Browsing by Author "Gronow, Jan R."

Now showing 1 - 9 of 9
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    Achieving equilibrium status and sustainable landfill - the holy grail?
    (The Waste Conference Ltd, 2004-09) Hall, D. H.; Gronow, Jan R.; Smith, Richard; Blakey, N.
    This paper presents the results of a research contract jointly funded by the Environment Agency and ESART examining the residues of likely post-Landfill Directive waste streams that will need to go to landfill and the time taken to achieve sufficient stabilisation such that management controls can be removed. The first part of the project has identified a number of processes that are likely to be adopted by the waste management industry in order to meet the biodegradable waste diversion targets. Both leachate quality and landfill gas generation data has been assessed for each residue stream. Forward modelling has been undertaken on these data using LandSim2.5 within GoldSim to assess the likely period of management needed in order to achieve equilibrium status.
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    Assessment of municipal waste compost as a daily cover material for odour control at landfill sites.
    (Elsevier Science B.V., Amsterdam., 2005-01-01T00:00:00Z) Hurst, C.; Longhurst, Philip J.; Pollard, Simon J. T.; Smith, Richard; Jefferson, Bruce; Gronow, Jan R.
    The ability of municipal waste compost as a daily cover material to reduce the odorous emissions associated with landfill surfaces was investigated. Trials were carried out using landfill gas, a certified sulphurous gas mix and ambient air as a control. Odorous gas was passed through portable test column filled with compost at different densities (590 kg/m3 and 740 kg/m3). Gas samples were taken from the inlet, outlet and at varying column depths and examined using a combination of sensory analysis (olfactometry) and a novel analytical method (Transportable Selected Ion Flow Tube – TSIFT). Results for the trials using landfill gas showed a 69% odour reduction (OU/m3) through the column for compost with a bulk density of 590 kg/m3, and a reduction of 97% using compost with a bulk density of 740 kg/m3. TSIFT analysis showed an overall decrease in the concentration of terpenes, and sulphurous compounds in the outlet gas from the column for both bulk densities. No significant trend could be identified for the concentrations at different depths within the column. Results show the ability of compost to reduce landfill odours under differing conditions. The inconclusive data provided by TSIFT analysis may be due to the analysis of compounds that are not contributing to odour, and thus highlights the potential for synergetic effects and the importance of sensory measurement when examining odorous emission
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    Charaterisation of treated wastes to support an evidence base for sustainable waste management.
    (The Waste Conference Limited, 2006-09) Lewin, Kathy; Godley, Andrew R.; Turrell, J.; Smith, Richard; Frederickson, Jim; Graham, Adele; Gronow, Jan R.; Blakey, N.
    Defra must consider policies and strategies to manage environmental challenges such as climate change and sustainability. At a basic level the strategies need good quality data on waste characteristics. The dataset for UK wastes, in particular the new generation of treated wastes, is not fit for this purpose. This paper outlines the gaps in knowledge needed to underpin policy development and initial findings from a new project funded under Defra’s Waste and Resource Management Research Programme. The project team from WRc, Open University and Cranfield University aims to improve understanding of the characteristics of treated organic and inorganic wastes, methods of testing and knowledge of treatment process performance. Potential opportunities from the research are also described. New data will be collated into the presentation.
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    Estimating Pollutant Removal Requirements for Landfills in the UK: I. Benchmark Study and Characteristics of Waste Treatment Technologies
    (Taylor & Francis, 2006-12-01T00:00:00Z) Hall, D. H.; Drury, D.; Gronow, Jan R.; Rosevear, Alan; Pollard, Simon J. T.; Smith, Richard
    Introduction of the EU Landfill Directive is having a significant impact on waste management in the UK and in other member states that have relied on landfilling. This paper considers the length of the aftercare period required by the municipal solid waste streams that the UK will most probably generate following implementation of the Landfill Directive. Data were derived from literature to identify properties of residues from the most likely treatment processes and the probable management times these residues will require within the landfill environment were then modelled. Results suggest that for chloride the relevant water quality standard (250 mg l−1) will be achieved with a management period of 40 years and for lead (0.1 mg l−1), 240 years. This has considerable implications for the sustainability of landfill and suggests that current timescales for aftercare of landfills may be inadequ
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    Estimating Pollutant Removal Requirements for Landfills in the UK: II. Model Development
    (Taylor & Francis, 2006-12-01T00:00:00Z) Hall, D. H.; Drury, D.; Gronow, Jan R.; Rosevear, Alan; Pollard, Simon J. T.; Smith, Richard
    A modelling methodology using a leachate source term has been produced for estimating the timescales for achieving environmental equilibrium status for landfilled waste. Results are reported as the period of active management required for modelled scenarios of non-flushed and flushed sites for a range of pre-filling treatments. The base scenario against which results were evaluated was raw municipal solid waste (MSW) for which only cadmium failed to reach equilibrium. Flushed raw MSW met our criteria for stabilisation with active leachate management for 40 years, subject to each of the leachate species being present at or below their average UK concentrations. Stable non-reactive wastes, meeting EU waste acceptance criteria, fared badly in the non-flushed scenario, with only two species stabilising after a management period within 1000 years and the majority requiring >2000 years of active leachate management. The flushing scenarios showed only a marginal improvement, with arsenic still persisting beyond 2000 years management even with an additional 500 mm y−1 of infiltration. The stabilisation time for mechanically sorted organic residues (without flushing) was high, and even with flushing, arsenic and chromium appeared to remain a problem. Two mechanical biological treatment (MBT) scenarios were examined, with medium and high intensity composting. Both were subjected to the non-flushing and flushing scenarios. The non-flushing case of both options fell short of the basic requirements of achieving equilibrium within decades. The intense composting option with minimal flushing appeared to create a scenario where equilibrium could be achieved. For incinerator bottom ash (raw and subjected to various treatments), antimony, copper, chloride and sulphate were the main controls on achieving equilibrium, irrespective of treatment type. Flushing at higher flushing rates (500 mm y−1) failed to demonstrate a significant reduction in the management period requi
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    Estimating Pollutant Removal Requirements for Landfills in the UK: III. Policy Analysis and Operational Implications.
