Characterization of fuel gas products from the treatment of solid waste streams with a plasma arc torch

This work addresses the plasma treatment of two solid waste streams and production of fuel gases from the process. In this study, carpet waste and simulated solid wastes generated by a United States Air Force Basic Expeditionary Airfield Resources Base deployment were used. Waste was treated in a furnace fitted with a 100kW plasma arc torch. The off gas was analyzed to determine its composition. The product gas was composed primarily of carbon monoxide and hydrogen, with small amounts of methane, benzene and toluene also detected. These experiments demonstrate the feasibility of producing fuel gases by plasma treatment of the solid waste streams. While the thermal energy value of the fuel gas produced in these experiments was less than the energy input, a higher waste-to-fuel gas conversion efficiency is expected in full-scale application.     

Assessment of the greenhouse effect impact of technologies used for energy recovery from municipal waste: A case for England

Waste management activities contribute to global greenhouse gas emissions approximately by 4%. In particular the disposal of waste in landfills generates methane that has high global warming potential. Effective mitigation of greenhouse gas emissions is important and could provide environmental benefits and sustainable development, as well as reduce adverse impacts on public health. The European and UK waste policy force sustainable waste management and especially diversion from landfill, through reduction, reuse, recycling and composting, and recovery of value from waste. Energy from waste is a waste management option that could provide diversion from landfill and at the same time save a significant amount of greenhouse gas emissions, since it recovers energy from waste which usually replaces an equivalent amount of energy generated from fossil fuels. Energy from waste is a wide definition and includes technologies such as incineration of waste with energy recovery, or combustion of waste-derived fuels for energy production or advanced thermal treatment of waste with technologies such as gasification and pyrolysis, with energy recovery. The present study assessed the greenhouse gas emission impacts of three technologies that could be used for the treatment of Municipal Solid Waste in order to recover energy from it. These technologies are Mass Burn Incineration with energy recovery, Mechanical Biological Treatment via bio-drying and Mechanical Heat Treatment, which is a relatively new and uninvestigated method, compared to the other two. Mechanical Biological Treatment and Mechanical Heat Treatment can turn Municipal Solid Waste into Solid Recovered Fuel that could be combusted for energy production or replace other fuels in various industrial processes. The analysis showed that performance of these two technologies depends strongly on the final use of the produced fuel and they could produce GHG emissions savings only when there is end market for the fuel. On the other hand Mass Burn Incineration generates greenhouse gas emission savings when it recovers electricity and heat. Moreover the study found that the expected increase on the amount of Municipal Solid Waste treated for energy recovery in England by 2020 could save greenhouse gas emission, if certain Energy from Waste technologies would be applied, under certain conditions.     

An evaluation of four key methods for monitoring household waste prevention campaigns in the UK

Household waste prevention in England has been recognised in national strategy as a key component for future sustainable practice. To support the policy agenda, the Department of Environment, Food and Rural Affairs (Defra) in England has funded an extensive programme of fundamental research in the area. The specific research aim reported on here, in this Defra funded project, was to trial and assess methods for monitoring and evaluating approaches detailed in the National Resource and Waste Forum (NRWF)’s Household Waste Prevention Toolkit. The methods that formed the basis for the four research Objectives for the project were: using pilot and control areas (core Objective), tracking waste arisings, measuring specific activities and declared awareness and behaviour surveys. A primary objective of this research was to quantify the direct waste tonnage impacts of implementing a targeted household waste campaign in Dorset County, UK. A key performance indicator chosen for this assessment was the weight of waste collected at the kerbside from households. In an area where a waste prevention campaign is well planned and implemented then reductions in household waste arisings in pilot areas can be in the region of 2% per annum. This method for monitoring can be used, in the hands of an expert project team, to communicate to the public the direct benefits of waste prevention. It was found that there are a wide range of factors that need to be taken into account in the UK, and that these had hitherto been given little prominence, such as careful matching of pilot and control areas – this proved problematical in this research. However, a range of techniques used to support the methods, e.g. doorstepping surveys and focus groups could not show clear attributable waste prevention impacts but their findings could be used to direct new future messages to the public. The most successful and measurable campaign activities that were revealed by evaluation were: mail preference registrations, Home composting and doorstepping. An expert evaluation of all major methods found that no clear preference was revealed as to which were the most useful. None of the methods were judged very poor neither very good, all had major issues about their use. Tracking waste arisings and focus groups were assessed to be the best techniques in terms of input effort to output value. It is likely that waste prevention teams for household waste will need very careful training in the cost-effective use of the NRWF Toolkit before they are competent to apply it to a given place; the issues are more complex than were first thought.     

