Seismic performance of geomembrane placed on a slope in a MSW landfill cell -A centrifuge study

Geomembranes are one of the most commonly used geosynthetics in landfill liner systems. They retain the leachate produced by the waste and prevent leakage. Geomembranes may experience harsh environmental conditions such as extreme temperatures or earthquake loading. Earthquake loading can be an extreme loading case for landfills located in seismic regions. This study, based on dynamic centrifuge testing, investigates the effects of simulated earthquake loading on the tension experienced bythe geomembrane on a landfill slope. The landfill modeled in the dynamic centrifuge test was a municipal solid waste (MSW) landfill cell with a single geomembrane-clay liner system (45° side slope and 10 m slope length). The paper shows that moderate earthquake loading (base acceleration between 0.1g to 0.2g) can result in transient increases of around 20% in geomembrane tension, with permanent tension increases of around 5%.

Centrifuge modelling and dynamic testing of municipal solid waste (MSW) landfills

An investigation into the seismic behaviour of municipal solid waste (MSW) landfills by dynamic centrifuge testing was undertaken. This paper presents physical modelling of MSW landfills for dynamic centrifuge testing, with regard to the following research areas: 1. amplification characteristics of municipal solid waste; 2. tension induced in geomembranes placed on landfill slopes due to earthquake loading; 3. damage to landfill liners due to liquefaction of foundation soil. A model waste, that has engineering properties similar to MSW, is presented. A model geomembrane that can be used in centrifuge tests is also presented. Results of dynamic centrifuge tests with the model geomembrane showed that an earthquake loading induces additional permanent tension (∼25%) in the geomembrane. © 2006 Taylor & Francis Group.

Centrifuge modelling and dynamic testing of municipal solid waste (MSW) landfills

An investigation into the seismic behaviour of municipal solidwaste (MSW) landfills by dynamic centrifuge testing was undertaken. This paper presents physical modelling of MSW landfills for dynamic centrifuge testing, with regard to the following research areas: 1. amplification characteristics of municipal solid waste; 2. tension induced in geomembranes placed on landfill slopes due to earthquake loading; 3. damage to landfill liners due to liquefaction of foundation soil. A model waste, that has engineering properties similar to MSW, is presented. A model geomembrane that can be used in centrifuge tests is also presented. Results of dynamic centrifuge tests with the model geomembrane showed that an earthquake loading induces additional permanent tension (∼25%) in the geomembrane. © 2006 Taylor & Francis Group, London.

A concise review on some frequently used solid waste management technologies and their effects into the environment and human health

uma revisão sobre alguns estudos epidemiológicos melhorará a compreensão quanto aos efeitos potenciais na saúde da gestão de resíduos e permitirá obter informação importante em termos de trabalho futuro. Alguns estudos mostraram associações significativas entre diversos métodos de gestão de resíduos e impactos potenciais na saúde humana. noutros estudos as associações foram consideradas inconsistentes ou susceptíveis de conduzir a equívocos, sendo necessários mais estudos epidemiológicos para averiguar as consequências para a saúde humana e para determinar os seus efeitos toxicológicos directos, assegurando assim que a gestão de resíduos representa um risco mínimo para a saúde. os estudos epidemiológicos devem ser analisados com uma mente aberta, tomando em consideração factores como o estatuto social e a migração das populações. A review of a few epidemiologic studies will improve the understanding of the potential health effects of waste management and will provide important information regarding future work. several studies showed significant relationships between several methods of waste management and potential impacts on human health. in other studies associations were found to be inconsistent or equivocal and more specific epidemiological studies must be performed to assess consequences to human health and to determine their direct toxicological effects, thus ensuring that waste management pose minimum risk to health.

The treatment of landfill leachate using natural systems

Leachate may be defined as any liquid percolating through deposited waste and emitted from or contained within a landfill. If leachate migrates from a site it may pose a severe threat to the surrounding environment. Increasingly stringent environmental legislation both at European level and national level (Republic of Ireland) regarding the operation of landfill sites, control of associated emissions, as well as requirements for restoration and aftercare management (up to 30 years) has prompted research for this project into the design and development of a low cost, low maintenance, low technology trial system to treat landfill leachate at Kinsale Road Landfill Site, located on the outskirts of Cork city. A trial leachate treatment plant was constructed consisting of 14 separate treatment units (10 open top cylindrical cells [Ø 1.8 m x 2.0 high] and four reed beds [5.0m x 5.0m x 1.0m]) incorporating various alternative natural treatment processes including reed beds (vertical flow [VF] and horizontal flow [HF]), grass treatment planes, compost units, timber chip units, compost-timber chip units, stratified sand filters and willow treatment plots. High treatment efficiencies were achieved in units operating in sequence containing compost and timber chip media, vertical flow reed beds and grass treatment planes. Pollutant load removal rates of 99% for NH4, 84% for BOD5, 46% for COD, 63% for suspended solids, 94% for iron and 98% for manganese were recorded in the final effluent of successfully operated sequences at irrigation rates of 945 l/m2/day in the cylindrical cells and 96 l/m2/day in the VF reed beds and grass treatment planes. Almost total pathogen removal (E. coli) occurred in the final effluent of the same sequence. Denitrification rates of 37% were achieved for a limited period. A draft, up-scaled leachate treatment plant is presented, based on treatment performance of the trial plant.

