1,225 research outputs found
Environment Agency review of methods for determining organic waste biodegradability and municipal waste diversion.
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
Characterisation of untreated and treated biodegradable wastes
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
Application of DR4 and BM100 Biodegradability tests to treated and untreated organic wastes
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
The Behaviour of Drive-in Storage Structures
The paper describes the behaviour of Drive-in and Drive-thru pallet rack structures. It proposes a number of simplified two-dimensional models for the analysis of such structures. These models are shown to be conservative and take account of the non-linear behaviour of the structures. The paper makes some comparisons between the output from these and a 3-D finite element program. The effects of friction between the pallet and the supporting rail is discussed briefly
The Design of the Pallet Program
This paper describes the procedures underlying the development of the Pallet program which has been produced to design regular pallet racks according to the FEM code. The program determines the buckling load of the equivalent free sway structure and, using stability functions, calculates the axial and shear forces and the bending moments within the structure including the non-linear P - Δ effects. Twelve different combinations of load are analysed and design checks given in the FEM code applied. The paper discusses the different modes of operation of the program. Finally the accuracy of the program is discussed together with future developments
Low cost filter for trickle irrigation
CLEAR water is essential for a successful trickle irrigation scheme. Most water sources are not sufficiently clean and some form of filtration is necessary
Rotational Stiffnesses of Semi-rigid Baseplates
The paper describes a test procedure to determine the rotational stiffnesses and moment-curvature relationships of semi-rigid baseplates of cold-formed structures. The influence of the modulus of the foundation subgrade on baseplate performance is determined. Increasing the axial load applied to a baseplate is shown to increase the ultimate moment-rotation capacity of a baseplate
- …