Differentiation of physical from chemical toxicity in solid waste fish bioassays

This study showed that particulate (i.e., physical) toxicity was responsible for rainbow trout deaths in bioassays with two separate solid wastes. This conclusion was based on: (1) fish necropsies which indicated physical damage to gills but no evidence of chemical damage to liver or kidney, (2) chemical analyses which indicated that levels of Priority Pollutants and other target compounds were too low to cause the observed toxicity, (3) structural and chemical analyses of the waste particles which showed that these consisted of inert materials, and (4) the use of centrifugation techniques to remove most of the suspended particulate material in bioassay tanks resulting in an elimination of most of the toxicity. The particles associated with the lethal effects were approximately 5 to 10 μm in size. Regulatory testing of solid wastes must distinguish physical and chemical toxicity since disposal options can vary depending on the mode of toxicity. For instance, chemical toxicity raises concern regarding leaching through soils into groundwater, whereas if physical particles are responsible for toxicity, such leaching is not of concern.     

Environmental impact of radioactive waste management in the nuclear industry

Radioactive wastes from the nuclear industry are classified into low, intermediate and high activity levels, and problems of their storage and release examined in detail. Current means of storage are considered with reference to processing of low and intermediate level liquid waste, processing of high level waste, processing of airborne waste, and ground disposal and processing of solid waste. Release is discussed in terms of effluent release limits, monitoring and the use of permanent records, impact of release to the human environment, impact of release to the material environment, and guides for preventing accidental release. Contamination of the shore of Lake Huron from radioactive fallout is discussed as a particular example. Problems to be solved are identified in three main areas: gaseous wastes, actinide-contaminated wastes, and permanent disposal, and some specific suggestions for study are made.     

云贵高原农村地区生活垃圾特性与管理分析

鉴于当前农村生活垃圾的污染日益突出,且云贵高原农村地区生活垃圾的研究尚处于空白,随机选择了该地区9个自然村,通过访问式问卷调查、现场采样、实验室测试等方法,对当地农村生活垃圾的特性、群众对生活垃圾的认知以及参与管理的意愿进行了调研,以期为农村生活垃圾的管理与处理处置提供理论支撑和技术指导。研究表明：云贵高原农村地区生活垃圾产生量为160g·人-1·d-1;主要组分有厨余类、灰土类、橡胶类、纸类和木竹类;垃圾容重、含水率、灰分、可燃物和热值分别为106kg·m-3、39．16％、19．48％、41．37％和7615kJ·kg-1。此外,云贵高原农村地区群众对生活垃圾的污染性认知主要来自于直观感受,对可回收生活垃圾的认知直接受当地废品回收商的影响,对有毒有害生活垃圾的认知不足;群众对生活垃圾处理处置的支付意愿较好,参与生活垃圾保洁和管理工作的意愿较强,该地区已基本具备开展农村生活垃圾管理与处理的群众基础。     

自然村生产生活废弃物循环利用模式及其评价研究

农业农村生产生活废弃物循环利用是实现农村人居环境治理、提高资源利用效率的重要途径,对美丽乡村建设具有重要意义。该文以自然村为研究对象,采用层次分析法和模糊评价法相结合的方法,统筹考虑生产生活废弃物循环利用,构建了自然村生产生活循环技术模式评价指标体系,确定各项指标的权重,建立评价方法。以河北邢台市山区某村为例,针对其生产生活废弃物产生特点,构建生产生活废弃物循环利用体系,该村农业废弃物以果木剪枝、生活垃圾、生活污水、人畜粪尿等为主,通过构建以果木剪枝热解+炭基有机肥还田为纽带的循环利用模式,辅以污水处理利用技术,实现了废弃物能源化和就地肥料化利用。通过对该自然村循环利用模式进行实地评价验证,结果表明该自然村生产生活循环技术模式评分结果为优。该文为中国村镇废弃物循环利用技术模式选择、农村人居环境改善和农业绿色发展提供参考和借鉴。     

