Hazardous Waste Generation and Disposal: Options for Developing Countries

The industrial harzardous waste problem is going to be explosive in developing countries as they industrialize further. This paper examines the hazardous waste problem, highlights some toxic waste types, and provides a list of industries that generate most of those wastes. Technological, economic and institutional measures that could be combined to mitigate the hazardous waste problem in developing countries are described, and recommendations for dealing with the problem are presented.     

Critical review of industrial and medical waste practices in Dar es Salaam City

Industrial and medical wastes constitute a larger part on what is known as ‘hazardous wastes’. The production of these wastes is and will continue to be an on going phenomenon as long as human civilization persists. The health impacts of direct and indirect exposure to hazardous wastes include carcinogenic effects, reproductive system damage, respiratory effects, central nervous system effects, and many others. Today, many developed countries have legal provisions with regard to proper management of hazardous wastes. Tanzania, like many developing countries, has little emphasis on the proper handling and disposal of hazardous wastes. There is a serious inadequacy in handling industrial and medical solid wastes in the Dar es Salaam City. Improper waste deposition is increasingly becoming a potential public health risk and an environmental burden. Due to poor control of waste, industrialists and hospital owners are not well checked on how they handle and dispose of the wastes they produce with the result that many hazardous wastes reach the Vingunguti dumpsite without notice. Data on waste generation in Dar es Salaam is also inadequate, making it difficult to plan an efficient solid waste system. Promotion of public awareness, legislation and regulations enforcement and establishment of a proper sanitary landfill are considered to be principal remedial measures to ensure sound environmental maintenance. This paper summarizes the findings of the study on the practices of industrial and medical waste management in Dar es Salaam. The author aims to express the inadequacy in hazardous waste management and suggests possible measures to be applied in order to rectify the situation.     

Reclamation of wastes contaminated by copper,lead, and zinc

Waste materials containing toxic levels of copper, lead, and zinc, such as mine and smelter wastes, present difficult conditions for the establishment of vegetation. This article reviews the many attempts which have been made to reclaim these wastes. Inert wastes from mining and quarrying operations, such as slate quarry waste and certain colliery shales, seem to be good materials for reclaiming wastes contaminated by copper, lead, and zinc. Organic wastes, such as sewage sludge and domestic refuse, may provide only a temporary visual improvement and stabilization of the toxic materials.Nontolerant plant materials may often be planted directly on modern waste materials, which are less toxic than they were in the past. However, tolerant plant materials are needed for revegetating waste materials produced by early and more primitive extraction methods.     

生产者责任延伸制与电子废弃物管理——环境法规

日益增加的固体废弃物和工业废弃物已成为主要的社会问题。回收服务相对来说还很不足,导致很多废弃物只能进行简单的填埋、焚烧处理。这将导致严重的环境污染。借鉴国外一些发达国家废物管理领域的政策趋势,我国近年来出台了一系列关于电子废弃物管理的政策法规,但也暴露出正规的废物处理企业无法取得规模收益,入不敷出,电子废弃物处理基金的征收及补贴对象不明确等诸多问题。引入生产者责任延伸制将外部影响内部化,在理念和功能等方面适应了电子废弃物管理的需要。     

Nickel recovery/removal from industrial wastes: A review

Nickel is an important metal, heavily utilized in industry mainly due to its anticorrosion properties. As a consequence, nickel containing wastes such as spent batteries and catalysts, wastewater and bleed-off electrolytes are generated in various processes. These wastes could have a negative impact on the environment and human health if they contaminate soil, water and air. The present review addresses the environmental and economical aspects of nickel recovery/removal from various types of wastes. The main physico-chemical technologies for processing various effluents and wastewaters containing nickel are reviewed and discussed. Nickel recovery from spent batteries, catalysts, electronic waste and other sources is described. Hydrometallurgical approaches are emphasized. Recovery of nickel from wastes is important not only for economical aspects, but also for environmental protection.     

