Coal fly ashes and metallurgical slags are currently widely used as supplementary cementitious materials in production of Portland cement-based concretes. However, this application makes very poor use of the intrinsic reactivity of the glassy phases present in the waste materials, and can hardly...

The present paper aims to assess the effect of various additives on the compressive strength of inorganic polymers (geopolymers) synthesised using low Ca electric arc ferronickel slag and alkali activating solutions. The main operating parameters include pre-curing (48 hours), temperature (40 to 80...

Fly ash is an important industrial by-product that comes from the combustion of coal, for the production of electrical energy. In our country, only a small percentage is used for the construction of technical projects, while the rest is stockpiled, causing serious problems. Because of its great...

The ability of activated carbon and different low-cost by-products and waste material as sorbents to remove various reactive dyes from aqueous solutions and wastewaters was investigated. All aqueous dye solutions contained 2,000 mg l-1 NaCl, to mimic real dye wastewater. Batch kinetic and isotherm...

A procedure that should be implemented for the evaluation of materials suitability, in terms of their use as metal retention agents, is presented. It derives from a review of materials and waste treatment mechanisms, which has been studied and is also presented. Lignite fly ash, agricultural ashes...

Laboratory column tests were conducted to study the efficiency of lignite fly ash barriers in removing heavy metal ions, such as Fe, Zn, Mn, Ni, Cd, Co, Al and Cu, present in high concentrations in acidic leachates produced in mining and waste disposal sites. The experimental configuration comprised...

A main problem related to coal ash disposal is the heavy metal content of the residue. In this regard, experimental results of numerous studies have indicated that toxic trace metals may leach when fly ash and bottom ash contacts with water. In this study, fly ash and bottom ash samples obtained...

Fly ash (FA) and fluidized bed ash (FBA) solutions were evaluated as amendments for acid-disturbed lands, more specifically for treating acidic and metal contaminated soil. While titrating the ash materials with different volumes of acid, pH changes were monitored as a function of time and the acid...

Adsorption and removal of commercial dyes were studied in aqueous suspensions of fly ash mixtures with a sandy clay loam soil of low organic matter content. The commercial dyes, acid orange 7, acid yellow 23, disperse blue 79, basic yellow 28 and direct yellow 28 represent the widely used nitroazo...

More than 73% of the electrical power requirements of Greece are generated in lignite-fired power plants. Greece is the thirteenth largest coal and the fifth largest lignite producer in the world. The lack of domestic high-rank coals makes necessary to use low quality lignite for power generation in...

Coals contain elements which, although usually found in concentrations lower than 1% (trace elements), can give rise to environmental or technological problems. After gasification most of these elements may occur in gas phase in different proportions. In order to avoid the problems that the presence...

The objective of this study was set on three goals: (i) Chemical and radiological characterization and leaching properties of the mixture of fly and bottom ash, (ii) Chemical, radiological and mineralogical characterization of the Kastela Bay sediments, and (iii) Estimation of the influence of...

Slurry seal is applied for low-cost paving and surface maintenance. The principal materials used to create slurry seal are aggregates, asphalt emulsion, water and fillers like Portland cement (mainly), lime and other materials. This paper presents the use of alternative fillers instead of expensive...

A crucial aspect in environmental sciences is related to the transportation, accumulation and fate of solid organic particles not native to the sediments. In this study we present the petrographical features of seven sediment samples obtained from aquatic environments in Sweden, Finland and The...