Fermentable sugars recovery from lignocellulosic waste-newspaper by catalytic hydrolysis

The urgent need for alternative renewable energies to supplement petroleum-based fuels and the reduction of landfill sites for disposal of solid wastes makes it increasingly attractive to produce inexpensive biofuels from the organic fraction of the municipal solid waste. Therefore, municipal waste in the form of newspaper was investigated as a potential feedstock for fermentable sugars production. Hydrolysis of newspaper by dilute phosphoric acid was carried out in autoclave Parr reactor, where reactor temperature and acid concentration were examined. Xylose concentration reached a maximum value of 14 g/100 g dry mass corresponding to a yield of 94% at the best identified conditions of 2.5 wt% HPO, 135°C, 120 min reaction time, and at 2.5 wt% HPO, 150°C, and 60 min reaction time. For glucose, an average yield of 26% was obtained at 2.5 wt% HPO, 200°C, and 30 min. Furfural and 5-hydroxymethylfurfural (HMF) formation was clearly affected by reaction temperature, where the higher the temperature the higher the formation rate. The maximum furfural formed was an average of 3 g/100 g dry mass, corresponding to a yield of 28%. The kinetic study of the acid hydrolysis was also carried out using the Saeman and the two-fraction models. It was found for both models that the kinetic constants (K) depend on the acid concentration and temperature. The degradation of HMF to levulinic acid is faster than the degradation of furfural to formic acid. Also, the degradation rate is higher than the formation rate for both inhibitors when degradation is observed.

Contemporary environmental issues of landfill leachate: assessment & remedies

Landfills are the primary option for waste disposal all over the world. Most of the landfill sites across the world are old and are not engineered to prevent contamination of the underlying soil and groundwater by the toxic leachate. The pollutants from landfill leachate have accumulative and detrimental effect on the ecology and food chains leading to carcinogenic effects, acute toxicity and genotoxicity among human beings. Management of this highly toxic leachate presents a challenging problem to the regulatory authorities who have set specific regulations regarding maximum limits of contaminants in treated leachate prior to disposal into the environment to ensure minimal environmental impact. There are different stages of leachate management such as monitoring of its formation and flow into the environment, identification of hazards associated with it and its treatment prior to disposal into the environment. This review focuses on: (i) leachate composition, (ii) Plume migration, (iii) Contaminant fate, (iv) Leachate plume monitoring techniques, (v) Risk assessment techniques, Hazard rating methods, mathematical modeling, and (vi) Recent innovations in leachate treatment technologies. However, due to seasonal fluctuations in leachate composition, flow rate and leachate volume, the management approaches cannot be stereotyped. Every scenario is unique and the strategy will vary accordingly. This paper lays out the choices for making an educated guess leading to the best management option.

Factors Influencing the Implementation of Site Waste Management Plans on UK Projects of all sizes

The purpose of this research is to identify and assess the opportunities and challenges of implementing a Site Waste Management Plan (SWMP) on projects irrespective of size. In the UK, construction and demolition waste accounts for a third of all UK waste. There are a number of factors that influence the implementation of SWMPs. In order to identify and analyse these factors, 4 unstructured interviews were carried out and a sample of 56 participants completed a questionnaire survey. The scope of the study was limited to UK
construction industry professionals. The analysis revealed that more needs to be done if the industry is to meet government targets of reduction in construction related waste going to landfill. In addition, although SWMP may not yet be legally required on all construction projects, clients and contractors need to realise
the benefits to cut costs and implement best practice by adopting a SWMP. The benefits of implementing a SWMP will not only help to achieve this but also gain significant cost savings on projects and is also extremely beneficial to the environment. This study presents evidence that contractors need to do more to reduce waste and draws a clear link between waste reduction and the implementation of SWMPs. The findings are useful in the ongoing efforts to encourage the industry to find smarter, more efficient and less
damaging ways to operate

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.

Graphical abstract
Despite the differences in the levels of waste generation in both the Czech Republic and Ireland, each country can learn from each other in order to meet the recycling and recovery targets set by the European Union's (EU) Waste and Landfill Directives. 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. In addition, there needs to be minimum safe standards when land-spreading organic agricultural and organic municipal and industrial materials on agricultural land used for food production, as well as incentives to increase BMW diversion from landfill such as the increased landfill levy implemented in Ireland and the acceptance of MBT and/or incineration as a means of treating residual waste.