永荣矿区煤矸石的多途径综合利用

本文叙述了永荣矿务局开发利用煤矸石及其二次废渣的多项途径和方法，利用煤矸石生产矸石砖，发电，利用发电炉渣生产水泥和蒸养砖，改良土壤等，同时，提出一些探讨性意见。     

Additives to reduce ammonia and odor emissions from livestock wastes: a review

This paper reviews the use of additives to reduce odor and ammonia (NH3) emissions from livestock wastes. Reduction of NH3 volatilization has been shown to be possible, particularly with acidifying and adsorbent additives, and potential exists to develop further practical and cost-effective additives in this area. Masking, disinfecting, and oxidizing agents can provide short-term control of malodor, but as the capacity of these additives is finite, they require frequent reapplication. Microbial-based digestive additives may offer a solution to this problem as they are regenerative, but they appear to have been developed without a thorough understanding of microbiological processes occurring in livestock wastes. Currently, their use to reduce odor or NH3 emissions cannot be recommend. If the potential of these types of additives is to be realized, research needs to shift from simply evaluating these unknown products to investigating known strains of bacteria or enzymes with known modes of action. To protect the farmers' interest, standard independent test procedures are required to evaluate efficacy. Such tests should be simple and quantify the capacity of the additive to perform as claimed. The principle use of additives needs to be identified and addressed during their development. Producers may not use effective additives in one area if they further compound other problems that they perceived to be more important. There is the potential to use additives to treat other problems associated with livestock wastes, particularly to improve handling properties, reduce pollution potential to watercourses, and reduce pathogenic bacteria. Further work is required in these areas.     

四川省固体废物处置现状及对策探讨

我国《固体废物污染环境防治法》（以下简称《固废法》）自1996年4月1日颁布实施8年来，在实际工作中面临了许多新的问题。因此，立法机关重新修订了《固废法》，并于2004年4月1日起生效。由此可以看出，固废的污染防治越来越得到重视。我省固体废物产生量近年来一直呈上升趋势，但其综合利用率和处置率偏低，造成的污染日趋严重。本文分别对我省一般工业固废、危险废物和生活垃圾处置现状进行分析，提出提高我省固废处置几点建议。     

Recovery of biomass wastes by hydrolysis in sub-critical water

The recovery of waste substances is important not only for the prevention of environmental issues, but also for the rational utilization of natural resources. Hydrolysis reaction in sub-critical water is a promising method for the treatment of organic wastes and has been attracting worldwide attention. In this paper, sub-critical water hydrolysis was employed as a method for producing amino acids, reducing sugars, bio-oil and gas fuels from biomass wastes. The current statuses of these useful chemicals production from biomass wastes by hydrolysis in sub-critical water were reviewed. The review indicates that sub-critical water hydrolysis can be an efficient process for recovering useful chemicals from biomass wastes. This method is renewable, sustainable, efficient, and safe for the environment.     

新疆油田稠油开发固体废物对环境的影响及处置措施

新疆油田九1～九5区稠油开发过程中,产生了大量的固体废物,主要包括落地原油、废钻井液和岩屑及原油处理站的含油泥砂,如果处理不当,会对环境造成极大的危害。通过对各主要污染物的环境影响分析,提出了几种针对性的防治措施,以确保油田开发实现清洁生产,达到经济效益、环境效益和社会效益统一。     

Efficacy of vermicomposting for recycling organic portion of hospital wastes using <Emphasis Type="Italic">Eisenia fetida</Emphasis>: standardization of cow manure proportion to increase enzymatic activities and fungal biomass

Hospital wastes are infectious wastes generated in hospitals and need to be disposed in such a way that they do not spread disease. In this experiment, 5, 10, 15 and 20% cow manure (CM) were mixed with hospital wastes (HW), and mixed wastes were subjected to vermicomposting. In control treatment, only HW was used for vermicomposting. Results suggested that significantly (P ≤ 0.05) higher total nitrogen content was recorded in vermicomposts when 10% or more CM was added to HW. Higher mineralization rate (decrease in C/N ratio) and cellulase activity is probably responsible for rapid organic matter decomposition (loss of total organic carbon). Ergosterol content i.e., total fungal biomass and cellulolytic fungal population were almost constant initially, but increased in the latter stage of vermicomposting. All the vermicompost samples, prepared in this experiment, showed the absence of coliform bacteria. Therefore, it could be concluded that 10% CM addition with HW was the most economical to obtain best quality vermicompost in terms of nutrient content and microbial status.     

An overview for the utilization of wastes from stainless steel industries

Significant quantities of wastes are generated as the waste materials or byproducts every day from stainless steel processes. According to the origins and characteristics, the stainless steel wastes can be mainly classified into two categories, slags and dusts. They usually contained considerable quantities of valuable metals and materials. This paper summarized and analyzed the generation, composition, characteristics and the leaching behaviors of the most of wastes obtained from the stainless steel processes. On this basis, a review of several methods for treating the various stainless steel wastes was made. It is very essential not only for recycling the valuable metals and mineral resources but also for protecting the environment.     