采用厌氧分步固体反应器系统进行蔬菜废弃物厌氧分解

最近获得专利的厌氧分步固体反应系统(美国专利号6342378B1)是一种新型的用于将固体废弃物转化为沼气以获取生物能源的新技术。此技术已被用以转化多种固体废弃物的科学研究,其中包括作物秸秆、动物粪便、食品废弃物和城市固体废弃物。研究结果证明,此技术不仅先进可行,而且操作简单。根据此技术,一种大型的用于将废弃物转化为能源的厌氧分步固体反映系统已经在美国开发出来。该文主要介绍此技术用于大蒜废弃物转化的研究结果     

Synthesis of zeolite from waste lignite ash from Thailand

Almost all the lignite ash from the coal thermal power plants in Maemoa, Lumpang Province, Thailand is disposed of as solid wastes. However, the number of reclaimed sites for the disposal of the wastes is not sufficient to handle the large amount of wastes. Therefore, the development of a technique for the utilization of lignite ash is essential to preserve the environment and to recycle the waste materials. Lignite ash is composed of inorganic compounds mainly present as glasses resulting from fusion during their combustion. The chemical composition of these glasses is similar to that of volcanic glass in nature and changes easily to zeolite-like substances by hydrothermal treatment with an alkali. Henmi (1987) reported the synthesis of hydroxysodalite, a kind of zeolite, from waste coal ash. Zeolites are crystalline, hydrated aluminosilicates with a three-dimensional crystal structure and have the attractive cation-exchange properties in agricultural applications (Ming and Mumpton 1989). In the present study, attempts were made to synthesize zeolitelike substances from lignite ash from Thailand, in order to develop a new method for the disposal of industrial wastes. Although the synthesis of zeolite-like substances from waste coal ash had been reported in different countries after the publication of Henmi (1987), this method was applied for the first time in Thailand for the treatment of lignite ash.     

Some perspectives on the paper industry's use of waste paper

The paper industry has traditionally sought fibrous resources from trees, wood residues and waste paper. Emphasis is shifting back to waste paper after 30 yr of relative decline in recycling. Management of fiber resources by major timber holding companies is being expanded to include waste paper. In the next decade the structure of the paper industry will reflect a residuals based process technology relating to both city and forest. Recovery of waste paper can be feasible with source separation or dry separation technology. The outlook for recycling more old newspapers, old corrugated containers and mixed papers from office buildings is very good. Waste paper use in the U.S.A. will double between 1972 and 1985 from 13 million tons to 26 million tons. In addition, a world fiber supply shortage will stimulate further recovery and export of waste fibers. The energy content of paper is about 7500 Btu lb^?1, not much below that of Wyoming coal. Recovery of the energy content of paper is an integral part of current efforts to convert mixed wastes to fuel or steam. By 1990 about 50 % of the waste paper generated will be usefully recovered - about 30 % will be recycled, or exported and 20 % will be burned for its energy content.     

水车式增氧机驱动下方形圆切角养殖池集污水动力试验

为探究水车式增氧机驱动下方形圆切角养殖池内污物汇集规律与流场分布特性,该研究通过物理模型试验研究了水车式增氧机在不同布设角度θ（θ为叶轮轴线与养殖池中线组成的锐角）、布设距离比d/a（d为叶轮轴线中点与最近池壁之间的距离,a为池壁边长）以及驱动流速v对方形圆切角养殖池内污物汇集与流场特性的影响。试验通过相机采集池底污物分布图像、声学多普勒流速仪测量养殖池内流场分布,利用MATLAB软件处理分析污物图像以及流速数据。结果表明：在池内形成有效水平环流是污物向池心汇集的首要条件,但水车式增氧机布设角度、布设距离比和驱动流速都影响池内有效环流的形成;在水车式增氧机靠近池壁布设工况下,其与池壁的夹角设置为70°时,集污效果最优;在水车式增氧机远离池壁布设工况下,其与池壁的夹角设置为45°时,集污效果最优,随着布设距离比的增加,中心集污效果增强,但是圆切角周边出现集污死角;水车式增氧机驱动流速影响养殖池内污物汇集,而且只有在水车式增氧机布设距离比和布设角度都合适的工况下,增加驱动流速,才能增强污物汇集效果。研究结果可为方形圆切角养殖池内水车式增氧机的布设方式提供参考与依据。     

