Verification of exponential distribution of arrival and service times at municipal solid waste facilities

Vehicle queuing at municipal solid waste (MSW) facilities causes economic and environmental damage. In the United States, typical MSW receiving facilities (transfer, recycling, energy recovery, and landfill) have three queues: one at the entrance weighing station, one at the waste tipping location, and one at the exit weighing station. A common method of determining queue behavior relies on equations that assume exponentially distributed arrival and service times, but there has not been a comprehensive study to determine whether this assumption is valid for a variety of MSW facilities and conditions. In this study, data were gathered from two transfer stations, two energy recovery plants, and one transfer/landfill facility. Among the five facilities there was a variety of queuing styles. The data were plotted as an inverse exponential relationship and linearized. The linearized plots were regressed and R ² values were calculated. It was determined that the negative exponential relationship can be used to describe arrival times at all three queues and service times at weighing queues. The queuing equations are therefore theoretically supported for use at entering and exiting weighing queues and moderately theoretically supported for use at tipping queues.     

Stochastic modeling and optimization of medical waste collection in Northern Jordan

Jordan has witnessed a rapid increase in healthcare facilities during the last two decades. As a consequence, the amount of generated medical waste have been increased rapidly and a proper management system is indeed needed to eliminate the environmental and health hazards resulted from such waste. An approved medical waste treatment facility is the incinerator located at the northern region of Jordan which serves the four northern governorates. Two trucks are used to pickup waste from the hospitals in these governorates to be treated at the incinerator. In this paper, a route scheduling model is proposed to minimize the total travel distance which in turn minimizes transportation cost and reduces emissions. The proposed model takes into account the capacity of trucks, number of visits per week, timing between visits along with the service level required by the hospitals. An optimal routing schedule was found and verified. Compared to current routing schedule, a saving of 102 km per week was achieved.     

Survey of carbonization facilities for municipal solid waste treatment in Japan

The operations of carbonization facilities for municipal solid waste treatment in Japan were examined. Input waste, system processes, material flows, quality of char and its utilization, fuel and chemical consumption, control of facility emissions, and trouble areas in facility operation were investigated and analyzed. Although carbonization is a technically available thermochemical conversion method for municipal solid waste treatment, problems of energy efficiency and char utilization must be solved for carbonization to be competitive. Possible solutions include (1) optimizing the composition of input waste, treatment scale, organization of unit processes, operational methods, and quality and yield of char on the basis of analysis and feedback of long-term operating data of present operating facilities and (2) securing stable char demands by linking with local industries such as thermal electric power companies, iron manufacturing plants, and cement production plants.     

Electronic tracking and management of industrial waste in Taiwan

This study discusses an online reporting system used for waste flow tracking (auditing) and investigation of violations. In contrast to systems used in other countries, this system requires waste generators and transporters, as well as the treatment, storage, and disposal facilities (TSDFs) to file online reports on the movement of industrial waste within 24 h of being shipped, received, or completely treated. This system also provides online analytical processing for reporters to analyze all their data, thereby encouraging self-management of waste. Currently there are 25,861 generators, 4,963 transporters, and 865 TSDFs in Taiwan that are required to file online reports. Approximately 80 % of all waste generated in Taiwan is reported using this system. More than 7,000 vehicles are equipped with a global positioning system (GPS) for waste tracking, among which over 2,000 transport hazardous waste. Disposal vehicles transmit their locations to the Control Center every 30 s. Database quality has been enhanced through auditing and inspection for more than 12 years since this system was established. It serves as a “single portal” for industrial waste management and facilitates informed decision making for resource exchange and material flow among various industries to achieve resource and environmental sustainability.     

An investigation on the fuel savings potential of hybrid hydraulic refuse collection vehicles

Refuse trucks play an important role in the waste collection process. Due to their typical driving cycle, these vehicles are characterized by large fuel consumption, which strongly affects the overall waste disposal costs. Hybrid hydraulic refuse vehicles offer an interesting alternative to conventional diesel trucks, because they are able to recuperate, store and reuse braking energy. However, the expected fuel savings can vary strongly depending on the driving cycle and the operational mode. Therefore, in order to assess the possible fuel savings, a typical driving cycle was measured in a conventional vehicle run by the waste authority of the City of Stuttgart, and a dynamical model of the considered vehicle was built up. Based on the measured driving cycle and the vehicle model including the hybrid powertrain components, simulations for both the conventional and the hybrid vehicle were performed. Fuel consumption results that indicate savings of about 20% are presented and analyzed in order to evaluate the benefit of hybrid hydraulic vehicles used for refuse collection.     

