纳米材料在环境中的应用及生物毒性研究进展

本文介绍了目前环境中存在的几种主要典型的人工纳米颗粒物的性质特点,并综述了不同纳米材料在水环境污染控制中的应用,同时对纳米颗粒的环境行为及生物毒性相关领域进行介绍,阐述了纳米颗粒对生物的可能致毒机理。最后文章总结了纳米材料在环境中的行为和毒性研究中所存在的问题,并在此基础上展望了需要拓展与深入的研究方向,希望有助于促进纳米材料在环境中的应用、提高对纳米材料环境行为的认识及降低纳米材料的生态风险,推动纳米科技的持续、健康发展。     

纳米材料在环境保护中的应用与发展

综述了纳米材料的环保功能以及其在环境保护中的应用，并列举了近年出现的纳米环保产品，提出了纳米材料在环保应用中存在的问题。     

纳米技术在水处理中的应用

介绍纳米技术和纳米材料在水处理中的应用研究现状与前景。     

膨润土-天然纳米材料在环保和荒漠化治理中的应用

本文概略介绍了天然纳米材料－膨润土在国内外环境保护和荒漠化治理中的应用概况及前景。     

水体中硝酸盐污染治理材料研究进展

硝酸盐是我国水体中主要的污染物之一,其去除方法主要包括离子交换法、反渗透法、电化学法、吸附法、化学法、生物法等。其中因吸附法操作简便、设计简单,近年来各种吸附材料被广泛研究和应用;在化学法中,纳米材料因其体积小、表面积大、反应活性高,在水体中硝酸盐的处理中具有广泛的应用前景。介绍了吸附和纳米材料在水体中硝酸盐的去除中的研究现状,并对水体中的硝酸盐去除技术趋势做综述。     

环境保护新曙光——纳米材料在环保中的应用

本文介绍了纳米TiO2光催化性的作用机理以及在环境保护中的应用，并对其应用前景及存在的问题作了简要地阐述。此外还介绍了纳米氧化锌及纳米稀土钙钛矿复合氧化物等纳米材料在环境保护中的应用。     

碳纳米管在环境样品前处理中的研究现状及应用进展

纳米碳管是一种新型的纳米材料,其独特的分子结构和性能引起了人们的广泛关注。本文重点评述了纳米碳管在环境样品前处理特别是在固相萃取和固相微萃取方面的研究现状与应用进展,并对纳米碳管的应用前景进行了展望。     

基于纳米技术的环境保护新材料与污染防治新工艺的研究

纳米科技是面向21世纪的核心战略科技,它为解决环境保护与经济发展的矛盾提供了有力的技术手段.通过将纳米技术引入环境保护与污染防治的研究领域,概述了纳米技术的内涵、纳米材料的特殊性质,全面介绍了纳米技术在环境保护新材料与污染防治新工艺中的应用情况,展望了纳米技术在环保领域的研究发展方向,表明利用纳米技术解决环境问题将成为未来环境保护发展的必然趋势.     

MOFs光催化降解有机污染物研究进展

在阐述金属-有机框架材料(MOFs)特性的基础上,介绍了近年来MOFs光催化降解染料、药物分子以及苯酚类典型的有机污染物的最新进展,合理调控MOFs的结构是有效提高其光催化性能的途径之一。将金属或非金属离子掺杂到MOFs中,或将MOFs负载到碳纳米材料上,可扩展其光响应区域,从而增强其对有机物光降解的催化活性。同时,还对MOFs光催化剂今后的发展前景进行了展望,选择适当的无机光敏纳米材料与MOFs掺杂,可以有效提高MOFs的光催化剂活性,有较大的发展空间。     

CO2开关型溶剂及表面活性剂的研究进展与应用

CO_2开关型溶剂及表面活性剂在通入和排出CO_2前后,其化学性质能发生可逆变化,是一类新型的智能溶剂。介绍4种类型CO_2开关型溶剂的开关机理,分析了脒基体系、胍基体系、胺基体系3种类型的CO_2开关表面活性剂的开关机理及研究进展。探讨了CO_2开关型溶剂与表面活性剂在油类提取、制备纳米材料、乳液聚合、含油土壤修复、智能给药、基因载体等方面的应用。分析讨论了当前开关型有机溶剂存在的问题以及研究趋势,并对其发展前景进行了展望。     

纳米催化剂的特性及其在环保领域的应用

纳米催化剂作为新一代高效环保催化剂,在环保领域有着广阔的应用前景.本文概述了纳米催化剂的结构与特性,介绍了目前在环境保护和环境治理方面研究和应用较多的几种纳米催化材料,最后还对其存在的问题进行了分析和展望.     

