Alternatives for treatment and disposal cost reduction of regulated medical wastes

Many hospitals or health care facilities have faced financial difficulties and thus they have attempted to find cost-effective treatment and disposal methods of their regulated medical wastes (RMWs). This study investigated generation volume and sources, composition, and treatment and disposal methods for RMWs obtained from three out of the five typical city hospitals in Massachusetts for which we could obtain relevant data on medical waste. Also, this study compared the generation patterns and amounts of RMWs between the hospital and the medical school. The yearly operational treatment and disposal costs of RMWs based on different treatment and disposal methods were analyzed for one hospital. The most cost-effective option of four different treatment and disposal options studied was to combine on-site incineration and microwave technologies. Finally, this study identified measures for the effective waste characterization methods for the reduction of treatment and disposal costs of RMWs. By careful exclusion of non-RMW from RMW waste streams, hospitals can reduce the RMW volume that requires special treatment and reduce disposal costs.     

Leachate from land disposal of coal fly ash

The results of large-scale lysimeter tests in which two pulverized coal fly ashes (PCFA) have been exposed to natural weather conditions for up to seven years are presented and compared with those of laboratory leaching tests. Laboratory column leaching tests on PCFA show good reproducibility, and comparisons between lysimeter and laboratory leaching results are promising for several salt ions and trace elements in the leachate when expressed in terms of the leachate to solids ratio (L/S). A long-term disposal strategy which takes into account the largely insoluble nature of PCFA is suggested.     

Estimating the costs of corrective action at land disposal facilities

The U.S. Environmental Protection Agency (EPA) has proposed regulations that would require corrective action (e.g., soil excavation and groundwater removal and treatment) at municipal solid waste landfills (MSWLFs) and hazardous waste treatment, storage, and disposal facilities (TSDFs). This paper presents an overview of the proposed corrective action regulations, and discusses their relationship to proposed or existing closure and post-closure care regulations. The paper then presents estimated corrective action cost curves for various MSWLF scenarios defined by landfill area, average waste thickness, and the presence or absence of a clay liner. The paper finally illustrates the economic benefits of sound closure and postclosure care by comparing estimated costs of corrective action to estimated costs of closure and postclosure care at MSWLFs.     

Using MCDA and GIS for hazardous waste landfill siting considering land scarcity for waste disposal

The main aim of this study was to develop a procedure that minimizes the wasting of space for the siting of hazardous waste landfills as part of a solid waste management system. We wanted to tackle the shortage of land for waste disposal that is a serious and growing problem in most large urban regions. The procedure combines a multi-criteria decision analysis (MCDA) approach with a geographical information system (GIS). The GIS was utilised to obtain an initial screening in order to eliminate unsuitable areas, whereas the MCDA was developed to select the most suitable sites. The novelty of the proposed siting procedure is the introduction of a new screening phase before the macro-siting step aimed at producing a “land use map of potentially suitable areas” for the siting of solid waste facilities which simultaneously takes into consideration all plant types. The issue of obtaining sites evaluations of a specific facility was coupled with the issue of not wasting land appropriate to facilitate other types of waste management options. In the developed case study, the use of an innovative criteria weighting tool (the “Priority Scale”) in combination with the Analytic Hierarchy Process was useful to easier define the priorities of the evaluation criteria in comparison with other classic methods such as the Paired Comparison Technique in combination with the Simple Additive Weighting method.     

略谈清洁生产战略在医院废物处理中的指导意义

清洁生产战略作为环境管理的一项手段,是实现可持续发展战略的一项重要举措.医院废物作为一种危险废物,在其处理处置过程中,也应引入清洁生产思想,这对于有效利用资源和能源,减轻环境压力,都具有重要意义.     

