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1.
资源可持续利用是实现中国可持续发展和生态文明的重要保障,然而过去30多年经济的快速发展带来了严重的资源短缺和环境污染。为了揭示1949年以来尤其是改革开放以来中国资源利用与经济发展之间的关系,论文系统梳理中国资源供给状况,总结中国资源进出口及资源产出率演化特点、面临的挑战及相应的对策。研究发现:中国近年来进口以金属矿产、石油、部分固体废弃产品构成的自然矿产和城市矿产资源为主,主要出口以工业产品、水海产品等为代表的资源类型,进出口的结构类型随年份变化不大,但进口量呈现快速增长的态势;中国资源产出率逐步增长,达到1.6元/kg,但仍与发达国家有较大差距。为了应对面临的挑战,未来中国应着力提升在全球价值链的地位,同时国内应大力发展循环经济,提高资源产出率。  相似文献   

2.
In this paper, we present an overview of guidelinesdeveloped for the monitoring, evaluation, reporting,verification, and certification (MERVC) ofenergy-efficiency projects for climate changemitigation. The monitoring and evaluation ofenergy-efficiency projects is needed to determine moreaccurately their impact on greenhouse gas (GHG)emissions and other attributes, and to ensure that theglobal climate is protected and that countryobligations are met. Reporting, verification andcertification will be needed for addressing therequirements of the Kyoto Protocol. While the cost ofmonitoring and evaluation of energy-efficiencyprojects is expected to be about 5–10% of a project'sbudget, the actual cost of monitoring and evaluationwill vary depending on many factors, including thelevel of precision required for measuring energy andGHG reductions, type of project, and amount of fundingavailable.  相似文献   

3.
珊瑚钨锡矿硅质尾矿中Cd、As、Zn、F富集迁移及环境污染   总被引:1,自引:0,他引:1  
硅质尾矿在释放中性矿山废水(NMD)时所伴生的多元素复合污染问题值得重视。本文以桂东北珊瑚矿尾矿作为研究对象,通过分析该尾矿的组构、元素富集及迁移特性,筛选出主要污染元素,并探讨尾矿胶结层对元素富集迁移的影响。结果表明:(1)该尾矿中Cd、As、Zn及F富集程度较高、可交换态含量(易迁移释放量)较大,是主要的污染元素,而Cu、Pb、Tl产生污染的可能性较小;(2)胶结层对重金属具有再富集作用,但其对可交换态Cd、As(Tl)再富集明显,而对可交换态Cu、Pb、Zn再富集则不明显。胶结层中次生伊利石、石膏等胶结物趋向于吸附富集活性可交换态Cd、As。这表明该尾矿可能迁移释放出含Cd、As浓度较高的NMD。研究表明,硅质尾矿风化释出NMD的同时,可能伴生Cd、As、Zn等重金属以及F的复合污染。  相似文献   

4.
山水林田湖草生态保护修复试点战略路径研究   总被引:1,自引:0,他引:1  
王波  何军  王夏晖 《环境保护》2020,48(22):50-54
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5.
张杨  杨洋  江平  邓红蒂  祁帆  李强  常献伟  程鹏 《自然资源学报》2022,37(11):3005-3018
山水林田湖草生命共同体是对人与自然和谐统一关系的新认知,是生态文明理论的重要组成部分。以建立一个山水林田湖草生命共同体的研究范式为目的,系统剖析了山水林田湖草生命共同体理论与应用在基础探索、快速发展和多元繁荣三个阶段的研究重点与特征;再次审视了山水林田湖草生命共同体的内涵、阐明了概念新认知、基本特征、人与生命共同体关系;最后提出面向山水林田湖草生命共同体的“问题—目标—时空策略—目的”的实施路径,及构建以自然资源监测监管体系、自然资源资产产权体系、国土空间规划体系、国土空间用途管制体系、国土空间生态修复体系、法律法规体系等为主的制度体系,进而提升其科学性和实用性,为构建国土空间治理体系及治理能力现代化提供决策支撑。  相似文献   