    (Taylor & Francis, 2007-01-01T00:00:00Z) Hall, D. H.; Drury, D.; Gronow, Jan R.; Pollard, Simon J. T.; Smith, Richard
    The policy analysis and management implications for achieving landfill equilibrium status within a sustainable timescale (decades rather than centuries) are presented based on modelled results reported previously. Until relatively recently, timescale estimates suggested that equilibrium or landfill completion could be achieved within 40-60 years i.e. the same order of magnitude as financial provision for aftercare. However results of modelling in this study (reported in previous paper) suggest that timescales may be considerably longer (many centuries in some instances) suggesting that financial provision may be inadequate. The role of the most promising and available waste treatment technologies and strategic waste management options in contributing towards achieving equilibrium status are discussed. Results suggest that a re- examination of techniques for accelerating landfill stabilisation, including aerobic and bioreactor landfill, is warranted.
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    Estimating the post-closure management time for landfills containing treated MSW residues.
    (Eurowaste, 2005-10) Hall, D. H.; Gronow, Jan R.; Smith, Richard; Rosevear, Alan
    The Landfill Directive will require the pre-treatment of MSW prior to landfilling. The removal of progressively increasing proportions of the biodegradable fractions from landfilled waste, and the UK Government’s commitment to increase recycling of key waste fractions, will lead to an inevitable change, from the disposal of raw MSW, to the disposal of MSW treatment residues, to landfill. This will undoubtedly change the type and rate of emissions from landfills. The question that this research project has sought to answer is “how long will active management be required for different MSW treatment residues?” The term equilibrium status has been used to define the end point beyond which management of wastes is no longer necessary. Calculating the equilibrium status of waste involves an assessment of the landfill gas emissions, leachate quality and hydraulic status of the landfill. These key parameters change with time as the landfill evolves. Equally, the engineering performance of a site is also changing with the gradual degradation of the liner and capping systems. The question posed above is therefore not easily answered.
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    Spray irrigation of landfill leachate: estimating potential exposures to workers and bystanders using a modified air box model and generalised source term
    (Elsevier Science B.V., Amsterdam., 2005-02-01T00:00:00Z) Gray, Duncan; Pollard, Simon J. T.; Spence, Lynn; Smith, Richard; Gronow, Jan R.
    Generalised source term data from UK leachates and a probabilistic exposure model (BPRISC4) 12 were used to evaluate key routes of exposure from chemicals of concern during the spraying 13 irrigation of landfill leachate. Risk estimates secured using a modified air box model are reported 14 for a hypothetical worker exposed to selected chemicals within a generalised conceptual exposure 15 model of spray irrigation. Consistent with pesticide spray exposure studies, the key risk driver is 16 dermal exposure to the more toxic components of leachate. Changes in spray droplet diameter 17 (0.02-0.2 cm) and to spray flow rate (50-1000 l/min) have little influence on dermal exposure, 18 although the lesser routes of aerosol ingestion and inhalation are markedly affected. The risk 19 estimates modelled using this conservative worst case exposure scenario are not of sufficient 20 magnitude to warrant major concerns about chemical risks to workers or bystanders from this 21 practice in the general sense. However, the modelling made use of generic concentration data for 22 only a limited number of potential landfill leachate contaminants, such that individual practices 23 may require assessment on the basis of their own merits.
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    A strategy for emissions based regulation of landfill gas.
    (2003-10-01T00:00:00Z) Deed, C.; Gronow, Jan R.; Rosevear, Alan; Smith, Richard; Braithwaite, P.
    The Environment Agency (the Agency) is responsible for the regulation of landfill sites in England and Wales. Since its formation, the Agency’s regulatory strategy for landfill gas has been to require operators to demonstrate best practice. However, this approach does not allow environmental outcomes from site-specific landfill gas management to be easily illustrated or quantified. Greater clarity is now given to these environmental outcomes by augmenting best practice regulation of landfill gas with emissions-based regulation. This will require a “step change” in the management of landfill gas. However, it will enable the operator and regulator alike to respond to public concerns regarding landfill gas, including increasingly complicated health- related i