Waste collection multi objective model with real time traceability data

Waste collection is a highly visible municipal service that involves large expenditures and difficult operational problems, plus it is expensive to operate in terms of investment costs (i.e. vehicles fleet), operational costs (i.e. fuel, maintenances) and environmental costs (i.e. emissions, noise and traffic congestions). Modern traceability devices, like volumetric sensors, identification RFID (Radio Frequency Identification) systems, GPRS (General Packet Radio Service) and GPS (Global Positioning System) technology, permit to obtain data in real time, which is fundamental to implement an efficient and innovative waste collection routing model. The basic idea is that knowing the real time data of each vehicle and the real time replenishment level at each bin makes it possible to decide, in function of the waste generation pattern, what bin should be emptied and what should not, optimizing different aspects like the total covered distance, the necessary number of vehicles and the environmental impact. This paper describes a framework about the traceability technology available in the optimization of solid waste collection, and introduces an innovative vehicle routing model integrated with the real time traceability data, starting the application in an Italian city of about 100,000 inhabitants. The model is tested and validated using simulation and an economical feasibility study is reported at the end of the paper.     

An integrated analytical framework for quantifying the LCOE of waste-to-energy facilities for a range of greenhouse gas emissions policy and technical factors

This study presents a novel integrated method for considering the economics of waste-to-energy (WTE) facilities with priced greenhouse gas (GHG) emissions based upon technical and economic characteristics of the WTE facility, MSW stream, landfill alternative, and GHG emissions policy. The study demonstrates use of the formulation for six different policy scenarios and explores sensitivity of the results to ranges of certain technical parameters as found in existing literature. The study shows that details of the GHG emissions regulations have large impact on the levelized cost of energy (LCOE) of WTE and that GHG regulations can either increase or decrease the LCOE of WTE depending on policy choices regarding biogenic fractions from combusted waste and emissions from landfills. Important policy considerations are the fraction of the carbon emissions that are priced (i.e. all emissions versus only non-biogenic emissions), whether emissions credits are allowed due to reducing fugitive landfill gas emissions, whether biogenic carbon sequestration in landfills is credited against landfill emissions, and the effectiveness of the landfill gas recovery system where waste would otherwise have been buried. The default landfill gas recovery system effectiveness assumed by much of the industry yields GHG offsets that are very close to the direct non-biogenic GHG emissions from a WTE facility, meaning that small changes in the recovery effectiveness cause relatively larger changes in the emissions factor of the WTE facility. Finally, the economics of WTE are dependent on the MSW stream composition, with paper and wood being advantageous, metal and glass being disadvantageous, and plastics, food, and yard waste being either advantageous or disadvantageous depending upon the avoided tipping fee and the GHG emissions price.     

Application of a Proposed Generic LLW Waste Package Analysis With Changing Infiltration in a Humid Environment

Corrosion of carbon steel boxes filled with low‐level radioactive waste and buried within a near surface disposal facility in a humid environment was evaluated using an integrated systems approach framework. The time to hydraulic failure from initial burial to development of holes through the wall of a given waste package from pitting corrosion was calculated for four corrosion scenarios under two different corrosion cases. The two corrosion cases chosen were a constant rate of corrosion and a slowing rate of corrosion. Corrosion rates were estimated for carbon steel buried in soil from several historical studies and related to the corrosivity and aeration profile of the soil. The scenarios were chosen to represent a range of possible conditions at current and future U.S. Department of Energy disposal facilities. For each scenario, once the time to hydraulic failure had been estimated, the amount of liquid present in each waste package at the time of failure was calculated as an estimate of leachate available for subsurface transport. The Savannah River E‐Area Engineered Trench was used as a basis for the hypothetical disposal facility. © 2016 Wiley Periodicals, Inc.     

