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.     

水泥工业节能环保新技术

我国目前新型预分解水泥生产技术已基本达到高效节能的先进水平,新型干法水泥窑的纯低温余热发电、工业废渣的综合利用和水泥窑处理废弃物技术的研究开发,使这项传统意义上的高能耗产业成为资源综合利用、节能环保、利用废渣的重要产业。     

固体废弃物在软土加固中的应用现状

人口增长、迅速城镇化、工业化和经济发展导致在全球范围内以惊人的速度产生大量固体废弃物(以下简称固废),所以最大限度地利用固废生产绿色建材是当今材料业的一个研究热门。水泥作为一种最常见的软土固化剂,大量的生产造成了一定的环境破坏和资源消耗,而一些固废经过粉化之后,存在较好的水化活性,具有一定的胶凝性能,故利用这些固废替代水泥用于制作软土固化剂存在可能性。目前关于固废在软土固化剂上的研究较少,因此,利用固废研制一种软土固化剂,用来替代水泥,不仅能够节约资源,而且能够有效的保护环境。     

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.     

固废制备高贝利特硫铝酸盐水泥的研究进展

高贝利特硫铝酸盐水泥具有早期强度高、后期强度发展好的特点,生产能耗低且CO2排放量少。从固废原料的利用、水泥制备工艺与水泥性能3个层面,综述了固体废弃物制备高贝利特硫铝酸盐水泥的研究现状;并提出固废制备高贝利特硫铝酸盐水泥需进一步研究和解决的问题,如大宗固废原料的利用、全固废制备技术及固废重金属固化、溶出评价等,亦为今后理论研究与实践发展的新路径。     

危险废物固化体存储设施的抗震性能分析

危险废物由于自身的危害性,对存储设施有着严苛的要求.为了研究危险废物固化体存储设施的抗震性能,本文利用ABAQUS软件建立危险废物固化体存储设施有限元模型,并分析其在地震作用下的结构强度.模型分为单管模型和整体模型,单管模型由单个存储管和多个危险废物固化体组成,整体模型由48根存储管、支撑架、立柱和脚柱组成.对于单管模...     

Management of hazardous waste: a case study in India

A study of identification of hazardous waste generators, quantification and classification of hazardous wastes in accordance with Indian hazardous waste classification system in the five major industrial districts of Gujarat (covering 15 industrial estates) was carried for the purpose of hazardous waste management planning in the region. The contribution of hazardous waste generation by different sizes of generators is estimated. The total quantity of hazardous waste generated in these districts was about 0.44 million tonne per annum. On the basis of waste classification, it was found that waste category number 12 (sludge from effluent treatment plant) and waste category number 9 (waste from dye and dye intermediate units) were dominant among the other categories of wastes generation in each district. In order to reduce burden on land, the hazardous wastes suitable for recovery and recycling in the industrial regions have also been quantified at about 45% of the total quantity generated. Among this the maximum proportion of recyclable waste is from dye and dye intermediate units as sludge and residue which were being disposed off in low lying area in the country.

The study also provides information on the quantity of hazardous wastes which were suitable for secure landfill, with or without pre‐treatment, and for incineration. A plan for hazardous waste management for the region is proposed for implementation.     

焚烧灰中重金属溶出行为及水泥固化机理

垃圾焚烧飞灰是生活垃圾焚烧后烟气除尘器收下的物质，因其中含有水浸出性的重金属物质而被认为是危险废物，必须对之进行稳定化处理．主要研究了焚烧飞灰中重金属物质的浸出问题，考察了水泥对焚烧飞灰中重金属物质固化的效果．研究表明，用水泥稳定固化焚烧飞灰中重金属物质的效果良好，重金属物质通过物理固封、替代或吸附等形式可固化进水泥水化产物结构中．     

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.     

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。     

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.     

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.     

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.     