6.
水体富营养化的形成、危害和防治   总被引:66,自引:3,他引:66  
对水体富营养化的形成过程、富营养化给水质造成的影响和危害及富营养化问题的防治对策进行了简要的概括和总结。认为富营养化问题应该引起我们足够的重视  相似文献   

7.
Sediments in Lake Izabal, Guatemala, contain substantial lead (Pb), zinc (Zn), and nickel (Ni). The lack of historical data for heavy metal concentrations in the sediments makes it difficult to determine the sources or evaluate whether inputs of metals to the lake have changed through time. We measured the relative abundances and concentrations of Pb, Zn, and Ni by X-Ray Fluorescence core scanning and by Inductively Coupled Plasma Optical Emission Spectrometry in three sediment cores to explore stratigraphic distributions of metals in the lake deposits. High amounts of Pb and Zn in the core taken near the Polochic Delta suggest that galena and sphalerite mining increased Pb and Zn delivery to Lake Izabal between ~1945 and 1965 CE. An up-core Ni increase in the core taken near a different mine on the north shore of Lake Izabal suggests that recent nickel mining operations led to an increase in Ni concentrations in the local sediments, but amounts in the other cores indicate that Ni is not widely distributed throughout the lake. Sediment cores from Lake Izabal are reliable recorders of heavy metal input to the lake, and were measured to establish background metal levels, which would otherwise be unavailable. Concentrations of Pb, Zn, and Ni in older, pre-20th-century Lake Izabal sediments reflect input from natural erosion of bedrock. Our results provide previously unavailable estimates of background metal concentrations in Lake Izabal before the onset of mining. These results are necessary for future monitoring related to mining contamination of the lake ecosystem.  相似文献   

8.
Sathaye  J.A.  Makundi  W.R.  Andrasko  K.  Boer  R.  Ravindranath  N.H.  Sudha  P.  Rao  S.  Lasco  R.  Pulhin  F.  Masera  O.  Ceron  A.  Ordonez  J.  Deying  X.  Zhang  X.  Zuomin  S. 《Mitigation and Adaptation Strategies for Global Change》2001,6(3-4):185-211
This paper summarizes studies of carbon (C) mitigation potential and costs of about 40 forestry options in seven developing countries. Each study uses the same methodological approach – Comprehensive Mitigation Assessment Process (COMAP) – to estimate the above parameters between 2000 and 2030. The approach requires the projection of baseline and mitigation land-use scenarios. Coupled with data on a per ha basis on C sequestration or avoidance, and costs and benefits, it allows the estimation of monetary benefit per Mg C, and the total costs and carbon potential. The results show that about half (3.0 Pg C) the cumulative mitigation potential of 6.2 Petagram (Pg) C between 2000 and 2030 in the seven countries (about 200× 106 Mg C yr-1) could be achieved at a negative cost and the remainder at costs ranging up to $100 Mg C-1. About 5 Pg C could be achieved, at a cost less than $20 per Mg C. Negative cost potential indicates that non-carbon revenue is sufficient to offset direct costs of these options. The achievable potential is likely to be smaller, however, due to market, institutional, and sociocultural barriers that can delay or prevent the implementation of the analyzed options.  相似文献   

9.
Co-exposure to heavy metal and antibiotic pollution might result in complexation and synergistic interactions, affecting rice growth and further exacerbating pollutant enrichment. Therefore, our study sought to clarify the influence of different Tetracycline (TC) and Cadmium(Cd) concentration ratios (both alone and combined) on rice growth, pollutant accumulation, and transportation during the tillering stage in hydroponic system. Surprisingly, our findings indicated that the interaction between TC and Cd could alleviate the toxic effects of TC/Cd on aerial rice structures and decrease pollutant burdens during root elongation. In contrast, TC and Cd synergistically promoted the accumulation of TC/Cd in rice roots. However, their interaction increased the accumulation of TC in roots while decreasing the accumulation of Cd when the toxicant doses increased. The strong affinity of rice to Cd promoted its upward transport from the roots, whereas the toxic effects of TC reduced TC transport. Therefore, the combined toxicity of the two pollutants inhibited their upward transport. Additionally, a low concentration of TC promoted the accumulation of Cd in rice mainly in the root tip. Furthermore, a certain dose of TC promoted the upward migration of Cd from the root tip. Laser ablation-inductively coupled plasma mass spectrometry demonstrated that Cd mainly accumulated in the epidermis and stele of the root, whereas Fe mainly accumulated in the epidermis, which inhibited the absorption and accumulation of Cd by the rice roots through the generation of a Fe plaque. Our findings thus provide insights into the effects of TC and Cd co-exposure on rice growth.  相似文献   