A GIS based transportation model for solid waste disposal--a case study on Asansol municipality

Uncontrolled growth of the urban population in developing countries in recent years has made solid waste management an important issue. Very often, a substantial amount of total expenditures is spent on the collection of solid waste by city authorities. Optimization of the routing system for collection and transport of solid waste thus constitutes an important component of an effective solid waste management system. This paper describes an attempt to design and develop an appropriate storage, collection and disposal plan for the Asansol Municipality Corporation (AMC) of West Bengal State (India). A GIS optimal routing model is proposed to determine the minimum cost/distance efficient collection paths for transporting the solid wastes to the landfill. The model uses information on population density, waste generation capacity, road network and the types of road, storage bins and collection vehicles, etc. The proposed model can be used as a decision support tool by municipal authorities for efficient management of the daily operations for transporting solid wastes, load balancing within vehicles, managing fuel consumption and generating work schedules for the workers and vehicles. The total cost of the proposed collection systems is estimated to be around 80 million rupees for the fixed cost of storage bins, collection vehicles and a sanitary landfill and around 8.4 million rupees for the annual operating cost of crews, vehicles and landfill maintenance. A substantial amount (25 million rupees/yr) is currently being spent by AMC on waste collection alone without any proper storage/collection system and sanitary landfill. Over a projected period of 15 yr, the overall savings is thus very significant.     

Industrial storm water pollution prevention: Effectiveness and limitations of source controls in the transportation industry

Industrial activities that are sources of pollutants in storm water runoff at typical facilities of the transportation industry are identified by site investigations at five facilities. This research then evaluates pollution prevention measures implemented to reduce those pollutants, as required by storm water regulations under the U.S. Clean Water Act. Activities that potentially generate storm water pollutants, particular to facilities of this industry, include: vehicle maintenance; vehicle fueling; vehicle washing; and activities on paved access roads and vehicle storage areas. Activities common to this industry, but also found in other industries, include: storage and handling of process materials and wastes; operation of industrial equipment located outdoors or exposed to storm water; and design and operation of site drainage facilities. Most control measures cited in the compliance documents of the facilities in the case studies were not developed specifically for storm water pollution prevention, but serve to reduce storm water pollutants as part of compliance with regulations for hazardous waste, wastewater, worker safety, or other purposes. Most identified control measures were operational practices or employee procedures, rather than structural facility modifications or devices to remove pollutants. Implementation of such measures is difficult to enforce or verify by regulatory agencies, and evidence at the case study facilities suggests that measures described similarly at different facilities are unevenly implemented and unequally effective at controlling storm water pollutants.     

Approximate cost functions for solid waste treatment facilities.

Cost estimation is a basic requirement for planning municipal solid waste management systems. The variety of organizational, financial and management schemes and the continuously developing technological advancements render the economic analysis a complex task, made more complex by the scarcity of real cost data. The objectives of this paper were: (1) to explore the problems arising in getting cost estimates from scattered and limited published data; (2) to suggest a procedure for generating cost functions relating initial set-up cost and operating cost with facility size; and (3) to present such cost functions, relevant to European states, for selected types of solid waste treatment and disposal facilities. Regarding the problems of available scarce data, one needs to deal with cost figures which correspond to facilities with variations in size, technology, year of construction, working conditions, level of technological automation, environmental impacts, social acceptance, capacity utilization rate, composition of inflowing waste, waste management policies, degree of compliance with quality standards, etc. The paper addresses this issue and discusses the proper use of statistical analyses in such cases of fragmented data; moreover, it points out some usual misuses of statistics by analysts and the danger of getting erroneous results. The suggested process for generating cost functions acceptable to the decision-makers is pivoted around the question of acceptable approximation level. Finally, approximate cost curves are suggested for waste-to-energy facilities, landfilling facilities, anaerobic digestion facilities and composting facilities.     

