Hazardous chemical site remediation through capping: Problems with long-term protection

The capping of waste management units and contaminated soils is receiving increasing attention as a low-cost method for hazardous chemical site remediation. Capping is used to prevent further groundwater pollution by existing waste management units and contaminated soils through limiting the moisture that enters the wastes. In principle, for wastes located above the water table, the construction of an impermeable cap can prevent leaching of the wastes (leachate generation) and groundwater pollution. In practice, appropriately designed and constructed RCRA caps can provide for only short-term prevention of groundwater pollution. Alternative approaches are available for capping of wastes that can be effective in preventing moisture from entering the wastes and concomitant groundwater pollution. These approaches recognize the inability of the typical RCRA cap to keep wastes dry for as long as waste constituents will be a threat and, most importantly, provide the necessary funds to effectively address all plausible worst-case scenario failures that could occur at a capped waste management unit or contaminated soil area.     

A multi-criteria assessment of scenarios on thermal processing of infectious hospital wastes: A case study for Central Macedonia

In Greece more than 14,000 tonnes of infectious hospital waste are produced yearly; a significant part of it is still mismanaged. Only one off-site licensed incineration facility for hospital wastes is in operation, with the remaining of the market covered by various hydroclave and autoclave units, whereas numerous problems are still generally encountered regarding waste segregation, collection, transportation and management, as well as often excessive entailed costs. Everyday practices still include dumping the majority of solid hospital waste into household disposal sites and landfills after sterilization, still largely without any preceding recycling and separation steps. Discussed in the present paper are the implemented and future treatment practices of infectious hospital wastes in Central Macedonia; produced quantities are reviewed, actual treatment costs are addressed critically, whereas the overall situation in Greece is discussed. Moreover, thermal treatment processes that could be applied for the treatment of infectious hospital wastes in the region are assessed via the multi-criteria decision method Analytic Hierarchy Process. Furthermore, a sensitivity analysis was performed and the analysis demonstrated that a centralized autoclave or hydroclave plant near Thessaloniki is the best performing option, depending however on the selection and weighing of criteria of the multi-criteria process. Moreover the study found that a common treatment option for the treatment of all infectious hospital wastes produced in the Region of Central Macedonia, could offer cost and environmental benefits. In general the multi-criteria decision method, as well as the conclusions and remarks of this study can be used as a basis for future planning and anticipation of the needs for investments in the area of medical waste management.     

Scenario of solid waste reuse in Khulna city of Bangladesh

The reuse and recycling of waste materials are now sincerely considered to be an integral part of solid waste management in many parts of the world. In this context, a vast number of options ranging from small scale decentralized to larger scale centralized plants have been adopted. This study aimed at investigating the waste reuse schemes in Khulna city located in the southern part of Bangladesh and ranked third largest city in the country. The shops for reusable material (SRM) were mostly situated around railway, waterway, and truck station markets which provided easy transportation to further locations. For the reuses of waste materials and products, a chain system was found to collect reusable wastes under a total number of 310 identified SRM with 859 persons directly or indirectly involved in the scheme. This was a decentralized waste management system with self sufficient (autonomous) management. According to mass balance, about 38.52 tons d^?1 solid wastes were reused in Khulna city area, accounting for 7.65% of the total generated wastes. This study revealed that apparently a silent, systematic, smooth, and clean reuse chain has been established in Khulna city area under private initiatives, whose sustainability was confirmed over the years in the country without any official or formal funds. However, proper adjustment between the higher and lower chain in the materials flow path, as well as personal hygiene training for the workers, would further improve the achievements of the established reuse scheme.     

Energy implications of the thermal recovery of biodegradable municipal waste materials in the United Kingdom

Waste management policies and legislation in many developed countries call for a reduction in the quantity of biodegradable waste landfilled. Anaerobic digestion, combustion and gasification are options for managing biodegradable waste while generating renewable energy. However, very little research has been carried to establish the overall energy balance of the collection, preparation and energy recovery processes for different types of wastes. Without this information, it is impossible to determine the optimum method for managing a particular waste to recover renewable energy. In this study, energy balances were carried out for the thermal processing of food waste, garden waste, wood, waste paper and the non-recyclable fraction of municipal waste. For all of these wastes, combustion in dedicated facilities or incineration with the municipal waste stream was the most energy-advantageous option. However, we identified a lack of reliable information on the energy consumed in collecting individual wastes and preparing the wastes for thermal processing. There was also little reliable information on the performance and efficiency of anaerobic digestion and gasification facilities for waste.     

