Water Quality and Pollution in the Hunchun Basin, China

Chemical properties and pollution of water resources were studied in the Hunchun basin, which is located in northeast China and borders directly North Korea and Russia along the Tumen river. Water quality was characterised according to its major constituents and geological features. Ground waters could generally be grouped into (Ca+Mg)-HCO₃ type and (Ca+Mg)-(SO₃+Cl) type in first and the second terrace areas, respectively. The mixing of these two types depends on the local conditions, such as pumping or permeability variations.Hunchun city is a pollution source for local water resources due to its uncontrolled sewage and urban discharge. In a previous study of the southwestern part of the Hunchun basin, groundwater contamination by Fe, Mn and NO₃-N was reported. In addition, this study identified Cd and F as prevailing contaminants in the water resources. Pollution of water resources by these contaminants appeared to be affected by the application of fertilisers, irrigation practice, variation of aquifer characteristics, solubility of mineral phases, and discharge of domestic sewage. Wide distribution and high levels of Cd and F in surface- and ground waters could pose significant problems if they are utilised as major water supply sources.     

中国水资源管理问题及对策

水资源管理是当今大多数国家资源管理的难题。中国由于其自身的具体国情,在水资源管理上又有新的管理困境。本文对这一困境进行剖析并提出解决问题的对策。     

生态流量的法律表达及制度实现

生态流量制度是流域生态环境保护的重要制度保障,是水资源、水环境、水生态“三位一体”保障体系的重要组成部分,是满足水生态承载能力刚性约束的制度体现。目前,水资源开发利用以及水环境污染防治由《水法》以及《水污染防治法》做出了全面规定,而保障水生态功能实现的生态流量则作为水电工程环境影响评价制度的一个因子予以考量,这显然无法达成“维持水体生态功能”之目标。生态流量制度作为保护水生态功能的独立法律制度,应当在涉水立法中予以明确,同时形成完整的生态流量制度体系。基于此,本文对生态流量在立法中的法律表达提出制度建议,包括:①生态流量底线是为了满足流域及其周边区域原有生态系统功能所需要的水流数量以及水文过程的最低要求。生态流量底线制度包括生态流量底线的划定、生态流量监测以及生态流量底线的适应性管理。②流域生态流量协议,是在生态流量底线之上企业与政府达成的更高标准的生态流量约束,是企业与政府合作进行生态环境治理的新模式;是政府、企业、社会共同保障水生态的制度体现;它在公众参与的基础上形成流域规则嵌套,通过绿色水电认证提高企业落实的积极性。③生态流量法律责任制度依据生态流量底线和流域生态流量协议为用水主体设置的不同义务,分别规定了不同的法律责任。违反生态流量底线要求且拒不改正的按日连续处罚,体现出督促企业遵守生态流量底线要求的立法目的;仅违反流域生态流量协议而未突破生态流量底线要求的,则追究其违约责任,撤销其已享受的生态环境优惠,体现对其违背契约精神的惩罚。     

大辽河流域土壤中微塑料的丰度与分布研究

微塑料在海洋生态系统中的分布特征已有不少研究,但人类活动强度较大的流域土壤中微塑料的污染研究仍存在较大空白。以大辽河流域为研究对象,采集附近8个土壤样品,采用密度浮选法,结合体视显微镜及显微红外光谱(μ-FTIR),进行了大辽河流域土壤中微塑料的组成及分布特征研究。结果表明,土壤中微塑料颜色以白、蓝和绿色为主(88.03%),形状以碎片、薄膜和泡沫为主(总占比为96.32%),土壤中粒径为500～1 000μm的微塑料最多(41.10%),其次依次为1 000～2 000μm(26.38%)、100～500μm(19.33%)和2 000～5 000μm(11.66%)。粒径为0～100μm的微塑料和>5 000μm的塑料碎片所占比例最小(均小于1.00%)。薄膜类和碎片类微塑料的主要成分分别是聚乙烯(PE)和聚丙烯(PP),颗粒类和泡沫类的主要成分是聚苯乙烯(PS),纤维类微塑料的主要成分是聚酰胺(PA)。土壤中微塑料平均丰度为(273.33±327.65)个·kg~(-1)。总体上,该研究区域土壤中微塑料的污染程度处于中等偏低水平。     

Effect of injection timing,injector opening pressure and nozzle geometry on the performance of a compression ignition engine operated on non-edible oil methyl esters from different sources

Increasing cost of fossil fuels, environmental threats from exhaust emissions and their depleting nature have generated intense international interest in developing renewable and alternative fuels for internal combustion engines. This study investigates the suitability of different non-edible-derived biodiesels such as cottonseed oil methyl ester (COME), honne oil methyl ester (HnOME) and honge oil methyl ester (HOME) to four-stroke, single-cylinder compression ignition (CI) engine. Engine tests were conducted to study the effect of fuel injection timing (IT), fuel injector opening pressure (IOP) and injector nozzle geometry on the performance, combustion and emission characteristics of COME, HnOME and HOME in the modified CI engine. IT was varied from 19° to 27° before top dead centre (bTDC) in steps of 4° bTDC; IOP was varied from 205 to 240 bar in steps of 10 bar. Nozzle injectors of three to five holes, each of 0.3 mm size, were selected for the study. It was concluded that a retarded IT of 19° bTDC increased IOP of 230 bar, and four-hole nozzle injector of 0.3 mm size resulted in overall better engine performance with increased brake thermal efficiency and reduced hydrocarbon and carbon monoxide smoke emissions for the fuels tested.     