Nanoparticle aggregation: challenges to understanding transport and reactivity in the environment

Unique forms of manufactured nanomaterials, nanoparticles, and their suspensions are rapidly being created by manipulating properties such as shape, size, structure, and chemical composition and through incorporation of surface coatings. Although these properties make nanomaterial development interesting for new applications, they also challenge the ability of colloid science to understand nanoparticle aggregation in the environment and the subsequent effects on nanomaterial transport and reactivity. This review briefly covers aggregation theory focusing on Derjaguin-Landau-Verwey-Overbeak (DLVO)-based models most commonly used to describe the thermodynamic interactions between two particles in a suspension. A discussion of the challenges to DLVO posed by the properties of nanomaterials follows, along with examples from the literature. Examples from the literature highlighting the importance ofaggregation effects on transport and reactivity and risk of nanoparticles in the environment are discussed.     

SOIL EROSION AND SEDIMENT YIELD PREDICTION ACCURACY USING WEPP1

ABSTRACT: The objectives of this paper are to discuss expectations for the Water Erosion Prediction Project (WEPP) accuracy, to review published studies related to WEPP goodness of fit, and to evaluate these in the context of expectations for WEPP's goodness of fit. WEPP model erosion predictions have been compared in numerous studies to observed values for soil loss and sediment delivery from cropland plots, forest roads, irrigated lands and small watersheds. A number of different techniques for evaluating WEPP have been used, including one recently developed where the ability of WEPP to accurately predict soil erosion can be compared to the accuracy of replicated plots to predict soil erosion. In one study involving 1,594 years of data from runoff plots, WEPP performed similarly to the Universal Soil Loss Erosion (USLE) technology, indicating that WEPP has met the criteria of results being “at least as good with respect to observed data and known relationships as those from the USLE,” particularly when the USLE technology was developed using relationships derived from that data set, and using soil erodibility values measured on those plots using data sets from the same period of record. In many cases, WEPP performed as well as could be expected, based on comparisons with the variability in replicate data sets. One major finding has been that soil erodibility values calculated using the technology in WEPP for rainfall conditions may not be suitable for furrow irrigated conditions. WEPP was found to represent the major storms that account for high percentages of soil loss quite well—a single storm application that the USLE technology is unsuitable for—and WEPP has performed well for disturbed forests and forest roads. WEPP has been able to reflect the extremes of soil loss, being quite responsive to the wide differences in cropping, tillage, and other forms of management, one of the requirements for WEPP validation. WEPP was also found to perform well on a wide range of small watersheds, an area where USLE technology cannot be used.     

A comprehensive review of the energy efficiency on nano coated fin and tube condenser

The condenser is a piece of equipment used to effectively transfer heat from water to the environment. The fin and tube condenser is the most commonly used in commercial applications. The improved performance of heat transfer in the fin and tube condenser is a significant area of study all over the world because optimizing the efficiency of heat transfer in the condenser will contribute to enhancing the effectiveness of system performance. The vapor deposition, plasma spray, and thermal spray techniques are being used, and it is determined that a heat transfer enhancing coating improves condenser performance. This review discusses the nanomaterial coating over the fin and tube condenser in detail. The various nanomaterial coatings with various propositions and coating methods had been discussed with the evidence of previous researchers. At a 50-degree inclination angle on the condensate plate, the condensate over the coating surface increases by more than 30%. The thermal properties of the working fluid are improved over the condenser, and the overall effectiveness of the condenser is increased by approximately 40% over the non-coated condenser. A 1% volumetric concentration of Nanoparticles in the coated material achieves a maximum efficiency increase of 78.7%.     

