PHOSPHATE IN WATERS: I. REDUCTION USING NORTHERN LIGNITE FLY ASH1

Fly ashes fiom lignite coal fixed steam electric plants contain appreciable amounts of materials that can, in principle, decrease the phosphorus concentration in surface waters. Typical samples of un-weathered fly ash were used to test efficacies of removal of phosphorus from standard phosphate solutions and actual lake water samples. The effects of changing parameters such as contact time, pH, fly ash/water ratios, and solution temperature are presented. Water soluble and insoluble factors in the ash both appear to be reactive constituents. Trials with municipal waste waters showed near quantitative removal of ortho-phosphate.     

Bioremediation of Soil Degraded by Sewage Sludge: Effects on Soil Properties and Erosion Losses

Soils in the Mediterranean area are very prone to erosion due to the loss of organic matter and the consequent lack of protective vegetation. In this experiment a Mediterranean degraded soil with a 15% slope was amended at a rate of 250 t ha^–1 wet weight with sewage sludge and with a mixture of sewage sludge and barley straw (70% carbon from sewage sludge and 30% from the straw) in order to study their influence on soil structure recovery and hence the soilss resistance to erosion processes. Both types of organic amendment led to an improvement in several soil properties (physical, biological, and microbiological) as a result of the spontaneous growth plant covering that became evident three months after amendment. This vegetation remained throughout the two years of the experiment and prevented the water erosion processes that normally precede soil degradation. Amendment by sewage sludge alone reduced soil loss by 80% compared with the control soil, while the mixture that included both sewage sludge and barley straw reduced losses by 84%, both reducing runoff by 57%. The amended soils showed increases in the percentage of stable aggregates, the levels of the total and water-soluble C fractions, microbial biomass C, basal respiration, and the activity of the different enzymes involved in the biogeochemical cycles of C, N, and P. The results confirm the usefulness of sewage sludge as an organic amendment for recovering damaged soils.     

分光光度法测定测田废水中的COD_(Cr)

为了快速监测油田废水中的化学需氧量ＣＯＤＣｒ,因此采用ＴＬ－１（Ａ）型污水ＣＯＤＣｒ速测仪进行加热催化消解,然后再用分光光度比色法测定ＣＯＤＣｒ,实验中进行了方法的准确度、精确度及Ｃｌ－影响实验,并与标准的重铬酸钾法进行了对比实验,结果说明分光光度法简单快速、重现性较好、准确度较高,对同一产品的测定结果与重铬酸钾法非常一致。因此,本方法可用于油田废水中的ＣＯＤＣｒ监测。     

中国城市综合减灾体系建设及其系统思考

从中国城市减灾现状分析入手,重点剖析城市减灾的可持续发展问题,并探讨了城市社会经济可持续发展中如何确立防灾减灾的地位．进而用系统科学思路研究城市综合减灾的体系建设问题,从一定意义上较为科学地解决了跨世纪的中国城市可持续发展的关键问题．     

防灾减灾系统工程的国际对比分析及建议

针对我国现存的灾害状况,本文通过国际对比的方法,对其他国家已有的减灾系统工程作了简单介绍,并结合我国实际,对未来建立减灾系统工程中应着重加强的薄弱环节作了分析,提出了加强立法工作,增加减灾投入,建立全国统一的减灾通讯系统的建议。     

城市地下水流场人工调控与减灾方案

以郑州市为例,针对城市区域长期过量开采地下水导致的一系列严重的环境地质灾害,诸如地下水水位持续下降形成区域地下水降落漏斗并不断扩张、含水层疏干、供水井吊泵、泉水断流、地下建筑工程浸没、地面沉降和塌陷等,探讨了城市地下水流场人工调控的减灾方案。建立了地下水系统的准三维动态数值仿真模型,以非均质各向同性渗流模型仿真地下水流,用不规则三角网格有限差分法求解了三维数值仿真模型。先解逆问题反求参数,再解正问题计算地下水各项资源量,数值仿真预报地下水渗流场至１９９８年。在此基础上,通过地下水渗流场的宏观调控与优化管理,使研究区内不合理开采地下水资源所引发的环境灾害减小到最低程度,为郑州市的环境减灾工作提供了科学依据。     

燃烧尾气中NOx选择性还原反应催化剂研究进展

介绍了从燃烧尾气中脱除ＮＯｘ的一系列选择性催化还原体系,其特色为能在氧浓度在较高条件下,利用燃烧尾气中未反应的有机物作还原剂,高选择性地与ＮＯｘ反应,其中负载Ｃｕ的ＺＳＭ－５催化剂有很高的活性,阐述了工业应用中存在的问题及对策。     

The Pollution Prevention Act of 1990: A Policy Whose Time Has Come or Symbolic Legislation?

/ In 1990, the United States officially entered the era of pollution prevention with passage of the Pollution Prevention Act. This paper analyzes EPA's implementation of the Pollution Prevention Act from its passage in 1990 to the present. It examines the barriers EPA must overcome if it is to effectively integrate pollution prevention into its existing regulatory structure, including impediments created by statutory and organizational structure, the existing relationship between EPA and the groups it regulates, the fragmented implementation scheme of national environmental regulation, the balancing of conflicting demands advanced by powerful interests, industry's economic and technical concerns, and institutional inertia. It also examines issues such as industry commitment, the limits of prevention, and measurement concerns. The findings suggest that EPA's efforts at shifting to a pollution prevention regulatory ethic that holds primacy over pollution control are mixed. Its organizational structure, statutory authority, and incentives system still reflect a single-medium pollution control focus, appropriations for pollution prevention programs and activities are paltry compared to traditional pollution control programs, and participation in the program is voluntary. Yet, the findings also point to some promising programs that are working to institutionalize a pollution prevention regulatory ethic, and many states appear very committed to the concept.KEY WORDS: Pollution prevention; Source reduction; Pollution control; Alternative regulatory design; Barriers to implementation     

中外大城市震灾管理模式的对比分析

对随机选取的8个发生在大城市的地震，分为发达国家和发展中国家两组，分别对其造成的死亡人数和经济损失以及震前准备、震后救援、致灾因素等管理措施进行了统计对比，并归纳出应该吸取的经验教训。     

论城市气象灾害及防治对策

依据国内外城市气候的观测资料和分析研究文献，从合理利用城市气候资源和防灾减灾角度，首次论述了城市气象灾害种类（公共、特定和相关三大类9种）以及防治对策。