Solid wastes generation in India and their recycling potential in building materials

Presently in India, about 960 million tonnes of solid waste is being generated annually as by-products during industrial, mining, municipal, agricultural and other processes. Of this ∼350 million tonnes are organic wastes from agricultural sources; ∼290 million tonnes are inorganic waste of industrial and mining sectors and ∼4.5 million tonnes are hazardous in nature. Advances in solid waste management resulted in alternative construction materials as a substitute to traditional materials like bricks, blocks, tiles, aggregates, ceramics, cement, lime, soil, timber and paint. To safeguard the environment, efforts are being made for recycling different wastes and utilise them in value added applications. In this paper, present status on generation and utilization of both non-hazardous and hazardous solid wastes in India, their recycling potentials and environmental implication are reported and discussed in details.     

Underground disposal of hazardous waste in Israel – Design principles and conceptual approach

The careless or unprofessional handling of hazardous wastes in many places around the world led to severe damage of nature, concurrent with considerable long-term health risks to human beings. This motivated several countries to develop new secure and sustainable waste management strategies in order to enhance the future quality of nature and life. The process of world globalization and the coalescence of its markets increased the importance of formulation and implementation of accepted environmental standards. The rising environmental and ecological awareness in Israel puts the contemporary and common waste handling practices under close scrutiny. An intensive exchange of experiences with other countries is called for, so that the responsible authorities can formulate improved and sustainable waste management strategies, which are specifically tailored to the particular environmental, demographic, economic and political conditions of Israel.The German environmental protection and waste legislation demands an underground disposal of highly contaminated wastes, in order to guarantee that harmful substances are excluded durably from the biosphere. In view of its size and the political situation in Israel, this way of waste disposal seems to be an appropriate waste management strategy aimed at minimising the environmental risks, and the harmful effect of hostile actions against deposits of hazardous wastes. The German waste management policies and practices, which are based on many years of experience, are reviewed first as a guideline for safe long-term underground disposal of hazardous wastes in Israel. Using these guidelines, potentially suitable locations in Israel are selected with special reference to their geohydrological, geological and geomechanical conditions, and then they were evaluated using environmental criteria derived from German standards of waste disposal. The results of this preliminary environmental evaluation, and some relevant geomechanical designs, are presented and discussed. Finally, economic aspects, and further steps, which are needed to safeguard future implementation of the underground disposal system, are considered.     

Optimal pricing and environmental improvement for a hazardous waste disposal supply chain with emission penalties

Hazardous waste management has become a municipal problem, associated with industrial development and changing consumption patterns. We study the hazardous waste management system as a supply chain with a disposal facility and a contractor, which serves customers with demand sensitive to price and environment impact. The government intervenes with this supply chain by imposing emission penalties that make the waste disposal facility responsible for reducing disposal process emissions. The Stackelberg game and Nash equilibrium are used to model the decision-making sequence between the disposal facility and the contractor. We specify different scenarios to model the hazardous waste management supply chain. The goal of this research is to find the optimal disposal service price and level of environmental improvement to mitigate adverse impacts and maximize profits. The applicability of dual-channel service in the hazardous waste supply chain is also investigated. Our study shows that the supply chain obtains the highest profit if both the disposal facility and the contractor operate in a centralized model. Under some scenarios, profitability improves if the disposal facility becomes active in waste collection and transportation under a dual-channel supply-chain model. Demand sensitivity to price and environmental impacts can affect the adopted level of improvement by disposal facilities.     

Land Disposal Practices in Europe and North America

This paper compares the land-based disposal of municipal and hazardous waste in Europe and North America, and the various disposal options are examined for each type of waste. It is concluded that landfill is still the most widely practised disposal method for most wastes in both continents. Other methods include composting, land farming, trenching/spraying, and deep underground disposal. More stringent controls on waste disposal are being introduced and a trend to seek greater uniformity of practice and standards is developing. However, local conditions, such as the nature of the wastes and the availability and nature of disposal sites, continue to work against this trend. There is no single method which is suitable for all wastes and for all conditions. The best environmental option for waste management will vary from place to place and waste to waste, therefore an imposed uniformity of practice is not in the best environmental interest.     

Community Planning for Small-Quantity Hazardous Waste Generators

Only recently has the small-quantity generator of hazardous waste come under federal or state regulation. The wastes produced by these generators, however, pose serious threats to health and environmental resources in almost every community. Local planners should and can design preventive strategies to deal with management of these wastes. Such strategies should include problem assessment, education programs, technical assistance to generators, and revision of local land use policy to prohibit improper disposal practices. This article presents new information useful to planners in assessing the problem in their communities, and it suggests elements of a planning approach to control the small-quantity hazardous waste stream.     

