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EXTRACTABILITY AND BIOAVAILABILITY OF HEAVY METALS AND SULFUR IN BOTTOM ASH AND FLY ASH FROM AN INDUSTRIAL POWER PLANT
Risto Pöykiö
Toivo Kuokkanen and Kauko Kujala
Hannu Nurmesniemi ABSTRACT
A five-stage sequential extraction procedure was used to determine the distribution of
11 metals (Cd, Cu, Pb, Cr, Mo, Zn, As, Co, V, Ni, Ba), and sulfur (S) in bottom ash and fly ash from a fluidized bed boiler at the
industrial power plant of Laanilan Voima Oy in Oulu, Northern Finland, into the following fractions: (1) water-soluble fraction (H2O),
(2) exchangeable fraction (CH3COOH), (3) easily reduced fraction (NH2OH-HCl), (4) oxidizable fraction (H2O2 + CH3COONH4), and (5)
residual fraction (HF + HNO3 + HCl). Although the metals were extractable in all fractions, the highest concentrations of most of the
metals occurred in the residual fraction. This fraction is the non-mobile fraction and is potentially the least harmful. The
concentration of easily soluble Ca (24.5 g kg-1 (d.w.) in the fly ash was ca. 15 times higher than the typical value of 1.6 g kg-1
(d.w.) in arable land in Central Finland indicating that the fly ash is a potential agent for soil remediation and improving soil
fertility. Both types of ash were alkaline (pH ~ 9.4 – 9.7), which means that they have a pH - buffering capacity. According to the
Finnish legislation, both types of ash can be used as a fertilizer in the forest. This paper covers also examples how ashes are utilized
in some Finnish pulp and paper mills.
MODELING LEACHATE TRANSPORT IN A SANITARY LANDFILL SYSTEM—NIGER DELTA AS A CASE STUDY
Awajiogak Anthony Ujile ABSTRACT
A quantitative design method for Municipal landfills has been developed. The design is
applicable in all environments based on the soil characteristics and other geotechnical parameters for natural attenuation type sanitary
landfills receiving wastes. This will enhance the control and monitoring of prospective ground water contamination. Attenuation
mechanisms and equations to determine the average contaminant concentration due to dispersion/dilution in groundwater is presented. The
principle of retardation factors and dilution calculations of pollutants provides optimum design details for landfill attenuation.
BAGASSE ASH UTILIZATION IN BUILDING INDUSTRY
S. M. Ali Jawaid ABSTRACT
India is one of the leading sugar producing countries of the world. Bagasse, a by
product of the sugar industry, is used as a fuel in the boilers leading to the generation of large volume of ash. Appreciating the
overall concern for environment and need for safe disposal and gainful utilization of Bagasse ash, an experimental study was carried out
to utilize the same in brick manufacturing industry. On the basis of this study, it is recommended that 24.5% bagasse ash is optimum
percentage to be used in the manufacturing of conventional bricks. It is found that bagasse ash bricks are better than traditional
bricks in the sense that bagasse ash bricks reduce the use of fertile soil of the earth for brick manufacturing, thus, protecting the
land for agricultural use.
UTILIZATION OF BAGASSE AND BAGASSE FLY ASH WASTES FOR LEAD REMOVAL
Sirawan Ruangchuay
Manaskorn Rachakornkij
Nurak Grisdanurak ABSTRACT
The purpose of this research is to remove lead from synthetic wastewater using sugar
factory wastes, bagasse and bagasse fly ash. Adsorption by these wastes can be used as an alternative to conventional treatment methods.
Bagasse was treated under acidic condition while bagasse fly ash was untreated. Batch study indicated that the removal efficiency
increased with increasing solution pH and adsorbent dose. Adsorption isotherms revealed that the Freundlich equation fitted the isotherm
data better than the Langmuir. Bagasse fly ash was more favorable than bagasse in removing lead and thus was a better adsorbent.
INTERNATIONAL TRADE IN WASTES, RECYCLING AND THE INFORMAL SECTOR—A THEORETICAL ANALYSIS
Ujjaini Mukhopadhyay ABSTRACT
Solid waste management in developing countries is usually characterized by two aspects:
first, the informal sector plays a crucial role in recovery and recycling of solid waste, and secondly, these countries are some of the
largest importers of wastes mainly used in recycling industries as intermediate goods. International agreements like the Basel
Convention prohibit trade in hazardous wastes, but there exist controversies regarding effects of free trade in non-hazardous wastes.
The paper attempts to examine the effects of trade liberalization on solid waste and pollution in a 3-sector general equilibrium model
in the presence of informal recycling industry using imported non-hazardous wastes as intermediary. It is assumed that the formal sector
augments pollution due to lax in governmental regulations, while recycling reduces pollution. Labor is measured in efficiency units,
where efficiency is inversely related to pollution. The paper shows that an increase in foreign capital inflow and reduction of tariff
on imported wastes may boost up informal waste recovery despite imported and domestic wastes being perfect substitutes. Informal
recycling may also expand, reduce pollution and improve the environment of the economy. Therefore it may be suggested that while
international agreements should prevent undesirable trade of hazardous goods, they should avoid restrictions on beneficial trade of
intermediary wastes between countries.
THE EFFECT OF SHREDDED WASTE TIRE ON THE SHEAR STRENGTH, SWELLING AND COMPRESSIBILITY PROPERTIES OF THE CLAYEY SOIL
Dr. Mousa Attom, Ph.D.
Dr. Taisir Khedaywi, Ph.D.
Sameer Ahmed Mousa ABSTRACT
The main objective of this paper is to study the effect of adding shredded waste tires
on shear strength, swelling, compressibility and permeability properties of clayey soils. For this purpose, three different types of
clayey soils were selected from Irbid city in northern part of Jordan and brought to Jordan University of science and technology soil
laboratory. The selection of three clay soils was based on their plasticity indices. The initial physical properties of these soils were
determined such as, specific gravity, Atterberg’s limits, maximum dry density and optimum moisture content, unconfined compressive
strength, cohesion and angle of internal friction, swelling pressure and consolidation. The shredded tires passed US sieve number 4 were
added to the soil at different percentages by dry weight of the soil. The percentages of shredded tires added to the soil were (2%, 4%,
6%, and 8%) by dry weight of soil for Atterberg’s limits, swelling pressure, and consolidation and 8 different percentages for
compaction test were added to the clayey soil namely ; (2%, 4%, 5%, 6%, 8%, 10%, 15%, 20%) by dry weight of soil. All samples were
prepared at 95% relative compaction and optimum moisture content. The test results showed that increasing the amount of shredded waste
tires will increase the shear strength and decrease plasticity index, maximum dry density, permeability, swelling pressure, swell
potential, and the compression index of the clayey soil.
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