景区污水处理工程中的应用。重点阐述了世博园污水的排放特性、组合工艺的组成及工程建设内容,并提出人工湿地组合工艺的几大特点及技术应用时需注意的问题。     

潜流人工湿地氮循环生态动力学模型研究

人工湿地作为一种新型的处理技术,在水环境保护中具有重要的意义和广阔的应用前景。然而目前人工湿地的设计和运行主要是建立在统计数据和经验公式的基础上,对人工湿地去除污染物的内在机制尚缺乏定量化的认识。通过对潜流人工湿地氮循环生态动力学模型的研究,系统地分析了潜流人工湿地中氮素的去除机制,对将来完善人工湿地处理技术的设计、运行和预测方法具有一定的借鉴意义。     

人工湿地系统中微生物的研究进展

微生物在人工湿地系统净化污水过程中发挥着重要作用。文章介绍了人工湿地系统中微生物的研究进展,重点讨论了人工湿地对病原微生物的去除以及系统基质中微生物的种群和活性等内容。     

人工湿地处理污水的效率与研究展望

文章阐述了人工湿地处理技术国内外的研究现状,人工湿地对有机物、氮、磷等的去除效率,分析了影响人工湿地处理效率的因素.表明人工湿地的类型、湿地植物种类、基质类型、湿地中微生物的种类和数量、温度、水力停留时间、水力负荷、湿地的运行管理等都会影响人工湿地的处理效率.根据人工湿地在污水处理中的研究和应用现状,指出了今后的研究方向.     

污水湿地处理系统中植物研究现状

文章陈述了植物在人工湿地中的作用,探讨了植物对人工湿地净化污水的影响,对人工湿地系统中植物的选择、种植与管理进行了阐述,提出了人工湿地系统研究与实践存在的问题,以期为人工湿地系统的工程设计、技术研究及运行管理提供参考。     

浅谈人工湿地在污水处理中的应用

在处理污水问题上,人工湿地具有其独特的优势,本文从分析人工湿地的处理机制出发,结合人工湿地在污水处理方面的现状及前景,阐述了人工湿地的应用、存在的问题以及改善措施。     

人工湿地在污水处理中的应用初探

介绍了人工湿地的概念及其对废水中污染物的去除机理，阐述了湿地植物的作用及如何对人工湿地进行维护与管理，举例说明了人工湿地在国内的应用及其发展前景。     

人工湿地生态安全评价指标体系的构建

由于人工湿地涉及的资源范围广、要素多、联系复杂,因此人工湿地生态安全评价指标体系的构建过程中指标的选取与量化具有模糊性和不确定性。本文利用层次分析法理论建立了人工湿地生态安全评价指标体系,通过专家打分,并采用层次分析法计算出各评价指标的权重,从而定量分析了各指标对人工湿地生态安全影响的重要性。该研究可为人工湿地生态安全评价提供参考依据。     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Characteristics of indoor/outdoor PM2.5 and elemental components in generic urban, roadside and industrial plant areas of Guangzhou City, China

Quantitative information on mass concentrations and other characteristics, such as spatial distribution, seasonal variation, indoor/outdoor （I/O） ratio, correlations and sources, of indoor and outdoor PM2.5 and elemental components in Guangzhou City were provided. Mass concentration of PM2.5 and elemental components were determined by standard weight method and proton-induced X-ray emission （PIXE） method. 18 elements were detected, the results showed positive results. Average indoor and outdoor PM2.5 concentrations in nine sites were in the range of 67.7-74.5μg/m^3 for summer period, and 109.9-123.7 μg/m^3 for winter period, respectively. The sum of 18 elements average concentrations were 5362.6-5533.4 ng/m^3 for summer period, and 8416.8-8900.6 ng/m^3 for winter period, respectively. Average concentrations of PM2.5 and element components showed obvious spatial characteristic, that the concentrations in roadside area and in industrial plant area were higher than those in generic urban area. An obvious seasonal variation characteristic was found for PM2.5 and elemental components, that the concentrations in winter were higher than that in summer. The I/O ratio of PM2.5 and some elemental components presented larger than 1 sometimes. According to indoor/outdoor correlation of PM2.5 and element concentrations, it was found that there were often good relationships between indoor and outdoor concentrations. Enrichment factors were calculated to evaluate anthropogenic versus natural elements sources.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

Developing a Regional Open Space Strategy (ROSS) for Central Puget Sound,Washington State,USA

Ecosystem services provided by the landscapes of regions and cities are critical to human and environmental health, quality of life, environmental justice, biodiversity and climate mitigation and adaptation. In the Pacific Northwest region of the US, a team led by the University of Washington Green Futures Lab is working to identify, conserve and enhance regionally-significant landscapes and to evaluate their contributions as ecosystem or “open space” services. This paper outlines the goals and planning methods of the ongoing Regional Open Space Strategy for Central Puget Sound (ROSS) project, and the frameworks and processes being developed to evaluate ecosystem and open space services in order to inform and influence local and regional governance structures and decisions.     