Washing of waste prior to landfilling

The main impact produced by landfills is represented by the release of leachate emissions. Waste washing treatment has been investigated to evaluate its efficiency in reducing the waste leaching fraction prior to landfilling. The results of laboratory-scale washing tests applied to several significant residues from integrated management of solid waste are presented in this study, specifically: non-recyclable plastics from source separation, mechanical-biological treated municipal solid waste and a special waste, automotive shredded residues. Results obtained demonstrate that washing treatment contributes towards combating the environmental impacts of raw wastes. Accordingly, a leachate production model was applied, leading to the consideration that the concentrations of chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN), parameters of fundamental importance in the characterization of landfill leachate, from a landfill containing washed wastes, are comparable to those that would only be reached between 90 and 220years later in the presence of raw wastes. The findings obtained demonstrated that washing of waste may represent an effective means of reducing the leachable fraction resulting in a consequent decrease in landfill emissions. Further studies on pilot scale are needed to assess the potential for full-scale application of this treatment.     

Management of immunization solid wastes in Kano State, Nigeria

Inadequate management of waste generated from injection activities can have a negative impact on the community and environment. In this paper, a report on immunization wastes management in Kano State (Nigeria) is presented. Eight local governments were selected randomly and surveyed by the author. Solid wastes generated during the Expanded Programme on Immunization were characterised using two different methods: one by weighing the waste and the other by estimating the volume. Empirical data was obtained on immunization waste generation, segregation, storage, collection, transportation, and disposal; and waste management practices were assessed. The study revealed that immunization offices were accommodated in either in local government buildings, primary health centres or community health care centres. All of the stations demonstrated a high priority for segregation of the infectious wastes. It can be deduced from the data obtained that infectious waste ranged from 67.6% to 76.7% with an average of 70.1% by weight, and 36.0% to 46.1% with an average of 40.1% by volume. Non-infectious waste generated ranged from 23.3% to 32.5% with an average of 29.9% by weight and 53.9% to 64.0% with an average of 59.9% by volume. Out of non-infectious waste (NIFW) and infectious waste (IFW), 66.3% and 62.4% by weight were combustible and 33.7% and 37.6% were non-combustible respectively. An assessment of the treatment revealed that open pit burning and burial and small scale incineration were the common methods of disposal for immunization waste, and some immunization centres employed the services of the state or local government owned solid waste disposal board for final collection and disposal of their immunization waste at government approved sites.     

Modeling of urban solid waste management system: the case of Dhaka city

This paper presents a system dynamics computer model to predict solid waste generation, collection capacity and electricity generation from solid waste and to assess the needs for waste management of the urban city of Dhaka, Bangladesh. Simulated results show that solid waste generation, collection capacity and electricity generation potential from solid waste increase with time. Population, uncleared waste, untreated waste, composite index and public concern are projected to increase with time for Dhaka city. Simulated results also show that increasing the budget for collection capacity alone does not improve environmental quality; rather an increased budget is required for both collection and treatment of solid wastes of Dhaka city. Finally, this model can be used as a computer laboratory for urban solid waste management (USWM) policy analysis.     

Healthcare waste management in the capital city of Mongolia

Inconsistencies are present in the management options for healthcare wastes in Mongolia. One of the first critical steps in the process of developing a reliable waste management plan requires the performance of a waste characterization analysis. The objectives of this study were an assessment of the current situation of healthcare waste management (HCWM) and characterization of healthcare wastes generated in Ulaanbaatar. A total about 2.65 tonnes of healthcare wastes are produced each day in Ulaanbaatar (0.78 tons of medical wastes and 1.87 tons of general wastes). The medical waste generation rate per kg/patient-day in the inpatient services of public healthcare facilities was 1.4-3.0 times higher than in the outpatient services (P<0.01). The waste generation rate in the healthcare facilities of Ulaanbaatar was lower than in some other countries; however, the percentage of medical wastes in the total waste stream was comparatively high, ranging from 12.5% to 69.3%, which indicated poor waste handling practices. Despite the efforts for the management of wastes, the current system of healthcare waste management in Ulaanbaatar city of Mongolia is under development and is in dire need of immediate attention and improvement. It is essential to develop a national policy and implement a comprehensive action plan for HCWM providing environmentally sound technological measures to improve HCWM in Mongolia.     