Alternatives to incineration in remediation of soil and sediments assessed

Contamination of soil and sediment by pollutants represents a major environmental challenge. Remediation of soil during the original Superfund years consisted primarily of dig and haul, capping, or containment. The 1986 amendments to CERCLA—SARA—provided the incentive for treatment and permanent remedies during site remediation. Thermal treatment, which routinely achieves the low cleanup criteria required by RCRA land-ban regulations, became one of the major technologies used for cleanup under the concept of ARAR. As the remediation industry matured and recognized specific market niches in soil remediation, a number of new technologies emerged. Thermal desorption, bioremediation, soil vapor extraction, soil washing, and soil extraction are being used on sites at which the technology offers advantages over incineration. In addition, a continuing stream of emerging technologies is being presented that requires careful evaluation relative to existing cleanup methods. Each of these technologies offers a range of options for achieving appropriate cleanup criteria, application to different soil matrices, cost, time of remediation, and public acceptability. Balancing cleanup criteria defined by regulation or risk assessment with technology cost and capability affords the opportunity to solve these problems with appropriate balance of cost and protection of human health and the environment.     

Evaluating waste disposal systems

Waste disposal systems conventionally exhibit many problems, such as difficulties in finding final disposal sites for incinerator residues and the issue of how to recycle waste materials. Some new technologies have been developed to solve such problems, including ash melting and gasification melting. Furthermore, to improve the power generation efficiency of waste treatment facilities so that their energy is used more efficiently, combined stoker/gas turbine power generation (super waste power generation) technology has been developed. Through examination of two cases in this study, environmental impacts and costs were determined using lifecycle assessment (LCA) and lifecycle cost (LCC) methods in a model city. In case 1, a stoker furnace was compared to a combined stoker/gas turbine system. In case 2, a stoker furnace plus ash melting system was compared to a gasification melting system. The results demonstrate that the stoker furnace has a lower environmental impact than the combined stoker/gas turbine system in case 1, and that the stoker plus ash melting system costs less than the gasification melting system in case 2, but both systems had strong impacts on the environment.     

Waste disposal technology transfer matching requirement clusters for waste disposal facilities in China

Even though technology transfer has been part of development aid programmes for many decades, it has more often than not failed to come to fruition. One reason is the absence of simple guidelines or decision making tools that help operators or plant owners to decide on the most suitable technology to adopt. Practical suggestions for choosing the most suitable technology to combat a specific problem are hard to get and technology drawbacks are not sufficiently highlighted. Western counterparts in technology transfer or development projects often underestimate or don’t sufficiently account for the high investment costs for the imported incineration plant; the differing nature of Chinese MSW; the need for trained manpower; and the need to treat flue gas, bunker leakage water, and ash, all of which contain highly toxic elements.This article sets out requirements for municipal solid waste disposal plant owner/operators in China as well as giving an attribute assessment for the prevalent waste disposal plant types in order to assist individual decision makers in their evaluation process for what plant type might be most suitable in a given situation. There is no ‘best’ plant for all needs and purposes, and requirement constellations rely on generalisations meaning they cannot be blindly applied, but an alignment of a type of plant to a type of owner or operator can realistically be achieved. To this end, a four-step approach is suggested and a technology matrix is set out to ease the choice of technology to transfer and avoid past errors. The four steps are (1) Identification of plant owner/operator requirement clusters; (2) Determination of different municipal solid waste (MSW) treatment plant attributes; (3) Development of a matrix matching requirement clusters to plant attributes; (4) Application of Quality Function Deployment Method to aid in technology localisation.The technology transfer matrices thus derived show significant performance differences between the various technologies available. It is hoped that the resulting research can build a bridge between technology transfer research and waste disposal research in order to enhance the exchange of more sustainable solutions in future.     

Revegetating industrial waste disposal sites

Short-rotation tree plantations were established at seven industrial waste disposal sites in southern Finland. Altogether 31,500 willow cuttings were planted between 1984 and 1989. Neutralized residue from a titanium dioxide pigment process had an unfavourable influence on growth. Biological sludges from a municipal sewage treatment plant, and pulp and paper mills were too compact to be used alone as substrate, but gave a good supply of nutrients. Sand, bark and de-inking waste were sufficiently porous, but were low in nutrients. A mixture of different waste materials is therefore recommended as a substrate for willow stands. Replacement of a natural soil cover with waste material allows disposal of a greater volume of refuse and diminishes the costs of revegetation. The landfill characteristics have to be taken into account. The high temperature of bark also disturbed the growth of willow stands. Ferrous sulphate in the landfill limits the possibility of irrigating the stand. The highest biomass production of the stands exceeded that of normal Finnish forest. Willow stands can be used for landscaping industrial waste disposal sites, for increasing evapotranspiration and minimizing leachate discharge.     

