A comprehensive waste collection cost model applied to post-consumer plastic packaging waste

Post-consumer plastic packaging waste (PPW) can be collected for recycling via source separation or post-separation. In source separation, households separate plastics from other waste before collection, whereas in post-separation waste is separated at a treatment centre after collection. There are also two collection schemes, either curb side or via drop-off locations. These different schemes have impact on total costs of collection at the municipal level. It can also influence the facility choices and network design. Therefore, a method which can compare costs of various collection schemes is needed.A comprehensive cost model was developed to compare costs of municipal collection schemes of PPW. The ‘municipal waste collection cost model’ is based on variables including fixed and variable costs per vehicle, personnel cost, container or bag costs as well as on emission costs (using imaginary carbon taxes). The model can be used for decision support when strategic changes to the collection scheme of municipalities are considered. The model takes into account the characteristics of municipalities, including urbanization degree and taxation schemes for household waste management.The model was applied to the Dutch case of post-consumer plastic packaging waste. Results showed that that in general post-separation collection has the lowest costs and curb side collection in urban municipalities without residual waste collection taxing schemes the highest. These results were supported by the conducted sensitivity analysis, which showed that higher source separation responses are negatively related to curb side collection costs. Greenhouse gas emission costs are a significant part of the total costs when collecting post-consumer plastic packaging waste due to the low density to weight ratio of the materials collect. These costs can amount to 15% of the total collection costs.     

Market imperfections in recycling markets: conceptual issues and empirical study of price volatility in plastics

The effectiveness of recycling depends upon efficient functioning of secondary material markets. This paper focus on the role that price volatility can play in slowing investment and market development. However, a statistical analysis of the relative volatility of secondary and primary material prices does not confirm the widely-held belief that relative price volatility is higher in secondary than in primary materials, at least at national levels.An econometric estimation of the determinants of plastic recovery volumes in Seattle contributes to the literature in four ways: the use of monthly (as opposed to annual) data; the use of local (as opposed to national) data; the use of an explanatory variable to reflect price volatility; and, the focus on plastics, which have not been examined previously. Some tentative conclusions can be made: the results generally support the principal hypothesis that price volatility has a negative effect on recovery of secondary materials; in addition, and consistent with previous studies, price elasticities are low and insignificant; and finally, policy factors are clearly important. The concluding section treats the economic and policy implications of market inefficiency in secondary material markets.     

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 plastic packaging waste: Material origin,methods, properties

The global plastics production has increased annually and a substantial part is used for packaging (in Europe 39%). Most plastic packages are discarded after a relatively short service life and the resulting plastic packaging waste is subsequently landfilled, incinerated or recycled. Laws of several European and Asian countries require that plastic packaging waste collected from households has to be sorted, reprocessed, compounded and reused. These recycling schemes typically produce milled goods of poly(ethylene terephthalate) (PET), poly(ethylene) (PE), isotactic poly(propylene) (PP), mixed plastics, and agglomerates from film material. The present study documents the composition and properties of post-consumer polyolefin recyclates originating from both source separation and mechanical recovery from municipal solid refuse waste (MSRW). The overall composition by Fourier transform-infrared (FT-IR) spectroscopy and differential scanning calorimetry (DSC) were determined and compared with the sorting results of the sorted fractions prior to the reprocessing into milled goods. This study shows that the collection method for the plastic packaging waste has hardly any influence on the final quality of the recyclate; however, the sorting and reprocessing steps influence the final quality of the recyclate. Although the mechanical properties of recyclate are clearly different than those of virgin polymers, changes to the sorting and reprocessing steps can improve the quality.     

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.     

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.     

Sustainable recycling model: A comparative analysis between India and Tanzania

Higher economic growth in developing countries has caused higher amounts of wastes. Local government authorities in these countries usually fail to provide adequate services to dispose the increasing amounts of waste, resulting in threats for both the population and environment health. There is therefore an urgent need for recycling as a form of waste management in order to stop the devastating effects of solid waste in developing countries. Using a qualitative method of analysis, this study presents a model to measure and rank the sustainability of recycling programs in India and Tanzania. The model consists of six main constructs including “production, economic, governmental, social, technological, and international factors”. The results showed that India outperforms Tanzania in sustainable recycling programs: per capita waste generated per day in Delhi is higher than in Dar es Salaam; the government of India focuses more on developing recycling plans and techniques as compared to the government of Tanzania where the country is not actively involved in the recycling process; and the solid waste management planning in India is being performed better than Tanzania.     