废液添加量对麦草废渣颗粒燃料成型及性能的影响

为了提高麦草制浆过程废弃物的资源化利用价值,采用液压压缩成型方法将备料工段麦草废渣和生物机械制浆废液混合处理后放入模具在室温、成型压力为10 MPa和保压时间3 min条件下制备成直径为13 mm的麦草废渣颗粒燃料,并在密封袋中进行平衡.探究了废液添加量(麦草废渣和废液混配质量比)分别在1:1、1:5、1:10、1:1...     

The use of Folsomia candida (Collembola,Isotomidae) in bioassays of waste

There is a high probability that urban compost, sewage sludge and ash will come in contact with natural terrestrial ecosystems. The present paper investigates the extent to which the Folsomia candida population development test (now a standardised ecotoxicological test, ISO 11267, for testing the impact of pure chemicals on soil fauna) can be applied to the detection of the toxicity of these wastes, the goal being to evaluate ecotoxicity of wastes before they are spread on land. We show that some potentially useful information on waste toxicity can be obtained with this test, but the results must be interpreting with caution, indeed, problems can arise from differences in pH, humidity and organic matter content of the waste relative to the characteristics of the dilution soil. On the basis of the results of these assays, we propose a classification of the toxicity of seven wastes.     

餐厨垃圾干发酵滚动式质热交换反应器设计与性能试验

为解决干式厌氧发酵传质传热效果差,易造成微生物生长代谢不均匀等问题,该研究设计一款反应器,利用罐体滚动代替搅拌,使底物自由混合,大幅度解决了干式发酵的阻碍。通过中温批次发酵验证反应器性能,并与搅拌式反应器进行对比,结果表明:滚动式反应器发酵过程中甲烷体积分数最高达74.89%;发酵前期挥发性脂肪酸有一定程度的积累,但在中期被迅速消耗,且未对产气和pH值造成明显影响;底物挥发性固体去除率高达68.74%,发酵体系稳定。微生物群落结构随着发酵进行,不同时期呈现动态变化,厚壁菌门(Firmicutes)是发酵体系中绝对的优势细菌门,最主要的古菌门是广古菌门(Euryarchaeota)。混合营养型的甲烷八叠球菌属(Methanosarcina)伴随着发酵的推进成长为绝对优势甲烷菌属。     

Regional solid waste management policy

A Bay Area Council study of solid waste management in the nine-county San Francisco Bay Area has concluded that there exists an appropriate role for region-wide planning of resource recovery and multi-county solid waste management systems. The Council recommendations divide regional solid waste management responsibilities between the private and public sector, and among different levels of government, from cities and counties to the federal level. The Bay Area and other of the nation's metropolitan areas are facing major decisions relative to solid waste management. Such decisions will require greatest consideration of the entire region's needs and resources which transcend local government boundaries. The Council Report offers for evaluating regional solid waste management project proposals forty technical criteria and forty financial criteria considerations. The report recommends a flexible solid waste management system with the advantage of allowing different technologies to exist within the total regional system. This is important because of both advancing technology and possible changes in packaging and manufacturing processes which could alter the composition and volume of solid waste.     

