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MUNICIPAL SOLID WASTE TREATMENT AND RECYCLING TECHNOLOGIES FOR DEVELOPING COUNTRIES — A TYPICAL NIGERIAN CASE STUDY
Chidubem Uchendu, M.Sc. ABSTRACT
Nigeria is a land endowed with abundant human and natural resources. These natural resources are converted to waste
by anthropogenic causes. Each year, about 5.9 million tonnes of municipal solid waste is generated in Nigeria. This is
not unusual. The only problem is in the way these wastes are handled. Most of them are dumped indiscriminately in open
and unsecured landfills or water bodies. Some are even burnt openly without energy recovery.
IS RECYCLING GARBAGE? — THE REPORT OF A PILOT STUDY AT BARRY UNIVERSITY, MIAMI, FLORIDA
Anita Závodská, Ph.D. ABSTRACT
The battle against contamination in material recycling is an on-going
one, and therefore, it was not unfamiliar in a pilot recycling project that was conducted at the Doral off campus-site
of Barry University’s School of Adult and Continuing Education (ACE). In mid-January 2003, two well-labeled recycling
bins, set visibly apart from the garbage receptacle, were placed in the three classrooms at the Doral site. One bin
was strictly for office paper, while the other was for drinking containers made of plastic (#1 and #2 only), glass and
aluminium. The bins were emptied weekly for a seven-week period, and the weight and composition of the collected
materials were noted. The weight and composition of the garbage were also noted for comparison. The purpose of this
study was to characterise and analyse the site’s waste stream, and to then, use the collected data in the institution
of a formal method of recycling, where the useful materials would be hauled away by a commercial entity because at the
time of the study, no recycling was being done at the site. If this were proven to work efficiently at Doral, then, in
time, the goal would be to institute similar programmes at ACE’s fourteen other off-campus sites throughout the state
of Florida.
HEAT RECOVERY OPPORTUNITIES FROM A GRAIN DUST COMPOSTING PILE
Mohamad Al-Widyan, Associate Professor ABSTRACT
In Jordan, large proportions of both the NGP and hard currency go for
imported energy. Meanwhile, large quantities of grain dust are continuously produced locally and dumped uselessly.
Thus, this study was set out to examine the opportunities of heat energy recovery from a composting pile of grain
dust. Amounts of the material were arranged in piles with passive and forced aeration schemes and measurements of
their temperature and heat transfer rates to water and air were made. It was found that the two small laboratory scale
piles effected significant rise in water and air temperature of up to 35 oC above the ambient and a rate of heat
transfer in the range of up to 600 Js-1/m3 during the test periods for up to 30 days. It was also found that under
local prevailing climatic conditions, pile moisture deceased relatively quickly below the minimum optimal levels
calling for relatively frequent wetting of the aerated and insulated piles.
PREDICTION OF THE HYDRAULIC CONDUCTIVITY OF CLAY LINERS FOR EFFICIENT CONSTRUCTION AND MONITORING OF CLAY LINERS IN LANDFILLS
Frank Atuahene, Ph.D., M.ASCE ABSTRACT
The hydraulic conductivity or coefficient of permeability is the most
important property of compacted clay in the design of waste containment structures such as landfills. The geotechnical
engineering profession has experienced difficulties over the years with the reliable prediction of hydraulic
conductivity in the field. This study establishes a model for the prediction of the hydraulic conductivity of clay
liners (compacted clay) based on its water content and dry unit weight. General linear and polynomial regression
analyses were carried out on previously published data obtained from hydraulic conductivity tests on thirteen
compacted clay soils used for clay liners at landfills throughout the United States to establish a model for
predicting hydraulic conductivity with 95% confidence level. The consistency and accuracy of the proposed model with
independent variables W (water content) and D (dry unit weight), Model WD, in predicting the hydraulic conductivity
make it superior to existing models. The accuracy is measured by comparing hydraulic conductivity measured by a
permeameter, (obtained from a publication by Benson and Trast, 1995), and that calculated using the model for the same
sample of soil. With such a model, the hydraulic conductivity of clay liners could be predicted during and after
construction without using lengthy and cumbersome methods.
DRIVING THE WASTE PREVENTION AGENDA — AN EVALUATION OF WEIGHING KERBSIDE HOUSEHOLD WASTE ARISINGS METHODOLOGY, IN DORSET, UK
Mike Read
Marten K. Gregory
Paul S. Phillips
Household waste prevention in England has been recognised in national
strategy as a key component for future sustainable practice. To support the policy agenda, the Department of
Environment, Food and Rural Affairs (Defra) in England has funded an extensive programme of fundamental research in
the area. Previous attempts to assess the impacts of waste prevention initiatives have faced a number of problems.
These have generally centred on difficulty in separating the effects of initiatives from external factors and
inadequate sample sizes or methodology. The specific research aim reported on here, in this Defra funded project, was
to trial and assess methods for monitoring and evaluating approaches detailed in the National Resource and Waste Forum
(NRWF)’s Household Waste Prevention Toolkit. The primary objective of this research was to quantify the direct waste
tonnage impacts of implementing a targeted household waste campaign in Dorset. The key performance indicator chosen
for this assessment was the weight of waste collected at the kerbside from households. The results are informative and
will help future teams design campaigns on the basis of rigorous methodology. It was found that there are a wide range
of factors that need to be taken into account and that had hitherto been given little prominence, such as careful
matching of pilot and control areas. Analysis of the results leads to the conclusion that waste arisings for residual
waste has decreased in the pilot area (≈ 10.5%) more than the controls (e.g. ≈ 5.5%). This method for monitoring can
be used, in the hands of an expert project team, to communicate to the public the direct benefits of waste prevention.
SIMULATION OF LEACHATE PRODUCTION FROM AN ARID SOLID WASTE LANDFILL USING HYDROLOGIC EVALUATION OF LANDFILL PERFORMANCE (HELP) MODEL
Hani Abu Qdais, Fayez Abdulla, and Luay Qrenawi
Landfill leachate is a byproduct of the landfilling process.
Unless properly managed, leachate will lead to several adverse environmental and health impacts. In arid regions where
precipitation amounts are low, the perception is that leachate generation is minimal. Therefore, leachate generation
has been neglected and not given the required attention. However, evidence from field practices show that arid
landfill leachate may be a significant problem that should be considered.
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