Disposal of water treatment wastes containing arsenic — A review

Solid waste management in developing countries is often unsustainable, relying on uncontrolled disposal in waste dumps. Particular problems arise from the disposal of treatment residues generated by removing arsenic (As) from drinking water because As can be highly mobile and has the potential to leach back to ground and surface waters. This paper reviews the disposal of water treatment wastes containing As, with a particular emphasis on stabilisation/solidification (S/S) technologies which are currently used to treat industrial wastes containing As. These have been assessed for their appropriateness for treating As containing water treatment wastes. Portland cement/lime mixes are expected (at least in part) to be appropriate for wastes from sorptive filters, but may not be appropriate for precipitative sludges, because ferric flocs often used to sorb As can retard cement hydration. Brine resulting from the regeneration of activated alumina filters is likely to accelerate cement hydration. Portland cement can immobilise soluble arsenites and has been successfully used to stabilise As-rich sludges and it may also be suitable for treating sludges generated from precipitative removal units. Oxidation of As(III) to As(V) and the formation of calcium-arsenic compounds are important immobilisation mechanisms for As in cements. Geopolymers are alternative binder systems that are effective for treating wastes rich in alumina and metal hydroxides and may have potential for As wastes generated using activated alumina. The long-term stability of cemented, arsenic-bearing wastes is however uncertain, as like many cements, they are susceptible to carbonation effects which may result in the subsequent re-release of As.     

Environmental experts in the motor industry

Hazardous wastes are posing the greatest threat to the environment than ever before. Indiscriminate transfer of technology from the Developed Nations for the production of highly hazardous chemicals can lead to a frequent contamination of the environment with the hazardous wastes. The situation appears to be very serious in many of the Third World Nations, where basic problems of water supply and sanitation still need a solution. Contamination of the ground and surface waters with hazardous materials is likely to increase in the developing countries, owing to lack of suitable monitoring techniques. Location of the industries producing hazardous chemicals in the crowded cities has to be prevented to obviate recurrence of serious catastrophes in future. The situation appears to be equally alarming in the developed countries, where ground and surface waters are at a greater risk of contamination with the hazardous wastes. Co disposal of solid chemical wastes with the municipal solid wastes will result in a greater contamination of the ground and surface waters, with longer lasting environmental effects. Hazardous gaseous spills can have serious environmental effects, particularly if the spills contain radioactive contaminants. The intensity of a hazardous gaseous spill can be greatly enhanced under abnormal meteorological conditions.     

Capacity planning for waste management systems

The capacity planning problem examined in this paper has a number of applications in the environmental management area including municipal solid waste management, hazardous waste treatment and disposal, and municipal wastewater sludge management. A dynamic programming formulation is presented for the specific capacity planning problem, and considerations of problem structure that allow computational efficiencies are discussed. This long-term planning model is applied to hypothetical and case-study problems from the municipal solid waste management area. The problem is generalized and compared to other problem types in the capacity planning literature.     

香港建筑废物再生骨料混凝土的研究进展

减少,回收和再利用各种废物是当今世界可持续发展的战略之一.香港的建筑工业每天都要产生大量的建筑废物,处理和管理这些建筑废物已经成为严重的社会问题和环境问题.随着经济的快速增长,国内的一些大城市中建筑废物的处理和管理同样成为主要的环境和社会问题之一.回收和再利用建筑废物,不仅可以节约处理建筑废物的土地,减少管理和处理建筑废物的成本,而且可以节约大量的自然资源.香港政府已经建立了回收和筛选建筑废物的设施.香港理工大学在回收和再利用建筑废物领域开展了近十年的研究工作,取得了一定的成果并向香港政府推荐了再生骨料回收再利用的规范.笔者介绍香港理工大学在研究建筑废物再生骨料混凝土方面取得的成果,包括建筑废物再生骨料环保砖、粉煤灰再生骨料混凝土、蒸汽养护再生骨料混凝土等.并介绍再生骨料混凝土在香港湿地公园的应用情况.这些技术成果将对回收和利用建筑废物起到促进作用.     