政府强互惠激励下跨界流域一级水权分散优化配置模型

我国跨界流域水资源冲突问题较严重,一级水权集中配置方案因其过于理想化而实施效率低下,难以应对冲突。提出应在规划和决策的前期给予各类主体充分的利益表达机会,创新一级水权配置模式,构建政府强互惠激励政策协调下的多用水主体分散优化配置模型。首先将分散优化与集中优化进行对比,分析政府强互惠激励下的分散优化协调机制对提高跨界流域水资源的配置效率和配置方案的可操作性的作用;基于分散优化的基本模型,加入政府强互惠节水激励政策,通过节水激励水价这一因子代替原分散优化模型的自利因子,构建一般的一级水权分散优化模型和政府强互惠激励下的一级水权分散优化模型;以漳河流域为例,对模型进行计算及对比分析。研究结果表明:一般分散优化配置模式中,主体的自利性使得流域整体利益受损,尤其是在来水极少的年份;政府强互惠激励下的分散优化配置模式能够兼顾流域宏观和微观的利益。来水量对于跨界流域一级水权配置模式有重要影响,来水量充裕时,政府可放手用水主体进行自主治理,降低行政管理成本;来水量短缺时,政府必须注意改变管理模式,对不同用水主体实施差异化政策激励,加强主体的节水动力;来水量越少,政府强互惠激励下的分散优化配置模式优势越明显。由于既充分考虑各用水主体的利益又能体现流域统一管理理念,因此,政府强互惠激励下的跨界流域一级水权分散优化配置模式在当前流域统一管理和区域分块管理相结合的管理体制下避免了权力冲突。     

Amazonian freshwater habitats experiencing environmental and socioeconomic threats affecting subsistence fisheries

Matching the trend seen among the major large rivers of the globe, the Amazon River and its tributaries are facing aquatic ecosystem disruption that is affecting freshwater habitats and their associated biodiversity, including trends for decline in fishery resources. The Amazon’s aquatic ecosystems, linked natural resources, and human communities that depend on them are increasingly at risk from a number of identified threats, including expansion of agriculture; cattle pastures; infrastructure such as hydroelectric dams, logging, mining; and overfishing. The forest, which regulates the hydrological pulse, guaranteeing the distribution of rainfall and stabilizing seasonal flooding, has been affected by deforestation. Flooding dynamics of the Amazon Rivers are a major factor in regulating the intensity and timing of aquatic organisms. This study’s objective was to identify threats to the integrity of freshwater ecosystems, and to seek instruments for conservation and sustainable use, taking principally fish diversity and fisheries as factors for analysis.     

基于DEA模型的太湖流域企业污水治理效率

运用数据包络分析DEA方法,建立了太湖殷村港流域工业园区企业污水治理效率评价体系,并利用该体系对园区内企业污水治理效率进行了实证研究。利用效率评价函数对园区内20家企业进行评价,结果表明,其中4家企业达到环境治理效率相对高效;20家企业的废水排放量、COD和NH3-N排放削减总量分别为3691860、217．53和14．64t／a,削减潜力较大。实证研究结果表明,该环境绩效评价系统可为园区企业污水治理调控提出定量化的调整建议。     

潍河流域水质管理模型

水质管理模型包括河流模型、农业非点源污染模型和水库富营养化模型。河流模型选择ＱＵＡＬ２ＥＵ模型并加以改进,增加了模拟ＣＯＤ转化,底泥泛起和水体养鱼的非点输入功能,并将非点源模型和水库模型作了技术处理使之同河流模型有机结合在一起。     

人类活动对干旱区内陆河流域景观格局的影响分析——以新疆和田河中游地区为例

通过对新疆和田河中游地区1959年及2000年景观格局的对比分析,结果表明,干旱区内陆河流域基本维持了原宏观景观格局。但在小尺度上,人类通过调控水资源在空间分布的格局,影响了水在景观格局发展中的生态作用,进而影响了区域景观格局。人工渠、水库、居民地、农耕区等人为景观的出现及增多越来越影响着区域内的景观格局。这说明人类活动虽不是区域内景观格局发展的主导因素,但它对干旱区内陆河流域景观格局的影响力度与影响范围却越来越大。