发达国家和地区危险废物名录管理实践

危险废物名录制度是危险废物环境管理的基础。2016年6月14日,环境保护部、国家发改委、公安部联合公布了《国家危险废物名录》(2016年版),对2008年版危险废物名录进行了调整。本文介绍了主要发达国家和地区危险废物名录制度的基本情况,对其优缺点进行了对比分析,以期为更好的理解新版危险废物名录提供参考。主要发达国家和地区的危险废物名录管理体系具有以下优点:一是完善的危险废物豁免排除制度加强了企业和管理部门的责任意识。二是危险废物和一般固体废物共享分类体系便于对废物的统筹管理,废物代码内容翔实,增加了名录的可操作性。三是基于不同处理责任主体进行分类,避免了名录方式或列举方式造成的"漏分"现象。四是根据环境风险实行分级管理,重点突出。同时存在几点不足:一是鉴别程序繁琐,降低了危险废物处置效率;二是存在部分行业产生的废物遗漏、同类危险废物分类过细等问题;三是部分国家危险废物分类过于笼统,不利于企业对危险废物种类及属性的识别。     

A review on tertiary recycling of high-density polyethylene to fuel

Plastics have become an indispensable ingredient of human life. They are non-biodegradable polymers of mostly containing carbon, hydrogen, and few other elements such as chlorine, nitrogen etc. Rapid growth of the world population led to increased demand of commodity plastics. High density poly ethylene is one of the largest used commodity plastics due to its vast applications in many fields. Due to its non bio degradability and low life, HDPE contributes significantly to the problem of Municipal Waste Management. To avert environment pollution of HDPE wastes, they must be recycled and recovered. On the other hand, steady depletion of fossil fuel and increased energy demand, motivated the researchers and technologists to search and develop different energy sources. Waste to energy has been a significant way to utilize the waste sustainably, simultaneously add to meet the energy demand. Plastics being petrochemical origin have inherently high calorific value. Thus they can be converted back to useful energy. Many researches have been carried out to convert the waste plastics into liquid fuel by thermal and catalytic pyrolysis and this has led to establishment of a number of successful firms converting waste plastics to liquid fuels. This paper reviews the production and consumption HDPE, different methods of recycling of plastic with special reference to chemical degradation of HDPE to fuel. This also focuses on different factors that affect these degradations, the kinetics and mechanism of this reaction.     

Municipal solid waste management in South Africa: from waste to energy recovery through waste-to-energy technologies in Johannesburg

ABSTRACT

“Waste-to-energy” (WTE) technologies have been presented as one of the avenues to improve the management of solid waste whilst promoting clean and healthy urban environments through the recovery of waste and generation of energy. Research suggests that with the right investment in technologies and institutional changes, waste can potentially become a resource that can contribute to the socio-economic development of cities. It is in this context that this paper presents a review of the literature on WTE technologies and their implications on sustainable waste management in urban areas. The paper particularly contributes to our understanding of WTE technologies and its potential on Municipal Solid Waste Management (MSWM) in Johannesburg, South Africa. It is estimated that the city of Johannesburg’s landfills airspace will be completely depleted by year 2023. This projection becomes a motivation for the identification of suitable WTE alternative avenues to manage waste in the city. The paper argues that WTE technologies can contribute significantly to sustainable waste management, economic growth, ecological and environmental well-being.     

