Dynamic Changes of Sandy Land in Northwest of Beijing, China

The area northwest of Beijing is one of the most important regions where many organizations invest and pay most attention. The environmental problems in this region affect not only Beijing but also the surrounding area. Based on observation of the characteristics of the change in sandy land, this study classified four types of dynamic change of sandy land, including extended sandy land, the reversely changed sandy land, the potential sandy land and no change in sandy land. Then the process and the trend of changes in sandy land and their environmental impact on the area northwest of Beijing were analyzed. The results show that the area of sandy land has increased in this region in the period of 1991 to 2002. Change between sandy land and grassland was the dominant change. It is found that the monitoring zones of Hunshandake sandy land and north of Yin Shan are regions with high ratio of extended sandy land, and are connected with widespread potential change of sandy land. This implies that these two regions have a high probability of increase in sandy land in the future. On the other hand, in the monitoring zone of Horqin sandy land and Ba Shang Plateau and its surrounding area, desertification had been controlled and the area of sandy land is expected to decrease. This indicates that the direction of the sandstorm to Beijing is expected to gradually move to the northwest. Furthermore, the decreases in sandy land and the reversing change from arable land to grassland and forests in the study region will affect the land quality and atmosphere. And the logistic multiple regression (LMR) model was employed to better understand the complexity and processes of increases in sandy land. This model predicts that there is a high probability of increases in sandy land in north of Siziwang Banner, Zhengxiangbai Banner and Zhenglan Banner. Finally, suggestions to the ecological construction of the study area have been proposed.     

氯苯驯化活性污泥对同类有机物的好氧降解性比较研究

利用测定微生物呼吸耗氧量的方法,对氯苯类中的５种优先污染物：氯苯,邻,间,对－二氯苯１,２,４－三氯苯,用接种活性污泥和经氯苯驯化的污泥地它们的生物降解性能进行了测试。实验结果表明,用未经驯化的污泥,５种氯苯皆存在的抑制作用,抑制作用的大小和抑制时间的长短氯代程度和浓度的影响,用氯苯将此污泥驯化后,该污染不仅表现出对苯具有降解能力,而且也表现出邻二氯苯,间二氯苯等同类有机物的共代谢降解能力,经分析     

难降解有机物生物抑制特性的研究

对杂环化合物及多环芳烃的好氧生物降解抑制特性研究结果表明：咔唑、联苯等５种物质具有类似的抑制特性,表现在急性持久抑制及抑制强度大２方面,其抑制机理为不逆抑制;喹啉、吲哚等５种物质在高浓度时对苯酚的降解产生明显的初期抑制,历经诱导期,恢复期,最后进入正常降解期,其抑制机理为可逆抑制,萘的抑制属于竞争性抑制范畴。     

城市污水处理厂污泥直接热化学液化处理技术

污泥直接热化学液化技术是国外８０年代开始发展的一项污泥处理兼资源回收技术。它可使污泥中有机质的４０％以上转化为燃料油（热值≥３３ＭＪ／ｋｇ）,相应的有机碳转化率达到９０％左右。整个过程为一能量净输出过程。本文对其发展源流、研究现状和发展前景进行了综述和讨论。     

泡沫法分离表面活性物质的效率研究

本文介绍泡沫法净化表面活性废水的效率.探讨提浓效率与原水表面活性物质浓度的关系以及pH值与硬度对提浓效率的影响.     

一种新型的染料废水脱色混凝剂

亲水性染料废水用化学絮凝法处理效果较差。针对活性染料含有磺酸基的特点,对双氰胺-甲醛缩合物进行改性,获得一种分子量和电荷密度均可调节的阳离子聚合物MG。对MG的特性进行表征,研究不同性能MG在活性艳红X-3B的脱色净化中多种影响因素的规律,表明MG是一种性能稳定,有应用前景的染料废水处理剂。     

印染废水中低含量阴离子洗涤剂的二次标准加入法测定

用次氯酸钠-亚硝酸钠-氨基磺酸铵颅处理,以消除染料对测定的干扰;采用二次标准加入法,并利用简单的迭代运算,求得被测液中阴离子洗涤剂含量。本方法对印染废水的测定上下限分别为6.0mg/L和0.75mg/L。经5个实验室对LAS含量为0.78mg/L和6.7mg/L的实际印染废水的协作试验验证,其重复性相对标准偏差分别为5.0和4.5％,再现性相对标准偏差为5.2和9.7％。     

潜在有毒化学品优先控制名单筛选方法研究

在收集了国内外共37个不同化学品名单基础上,研究了我国潜在有毒化学品的筛选程序和评分系统。根据环境的9项指标和毒性的7项指标共16个参数,运用模糊数学方法计算了化学品的综合危害分值,藉此按其危害程度予以排序,从而选定了52种优先控制的有毒化学品名单,旨在对化学品应采取的适宜管理对策提供有效的科学依据。      

复合污染研究进展

复合污染是普遍存在的环境污染现象,本文在综述国内外复合污染研究现状的基础上,提出了复合污染的概念与分类方法,总结了有关复合污染交互作用的类型及其判断方法,重点论述影响复合污染生态效应的因子（污染物因子;生物因子;环境因子）和复合污染的作用机理（影响生物细胞结构;干扰生理活动与功能;竞争活性部位,络合或螯合作用）。     

催化光度法测定环境样品中微量Hg的研究

在酸性介质中,痕量Ｈｇ（Ⅱ）能显著催化空气中的Ｏ２氧化Ｋ４［Ｆｅ（ＣＮ）６］,生成蓝色化合物,反应对Ｈｇ（Ⅱ）为一级,催化反应的表观活化能为６２．９５ｋＪ·ｍｏｌ－１．据此建立了测定痕量Ｈｇ（Ⅱ）的动力学分析法,测定条件为Ｋ４［Ｆｅ（ＣＮ）６］：１．４×１０－３ｍｏｌ·Ｌ－１,［ＣＨ３ＣＯＯＨ］：０．１４ｍｏｌ·Ｌ－１,７５℃．在此条件下,线性测定范围为０．０２—０．７０μｇ·ｍｌ－１．本法重现性好,常见共存离子中除Ａｇ（Ｉ）严重干扰外,其余离子不影响测定．测定了水样及污泥样品中的Ｈｇ含量,结果满意