Use of Cement Kilns in Managing Solid and Hazardous Wastes: Implementation in Australia

The use of cement kilns for managing solid and hazardous wastes is facilitated by the high temperature, long gas retention periods, natural alkaline environment, minimum amount of waste produced and high thermal capacity. The main benefits include energy recovery, conservation of fossil fuels, reduction in cement production costs and the use of already existing facilities.
The test burns conducted in cement kilns worldwide have demonstrated very high destruction efficiencies for most stable organic compounds, with toxic contaminants barely above the background levels.
There are several cement plants in the US and Europe presently using solid and hazardous wastes as supplementary fuel. The application of this technology in Australia has been ignored in the past. An international conference (Kilnburn'92) on the role of cement kilns in waste management was held recently in Australia and has enhanced the implementation of this technology in Australia.     

Hazardous waste disposal in New Zealand

The quantities of hazardous wastes generated in New Zealand are relatively small, both in total volume and on a per capita basis: they consist principally of liquids and solids derived from primary industries such as horticulture and forestry, and from the Petroleum, chemical and manufacturing industries. There is no satisfactory inventory of hazardous waste quantities or relative toxicity at the national level, nor is there any central coordinating organisation responsible for the implementation of sound management strategies. Current legislation involves several Government departments in statutory or advisory roles connected with hazardous waste management, but administration of disposal practices devolves to regional and local authorities. The occasional uncontrolled discharge of chemical wastes, unsatisfactory past practices regarding landfill siting and leachate management, and the development of major petrochemical industries, together require better coordinated and enforced policies concerning hazardous waste disposal. The most widely advocated method of hazardous waste disposal for New Zealand is codisposal in appropriately sited and controlled landfills, with particular emphasis on protection of freshwater resources, both surface and subsurface. The secure landfill solution adopted for the Waireka chemical dump site near New Plymouth demonstrates that containment is a necessary management strategy in particular situations: alternative methods of disposal such as incineration of certain intractable wastes should also be promoted as technically feasible and environmentally acceptable. Greater use of replacement, recycling or reprocessing must be encouraged in order to minimise the quantities, and toxicity of hasardous wastes requiring disposal in New Zealand.     

Treatment of textile waste effluents by ozonation and chemical coagulation

Ozonation experiments in a multiple reactor system were conducted to investigate the efficiency of this process in reducing the color and chemical oxygen demand of the textile waste effluents. It has been observed that decolorization of those waste effluents can be achieved in less than 10 min in all tested cases. In conjunction with chemical coagulation, the chemical oxygen demand of those waste effluents can be consistently reduced by up to 70% or more. Ozonation is capable of decomposing the highly structured dye molecules into smaller ones which can be easily biodegraded in an activated sludge process. Hence combination of ozonation, chemical coagulation and the activated sludge processes can provide a very effective means for dealing with this particular type of industrial waste effluent.     

A study conducted to reduce construction waste generation in Turkey

Waste occurs within the lifecycle of buildings, during the construction, modification and demolition phases. These construction wastes become serious environmental problems in many countries and in Turkey. However, no net data regarding the amount of construction wastes exist in Turkey. During its period of usage, frequent interior modifications are made for various reasons, particularly true for residences in Turkey, thus generating construction wastes. The primary environmental target regarding this subject should be the prevention and reduction of construction waste generation. The aim of this study is to provide suggestions regarding the prevention/reduction of waste generated due to modifications done for various purposes in residences in Turkey. To this end, a survey of homeowners in Istanbul was conducted to determine the nature and purpose of modification work done in residences. In order to come up with solutions towards reducing the construction waste generation, it is vital that these reasons are known. In light of the causes determined, suggestions for solving the problems have been developed.     

城市建筑垃圾的资源化管理-以厦门为例

城市化快速发展产生大量的建筑垃圾,建筑施工和建筑拆除产生的建筑垃圾占垃圾总量的90%以上。同国外发达国家和地区相比,我国建筑垃圾管理的法律法规尚不完善,建筑垃圾的再利用水平和管理措施需要进一步加强。本文以厦门等低碳城市的建设为例,研究建筑垃圾的资源化管理,这项工作对低碳城市建设具有重要的示范和引导价值。     

Hazardous Waste Facility Siting A Role for Planners

Hazardous wastes present a critical environmental challenge for the United States in the 1980s. Part of the challenge involves cleaning up or containing abandoned and uncontrolled waste disposal sites. The larger part of the challenge is to properly manage the hazardous wastes that are keyed to the productivity of the national economy. This article briefly overviews what the wastes are and how much exists; what their potential is for adverse human health effects and environmental degradation; federal legislation designed to regulate hazardous wastes; and the nature of public opposition toward siting new facilities. This summary precedes a more in-depth discussion of research designed to assess land use suitability for siting new hazardous waste facilities based on water supply, and other physical and cultural siting criteria. Results indicate that initially suitable sites do exist for siting new facilities. Planners can play an important role by identifying suitable sites through their knowledge of land use, environment regulation, and with the aid of the screening process reported here.     