The willingness to household waste disposal practices of residents in rural China

Journal of Material Cycles and Waste Management - The increasing amount of household waste is becoming one of the major challenges in the sustainable development of rural areas in China. As most...     

Institutional and management approaches to solid waste disposal in large metropolitan areas

There are significant advantages to a consolidated institutional approach to the management of municipal solid waste transfer and disposal in large metropolitan areas. Both operational and environmental benefits can be achieved. On the other hand, it is argued that collection services do not necessarily benefit from centralization, since there are only limited economies of scale. Furthermore, there is abundant evidence that the private sector can provide conventional collection services more efficiently than the public sector. This paper examines a model of decentralized collection and centralized transfer and disposal that is in place at Norfolk, Virginia, U.S.A. and which is being applied in Monterrey, Mexico. The partial application of this model in the Federal District of Mexico City is also examined. Lessons are drawn for the application of such a model to metropolitan areas in other developing countries.     

Identification of novel eubacteria from spent mushroom compost (SMC) waste by DNA sequence typing: ecological considerations of disposal on agricultural land

A small study was undertaken to examine the microbiological characteristics of spent mushroom compost (SMC), which is the major waste by-product of the mushroom industry and which is regularly disposed off by application to agricultural land. The primary aim of this study was to examine SMC for the presence of faecal bacterial pathogens, including Campylobacter spp., Salmonella spp. and Listeria monocytogenes. Secondly it was desirable to quantify bacterial and fungal populations within SMC, and also qualitatively identify the diversity of bacterial populations within SMC, through employment of rDNA PCR and direct sequencing techniques on the culturable microflora. Conventional microbiological analyses of SMC material (n=30) from six commercial operations in both Northern Ireland and the Republic of Ireland, failed to detect Salmonella spp, Listeria spp. or Campylobacter spp. in any of the SMC material examined. Total aerobic plate counts gave a mean count of log10 7.01 colony forming units (cfu) per gram SMC material (range: log10 6.53-7.52 cfu/g). Fungal counts gave a mean count of log(10) 4.57 cfu per gram SMC material (range: log10 3.93-4.98 cfu/g). From a total of greater than 50 colony picks, a total of 12 bacterial morphotypes were identified and were further examined by employment of partial 16S rRNA gene amplification and sequencing techniques, yielding several genera and species, including Bacillus licheniformis, Bacillus subtilis, Klebsiella/Enterobacter sp. Microbacterium sp. Paenibacillus lentimorbus, Pseudomonas mevalonii, Sphingobacterium multivorum and Stenotrophomonas sp. This is the first preliminary report on the microbial diversity of SMC waste and demonstrates the presence of several species that have not been previously described in SMC, in addition to two potentially novel species within the genera Microbacterium and Stenotrophomonas. It is thereby important to examine the ecological microbe-microbe and plant-microbe interactions that are occurring between the native bacterial soil flora and those added annually (theoretically estimated at approximately 10(18) cells) through the application of SMC. Such studies would be beneficial in helping to ascertain the ecological consequences involved in the disposal of SMC waste on agricultural land.     

Municipal solid waste disposal in Portugal

In recent years municipal solid waste (MSW) disposal has been one of the most important environmental problems for all of the Portuguese regions. The basic principles of MSW management in Portugal are: (1) prevention or reduction, (2) reuse, (3) recovery (e.g., recycling, incineration with heat recovery), and (4) polluter-pay principle. A brief history of legislative trends in waste management is provided herein as background for current waste management and recycling activities. The paper also presents and discusses the municipal solid waste management in Portugal and is based primarily on a national inquiry carried out in 2003 and directed to the MSW management entities. Additionally, the MSW responsibility and management structure in Portugal is presented, together with the present situation of production, collection, recycling, treatment and elimination of MSW. Results showed that 96% of MSW was collected mixed (4% was separately collected) and that 68% was disposed of in landfill, 21% was incinerated at waste-to-energy plants, 8% was treated at organic waste recovery plants and 3% was delivered to sorting. The average generation rate of MSW was 1.32 kg/capita/day.     