A review of waste prevention through 3R under the concept of circular economy in China

The large waste generation has become one of the worldwide environmental problems. Circular economy has been seen as a way to tackle its urgent problems of environmental degradation and source scarcity. In recent years, under the concepts of circular economy, waste prevention through “Reduce, Reuse and Recycle” (3R) rules have attracted a broad concern in China. China has made some great achievements on waste management, and at the same time is facing many challenges. It is very necessary to share the management experiences and practices with the scholars and managers in other countries. This review covered the current situation and progress of circular economy development from the perspective of the legal regime and project practices, and the recycling practices of typical waste. The typical household wastes, including municipal solid wastes (MSW), e-waste, and end of life vehicles (ELV), were studied as the typical cases. Based on an examination of the statistical results, we also identified the potential problems and challenges for waste prevention through 3R in China. Finally, we provided some effective measures to further improve the waste management and recycling in China.     

The role played by environmental factors in the integration of a transfer station in a municipal solid waste management system

Transfer stations are an integral part of present-day municipal solid waste management systems. The main criteria used to decide on the location of a transfer station has traditionally been the minimization of transport costs, since it is cheaper to transport great amounts of waste over long distances in large loads than in small ones. In this study, we are going to consider the environmental factor in order to compare the feasibility of using a transfer station integrated within a waste management system. Applying the Life Cycle Assessment technique will enable us to obtain an objective parameter that quantifies the environmental impact of transportation and of operating a transfer station. Taking the current rates of solid wastes generation in the Plana region of Castellón (Spain) as our starting point, in this study we compare the environmental costs involved in the process of taking municipal wastes directly to the nearest waste treatment facility, with those involved in a waste management system integrating a transfer station. Comparing these two cases, an average reduction of 16.8% in the environmental impact can be obtained when a transfer station is incorporated in the waste management system.     

Municipal wastes and their solar transformities: an emergy synthesis for Macao

The debate over waste management practices has become increasingly important as human activities have begun to overload the biosphere's assimilative capacity. An effective waste management policy should be based on the principles of sustainable development, with wastes regarded as a potential resource rather than solely as something to eliminate. This approach requires an integrated waste management plan that makes full use of all available technologies. Macao is a highly populated consumer society that lacks natural resources and must therefore import almost all of its life-supporting goods and raw materials from regions outside the city. During the past 20 years, Macao has experienced an economic boom, accompanied by rapid socioeconomic development. Its discharged wastes have increased steadily during this period. This paper employs emergy analysis to investigate Macao's waste treatment in 1995, 1999, 2003 and 2004. The emergy of gaseous emissions was estimated to be 4.76 x 10(21) sej in 2004. Since 1992, Macao's municipal solid waste (MSW) has been incinerated to reduce its volume. The transformity of the fly ash and slag produced by this treatment in 2004, and the electricity generated by the incinerator, equaled 5.11 x 10(11) sej/g, 6.01 x 10(10) sej/g, and 7.61 x 10(6) sej/J, respectively. A large investment of natural resources and technology is required for the treatment of wastes; the feedback ratio of wastes, which represents the scale of the treatment of inputs, equaled 0.02 for MSW, 0.11 for sewage, and 0.06 for gaseous emissions.     

Management of hazardous waste in Thailand: present situation and future prospects

 This paper deals with the present scenario of hazardous waste management practices in Thailand, and gives some insights into future prospects. Industrialization in Thailand has systematically increased the generation of hazardous waste. The total hazardous waste generated in 2001 was 1.65 million tons. It is estimated that over 300 million kg/year of hazardous waste is generated from nonindustrial, community sources (e.g., batteries, fluorescent lamps, cleansing chemicals, pesticides). No special facilities are available for handling these wastes. There are neither well-established systems for separation, storage, collection, and transportation, nor the effective enforcement of regulations related to hazardous wastes management generated from industrial or nonindustrial sectors. Therefore, because of a lack of treatment and disposal facilities, these wastes find their way into municipal wastewaters, public landfills, nearby dump sites, or waterways, raising serious environmental concern. Furthermore, Thailand does not have an integrated regulatory framework regarding the monitoring and management of hazardous materials and wastes. In addition to the absence of a national definition of hazardous wastes, limited funding has caused significant impediments to the effective management of hazardous waste. Thus, current waste management practices in Thailand present significant potential hazards to humans and the environment. The challenging issues of hazardous waste management in Thailand are not only related to a scarcity of financial resources (required for treatment and disposal facilities), but also to the fact that there has been no development of appropriate technology following the principles of waste minimization and sustainable development. A holistic approach to achieving effective hazardous waste management that integrates the efforts of all sectors, government, private, and community, is needed for the betterment of human health and the environment. Received: February 26, 2001 / Accepted: October 11, 2002     

