Browsing by Author "Lewin, Kathy"

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    Application of DR4 and BM100 Biodegradability tests to treated and untreated organic wastes
    (2007-10) Godley, Andrew R.; Lewin, Kathy; Frederickson, Jim; Smith, Richard; Blakey, N.
    The aerobic DR4 and anaerobic BM100 biodegradability tests are currently applied in England and Wales for monitoring the reduction in biological municipal waste (BMW) achieved by mechanical biological treatment (MBT) plants (Environment Agency 2005). The protocol is applied only when outputs are landfilled and is based on estimating the reduction in potential biogas production between the MBT input, municipal solid waste (MSW), and all of the landfilled outputs, using the BM100 test. As this is a long term 100 day test the more rapid 4 day DR4 test may also be applied as this has been shown to correlate with the BM100 test. We have now applied the DR4 and BM100 tests to 132 organic waste samples including untreated and treated BMW and specific organic wastes. The results indicate that the correlation between the DR4 and BM100 tests has proved valid for mixed MSW derived BMW wastes. However when both tests are applied to specific organic wastes such as turkey feathers, cardboard packaging waste and pizza food wastes the correlation between the tests is less strong. It is concluded that the use of the DR4 and BM100 test correlation is valid for its designed application (monitoring MBT processes treating MSW derived mixed BMW), but that caution should be exercised when applying both tests to specific single component organic wastes.
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    Biodegradability determination of municipal waste: an evaluation of methods
    (The Waste Conference Limited, 2004-09) Godley, Andrew R.; Lewin, Kathy; Graham, Adele; Barker, H.; Smith, Richard
    The Environment Agency is required to monitor the diversion of biodegradable municipal waste (BMW) from landfill. Reliable methods are needed to measure the biodegradability of municipal waste, both as mixed municipal waste and as individually separated fractions. An evaluation of several methods was carried out using a variety of organic materials typically found in municipal solid waste. The assessment considered biological and non-biological methods to determine which provides the bestfit surrogate measurement for relative waste biodegradability. The biological methods tested were: the aerobic specific oxygen uptake rate, dynamic respiration index tests, and the anaerobic biochemical methane potential test. The non-biological methods evaluated were: dry matter, loss on ignition, total organic carbon, total nitrogen, water extractable dissolved organic carbon, biological oxygen demand, chemical oxygen demand, lignin and cellulose content and cellulase hydrolysis. This paper also reviews how such tests can be used to measure the relative biodegradation of municipal waste and benchmark the relative diversion from landfill achieved by the pre-treatment of municipal waste in a mechanical biological treatment (MBT) process.
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    Characterisation of untreated and treated biodegradable wastes
    (2007-10) Godley, Andrew R.; Frederickson, Jim; Lewin, Kathy; Smith, Richard; Blakey, N.
    As part of a Defra sponsored project (WRT220), approximately 40 biodegradable wastes were characterised according to biodegradability (DR4 and BM100), total PTE content, C:N ratio and biochemical composition. Two leaching tests were employed; upflow percolation test and a one step LS10 test; eluates were analysed for TOC, pH, electrical conductivity, PTEs and a range of cations and anions. This paper contains a limited set of data for a selection of untreated and treated waste types representing four waste treatment processes (composting, MBT, MHT, anaerobic digestion). The DR4 and BM100 tests were found to be appropriate for a wide range of waste types but where possible they should be used in conjunction with other related tests. Longer-term MBT composting processes appeared to produce compost material with reduced ammonium concentrations and extractability of some PTEs. Carbon content (carbon analyzer - LECO) could be estimated as C = LOI/1.9 which is a routine operation. N LECO values were approximately 12% greater than the equivalent N Kjeldahl values.
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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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    Environment Agency review of methods for determining organic waste biodegradability and municipal waste diversion.
    (Aqua Enviro Technology Transfer, 2003-11) Godley, Andrew R.; Lewin, Kathy; Graham, Adele; Smith, Richard
    The Environment Agency is required to regulate the landfilling of biodegradable organic wastes and their diversion from landfilling. Simple, cost effective, reliable and widely applicable methods for the measurement of organic waste and its biodegradability are needed for this activity. A review of such methods was carried out in order to select promising methods for an experimental screening exercise. The review considered both biological and non-biological methods including simple methods that may provide a surrogate measurement of waste biodegradability instead of the time-consuming biological methods. The biological methods selected for further evaluation were the aerobic specific oxygen uptake rate (SOUR) and dynamic respiration index (DRI) tests, and the anaerobic biochemical methane potential (BMP) test. The non-biological methods selected for further evaluation were dry matter (DM), loss on ignition (LOI), total organic carbon (TOC), total nitrogen (TN), water extractable dissolved organic carbon (DOC), BOD and COD, the lignin and cellulose content and the cellulase hydrolysis method. These tests are being evaluated on a wide variety of typical organic materials that might be found in municipal solid waste (MSW) such as newspaper corrugated paper, compost, kitchen waste (vegetable and animal), garden wastes (grass and twigs), nappies, cotton and wool textiles.