10.
不同玉米品种Cd、Pb、Zn和As积累与转运特性   总被引:2,自引:2,他引:0  
通过田间试验,研究了22个玉米品种同时在未污染、轻度、中度和重度重金属Cd、Pb、Zn和As复合污染农田土壤条件下,玉米植株各部位对Cd、Pb、Zn和As的富集和转运特性,并对Cd、Hg、As、Pb、Cr、Cu、Ni和Zn这8种重金属元素进行了主成分分析和相关性分析,探讨了玉米植株吸收Cd、Pb、Zn和As含量与土壤中重金属元素形态含量的关系.结果表明:①玉米植株不同部位Cd和Zn含量分布规律为:穗上茎叶>穗下茎叶>根>籽粒,Pb分布规律为:根>穗下茎叶>穗上茎叶>籽粒,As分布规律为:根>穗上茎叶>穗下茎叶>籽粒,分布规律的不同与作物本身积累特性以及研究区土壤中Cd、Pb、Zn和As的环境活性高低密切相关.②22个玉米品种遗传背景的较大差异造成品种间Cd和Pb的积累具有显著差异(P<0.05),表现为4种趋势:Cd和Pb复合高积累品种,单一Cd或Pb低积累品种(低Cd高Pb、低Pb高Cd),Cd和Pb复合低积累品种.其中3个品种籽粒Cd含量超过国家食品安全标准,14个品种茎叶Cd含量超过国家饲料卫生标准;所有品种茎叶和籽粒Pb含量均未超标,但部分品种籽粒Pb含量接近限值具有超标风险;不同玉米品种茎叶和籽粒As含量均远低于标准限值,表现出稳定的低积累特性;不同玉米品种茎叶Zn含量随土壤Zn含量的升高而升高,但籽粒Zn含量维持在满足植株正常生长的阈值范围内.③研究区玉米植株中Cd、Pb、Zn和As具有一定的同源性,主要受土壤中Cd、Pb、Zn和As污染物含量超标的影响较为深刻,这说明矿山采选和尾矿堆存带来的人为来源,玉米植株中Cu元素受到一定人为污染来源的影响,但影响程度有限;玉米植株中Hg、Ni和Cr元素间具有一定的同源性,说明成土母质和风化产物累积的自然来源.④玉米植株各部位Cd、Pb、Zn和As元素含量,以及Cr和Ni元素含量均具有极显著正相关性(P<0.01),Cd、Pb、Zn和As元素在植物体内的运输机制可能有共同之处,从玉米根部向地上部迁移方面表现出协同效应,Cr和Ni元素同样如此.而玉米茎叶中Hg与Cd、Pb、Zn和As元素,以及籽粒中Hg与Cd、Hg、As、Pb、Cr、Ni和Zn元素均表现出一定的拮抗作用.⑤采用对照优选法将同时满足:茎叶Cd、Pb和As含量未超过国家饲料卫生标准,籽粒Cd、Pb和As含量未超过国家食品安全标准,籽粒Cd、Pb和As聚类分析为低积累类群,植株茎叶和籽粒Cd、Pb和As富集和转运系数较低作为优选条件,筛选出C18(先玉335)可作为Cd、Pb和As复合低积累且籽粒Zn含量维持在正常水平的优选玉米品种,适宜在北方工矿企业周边重金属复合污染农田推广应用.  相似文献   