Medical waste management in Trachea region of Turkey: suggested remedial action.

The main objective of this paper was to analyse the present status of medical waste management in the Trachea region of Turkey and subsequently to draw up a policy regarded with generation, collection, on-site handling, storage, processing, recycling, transportation and safe disposal of medical wastes. This paper also presents the results of study about awareness on how to handle expired drugs. Initially all health-care establishments in Tekirda?, Edirne and Kyrklareli provinces in Trachea region were identified and the amounts of hospital wastes generated by each of them were determined. Current medical waste-management practices, including storage, collection, transportation and disposal, in surveyed establishments were identified. Finally, according to results, remedial measurements for medical waste management in these establishments were suggested. Unfortunately, medical wastes are not given proper attention and these wastes are disposed of together with municipal and industrial solid wastes. The current disposal method is both a public health and environmental hazard. When landfill sites are visited, many scavengers can be seen sorting for recyclable materials, a practice which is dangerous for the scavengers. In addition, it was found that some staff in health-care establishments are unaware of the hazard of medical wastes. It is concluded that a new management system, which consists of segregation, material substitution, minimization, sanitary landfilling and alternative medical waste treatment methods should be carried out. For the best appropriate medical waste management system, health-care establishment employers, managers and especially the members of house- keeping divisions should be involved in medical waste management practice.     

Report: future industrial solid waste management in pars Special Economic Energy Zone (PSEEZ), Iran.

The Pars Special Economic Energy Zone (PSEEZ) is located in the south of Iran, on the northern coastline of the Persian Gulf. This area was established in 1998 for the utilization of south Pars field oil and gas resources. This field is one of the largest gas resources in the world and contains about 6% of the total fossil fuels known. Petrochemical industries, gas refineries and downstream industries are being constructed in this area. At present there are three gas refineries in operation and five more gas refineries are under construction. In this study, different types of solid waste including municipal solid waste (MSW) and industrial wastes were investigated separately. The aim of the study was to focus on the management of the industrial wastes in order to minimize the environmental impact. In the first stage, the types and amounts of industrial waste in PSEEZ were evaluated by an inventory. The main types of industrial waste are oil products (fuel oil, light oil, lubricating oil), spent catalysts, adsorbents, resins, coke, wax and packaging materials. The waste management of PSEEZ is quite complex because of the different types of industry and the diversity of industrial residues. In some cases recycling/reuse of waste is the best option, but treatment and disposal are also necessary tools. Recently a design has been prepared for a disposal site in PSEEZ for the industrial waste that cannot be reused or recycled. The total surface area of this disposal site where the industrial waste should be tipped for the next 20 years was estimated to be about 42 000 m2.     

Estimation of construction waste generation and management in Thailand

This study examines construction waste generation and management in Thailand. It is estimated that between 2002 and 2005, an average of 1.1 million tons of construction waste was generated per year in Thailand. This constitutes about 7.7% of the total amount of waste disposed in both landfills and open dumpsites annually during the same period. Although construction waste constitutes a major source of waste in terms of volume and weight, its management and recycling are yet to be effectively practiced in Thailand. Recently, the management of construction waste is being given attention due to its rapidly increasing unregulated dumping in undesignated areas, and recycling is being promoted as a method of managing this waste. If effectively implemented, its potential economic and social benefits are immense. It was estimated that between 70 and 4,000 jobs would have been created between 2002 and 2005, if all construction wastes in Thailand had been recycled. Additionally it would have contributed an average savings of about 3.0 x 10(5) GJ per year in the final energy consumed by the construction sector of the nation within the same period based on the recycling scenario analyzed. The current national integrated waste management plan could enhance the effective recycling of construction and demolition waste in Thailand when enforced. It is recommended that an inventory of all construction waste generated in the country be carried out in order to assess the feasibility of large scale recycling of construction and demolition waste.     