Measurements of particulate matter concentrations at a landfill site (Crete,Greece)

Large amounts of solid waste are disposed in landfills and the potential of particulate matter (PM) emissions into the atmosphere is significant. Particulate matter emissions in landfills are the result of resuspension from the disposed waste and other activities such as mechanical recycling and composting, waste unloading and sorting, the process of coating residues and waste transport by trucks. Measurements of ambient levels of inhalable particulate matter (PM₁₀) were performed in a landfill site located at Chania (Crete, Greece). Elevated PM₁₀ concentrations were measured in the landfill site during several landfill operations. It was observed that the meteorological conditions (mainly wind velocity and temperature) influence considerably the PM₁₀ concentrations. Comparison between the PM₁₀ concentrations at the landfill and at a PM₁₀ background site indicates the influence of the landfill activities on local concentrations at the landfill. No correlation was observed between the measurements at the landfill and the background sites. Finally, specific preventing measures are proposed to control the PM concentrations in landfills.     

Behavior of PAHs from sewage sludge incinerators in Korea

Although production of sewage sludge increases every year, its proper treatment has only been recently raised as a new issue, as current landfill and ocean dumping arrangements are expected to become increasingly difficult to manage in the future. The Korean Ministry of Environment plans to diversify its processing facilities and expand its processing systems by 2011, with the purpose of processing all sludge produced in Korea. According to this plan, incineration (including incineration of municipal wastes) will process 30% of the entire sewage sludge throughout the country in 2011. This study reviews the characteristics of PAH, which is one of the organic substances found in sewage sludge during the incinerating process. The total amount of PAH produced from sewage sludge incineration was found to be 6.103 mg/kg on average, and investigation performed on 16 PAHs of inlets and outlets of the air control devices at five full-scale incineration facilities showed that concentrations of the PAHs on the inlet and on the outlet ranged from 3.926 to 925.748 microg/m(3) and from 1.153 to 189.449 microg/m(3), respectively. In the case of the incineration facility fed with municipal waste (95%) and sewage sludge (5%), the total of the PAH emissions concentration was higher than that found at the incineration facilities used exclusively to treat sewage. The combustion of waste vinyl and plastics contained in municipal waste fed into the facility might contribute to the high levels of PAHs in the stack gas. However more investigation is needed on the production mechanism of PAHs at different operating conditions of the incineration facilities, such as the types of waste, and other relevant factors.     

Comparison of LLW Disposal Facilities at Major Department of Energy Sites

Near surface disposal facility design and management are examined and compared using a systems approach that defines facility performance as a function of three components (or subsystems): the disposal facility design (cover systems and bottom liners); the properties of the waste (waste composition, waste form and waste package); and the site‐specific environmental features (climate, geology, and hydrology). We report an evaluation of five DOE near surface disposal facility case studies, selected to provide a “representative” sample that included disposal sites with a range of waste and environmental characteristics across the DOE. The facilities selected were the Savannah River E‐Area Engineered Trenches, Hanford Integrated Disposal Facility, Idaho Radioactive Waste Management Complex, Oak Ridge Environmental Management Waste Management Facility, and Nevada National Security Site Area 5. ©2015 Wiley Periodicals, Inc.     

Energy recovery and greenhouse gas reduction potential from food waste in Japan

Waste-to-energy is one effective waste management approach for a sustainable society. The purpose of this study was to clarify the potential for energy recovery and greenhouse gas (GHG) reduction that could be achieved by introducing anaerobic digestion (AD) facilities in the process of reconstructing aging incineration facilities in Japan. Using statistical data from 1068 incineration facilities, four future scenarios were considered and compared with the current situation. As results, compared with the current situation the amount of electricity generated could increase by 60 % in 2030, by combining AD facilities for food waste with new, high-efficiency incineration facilities for remaining municipal solid waste (MSW). From a life cycle perspective, net energy recovery in 2030 was approximately three times greater than in 2011, and GHG emission could be reduced by 27 %. The introduction of AD facilities is attractive for small authorities, which currently treat <100 t/day of MSW through incineration facilities without energy recovery. An AD facility is also beneficial for large authorities. On the contrary, in middle-scale authorities that treat 100–299 t/day of MSW, the reconstruction of incineration facilities to include electricity production capabilities requires careful consideration, because it will significantly influence energy recovery and GHG reduction effects.     