中国危险废物污染防治技术发展趋势与政策分析

本文对我国危险废物产生及废物流进行了分析,对我国危险废物污染控制原则、目标和处理处置技术现状及发展趋势进行了评价。以此为基础,提出了我国危险废物管理全过程污染防治的技术路线和技术政策。     

泰安市医疗废物的特性研究

通过实验分析了医疗废物的组成、灰分、水分、挥发分、固定碳和热值等特性参数,探讨其燃烧特性。研究表明,医疗废物具有高热值、高挥发分的特点,其热值远高于一般城市生活垃圾,而高挥发分的特点决定了其容易着火和稳定燃烧的特性。     

Economics and energetics of organic and conventional farming

The use of organic farming technologies has certain advantages in some situations and for certain crops such as maize; however, with other crops such as vegetables and fruits, yields under organic production may be substantially reduced compared with conventional production. In most cases, the use of organic technologies requires higher labor inputs than conventional technologies. Some major advantages of organic production are the conservation of soil and water resources and the effective recycling of livestock wastes when they are available.     

Development of a Commodity-by-industry Economic-Ecological Model of Water Demand in a Rural Economy

The main objective of this paper is to develop a commodity-by-industry economic-ecological model (CIEEM) based on data collected in a rural village in Nigeria and to assess its utility for measuring the implication of various economic activities on the demand for scarce water resources. Our primary concern is model construction and determination of the direct and total requirements of both economic commodities (inter-industry transactions) and ecological commodities (water, land and vegetation) used in the economy. Also considered is the discharge of ecological commodities (waste water and solid wastes) back to the environment. Results show that, despite sparse sectoral interdependence within the economic system, inputs and outputs of ecological commodities include significant indirect components that can only be captured in an input-output framework. The most intensive users of water based on the direct effects are animal husbandry, construction and irrigated agriculture; based on total effects they are catering/trading, construction and animal husbandry, in descending order.     

我国城市周边规划建设用地利用探讨

随着我国城市面积的不断扩大，大量的郊区耕地成为或即将成为城市的建设用地，同时与城市建设相伴相随的建筑渣土的堆放已成为城市的一大问题，本文按照循环经济原则，提出利用规划期内即将建设的城市周边耕地资源建立供应城市建筑的制砖企业，同时利用取土坑填埋建筑渣土，建立城市物质的有效循环，实现城市建筑的循环经济。并对此物质循环方式做了生态经济的分析，也对此物质循环中存在的障碍提出了解决的方法。     

Industrial symbiosis and waste recovery in an Indian industrial area

Recovery, reuse and recycling of industrial residuals, often dismissed as wastes, are common in India and other industrializing countries largely due to lower associated costs. Some wastes are reused within the facility where they are generated, others are reused directly by nearby industrial facilities, and some are recycled via the formal and informal recycling markets. Direct inter-firm reuse is the cornerstone of the phenomenon termed industrial symbiosis, where firms cooperate in the exchange of material and energy resources. This study applies material flow analysis to an economically diverse industrial area in South India to characterize the recovery, reuse and recycling of industrial residuals. It quantifies the generation of waste materials from 42 companies as well as the materials that are directly traded across facilities and those that are recycled or disposed. This study encompasses a business cluster in Mysore in the State of Karnataka, and is the first in India to thoroughly quantify material flows to identify existing symbiotic connections in an industrial area. Examined industries in this industrial area generate 897,210 metric tons of waste residuals annually, and recovered 99.5% of these, 81% with reused by the companies that generated them, with one company, a sugar refinery, processing most of this amount. Geographic data show that operations within 20 km of the industrial area receive over 90% of residuals exiting facility gates. Two-thirds of this amount goes directly to other economic actors for reuse. This study makes key contributions to the literature in distinguishing how particular types of materials are reused in different ways, the geographic extent of symbiotic activities and the important role of the informal sector in industrial waste management in industrializing regions.     

四川省危险废物管理现状分析及评价

随着城市化进程的加快,危险废物的产生量快速增加,数量多、分布广、危害大、潜在利用价值高,管理处理难度大,因此带来了巨大的环境安全隐患。本文利用相关调查统计数据,分析了四川省危险废物产生特性及污染特性,指出危险废物管理过程中出现的问题已成为阻碍四川省循环经济发展及生态省建设的壁垒,针对出现的问题,提出了相关对策和建议。     

山东省城市生活垃圾管理现状及对策

随着经济的发展,城市生活垃圾逐渐成为山东省面临的重大问题.系统分析了山东省城市生活垃圾的收运及处理现状,并对其对策进行了讨论,认为山东省应立足现实,完善城市生活垃圾管理体系;对城市生活垃圾分类收集,以源头控制为主,并逐步改进现有的较为单一的卫生填埋技术;尝试应用多种先进的综合处理新技术,改变传统的思维模式,加快城市生活垃圾处理市场化、产业化的步伐,走可持续发展之道路.