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砷的发生、形态、污染源及地球化学循环   总被引:7,自引:1,他引:6  
文章首先总结了砷在地表水、地下水、土壤、沉积物、岩石、大气中的含量和分布;归纳了砷的地球化学循环过程;分析了砷在水和土壤/沉积物固相中的形态;并重点阐述了砷在土壤和沉积物中的迁移转化机理。砷通常与Fe、Al、Mn的氧化物和氢氧化物、粘土矿物、硫化物、磷酸盐和碳酸盐矿物结合,砷的生物可用性和迁移性与其在土壤和沉积物中的形态有密切关系。文章最后定量阐述了砷的污染源,包括金属开采与冶炼,化学燃料的燃烧和含砷化学品使用。  相似文献   

17.
Boron- and cerium-codoped TiO2 photocatalysts were synthesized using modified sol-gel reaction process and characterized by X- ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), particle size distribution (PSD), diffuse reflectance spectra (DRS), and Brunauer-Emmett-Teller (BET). The photocatalytic activities were evaluated by monitoring the degradation of dye Acid Red B (ARB). The results showed that the prepared photocatalysts were mixed oxides mainly consisting of titania, ceria, and boron oxide. The structure of TiO2 could be transformed from amorphous to anatase and then to rutile by increasing calcination temperature; the transformation being accompanied by the growth of particle size without any obvious change in phase structure of CeO2. The XPS of B1.6Ce1.0-TiO2 prepared at 500℃ showed that a few boron atoms were incorporated into titania and ceria lattice, whereas others existed as B2O3. Cerium ions existed in two states, Ce^3+ and Ce^4+, and the atomic ratio of Ce^3+/Ce^4+ was 1.86. When boron and cerium were doped, the UV-Vis adsorption band wavelength showed an obvious shift toward the visible range (〈526 nm). As the atomic ratio of Ce/Ti increased to 1.0, the absorbance edge wavelength increased to 481 nm. The absorbance edge wavelength decreased for higher cerium doping levels (Ce/Ti=2.0). The particles size ranged from 122 to 255 nm with a domain at 168 nm (39.4%). The degradation of ARB dye indicated that the photocatalytic activities of boron- and cerium-codoped TiO2 were much higher than those of P25 (a standard TiO2 powder). The activities increased as the boron doping increased, whereas decreased when the Ce/Ti atomic ratio was greater than 0.5. The optimum atomic ratio of B/Ti and Ce/Ti was 1.6 and 0.5, respectively.  相似文献   

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谷胱甘肽S-转移酶的功能、应用及克隆表达   总被引:7,自引:0,他引:7  
谷胱甘肽S-转移酶(glutathione S-transferases,GSTs,E.C.2.5.1.18)是由多个基因编码、具有多种功能的超家族酶,广泛存在于动物、植物、微生物等多种生物组织中。在生物体遇到高盐、干旱、除草剂、有机污染物等逆境时,GSTs常发挥其Ⅱ相代谢酶和抗氧化酶的双重功能,以保护生物体免受逆境的损害。文章综述了GSTs的分类、结构、功能、应用及克隆表达等方面的研究进展。  相似文献   

20.
云台山景区位于贵州省东部的施秉县,是世界自然遗产提名地,发育白云岩喀斯特地貌。景区白云岩不仅是形成景观的物质基础,而且蕴含着丰富的岩石学、沉积学及地球化学信息。景区白云岩为准同生成因,岩石类型多样,主要有粉-微晶白云岩、不等晶白云岩、细-粉晶藻砂屑白云岩、层纹-条纹-条带-薄层状藻砂屑微-泥晶白云岩、亮-泥晶藻鲕粒藻砂屑白云岩及角砾状泥晶白云岩等6类。白云岩的δ13 C值变化在-1.81‰~1.44‰之间,平均值-0.78‰;δ18 O值变化在-7.39‰~-4.1‰之间,平均值-5.11‰。白云岩的沉积构造,既有层理构造,也有层面构造。层理构造主要有水平层理和水平条带层理,层面构造有对称波痕、不对称波痕及叠置波痕。景区白云岩的类型、结构、沉积构造及碳氧同位素组成特点所反映的沉积环境为局限碳酸盐台地,其水体较浅,但咸化程度高,水动力强度弱-中等。  相似文献   

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