CENTER PIVOT IRRIGATION IN THE COLUMBIA BASIN OF WASHINGTON AND OREGON: DYNAMICS AND IMPLICATIONS1

ABSTRACT: As of 1976 over 225,000 acres were being irrigated by center pivot units in a five-county area of the Columbia Basin in Oregon and Washington. Most of the development took place since 1970. Dynamic application of center pivot technology altered the concept of irrigability in the study area, converting lands that were often rolling, sandy, and plagued by wind erosion from low grade grazing to productive irrigated units. This development was entirely by private enterprise, with large corporate farms accounting for much of the effort. Little prior comprehensive planning or coordination took place. When the circulation of water is altered on such a massive scale, however, unplanned impacts may be far reaching. In this case they include:1) acceleration of the shift to high cost thermoelectric generation, 2) alteration of state institutions designed to allocate water, and 3) possible significant alterations of the socioeconomic fabric of small rural service centers.     

TECHNOLOGY,INSTITUTIONS, AND SOCIAL GOALS1

ABSTRACT: The cries of pending water crises are usually cast in terms of water availability and/or water quality. Unfortunately, the real factors underlying a perceived crisis are often overlooked and the solutions prescribed are fax from optimal when measured in either economic or social terms. Today's technology outstrips its implementation, yesterday's solutions are imposed on a new breed of problems, and a static game is being played in a dynamic world. There is a need for the application of innovative and revolutionary tactics, for modernizing institutions, and for educating technologists and decision makers alike in the art of communicating their views and skills. This is the challenge. If it is met, some predicted crises will not materialize, and many others will be diminished in scale. An exciting opportunity exists to extend the boundaries of a new era in water management.     

CONTROL OF LAKE PHOSPHORUS WITH ALUMINUM SULFATE: DOSE DETERMINATION AND APPLICATION TECHNIQUES1

ABSTRACT: Nutrient diversion does not always bring about prompt and sufficient reduction in lake phosphorus concentration due to recycling from nutrient rich sediments. Certain lakes and reservoirs may continue to experience nuisance algal blooms and require additional restorative steps. The phosphorus precipitation/inactivation technique is a procedure to remove phosphorus from the water column and to control its release from sediments in order to achieve P-limiting conditions to algal growth. Aluminum salts have been used in advanced waste water treatment to remove phosphorus and this technology was extended to lake rehabilitation. Guidelines for dose calculation and application are generally lacking, and are provided in this report. The dose determination suggested here allows maximum application of aluminum to bottom sediments and thus emphasizes long term control of phosphorus recycling. Dose can be calculated directly from the alkalinity of the water to be treated. Titration of lake water samples of Varying alkalinity allows the establishment of the relationship between residual dissolved aluminum, alkalinity, and dose which can then be employed for lake scale applications of alum to lakes and reservoirs. Application equipment and procedures are described. These depend on site characteristics and treatment objectives and include lakeside stores, a distribution pipe, and an application barge and manifold. Alum may also be used to meet other restoration objectives including the treatment of problem flows and the reduction of particulate concentrations.     

Environmental occurrences, behavior, fate, and ecological effects of nanomaterials: an introduction to the special series

The release of engineered nanomaterials (ENMs) into the biosphere will increase as industries find new and useful ways to utilize these materials. Scientists and engineers are beginning to assess the material properties that determine the fate, transport, and effects of ENMs; however, the potential impacts of released ENMs on organisms, ecosystems, and human health remain largely unknown. This special collection of four review papers and four technical papers identifies many key and emerging knowledge gaps regarding the interactions between nanomaterials and ecosystems. These critical knowledge gaps include the form, route, and mass of nanomaterials entering the environment; the transformations and ultimate fate of nanomaterials in the environment; the transport, distribution, and bioavailability of nanomaterials in environmental media; and the organismal responses to nanomaterial exposure and effects of nanomaterial inputs, on ecological communities and biogeochemical processes at relevant environmental concentrations and forms. This introductory section summarizes the state of knowledge and emerging areas of research needs identified within the special collection. Despite recent progress in understanding the transport, transformations, and fate of ENMs in model environments and organisms, there remains a large need for fundamental information regarding releases, distribution, transformations and persistence, and bioavailability of nanomaterials. Moreover, fate, transport, bioaccumulation, and ecological impacts research is needed using environmentally relevant concentrations and forms of ENMs in real field materials and with a broader range of organisms.     

膜覆盖条垛堆肥技术与应用案例

膜覆盖技术是一种改良的静态条垛堆肥技术,主工艺过程与传统高温好氧发酵工艺过程类似。介绍了膜覆盖堆肥系统的核心技术——功能性覆盖膜、曝气系统、卷膜设备;通过对膜覆盖系统的优势和不足的分析,得到该技术的适用范围;介绍了两个应用案例。