Understanding the RCRA corrective action process

The Resource Conservation and Recovery Act (RCRA) was enacted in 1976. The Hazardous and Solid Waste Amendments (HSWA) of 1984 specify “corrective action” requirements for protecting human health and the environment from environmental contamination at active hazardous waste treatment, storage, and disposal facilities. RCRA and its corrective action requirements are designed to prevent the creation of new Superfund sites by regulating and remediating active facilities. The RCRA corrective action process has four basic components: the facility assessment, facility investigation, corrective measures study, and corrective measures implementation. This article presents an overview of the RCRA corrective action process and presents four case studies from three U.S. EPA regions.     

Participatory approach, acceptability and transparency of waste management LCAs: case studies of Torino and Cuneo

The paper summarises the main results obtained from two extensive applications of Life Cycle Assessment (LCA) to the integrated municipal solid waste management systems of Torino and Cuneo Districts in northern Italy. Scenarios with substantial differences in terms of amount of waste, percentage of separate collection and options for the disposal of residual waste are used to discuss the credibility and acceptability of the LCA results, which are adversely affected by the large influence of methodological assumptions and the local socio-economic constraints. The use of site-specific data on full scale waste treatment facilities and the adoption of a participatory approach for the definition of the most sensible LCA assumptions are used to assist local public administrators and stakeholders showing them that LCA can be operational to waste management at local scale.     

A review of waste management practices and their impact on human health

This work reviews (i) the most recent information on waste arisings and waste disposal options in the world, in the European Union (EU), in Organisation for Economic Co-operation and Development (OEDC) countries, and in some developing countries (notably China) and (ii) the potential direct and indirect impact of waste management activities on health. Though the main focus is primarily on municipal solid waste (MSW), exposure to bioaerosols from composting facilities and to pathogens from sewage treatment plants are considered. The reported effects of radioactive waste are also briefly reviewed. Hundreds of epidemiological studies reported on the incidence of a wide range of possible illnesses on employees of waste facilities and on the resident population. The main conclusion of the overall assessment of the literature is that the evidence of adverse health outcomes for the general population living near landfill sites, incinerators, composting facilities and nuclear installations is usually insufficient and inconclusive. There is convincing evidence of a high risk of gastrointestinal problems associated with pathogens originating at sewage treatment plants. In order to improve the quality and usefulness of epidemiological studies applied to populations residing in areas where waste management facilities are located or planned, preference should be given to prospective cohort studies of sufficient statistical power, with access to direct human exposure measurements, and supported by data on health effect biomarkers and susceptibility biomarkers.     

Health-care waste management in Lao PDR: a case study.

This study investigated the health-care waste (HCW) management at each health-care facility level at two selected sites in the Lao People's Democratic Republic (Lao PDR): Vientiane Municipality; and Bolikhamxay province. It focused on the amount of HCW, its segregation and the factors influencing HCW management, particularly segregation procedures. A high proportion of incorrectly segregated medical waste was found at each level of health-care facility. Re-segregation revealed 39, 62, 57 and 37% at national hospital, provincial hospital, district hospital and health centre level, respectively, was poorly segregated. The mean of generated HCW was 0.62 kg/bed per day (Vientiane Municipality) and 0.38 kg/bed per day (Bolikhamxay) at two study sites. A higher proportion of medical waste (MW) from the inpatient department at the primary health-care level was found. Thus, HCW management at primary health-care facilities needs more attention and should be better understood.     

Solid recovery rate of food waste recycling in South Korea

Source-separated collection system of household food waste has been implemented national wide in South Korea. Food waste recycling rate that means conversion rate to recycle is over 90 % in present. However, over the value of 90 %, we need to enhance the efficiency of food waste recycling process. We analyzed material flow of 24 food waste recycling facilities and calculated solid recovery rate to key-process. We found that 3–13 % of the solids from food waste outflows with foreign materials and 27–33 % of the solids outflow with wastewater. As a result, solid recovery rates are 65.3, 60.9, and 56.3 % in wet feed facility, dry feed facility, and composting facility, respectively. Alternative ways to recovery solid from wastewater or collection tools to exclude plastic bags, salt, and moisture content are required to make food waste recycling more efficient.