Nitrogen cycling of atmosphere-plant-soil system in the typical Calamagrostis angustifolia wetland in the Sanjiang Plain, Northeast China

The nitrogen (N) distribution and cycling of atmosphere-plant-soil system in the typical meadow Calamagrostis angustifolia wetland (TMCW) and marsh meadow Calamagrostis angustifolia wetland (MMCW) in the Sanjiang plain were studied by a compartment model. The results showed that the N wet deposition amount was 0.757 gN/(m2·a), and total inorganic N (TIN) was the main body (0.640 gN/(m2·a)). The ammonia volatilization amounts of TMCW and MMCW soils in growing season were 0.635 and 0.687 gN/m2, and the denitrification gaseous lost amounts were 0.617 and 0.405 gN/m2, respectively. In plant subsystem, the N was mainly stored in root and litter. Soil organic N was the main N storage of the two plant-soil systems and the proportions of it were 93.98% and 92.16%, respectively. The calculation results of N turnovers among compartments of TMCW and MMCW showed that the uptake amounts of root were 23.02 and 28.18 gN/(m2·a) and the values of aboveground were 11.31 and 6.08 gN/(m2·a), the re-translocation amounts from aboveground to root were 5.96 and 2.70 gN/(m2·a), the translocation amounts from aboveground living body to litter were 5.35 and 3.38 gN/(m2·a), the translocation amounts from litter to soil were larger than 1.55 and 3.01 gN/(m2·a), the translocation amounts from root to soil were 14.90 and 13.17 gN/(m2·a), and the soil (0-15cm) N net mineralization amounts were 1.94 and 0.55 gN/(m2·a), respectively. The study of N balance indicated that the two plant-soil systems might be situated in the status of lacking N, and the status might induce the degradation of C. angustifolia wetland.     

三种含钙物质对土壤砷植物有效性的影响

综述含钙物质（生石灰（CaO）、熟石灰（Ca （OH）₂）及石灰石（CaCO₃））对土壤理化性质（pH值、有机质成分及其含量）、土壤微生物群落结构和As赋存形态及生物有效性的影响与机制,及其对植物As吸收积累和As耐性的影响与机制.综述内容可为准确理解含钙物质影响土壤As的生物有效性和植物对As吸收积累的过程机制,进而合理选择含钙物质调控土壤理化性质降低土壤As生物有效性及其生态环境风险提供理论依据和技术参考,对保障土壤种植安全和作物食品安全具有一定现实意义.     

Integrating mitigation and adaptation into climate and development policy: three research questions

The potential for developing synergies between climate change mitigation and adaptation has become a recent focus of both climate research and policy. Presumably the interest in synergies springs from the appeal of creating win–win situations by implementing a single climate policy option. However, institutional complexity, insufficient opportunities and uncertainty surrounding their efficiency and effectiveness present major challenges to the widespread development of synergies. There are also increasing calls for research to define the optimal mix of mitigation and adaptation. These calls are based on the misguided assumption that there is one single optimal mix of adaptation and mitigation options for all possible scenarios of climate and socio-economic change, notwithstanding uncertainty and irrespective of the diversity of values and preferences in society. In the face of current uncertainty, research is needed to provide guidance on how to develop a socially and economically justifiable mix of mitigation, adaptation and development policy, as well as on which elements would be part of such a mix. Moreover, research is needed to establish the conditions under which the process of mainstreaming can be most effective. Rather than actually developing and implementing specific mitigation and adaptation options, the objective of climate policy should be to facilitate such development and implementation as part of sectoral policies. Finally, analysis needs to focus on the optimal use and expected effectiveness of financial instruments, taking into account the mutual effects between these instruments on the one hand, and national and international sectoral investments and official development assistance on the other.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Biochar: A review of its impact on pesticide behavior in soil environments and its potential applications

Biochar is produced from the pyrolysis of carbon-rich plant- and animal-residues under low oxygen and high temperature conditions and has been increasingly used for its positive role in soil compartmentalization through activities such as carbon sequestration and improving soil quality. Biochar is also considered a unique adsorbent due to its high specific surface area and highly carbonaceous nature. Therefore, soil amendments with small amounts of biochar could result in higher adsorption and, consequently, decrease the bioavailability of contaminants to microbial communities, plants, earthworms, and other organisms in the soil. However, the mechanisms affecting the environmental fate and behavior of organic contaminants, especially pesticides in biochar-amended soil, are not well understood. The purpose of this work is to review the role of biochar in primary processes, such as adsorption–desorption and leaching of pesticides. Biochar has demonstrable effects on the fate and effects of pesticides and has been shown to affect the degradation and bioavailability of pesticides for living organisms. Moreover, some key aspects of agricultural and environmental applications of biochar are highlighted.