Institutional and financial consideration in regional solid waste management

Lack of urban land for solid waste disposal and growing public pressures to increase recycling are forcing many urban areas to change traditional solid waste management practices. Development of regional solid waste management plans requires interrelated studies of technical, institutional, and financial alternatives. When the goal of the technical studies is to improve existing waste management practices and to emphasize resource recovery, the resulting physical program will require not only changes in existing practices but possibly substantial capital investment as well. Changes in solid waste management practices are bringing to light new political and organizational problems. Regional planning, regulation, and financing tends to conflict with the long history of local control. Technical solutions are erasing the political boundaries within which the problems were previously containable. The use of a separate regional agency to implement a regional solid waste program is one institutional alternative that may be justified under certain circumstances. In many cases, however, the joint powers agency offers a more flexible means of providing regional direction because it permits the broad political representation needed to deal with problems of site changes, waste transport over jurisdictional boundaries, and shifting priorities in waste management. In California, joint powers agencies have separate legal standing to sell revenue bonds on behalf of the area served. A prime consideration in resolving the political and organizational problems is to preserve and possibly to enhance the role of private industry by such means as reducing the costs of financing facilities and equipment, sharing the risk of investment in resource recovery facilities, and preserving an atmosphere of competition for solid waste franchises.     

Solid Wastes In Urban And Rural Areas Of Ibadan,Nigeria: Composition,Treatment And Public Health Concerns

The composition of solid waste produced at various locations in Nigeria differs considerably because the amounts generated and the constituents thereof are determined by social customs and living standards. Nigeria has undergone extensive industrial development which has often changed the composition of domestic solid waste as well as agricultural wastes. The disposal and utilization of these mixed wastes has presented new risks and problems for our society and environment. Though most solid waste in Nigeria contains little human and animal material, pathogenic organisms affecting both continue to be present. Potential risks to human health and the environment that can arise from domestic solid waste disposal and utilization in Nigeria include pollution of water and air, accidents, contact contamination and breeding sites for flies and rodents. There also are long-term problems in relation to the human food chain.     

Recovery of aluminum from solid waste

Several wet and dry methods for extracting Al from mixed municipal refuse and other Al-bearing wastes (such as auto shredder residues) are discussed. Analytical results are given for samples of non-ferrous metals and Al concentrates obtained from mixed solid wastes. These analyses include both the chemical constituents of the samples and observed melt losses. The analytical results are compared with specifications that have been developed for Al recovered from mixed municipal refuse. The various uses for this material by the Al industry are discussed.     

Managing contaminated sediments

Remediation techniques on contaminated sediments are generally much more limited than for most other solid waste materials, except for mine wastes. The widely diverse contamination sources in larger catchment areas usually produce a complex mixture of contaminants that is more difficult to treat than an industrial waste. In the first two chapters, additional information will be presented onin- situ treatment methods, which were the central topic in the Spittelwasser Case Study (JSS - Journal of Soils and Sediments, Vol. 1, No. 3, pp. 181–187), and on the development of ecologically sound dredging and processing techniques, where practical applicability had to be demonstrated as part of an integrated remediation chain. In the latter respect, mechanical separation of less strongly contaminated fractions may be a useful step prior to the final storage of the residues (chapter 2, Treatment of Strongly Contaminated Dredged Materials) For most sediments from maintenance dredging, there are more arguments in favor of ‘disposal’ rather than ‘treatment’ (chapter 3, Subaqueous Storage and Capping). Consideration about the comparative assessment of the two basic management options ofin- situ capping and dredging followed by sub-aqueous disposal are discussed on a legislative, economic and technical-environmental basis. The concept of capping of contaminated sedimentsin- situ has been developed in the last two decades as an ecologically sound and economic alternative to more costly remediation techniques. The main characteristics are related to the passive character of this concept, which minimizes labor and process costs. Mechanisms of contaminant retention in sediment caps is discussed with special regard to the chemical isolation component. From this consideration, the development of the active barrier concept is derived that denotes the use of reactive additives in capping layers to chemically bind one or more contaminants specifically.     

Microbial Approaches to Characterization of Composting Processes

? Passage in 1979 of the Resource Conservation and Recovery Act (RCRA) and the Clean Water Act by Congress resulted in a mandate to control and regulate the use of solid wastes on the land (Federal Register, 1979). The more recent landfill crisis followed by the ocean dumping ban and tightening of air emission standards has significantly influenced solid waste practice in the direction of biodegradation via composting.