The creosote content of used railway crossties as compared with European stipulations for hazardous waste

Through the history of railways, wooden crossties impregnated with potentially hazardous creosote tar have supported the rails. With impregnated crossties having a lifespan of approximately 50 years, their creosote content is considered as quite safely stored while in dug-down usage. This situation of relative safety does, however, change into acute risk upon replacement and destruction. Carrying a highly flammable content, creosote crossties discharge a pulse of carcinogenic PAH compounds if burnt as ordinary waste. Safe destruction is therefore required if concentrations exceed a critical limit stipulated by the European Union. Since safe destruction is a process of considerable expense, there is a tendency among financial stakeholders to underestimate the creosote content of used railway crossties. In order to actually test whether concentrations generally exceed the critical limit, a set of used creosote ties was therefore sampled while still situated in the railway embankment. With a standard sum of sixteen PAH compounds used as an expression of their total creosote content, the generic concentration was formally inferred and found to significantly exceed the critical limit. The same applies to the fraction of seven carcinogenic PAH compounds, that alone exceed the stipulated limit for hazardous waste. It was also found that the material of railway embankments, whether or not the crossties were used in switches and/or railway yards, and sample depth within the crossties, has a significant effect on creosote concentrations. Regardless of the status of these factors, the concentrations significantly exceed the critical limit that defines hazardous waste within the European Union.     

利用工业废渣制备水泥与废渣的水泥封固

从废渣对环境的危害程度可以分为基本无害废渣、有害废渣（包括无机有害废渣和有机有害废渣）以及核废料。随着工业废渣的日益增加,迫切需要一种能工业化生产、经济上合理又很有效的处理方法。本文阐述了废渣的处理方法,主要比较了利用废渣制备硅酸盐水泥及其复合水泥、硫铝酸盐水泥的优缺点以及采用这些水泥封固废渣的优缺点。硫铝酸盐水泥比硅酸盐水泥及其复合水泥更具优越性。     

Solid waste management in the tropics — a case study of the Nigerian urban environment

A study of solid municipal waste management in five conjested cities in the Eastern states of Nigeria was carried out. Random sampling of waste piles show that the percentage composition by weight of garbage range between 32–56%, rubbish 8–30%, Ash/Dust 15–35% and Miscellaneous wastes 4–12%. The wastes were of peculiar nature but varied only in quantity with each city. Interviews and questionnaire reports show that the Environmental Protection Agencies are still in an infant stage of operation and require improved funding by government and also private sector participation. A public enlightenment campaigns is recommended for proper education of the public on modern ways of garbage disposal. Poor composting of solid wastes in landfills located near highways is discouraged. Solid waste recycling and reclamation using an advanced tropical composter equipped with solar collectors or a continous flow digester are recommended.     

水泥窑协同处置危险废物技术及在石油化工行业的应用

围绕石油化工行业危险废物特征,结合危险废物的常规处置技术,探讨适合于该行业的危险废物处置技术.鉴于水泥窑协同处置技术的独特优势和发展前景,分析了其在石油化工行业危险废物处置上的可行性.     

Ultrasound-assisted Acid red dye removal using leather fibre wastes as matrix: ‘intra wastes interaction’ approach

It is desirable to make effective use of solid wastes, as well as waste liquors, of the dye house generated from leather processing. The present study deals with the adsorption of Acid red 26 (Xylidine ponceau) dye using leather fibre waste (buffing dust) as substrate matrix by the means of ultrasound, magnetic stirring and conventional heating. The research examined the effect of various process parameters: ultrasonic power, concentration of dye, temperature and time. The dye uptake data have been fitted with Freundlich and Langmuir isotherms, indicating a useful dye adsorption process. A mechanism for dye adsorption in leather fibres has also been proposed. This study shows that it is possible to remove dyes from dye house effluent streams using leather waste fibres of buffing dust by means of ultrasound. Two different toxic wastes produced by the same industry can be effectively contained. This ‘Intra wastes interaction’ approach could reduce the burden of discarding wastes of other materials in the leather industry.