Changes of Land Use and of Ecosystem Service Values in Sanjiang Plain, Northeast China

Agricultural activities, especially reclamation, are considered major threats to the wetland ecosystems in Sanjiang Plain, the largest concentrated area of the freshwater wetlands in China. In the past decades, the area of the cultivated land and its grain production have been increased at the cost of wetlands shrinkage. The large-scale land reclamation severely affected the ecosystems in this region. However, such effects at the regional scale are seldom evaluated quantitatively. We used three datasets of LANDSAT MSS and/or TM imagery to estimate the area changes and the transition of land use types from 1980 to 2000. We also valued changes in ecosystem services delivered by each land category using value coefficients published by Costanza et al. [Nature 387, 1997, 253–260]. Sensitivity analysis suggested that these estimates were relatively robust. Finally, the contribution of various ecosystem functions was ranked to the overall value of the ecosystem services in this study. According to our estimates, the total annual ecosystem service values in Sanjiang Plain have declined by about 40% between 1980 and 2000 ($156284–182572.18 million in total over 20 years). This substantial decline is largely attributed to the 53.4% loss of wetlands. For individual ecosystem functions, waste treatment, water supply and disturbance regulation account for more than 60% to the total ecological values. During those two decades, the contribution of disturbance regulation, cultural and recreation decreased, while the contribution of water regulation, nutrient cycling, food production, raw materials and climate regulation increased during the same period. We also put forward a few proposals concerning the future land use policy formulation and sustainable ecosystems. They are adjusting the ‘food first’ agricultural policy, establishing more nature reserves for wetlands, creating systems for the rational use of water, harnessing the degraded cultivated land and encouraging eco-tourism.     

天然气净化厂放空废气对环境的影响及控制措施

天然气净化厂除正常生产有工艺废气排放外,传统装置检修开停产过程、供电或设备异常情况下,会有大量酸气、原料气通过放空火炬燃烧后排放。文章主要分析了天然气净化装置放空废气排放情况及其对周边环境的影响,阐述了异常放空、检修开停产过程原料气和酸气放空的控制措施及其环境效益。     

含油污泥热解处理的试验与应用

介绍了欢三联含油污泥热解处理工程的工艺流程、技术要点、设计参数、运行效果和效益情况。调试工作表明,热解炉系统工艺作为一个整体,能够稳定有效运行,残渣的测验结果表明,残渣可以达到无害化程度,含油率小于0.3%(满足GB 4284-84《农用污泥中污染物控制标准》的要求)。以12t/d的处理量运行,能耗成本为74.47元/t,产生的经济效益为125.50元/t,同时产生较好的社会效益。另外,热解固态产物也有较好的利用价值,可以进一步研究利用。     

大连石化污水处理场二期活性污泥培养驯化的实践

A/O生化池首次启动时的生物培养至关重要。大连石化公司污水处理场二期工程采用生物接种、微生物的培养和驯化,得出:开始接种后,A、B两个系列A/O池的污泥浓度呈连续上升的趋势,污泥浓度增加到2000～3000mg/L,可以进入培养驯化阶段;控制好A/O池的pH值、碱度、无机盐、氮源、泥龄、污泥指数等运行参数,可以较好地调整控制微生物的生物氧化方向,尽快达到驯化目的。     

城市地下水可持续开采量确定方法的研究

首先介绍和分析了国内外相关地下水开采量概念,指出地下水的可持续利用是今后地下水资源发展的必然趋势.然后介绍了地下水可持续开采量的计算机仿真模型,指出传统的地下水开采量计算大都是采用确定性模型,在计算中忽略了一些不确定性因素.最后综述了考虑不确定性因素的随机模拟方法蒙特卡罗方法在地下水可持续开采方面的应用.     

Modeling community participation and other factors affecting biodiversity protection projects in China

A statistical model of community participation and investment in biodiversity protection projects was developed in order to understand patterns in the effectiveness of conservation actions in forest-edge communities in Gansu, China. Extensive questionnaires were used to validate the model. The effectiveness of biodiversity programs is strongly and positively influenced by the level of public participation and investment. Higher education improves the use of resources associated with conservation, such as reduced hunting, reduced use of forest products, and the use of fuels other than wood. Nevertheless, it will be important to balance the implementation of conservation programs with the rights of communities to earn or gather a livelihood. The CBI model will benefit from further development, but proves to be a valuable tool for evaluating the design and effectiveness of biodiversity protection programs. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

应用分散剂控制水面溢油污染的环境影响分析及建议

喷洒分散剂是一种广泛采用的水面事故性溢油应急措施.在分析了分散剂分散效果及其影响因素、分散剂的毒性及其生态环境影响、不同国家对于分散剂的使用及管理规定和中国关于分散剂的研究与使用管理现状的基础上,提出了中国分散剂研究与使用管理建议,主要包括:(1)建立国家级分散剂重点实验室,深入分散剂生态毒理学和迁移转归研究以及新型分散剂开发研究,提高中国在此研究领域的国际地位;(2)修订或建立中国分散剂分析、检验和使用相关标准;(3)建议海事和水运交通管理部门进行所辖区域溢油应急措施的风险评估,并加强对溢油应急事故处理中分散剂使用的授权和管理.     

北京市朝阳区城市生活垃圾组分分布特性研究

针对垃圾焚烧的需要,按垃圾组分低位热值重新进行了垃圾分类,检验了各组分的正态分布特性,得出了服从正态分布的垃圾组分的概率分布密度函数。进行了垃圾含水率的线性相关性分析,认为垃圾含水率与厨余的相关性最大,降水量对含水率影响不大。     

ICSTD反应器处理污泥的启动试验研究

新型内循环污泥浓缩消化反应器（ICSTD）处理污泥的启动运行试验采用某污水处理厂二沉池好氧活性污泥进行驯化培养,使反应器正常启动运行。在日处理量为50 L/d,进泥含水率为99.23％～99.46％,进泥VS/TS为0.65～0.73,进泥COD为4 115～5 780 mg/L,反应器容积负荷为1.31 kg COD/(m³·d)时,排泥含水率在96.2％～97.3％,排泥VS/TS为0.48～0.57,COD去除率在95％以上,出水pH在6.6～7.1,且上清液澄清。试验结果表明： ICSTD反应器处理污泥的启动试验,采用直接培养污泥启动的方式培养厌氧污泥历时66 d,能较快地培养厌氧污泥且运行稳定,对污泥的浓缩消化起到较好的作用,同时对反应器后续运行的消化效果提供了一个良好的条件。     

曝气生物滤池处理农村污水的中试研究

采用研制的曝气生物滤池对农村污水进行处理,研究其性能特点和影响因素。结果表明：在气水比为5∶1,水力停留时间（HRT）为15 h,进水COD浓度在250 mg/L以下时,COD和氨氮的去除率分别在80％和90％以上,出水COD和氨氮值达到国家《城镇污水处理厂污染物排放标准》一级A标准;反应器在冬季水温12℃以上运行时出水COD和氨氮值比在夏季运行时有所上升,但去除率仍在80%和90%以上,可以达到排放标准。