A rapid increase in composting technologies concomitant with increased environmental concern regarding the fate of bacteria, particularly pathogens, means that new opportunities and dangers exist with regard to microbial disposition of solid waste. The impact of new compost technologies on microorganism selection is not known and uncertainty exists as to survival mechanisms of potential pathogens initially present in waste. New microbial methodologies are needed to characterize bacteria involved in composting, and to determine the influence of compost technology on bacterial species selection, especially pathogens.     

A Review on Heavy Metal Ions and Dye Adsorption from Water by Agricultural Solid Waste Adsorbents

Agricultural solid wastes either in natural or in modified forms have been successfully used for decades as non-conventional cost-effective adsorbents for removing metal ions and dyes from their aqueous phase and have been recognized as a sustainable solution for wastewater treatment. Therefore, this review article provides extensive literature information about heavy metals and dyes, their classifications and toxicity, various treatment methods with emphasis on adsorption characteristics by numerous agricultural solid wastes, or agricultural solid waste-derived adsorbents under various physicochemical process conditions. This review article not only provided an up-to-date information on the application of sustainable low-cost alternative adsorbents such as agricultural solid wastes, agricultural by-products, and biomass-based cost-effective activated carbon and various other natural materials in the batch adsorptive removal of heavy metal and dye from aqueous phase but also presented a comprehensive compilation of adsorptive pollutant removal information based on various reported continuous column operation studies which is one of the new aspect to this review article. The effectiveness of various batch and column operational process parameters on mechanistic adsorptive removal of both heavy metals and dyes by various agricultural solid waste-based adsorbents has been critically discussed here. Batch and column adsorption mechanism, batch kinetics, column dynamic modeling, and adsorptive behavior of adsorbents under various process parameters have also been critically analyzed and compared. Finally, literature information on recovery and regeneration through desorption techniques and cost comparison of various agricultural solid waste adsorbents with commercial activated carbons have also been reported here. Conclusions have been drawn from the literature reviewed, and few suggestions for future research direction are proposed.     

农业固体废物分类及其污染风险识别和处理路径

防治农业固体废物污染,对保障农民身体健康,维护农业生态安全,促进农村经济社会可持续发展具有重要意义。在总结农业固体废物内涵和外延的基础上,探讨农业固体废物的主要来源、分类方法和基本特征,按照来源、毒性、组分和形态对农业固体废物进行了分类,剖析来源单一与类型多样的双重性、潜在污染与重要资源的两面性、周年持续与季节波动的复杂性等农业固体废物的基本特征。识别农业种植固体废物、畜禽水产养殖固体废物、废旧农业投入品和农产品初加工固体废物的潜在污染风险。梳理农业固体废物污染防治、处理利用代表性法规政策,分析农业固体废物全链条运营和监管体系,提出\     

Potentially mineralizable nitrogen from organic materials applied to a sandy soil: fitting the one-pool exponential model

Abstract. Over the last three decades there has been a great increase in the production of waste from urban, industrial and agricultural activity that could be recycled as a source of plant nutrients, and used to enhance soil quality. The use of these materials could partially offset the need for mineral fertilizers, giving both economic and environmental benefits. An incubation experiment was carried out using different organic waste materials applied to a Cambic Arenosol. Air-dried soil was mixed with increasing amounts of composted solid municipal waste, secondary pulp-mill sludge, hornmeal, poultry manure, solid phase from pig slurry, and composted pig manure, resulting in applications equivalent to 0, 40, 80, 120, 160 and 200 kg ha⁻¹ of Kjeldahl nitrogen. The samples were incubated for 244 days under a controlled environment of 24 °C and 60% water holding capacity of the soil. The increasing amounts of waste applied always led to a greater amount of potentially available nitrogen present in the soil/waste mixture. Based on the proportion of their active N fraction, wastes were ranked: poultry manure>hornmeal>solid phase from pig slurry>composted pig manure>secondary pulp-mill sludge>composted municipal solid waste. The results were well described by a one-pool exponential mineralization model, and mineral N formation was proportional to the quantity of waste applied. Of the wastes tested, those from animal sources showed greater nitrogen mineralisation. Nitrification was rapid, and concentrations of ammonium nitrogen remained relatively small.