Assessment of the coherence of the Swiss waste wood management

Waste wood recovery by thermal treatment with energy recovery or by recycling allows the substitution and conservation of primary resources. Swiss government notes the potential presence of tensions between policies which simultaneously encourage the cascade use of wood, the recycling or the energy recovery by thermal treatment of waste wood. The aim of the present research is to assess the coherence of waste wood management in Switzerland by a quantitative and qualitative approach. First, a material flow analysis allows to model the wood resources and waste wood metabolism over one century. The simulation results of various scenarios of waste wood management establish that the additional impacts of the immediate thermal treatment are less significant for the reduction of CO₂eq emissions but more significant for the energy production than its cascade treatments on Swiss territory. Secondly, a documentary analysis examines the determinants of the current waste wood treatments prevailing in Switzerland. Thus, the causes of the strong presence on Swiss territory of the sector of thermal treatment, the export of almost half of waste wood generated and the sub-exploitation of Swiss forest act as barriers or drivers that result in introducing a crowding-out effect where no amount of waste wood is available for recycling in Switzerland. The comparison of the results of the two approaches leads to the conclusion that the current waste wood management is coherent in relation to the various goals of the Swiss federal policies but the waste wood potential for energy production is not fully exploited. The recommendations on the waste wood management and the possibilities to use the model for other case studies are given in the conclusion.     

Comparison of energy produced from waste by removing its different components: A case study of the waste landfill in Tehran

In developing and populated cities such as Tehran, a massive amount of municipal solid waste (MSW), both wet and dry, is transferred to landfills daily. Combustion is one of the most common methods of using mixed waste energy from the past to the present. The Dulong formula is widely used to calculate the energy released from MSW combustion. According to the constituent components of Tehran MSW, removing food waste leads to an increase in energy potential, which will be a suitable condition for energy production. In this work, the energy derived from the combustion of mixed and separated dry MSW generated in Tehran was calculated using the experimental Dulong formula and tables in Integrated Solid Waste Management (Tchobanoglous et al. 1993, McGraw‐Hill). The Dulong formula indicates that the use of Tehran mixed MSW (without separating materials for recycling) as a fuel source yields 8,966.40 KJ/kg while the use of Tchobanoglous et al. (1993) tables can generate 8,236 kJ/kg. By removing food waste and recyclable materials, the potential of energy production changes to 22,047 kJ/kg using the Dulong formula and 16,207 kJ/kg and the Tchobanoglous et al. (1993) tables. It indicates increase by 1.46 times and 46%, respectively. Regarding the 200‐ton capacity of the Tehran waste incinerator, the Dulong formula indicated generation of 4,409 MJ/day energy, and the Tchobanoglous et al. table presents 3,241 MJ/day. Therefore, considering that Tehran generates more than 4,000 tons of reject waste daily, it can easily be converted to energy rather than landfilled. This can alleviate the problem of buying land and construction of landfills and leachate generation.     

Medical waste management in Korea

The management of medical waste is of great importance due to its potential environmental hazards and public health risks. In the past medical waste was often mixed with municipal solid waste and disposed of in residential waste landfills or improper treatment facilities (e.g. inadequately controlled incinerators) in Korea. In recent years, many efforts have been made by environmental regulatory agencies and waste generators to better manage the waste from healthcare facilities. This paper presents an overview of the current management practices of medical waste in Korea. Information regarding generation, composition, segregation, transportation, and disposal of medical wastes is provided and discussed. Medical waste incineration is identified as the most preferred disposal method and will be the only available treatment option in late 2005. Faced with increased regulations over toxic air emissions (e.g. dioxins and furans), all existing small incineration facilities that do not have air pollution control devices will cease operation in the next few years. Large-scale medical waste incinerators would be responsible for the treatment of medical waste generated by most healthcare facilities in Korea. It is important to point out that there is a great potential to emit air toxic pollutants from such incinerators if improperly operated and managed, because medical waste typically contains a variety of plastic materials such as polyvinyl chloride (PVC). Waste minimization and recycling, control of toxic air emissions at medical waste incinerators, and alternative treatment methods to incineration are regarded to be the major challenges in the future.     