Emissions of metals and polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs) from Portland cement manufacturing plants: inter-kiln variability and dependence on fuel-types

Emissions from Portland cement manufacturing facilities may increase health risks in nearby populations and are thus subject to stringent regulations. Direct testing of pollutant concentrations in exhaust gases provides the best basis for assessing the extent of these risks. However, these tests (i) are often conducted under stressed, rather than typical, operating conditions, (ii) may be limited in number and duration, and (iii) may be influenced by specific fuel-types and attributes of individual kilns. We report here on the results of more than 150 emissions-tests conducted of two kilns at a Portland cement manufacturing plant in Portugal. The tests measured various regulated metals and polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs). Stack-gas concentrations of pollutants were found to be highly variable, with standard deviations on the order of mean values. Emission rates of many pollutants were higher when coal was used as the main kiln fuel (instead of petroleum coke). Use of various supplemental fuels, however, had little effect on stack emissions, and few statistically significant differences were observed when hazardous waste was included in the fuel mix. Significant differences in emissions for some pollutants were observed between the two kilns despite their similar designs and uses of similar fuels. All measured values were found to be within applicable regulatory limits.     

Geotechnical requirements of subsurface repositories in mines,rock and salt caverns for interim or final disposal of hazardous wastes

The storage of hazardous wastes in subsurface facilities, i.e. in mines, salt caverns and hard rock caverns, offers a high degree of security potential. This is because the contaminants are entombed in geological formations of the deep underground a long way from the biosphere. In order not to prejudice the security offered by the geological barriers certain geotechnical demands have to be met with respect to stability, tightness and sealing in the construction of these subsurface waste repositories. Furthermore, prior to their emplacement, wastes have to be conditioned to exclude the possibility of reactions between the wastes and between the wastes and the surrounding material, e.g. rock or lining. Depending upon the intended function of the subsurface facility, i.e. for interim or final storage, different demands are pertinent with respect to the emplacement technology and the facility seal. In the following paper the geotechnical security objectives for subsurface repositories for interim and final storage are discussed and technical concepts for the construction and operation of mined, salt and hard rock caverns presented. The possibilities for using current mine operations and abandoned underground spaces for the storage of hazardous wastes are discussed.     

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.     

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.     

Reusing ceramic wastes in concrete

The ceramic industry is known to generate large amounts of calcined-clay wastes each year. So far a huge part is used in landfills. Reusing these wastes in concrete could be a win–win situation. For one hand by solving the ceramic industry waste problem and at the same time leading to a more sustainable concrete industry by reducing the use of non renewable resources like cement and aggregates and avoiding environmental problems related to land filled wastes. This paper examines the feasibility of using ceramic wastes in concrete. Results show that concrete with 20% cement replacement although it has a minor strength loss possess increase durability performance. Results also show that concrete mixtures with ceramic aggregates perform better than the control concrete mixtures concerning compressive strength, capillary water absorption, oxygen permeability and chloride diffusion thus leading to more durable concrete structures.     

The generation and disposal of solid wastes in Australia

In Australia there has been an increasing consumption of such materials as plastics, paper and metals which ultimately form solid wastes. It is expected that within the next 30 years the per capitasolid waste production, now 1#lb75 lbs/person/day, will double. This has led to a number of factors causing environmental problems. Attention is focussed on pollution, resource depletion and possible alternative resource usage, some of the problems which occur directly as a result of the consumption of a natural resource. In addition the problems caused by the production of waste containers, paper and such are discussed. These include garbage disposal and litter control in an urban society. Recycling of glass and paper products is now widely practised in Australia and plans have been made to recycle metal containers. In addition, some of the social issues pertinent to these topics are briefly outlined.     

Use of waste marble aggregates in concrete

Today we are faced with an important consumption and a growing need for aggregates because of the growth in industrial production, this situation has led to a fast decrease of available resources. On the other hand, a high volume of marble production has generated a considerable amount of waste materials; almost 70% of this mineral gets wasted in the mining, processing and polishing stages which have a serious impact on the environment. The processing waste is dumped and threatening the aquifer. Therefore, it has become necessary to reuse these wastes particularly in the manufacture of concrete products for construction purposes. The main goal of this study is to demonstrate the possibility of using marble wastes as a substitute rather than natural aggregates in concrete production. The paper presents the study methodology, the characterization of waste marble aggregates and various practical formulations of concrete. This experimental investigation was carried out on three series of concrete mixtures: sand substitution mixture, gravel substitution mixture and a mixture of both aggregates (sand and gravel). The concrete formulations were produced with a constant water/cement ratio. The results obtained show that the mechanical properties of concrete specimens produced using the marble wastes were found to conform with the concrete production standards and the substitution of natural aggregates by waste marble aggregates up to 75% of any formulation is beneficial for the concrete resistance.