Regeneration of spent organoclays after the sorption of organic pollutants: A review

Clay minerals modified with organic ions, also known as organoclays, have found applications in a wide range of organic pollution control fields because of their excellent sorption capacity towards organic pollutants. Regeneration of the spent organoclays after the sorption of organic pollutants is of great importance during their application in pollution control. In this review, the reported methods for the regeneration of the spent organoclays are summarized, including biological degradation, photo-assisted oxidation, chemical extraction/desorption, supercritical extraction, thermal desorption, et al. The characteristics and applications of these methods are briefly described. It shows that most of these methods have been developed for regenerating spent organoclays from wastewater treatment. The biological regeneration method, as an in situ, low cost and easy-operating method, is applicable for regenerating spent organoclays not only from wastewater treatment, but also from soil and groundwater remediation.     

Groundwater protection in mixed land-use aquifers

Compared with groundwater pollution episodes of a point-source nature, nonpoint-source contamination makes for particularly difficult policy design. This is especially true in the context of a mixed land-use aquifer, where the same pollutant may derive from various human land-use activities and in different concentrations. To data, the emprirical literature attempting to estimate the relative loadings of pollutants from alternative land uses is rather sparse. Yet this information is vital to a variety of numerical computer models used to predict likelihood of groundwater contamination, and the statistical results are useful in their own right for regional policy formation. Regression analysis is applied to estimate loadings of nitrate and sodium from various land uses. The model is then used to illustrate how well-intended local groundwater protection policies that fail to recognize land-use substitution and cross-pollutant effects may be misdirected.     

Seasonal influences on inorganic anion monitoring of the New Calabar River,Nigeria

The inorganic anion pollution of the New Calabar River surface water was investigated. Results showed seasonal variations in the inorganic anion levels. Water parameters such as sulfite, nitrate, phosphate, and alkalinity showed significantly higher values in the rainy season than in the dry season. Dissolved oxygen, pH, sulfide, sulfate, ammonia, and nitrite showed no significant differences between their rainy and dry season levels. Upstream-downstream changes were shown by conductivity, total dissolved solids, chloride, salinity, and temperature. Exceptions occurred in the nitrite levels, where the effect was minimal. Although the concentrations of some anions analyzed fell within internationally acceptable limits, the New Calabar River water is, in the main, polluted with inorganic anions and may be unacceptable for potable and industrial uses without treatment.     

河流汛期污染与源解析

对河流汛期污染的特点、产生原因与产生条件进行深入分析并进行产生源定量解析。结果表明汛期污染引起河流断面增加的COD通量枯水年份约占全年COD通量的55％－68％，丰水年可达91％－96％。在汛期COD增加量中，河流本底淮干1^#断面约占64％，洪河2^#和沙颍河3^#断面约占25％－38％；三断面水土流失引起增加量约占29％－41％，其他因素增加量淮干为6％，另两断面为26％－41％。     

甲醇装置污染源现状分析及控制对策

对甲醇装置“三废”及噪声污染源现状进行调查和分析，提出并采取了相应的控制对策。对目前存在的环保问题，提出了改进措施。     

World tropical wood trade : Economic overview

Tropical wood is attracting global attention in the light of dwindling sources of industrial raw material supplies, increasing concern for conservation and growing requirements for huge investments. This study examines the changing character of the world hardwood trade, and the factors that will affect future supply, demand and price. It also considers the likely implications of recent large-scale attempts to grow tropical species for pulp, developments in microtechnology and biotechnology on wood, and the proposed international commodity agreement for tropical timber. The study emphasizes the need for huge investments on a global scale in afforestation and research to fully realize the potential of the tropical biomass.     

癌症及其发生的水土环境

本文从环境学角度分析了癌症高发区的水土环境。表明癌症高发区除水土严重污染,许多常量成份出现异常外,一些微量元素还明显缺少或严重超量。     

Price Determination and Efficiency in the Market for South Platte Basin Ditch Company Shares

Water scarcity presents an obstacle to economic development in the western United States. Water rights markets help improve water allocation, allowing states to derive the highest economic benefit from available resources, and supporting new uses and economic development. However, the implicit (marginal) prices of water rights attributes are uncertain. To address this problem, we apply econometric analysis to a unique dataset to estimate the implicit values that market participants place on the attributes of shares of ditch company water rights in Colorado's South Platte River Basin. Our analysis demonstrates that ditch company share buyers value proximity of water diversion, reliability of water deliveries, and temporal flexibility of water use. To assess reliability we introduce the use of the coefficient of variation to capture, in one variable, the randomness of supply from ditch company shares that are not a single water right, but a portfolio of rights with different appropriation dates. Finally, we test and correct for spatial autocorrelation for the first time in a study of water market prices.     

结构噪声中低频噪声污染的环境监测

低频噪声不但影响人们的生产生活,同时对周围群众的身体健康也带来了危害。本文结合一些实例,对结构噪声中低频噪声污染的监测方法进行了一些探讨,并提出合理监测的几点建议。     

广州后航道水环境污染的变化特征和对策

从珠江广州河段后航道多年的水质变化状况与广州市部分区域污染源情况看水体环境污染的变化特征，并提出了治理对策的建议。