Municipal solid waste generation in Kathmandu, Nepal

Waste stream characteristics must be understood to tackle waste management problems in Kathmandu Metropolitan City (KMC), Nepal. Three-stage stratified cluster sampling was used to evaluate solid waste data collected from 336 households in KMC. This information was combined with data collected regarding waste from restaurants, hotels, schools and streets. The study found that 497.3 g capita(-1) day(-1) of solid waste was generated from households and 48.5, 113.3 and 26.1 kg facility(-1) day(-1) of waste was generated from restaurants, hotels and schools, respectively. Street litter measured 69.3 metric tons day(-1). The average municipal solid waste generation rate was 523.8 metric tons day(-1) or 0.66 kg capita(-1) day(-1) as compared to the 320 metric tons day(-1) reported by the city. The coefficient of correlation between the number of people and the amount of waste produced was 0.94. Key household waste constituents included 71% organic wastes, 12% plastics, 7.5% paper and paper products, 5% dirt and construction debris and 1% hazardous wastes. Although the waste composition varied depending on the source, the composition analysis of waste from restaurants, hotels, schools and streets showed a high percentage of organic wastes. These numbers suggest a greater potential for recovery of organic wastes via composting and there is an opportunity for recycling. Because there is no previous inquiry of this scale in reporting comprehensive municipal solid waste generation in Nepal, this study can be treated as a baseline for other Nepalese municipalities.     

含汞废弃荧光灯管处理现状及分析

废弃荧光灯管中含有金属汞,属于《国家危险废物名录》中的HW29含汞废物类,随意处置会破坏环境,危害人类健康,因此必须采取合理的方法对其进行处理。综合比较后发现资源化、无害化回收金属汞是最佳的处理方法。部分发达国家通过法律和技术手段的加强实现了对废弃荧光灯管的无害化回收处理,但我国在这方面的工作尚且不足,主要存在着灯管收集难、处理成本高等问题。因此,我国需要借鉴国外的管理经验,出台有效的法规措施,同时需要不断完善处理技术和大型工程建设。在我国节能减排和环境保护形势日益严峻的大环境下,辅之以合理的管理体制和技术手段,才能实现社会效益和经济效益双赢的局面。     

The potential contribution of sustainable waste management to energy use and greenhouse gas emission reduction in the Netherlands

Future limitations on the availability of selected resources stress the need for increased material efficiency. In addition, in a climate-constrained world the impact of resource use on greenhouse gas emissions should be minimized. Waste management is key to achieve sustainable resource management. Ways to use resources more efficiently include prevention of waste, reuse of products and materials, and recycling of materials, while incineration and anaerobic digestion may recover part of the embodied energy of materials. This study used iWaste, a simulation model, to investigate the extent to which savings in energy consumption and CO₂ emissions can be achieved in the Netherlands through recycling of waste streams versus waste incineration, and to assess the extent to which this potential is reflected in the LAP2 (currently initiated policy). Three waste streams (i.e. household waste, bulky household waste, and construction and demolition waste) and three scenarios compare current policy to scenarios that focus on high-quality recycling (Recycling+) or incineration with increased efficiency (Incineration+). The results show that aiming for more and high-quality recycling can result in emission reductions of 2.3 MtCO₂ annually in the Netherlands compared to the reference situation in 2008. The main contributors to this reduction potential are found in optimizing the recycling of plastics (PET, PE and PP), textiles, paper, and organic waste. A scenario assuming a higher energy conversion efficiency of the incinerator treating the residual waste stream, achieves an emission reduction equivalent to only one third (0.7 MtCO₂/year) of the reduction achieved in the Recycling+ scenario. Furthermore, the results of the study show that currently initiated policy only partially realizes the full potential identified. A focus on highest quality use of recovered materials is essential to realize the full potential energy and CO₂ emission reduction identified for the Netherlands. Detailed economic and technical analyses of high quality recycling are recommended to further evaluate viable integrated waste management policies.     

