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COMPATIBILITY OF CEREAL STRAW WITH HYDRATION OF CEMENT
P. Soroushian
O. Simsek
M. Elzafraney
T. Ghebrab ABSTRACT
Cereal straw is an abundantly available agricultural by-product with attractive
mechanical performance and cost position for reinforcement of cement-based products. The composition of straw, however, is distinguished
from that of wood by the presence of relatively large quantity extractives with potentially strong inhibitory effects on strength
development of cement. Thin-sheet fiber cement products offer attractive technical, economic and aesthetic qualities for use in diverse
building construction applications, including siding and tile backerboard. Commercially successful thin-sheet fiber cement products
generally utilize chemically processed wood pulp or mechanically milled wood as reinforcement for achieving enhanced levels of flexural
strength, toughness and workability. Cereal straw offers a slender geometry which favors their mechanical processing as replacement for
milled wood in thin-sheet cement products. As a renewable resource and as a generally low-valued agricultural residue, straw offers
economic and environmental advantages for replacement of wood in thin-sheet cement products. The differences in composition of wood and
straw should be considered in devising pre-treatment techniques for use of straw in conjunction with cement. Such pre-treatments should
address the potential for inhibitory effects of some straw constituents on strength development of cement.
COMPATIBILITY AND ATTENUATIVE PROPERTIES OF BLAST FURNACE SLAG TREATED LATERITE
Kolawole J. Osinubi
Adrian O. Eberemu ABSTRACT
Major concerns exist regarding potential pollution problems related to contamination by toxic
liquids emanating from waste landfills. Increasing environmental awareness is making it necessary to assess the effects of waste
leachates in proposed clayey liners for waste landfills. Results of a study on the feasibility of using laterite treated with ground
blast furnace slag (BFS) as a construction material for waste containment liners and impermeable covers are presented. Liners can be
constructed using laterite treated with ground BFS to meet the regulatory permeability value of < 1x 10-9 m/s. The effects of permeation
with municipal solid waste (MSW) leachate on compacted soil treated with up to 15% ground BFS at the energy of the British Standard
heavy (BSH) compaction using different molding water contents for a period of one month are reported. Batch equilibrium studies were
conducted for a duration of 48 hours using 0, 5, 10, 15 and 100% ground BFS treated soil, respectively. The MSW leachate had no
detrimental effect on the liner permeability. Adsorption isotherms were obtained for the cations of calcium, iron and chromium that were
selected to represent the dominant and critical contaminants in the leachate and these showed strong attenuative properties. 5% BFS
treatment gave the optimum mix performance.
APPLICATION OF IONIZING RADIATION FOR SLUDGE DISINFECTION AND ITS USE FOR IRRIGATION AND FERTILIZATION
G. Shani
S. Segman-Magidovich ABSTRACT
The sludge produced in the central, most populated area in Israel, is now dumped into
the sea. Ionizing radiation was used to investigate the possibility of developing an industrial method for disinfection of the sludge,
preparing it for use in farm land for irrigation and fertilization. A simple and inexpensive method for disinfection and preparing it
for agricultural use is proposed. Sludge samples were irradiated with photons and electrons, it was found that relatively low radiation
dose is enough to bring it to level A which is acceptable for the proposed use. Any dose of gamma radiation from a Co 60 source, from
0.2 Mrad and up, killed all coliforms in the sludge. Similar results were obtained for 3 MeV electrons. The irradiation stopped all
biological activity in the sludge, therefore causing the solid part to separate from the water and sink. This stopped the gas (odor)
emission from the sludge. The radiation did not have any effect on the heavy metals concentration in the sludge, but had some effect on
the concentration of some of the light elements (some of it remained in the solid). The water, containing important minerals, was then
tested for field irrigation. The product was tested for irrigation using droppers and found to be suitable.
SORPTION POTENTIAL OF THE BIOMASSES OF PEANUT HULL AND FLY ASH FOR DECOLOURIZATION OF METHYLENE BLUE AQUEOUS SOLUTION
G.M. Taha ABSTRACT
The sorption potential of either peanut hull or fly ash to decolourize the aqueous
solution of methylene blue (MB) was investigated at room temperature. Many operating variables were studied in a batch technique. Of
these, solution pH, dosage of the used sorbent biomass, initial dye concentration and the applied contact time.
AN IMPROVED NUMERICAL DESIGN METHOD FOR THE REMEDIATION OF CONTAMINATED SITES BASED ON
SENSITIVE TRACER TESTS
Kazuei Ishii and Toru Furuichi ABSTRACT
We proposed an improved numerical design method for the remediation of contaminated
sites based on a sensitive tracer test using rare earth metals such as holmium. The numerical design method was then applied to a real
contaminated site, where immediate countermeasures were required because of detection of high arsenic concentration in a spring near a
sea line outside the site. First, the sensitive tracer test using insium, europium and holmium under natural gradient condition revealed
the groundwater flow path from the three suspected source points to the sea line, and analysis of the breakthrough curve for each tracer
compounds determined the parameters, such as the hydraulic conductivity and dispersivity. A site-specific model representing the
distribution of acrcenic concentration in groundwater identified the source points, responsible for the contamination of the spring, and
revealed that contaminated groundwater might flow out of the site boundary. A vertical wall was designed to prevent contaminants
spreading from the site, and the change in the arsenic concentration after the construction of the vertical wall was predicted. The
prediction had similar tendency to the actual decrease in arsenic concentration over a two-year monitoring phase. Consequently, our
numerical design based on the sensitive tracer test predicted that the contamination level in the groundwater around the spring would
continuously decrease toward remediation.
DRIVING COMMERCIAL AND INDUSTRIAL WASTE REDUCTION IN QUEENSLAND, AUSTRALIA — THE
POTENTIAL APPLICATION OF A UK WASTE MINIMISATION CLUB MODEL
Georgina Davis
Paul Phillips and Thomas Coskeran ABSTRACT
Queensland (QLD) is the second largest state in Australia with an area of 1,734,157 km2
and a population of some 4,132,000 (less than 20% of Australia’s total population). The majority of QLD’s population is located in the
South East (SEQ) region around Brisbane and the Gold Coast with further population densities along the coast. SEQ is growing rapidly,
with SEQ receiving over 1,000 new immigrants (both interstate and international) to the region every week, which is stimulating the
housing, retail and commercial and industrial sectors. This growth in population and development is leading to an increase in waste
arisings across all sectors. During 2005, QLD generated approximately 444,000 tonnes of commercial and industrial waste, with only
23,000 tonnes being recycled, equating to only 5% of the amount generated. By comparison, during 2005 the UK generated 83 million tonnes
of commercial and industrial wastes of which approximately 45% was recycled. QLD has a suite of environmental and specific waste
management legislation relating to the management of all waste streams which adopts the waste management hierarchy. The regulatory
framework of any State or Country can if well designed drive sustainable waste management practices within the commercial and industrial
sectors.
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