Material Waste in the Northern Ireland Construction Industry: On-Site Management Causes and Methods of Prevention

The construction industry in Northern Ireland is one of the major contributors of construction waste to landfill each year. The aim of this research paper is to identify the core on-site management causes of material waste on construction sites in Northern Ireland and to illustrate various methods of prevention which can be adopted. The research begins with a detailed literature review and is complemented with the conduction of semi-structured interviews with 6 professionals who are experienced and active within the Northern Ireland construction industry. Following on from the literature review and interviews analysis, a questionnaire survey is developed to obtain further information in relation to the subject area. The questionnaire is based on the key findings of the previous stages to direct the research towards the most influential factors. The analysis of the survey responses reveals that the core causes of waste generation include a rushed program, poor handling and on-site damage of materials, while the principal methods of prevention emerge as the adequate storage, the reuse of material on-site and efficient material ordering. Furthermore, the role of the professional background in the shaping of perceptions relevant to waste management is also investigated and significant differences are identified. The findings of this research are beneficial for the industry as they enhance the understanding of construction waste generation causes and highlight the practices required to reduce waste on-site in the context of sustainable development.

Logistics and the waste sector: a London case study

London has traditionally exported most of its waste to former mineral workings in surrounding counties for landfill. Many of these sites are being filled and opportunities for new sites are limited. Virtually all waste reprocessing and recycling facilities, with the exception of textile sorting and some facilities for glass and organic waste composting, are outside London. The Mayor of London's Vision for Waste in London is that by 2020, municipal waste should not compromise London’s future as a sustainable city. This will involve managing waste better, so that its impact on the local and global environment and on London communities, economy and health is minimised. The majority of waste and recyclable materials in London are currently collected and transported for recovery, disposal or reprocessing by road in large vehicles. Environmental costs include, adding to congestion, noise, energy usage, air pollution, and accidents. The Mayor is keen to increase recycling and reuse of waste materials in London, and to ensure that as more of London's waste is diverted away from landfill sites to recycling facilities. Several projects and initiatives have been established and these are reviewed in the paper.

The economics of enhanced landfill mining: private and societal performance drivers

This paper addresses the economics of Enhanced Landfill Mining (ELFM) both from a private point of view as well as from a society perspective. The private potential is assessed using a case study for which an investment model is developed to identify the impact of a broad range of parameters on the profitability of ELFM. We found that especially variations in Waste-to-Energy (WtE efficiency, electricity price, CO2-price, WtE investment and operational costs) and ELFM support explain the variation in economic profitability measured by the Internal Rate of Return. To overcome site-specific parameters we also evaluated the regional ELFM potential for the densely populated and industrial region of Flanders (north of Belgium). The total number of potential ELFM sites was estimated using a 5-step procedure and a simulation tool was developed to trade-off private costs and benefits. The analysis shows that there is a substantial economic potential for ELFM projects on the wider regional level. Furthermore, this paper also reviews the costs and benefits from a broader perspective. The carbon footprint of the case study was mapped in order to assess the project’s net impact in terms of greenhouse gas emissions. Also the impacts of nature restoration, soil remediation, resource scarcity and reduced import dependence were valued so that they can be used in future social cost-benefit analysis. Given the complex trade-off between economic, social and environmental issues of ELFM projects, we conclude that further refinement of the methodological framework and the development of the integrated decision tools supporting private and public actors, are necessary.

Greenhouse gas emissions from waste management—assessment of quantification methods

Of the many sources of urban greenhouse gas (GHG) emissions, solid waste is the only one for which management decisions are undertaken primarily by municipal governments themselves and is hence often the largest component of cities’ corporate inventories. It is essential that decision-makers select an appropriate quantification methodology and have an appreciation of methodological strengths and shortcomings. This work compares four different waste emissions quantification methods, including Intergovernmental Panel on Climate Change (IPCC) 1996 guidelines, IPCC 2006 guidelines, U.S. Environmental Protection Agency (EPA) Waste Reduction Model (WARM), and the Federation of Canadian Municipalities- Partners for Climate Protection (FCM-PCP) quantification tool. Waste disposal data for the greater Toronto area (GTA) in 2005 are used for all methodologies; treatment options (including landfill, incineration, compost, and anaerobic digestion) are examined where available in methodologies. Landfill was shown to be the greatest source of GHG emissions, contributing more than three-quarters of total emissions associated with waste management. Results from the different landfill gas (LFG) quantification approaches ranged from an emissions source of 557 kt carbon dioxide equivalents (CO2e) (FCM-PCP) to a carbon sink of −53 kt CO2e (EPA WARM). Similar values were obtained between IPCC approaches. The IPCC 2006 method was found to be more appropriate for inventorying applications because it uses a waste-in-place (WIP) approach, rather than a methane commitment (MC) approach, despite perceived onerous data requirements for WIP. MC approaches were found to be useful from a planning standpoint; however, uncertainty associated with their projections of future parameter values limits their applicability for GHG inventorying. MC and WIP methods provided similar results in this case study; however, this is case specific because of similarity in assumptions of present and future landfill parameters and quantities of annual waste deposited in recent years being relatively consistent.