A comparison of biodegradable municipal waste (BMW) management strategies in Ireland and the Czech Republic and the lessons learned

In order to meet the recycling and recovery targets set forth by the European Union's (EU) Waste and Landfill Directives, both the Irish and Czech governments’ policy on waste management is changing to meet these pressures, with major emphasis being placed upon the management of biodegradable municipal waste (BMW). In particular, the EU Landfill Directive requires reductions in the rate of BMW going to landfill to 35% of 1995 values by 2016 and 2020 for Ireland and the Czech Republic, respectively. In this paper, the strategies of how Ireland and the Czech Republic plan to meet this challenge are compared. Ireland either landfills or exports its waste for recovery, while the Czech Republic has a relatively new waste management infrastructure. While Ireland met the first target of 75% diversion of BMW from landfill by 2010 and preliminary 2012 data indicate that Ireland is on track to meet the 2013 target, the achievement of the 2016 target remains at risk. Indicators that were developed to monitor the Czech Republic's path to meeting the targets demonstrate that it did not meet the first target that was set for 2010 and will probably not meet its 2013 target either. The evaluation reports on the implementation of Waste Management Plan of Czech Republic suggest that the currently applied strategy to divert biodegradable waste from landfill is not effective enough. For both countries, the EU Waste Framework and Landfill Directives will be a significant influence and driver of change in waste management practices and governance over the coming decade. This means that both countries will not only have to invest in infrastructure to achieve the targets, but will also have to increase awareness among the public in diverting this waste at the household level. Improving environmental education is part of increased awareness as it is imperative for citizens to understand the consequences of their actions as affluence continues to grow producing increased levels of waste.     

钻井废物综合治理技术的应用

针对急需解决的钻井废水、废气治理问题,以钻井作业大功率柴油机废气余热回收利用为出发点,研制了钻井废水废气综合治理设备。通过现场试验对钻井废水、废气治理效果及噪声影响的分析,试验结果表明,日处理钻井废水可达11～13m3/d,柴油机废气中污染物排放有一定程度的降低,柴油机高频噪声得到较明显降低,并有利于增加柴油机扭距。     

Towards a Zero Waste Strategy for an English Local Authority

Many developed countries are using a challenging Zero Waste concept to change current waste management practices to more sustainable methods of managing waste, including household waste. The concept includes waste prevention; high levels of recycling and recovery of all resources from waste; and behavioural change. This research provides a case study on the development of a Zero Waste Strategy (ZWS) for Charnwood Borough Council (CBC), an English Local Authority (LA), which has an established household waste management system.This paper describes the steps taken by the authors, together with CBC to devise and implement a ZWS. A series of focus groups were held involving elected members of the LA and members of the community. The aim was to identify the core aspects of environmental, operational and social demands in order to prioritise actions to be included in a draft ZWS. The draft underwent wider public consultation, which highlighted areas for revision, and following revision has been adopted by the LA. The ZWS takes into account local issues, local policies, alongside national strategies and legislation.Many of the options identified during this research complement each other and if used in combination may see large steps taken towards Zero Waste. This is difficult to achieve without a holistic approach to waste generation, collection, treatment and disposal. Key findings from this research are to switch the focus from recycling to reuse and waste prevention, alongside increasing education and behaviour change programmes for householders. Additionally, the potential value of separately collecting food waste, with a recognised high potential yield, must be explored to ensure meeting targets set in the ZWS and the requirements of the Landfill Directive.     