Using plastic bag waste to assess the reliability of self-reported waste disposal data

Direct waste analysis (DWA) and the material flows approach are the two standard methods to quantify aggregated waste streams and analyze waste composition. Yet, with the increasing application of producer responsibility measures, product-based waste data rather than aggregated waste data are becoming important. It is over this requirement that both approaches fail to some extent in delivering the type and quality of information that is needed. This study uses plastic bag waste as an illustration to show how self-reported questionnaire survey data may be used to assess disposal quantities of product-based waste types. The estimates from a large-scale questionnaire survey with over 4,100 completed cases were verified against DWA data of the same year in Hong Kong. It was found that self-reported data give systematically lower figures (on the order of 1.3-5 times) than those obtained from standard methods such as DWA for Hong Kong and the UK. However, it is demonstrated that self-reported data can be internally consistent. Also, the magnitude of underestimation may not be as considerable as it appears since the data from DWA are not themselves entirely accurate owing to the difficulties in obtaining a pure load of waste for field analysis and the variable moisture contents or contamination levels in waste material.     

The disposal of radioactive ferric floc

An iron hydroxide floc is used as treatment for adsorbing low amounts of actinides during nuclear fuel re-processing. This waste is cemented only after pre-treatment with Ca(OH)(2). Characterisation of all simulant material has been undertaken using XRD, TGA and SEM/EDS. The floc is a moderately alkaline colloidal slurry containing approximately 15wt% solids, with the main particulate being an amorphous hydrated iron oxide. The main phase formed during pre-treatment appears to be an X-ray amorphous hydrated calcium-ferrate phase. Embedded within this are small amounts of crystalline Ca(OH)(2), calcite, Fe(6)(OH)(12)(CO(3)), Ca(6)Fe(2)(SO(4))(3)(OH)(12).26H(2)O and Ca(3)B(2)O(6), and can form depending on concentrations of Ca(OH)(2) and time. Apart from Ca(OH)(2) and calcite, none of the crystalline phases detected during pre-treatment are detected when the floc is encapsulated in an OPC/PFA composite cement hydrated for 90 days. The main crystalline phase detected in the hardened wasteform is a solid solution hydrogarnet, Ca(3)AlFe(SiO(4))(OH)(8), known as C(3)(A,F)SH(4) in cement chemistry nomenclature.     

Telerobots for remote disposal of mixed waste

Two remote-controlled robotic submersible vehicles and an automated shredder are helping remove and dispose of highly reactive, sometimes explosive materials, dumped into a water-filled quarry at the U.S. Department of Energy's reservation in Oak Ridge, Tennessee. Human workers never enter the four-acre site, except for well-planned equipment maintenance and to shoot holes from a protected but into the retrieved containers, releasing pressure and exposing the contents to air and water. During its approximately two years of operation, the $8 million project has retrieved more than 15,000 items from the thirty feet of water at the bottom of the quarry.     

报废显像管的适用处置方法

指出了报废显像管的处理是报废电视机处理的关键步骤,分析了显像管屏、锥玻璃的结构组成,概述了报废显像管环保处理的几种方法,介绍了适用于报废显像管玻璃环保处理、再生利用的实用工艺过程.     

Passive Treatment Alternatives for Remediating Abandoned‐Mine Drainage

Abandoned‐mine drainage (AMD) is drainage flowing from or caused by surface mining, deep mining, or coal refuse piles that is typically highly acidic with elevated levels of dissolved metals. AMD results from the interactions of certain sulfide minerals with oxygen, water, and bacteria. Passive treatment systems have been used to remediate AMD at numerous sites throughout the United States. The theory behind passive treatment is to allow naturally occurring chemical, biological, and physical reactions that aid in AMD treatment to occur in the controlled environment of the system, not in the receiving water body. The advantages of passive treatment over active treatment include lower operation and maintenance costs, virtually no use of chemicals, and minimal energy consumption. The disadvantages are that smaller volumes of water are treated than with active systems, and discharges with high concentrations of dissolved metals and extremes of pH may have to be treated several times within one system to treat the discharge. AMD passive treatment systems include aerobic treatment systems and anaerobic treatment systems. It is estimated that it will take 50 years and between $5 billion and $15 billion to remediate all AMD problems in Pennsylvania. © 2001 John Wiley & Sons, Inc.