Auditing non-hazardous wastes from golf course operations: moving from a waste to a sustainability framework

This paper provides non-hazardous solid waste audit procedures and bench mark audit data for golf courses (GCs). The paper also demonstrates the narrow scope of solid waste audit data, and the need to move towards a broader auditing scope such as that contained in sustainability auditing frameworks. A case study of Clear Lake Golf Course, located in southwestern Manitoba, Canada was completed. Annual waste generation rates at the GC were estimated to be 46.2 tonnes/year with 83% of this material compostable. Grass clipping material generated from the putting greens accounted for 79% of the waste stream. The GC achieved a solid waste diversion rate of 81% (waste generated not destined for landfill per total waste material generated). A future, realistic target of 97% diversion was also identified. The 7 day audit period was found to be unsuitable for estimating grass clipping generation rates. Implementation of a broader sustainability framework for future audits will harmonize many existing management functions such as solid waste auditing, waste characterizations, pollution prevention, green procurement, customer satisfaction, and the efficiency of the operations.     

碳中和视域下的垃圾精细化治理：日本吸收性卫生用品回收体系的构建经验及启示

通过循环利用，减少吸收性卫生用品产量和废弃量的陡增所带来的碳排放量，将加速碳中和进程。日本提供了吸收性卫生用品回收体系构建的先行经验，即以“政府引导—企业运作—社会团体协作”为顶层架构，明确制度、完备设施、完善渠道、宣传到户等。建议我国取长补短，在夯实法律法规和优化主体协同机制的基础上，重点着眼于突破技术壁垒、推动智慧化监管、深化绿色理念，以点带面推进吸收性卫生用品的回收循环试点，进一步推动垃圾分类精细化治理的进程。     

Institutional quality effects on separate waste collection: some evidence from Italian provinces

Separate waste collection in Italy comes under the responsibility of local authorities, provinces, while national laws set quantitative targets to be achieved over time. Overall, just a few provinces have reached the thresholds set by the latest law (Legislative Decree 152/2006) and some territorial differentiation has been detected. The aim of this paper is twofold: to verify the effectiveness of Legislative Decree 152/2006 in promoting higher levels of separate collection and to test whether institutional quality (considering the following indicators: voice and accountability, regulatory quality, rule of law and corruption) affects provinces’ efficiency in the separate collection process. For this purpose, we implement the stochastic frontier analysis (SFA). Results suggest that the effectiveness of Legislative Decree 152/2006 has been affected by provinces’ institutional quality. In particular, the presence of institutional constraints did not allow the most virtuous provinces to achieve the targets set by law.     

Sound management of brominated flame retarded (BFR) plastics from electronic wastes: State of the art and options in Nigeria

Management of flame retarded plastics from waste electrical and electronic equipment (WEEE) has been posing a major challenge to waste management experts because of the potential environmental contamination issues especially the formation of polybrominated-dioxins and -furans (PBDD/F) during processing. In Nigeria, large quantities of electronic waste (e-waste) are currently being managed—a significant quantity of which is imported illegally as secondhand electronics. As much as 75% of these illegal imports are never reused but are rather discarded. These waste electronic devices are mostly older equipment that contains brominated flame retardants (BFRs) such as penta-brominated diphenyl ethers (PBDEs), and polybrominated biphenyls (PBBs) which are presently banned in Europe under the EU WEEE and RoHS Directives. Risk assessment studies found both to be persistent, bio-accumulative and toxic. The present management practices for waste plastics from WEEE in Nigeria, such as open burning and disposal at open dumps, creates potential for serious environmental pollution. This paper reviews the options in the environmentally sound management of waste plastics from electronic wastes. Options available include mechanical recycling, reprocessing into chemicals (chemical feedstock recycling) and energy recovery. The Creasolv^® and Centrevap^® processes, which are the outcome of the extensive research at achieving sound management of waste plastics from WEEE in Europe, are also reviewed. These are solvent-based methods of removing BFRs and they presently offer the best commercial and environmental option in the sound management of waste BFR-containing plastics. Because these developments have not been commercialized, WEEE and WEEE plastics are still being exported to developing countries. The industrial application of these processes and the development of eco-friendlier alternative flame retardants will help assure sound management of WEEE plastics.     

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.