填埋场场地复用技术与展望

城市垃圾卫生填埋场场地复用技术是一种能增大填埋场填埋能力，避免过高的填埋场地费用的新方法。该技术在德国和美国的实践都已取得了成功。为使该技术能在我国得到推广和应用，文中介绍了该技术的实施条件，列举了部分应用实例，分析了该技术的优势及潜在问题，最后对其在我国的应用前景进行了展望。     

中国废弃手机回收的管理策略研究

作为“城市矿产”的典型代表，废弃手机因其废弃数量大、稀贵金属品位高等特性而备受关注，但在推进废弃手机回收过程中存在诸多问题。本文以推动产业发展为立足点，梳理了影响废弃手机回收的两级制衡要素，通过构建GREY-DEMATEL模型，定量评估各要素对废弃手机回收的影响程度并确定优先等级。其中，完善废弃手机回收的管理制度及相应的经济扶持政策成为短期内应着力解决的核心问题，从长期发展来看，废弃手机的前端收集应成为产业关注的重点。基于此，本文立足于废弃手机回收的短期目标及长远发展，分别提出相应的管理策略，为再生资源产业的良性发展提供对策建议。     

Retail waste of horticultural products in Sweden

Waste of food is a topic of considerable policy interest. However, few studies have been done on food waste at the retail level. The aim of this study was to examine how large retail waste is for 16 different horticultural products, selected among typical fruit and vegetables. The levels of retail waste were examined in cooperation with one of the leading Swedish retail companies. The results showed that retail waste of horticultural products amounted between 0.4% and 6.3% of store supplies for different horticultural products. The results did not show that packaging reduced waste of horticultural products.     

Recycling for small island tourism developments: Food waste composting at Sandals Emerald Bay,Exuma, Bahamas

The ability for small islands to meet sustainability goals is exacerbated by the costs of transporting goods on, and then, wastes off the islands. At small scales, recycling can be prohibitive and complicated by labor costs; the need to profitably recycle and manage solid waste output from tourism is complicated by scale and available technologies. A multi-year study documents the amount of solid waste generated on Great Exuma (Exuma), The Commonwealth of The Bahamas since 2010 with one year of benchmarking, then limited recycling of food waste generation by an all-inclusive resort, Sandals Emerald Bay (SEB). For the island of Exuma, the rapid increase in the rate of accumulation of solid waste associated with a large destination resort has led to an increase in pests such as rats and flies, along with an increased occurrence of fires associated with unburied solid waste. Solid waste has accumulated faster than the island solid waste management can absorb. SEB kitchen and hotel operations contributes an estimated 36% of all solid waste generated on the island, about 1752 t¹ out of a total of 4841 t generated on the island in 2013 (exclusive of vegetation waste). Based on 4 weeks of benchmarking, 48.5% of all the waste coming out of the SEB resort is compostable, organic waste, but waste composition varies widely over time. Exuma Waste Management (EWM) and Recycle Exuma (RE), both privately-held Bahamian businesses, worked for one year (2012–2013) with SEB resort to implement a benchmarking and pilot recycling project to meet Earth Check green resort certification requirements. This paper outlines the costs and resources required for food waste recycling and some barriers to implementing more effective solid waste management for the tourism industry on small islands.     

Environmental and social implications of waste in U.S. agriculture and food sectors

Because the agriculture/food sectors appear to be driven by short-term economic and political forces, cheap energy, and agricultural-chemical technologies, waste and environmental/social problems in the agricultural/food sectors are estimated to cost the nation at least $150 billion per year. Most of the waste and environmental/social problems can be eliminated through better resource management policies and the adoption of sustainable agricultural practices.Based on a paper entitled Waste in U.S. Agricultural and Food Sectors—Environmental and Social Costs presented at the Gross National Waste Product Forum, Washington, D.C.