Mad cow and related diseases: Challenges for waste management

Mad cow disease and related transmissible spongiform encephalopathy diseases (TSEs) in both animals and humans have received worldwide attention. Interestingly, the issue of managing biohazardous wastes, for which TSE agents are an issue, has received little attention by environmental professionals. The burial of wastes associated with mad cow and related diseases may eventually lead to unusual challenges for remediation professionals. The core challenge is that medical researchers have confirmed the incredible difficulty in destroying TSE infectious agents or pathogens, generally called prions. Risk reduction is certainly possible with treatment technologies, but complete elimination of risk by reliable and verifiable destruction of all TSE agents is probably infeasible. Proving the efficacy of any waste treatment method for TSE-infected wastes is not practical because there is no commercially available test for TSE pathogens (although one is expected soon) and in only a few cases is there a reasonable surrogate approach. These circumstances have contributed to some biohazardous waste managers discounting the TSE issue. The goal of this article is to more thoroughly analyze available information and various risks to identify useful implications for alternative waste management technologies. A number of prudent actions can be taken in recognition of the TSE problem, including more careful assessment of treatment technologies, avoiding any reuse or recycling of waste treatment residues, using air pollution control systems to avoid releases of materials possibly containing infectious agents, and using wastewater pretreatment prior to sewer disposal.     

A systems analysis tool for construction and demolition wastes management

Managing construction and demolition (C&D) wastes has challenged many municipalities with diminishing waste disposal capacity. Facing such challenges, the Massachusetts Department of Environmental Protection proposed a policy restricting the landfill disposal of certain C&D waste materials, if unprocessed. This research is to study the potential economic impact of such restriction on construction contractors and C&D waste processors. A spreadsheet-based systems analysis model has been developed to assist the cost-benefit evaluation for various C&D waste management scenarios. The model, developed based on the mass balance principle, is designed to track a C&D waste stream through the various stages of a waste management system, i.e. generation, source separation, processing, recycling, and final disposal. This model, by incorporating the material flow data with the cost/revenue data associated with each management activity, can then provide an economic analysis for a proposed C&D waste management scenario. A case study illustrating the application of this model for Massachusetts is also presented.     

Potential use of feebate systems to foster environmentally sound urban waste management

Waste treatment facilities are often shared among different municipalities as a means of managing wastes more efficiently. Usually, management costs are assigned to each municipality depending on the size of the population or total amount of waste produced, regardless of important environmental aspects such as per capita waste generation or achievements in composting or recycling. This paper presents a feebate (fee+rebate) system aimed to foster urban waste reduction and recovery. The proposal suggests that municipalities achieving better results in their waste management performance (from an ecological viewpoint) be recompensated with a rebate obtained from a fee charged to those municipalities that are less environmentally sound. This is a dynamic and flexible instrument that would positively encourage municipalities to reduce waste whilst increasing the recycling.     

System performance assessment of final repository for radioactive wastes using first-order reliability method

When a final option for radioactive waste is determined, it is necessary to demonstrate compliance of disposal system chosen with relevant regulations. Considering the large number of physical and chemical factors involved, the complexity of their interrelationships, and long time periods, a system approach is required. A stochastic analysis is also needed to ensure that these regulatory criteria can be met with confidence. Among a variety of models developed to treat the effect of uncertainty on system performance, the first-order reliability method is suggested as an attractive tool to stochastic problems incorporating any amount of probabilistic information. Based on the first-order approximation, the method can give a probability of failure against a preselected target value, and information concerning the sensitivity of the outcome to variations in the input random variables and their statistical moments. In this paper, for reliable prediction of the performance of repository for radioactive wastes, first-order reliability method is applied in treating the parameter uncertainties of predictive models. First, a thickness of canister corrosion and breach time of canister is calculated using a uniform corrosion model, combined with the diffusional transport modeling of radionuclides in the backfill material. Second, a fractional release rate for each radionuclide is derived from the evaluation of the performance of a waste package which consists of canister and backfill material. Third, a cumulative release rate at the accessible environment is obtained by geosphere transport modeling with the source term given as a fractional release rate. The proposed first-order reliability method can be applicable to a full range of problems occurring in radioactive waste management and beyond.