The application of an electrochemical sensor, based on a glassy carbon electrode, modified with a cellulose acetate polymeric film bearing 2,6-dichlorophenolindophenol (CA/DCPI-CME), for flow injection analysis of sulphide, is described. The overall reaction was found to obey a catalytic regeneration mechanism (EC mechanism) and the electrochemical rate constant k(f) for the electrocatalytic ox...

An optical-fiber based evanescent ammonia vapor sensor was constructed with surface-passivated growth of zinc oxide (ZnO) nanostructures, which was achieved through a three-step wet chemical process. Initially, the ZnO nanostructures were synthesized using a wet-chemical method and subsequently surface-passivated with chalcogenide material compounds namely cadmium sulphide (CdS) and cadmium sel...

the trace element contents on the surface originated from mineralization would depend to the thickness of the calcrete layer above the ore deposit on the surface. a very thick layer of calcrete may not allow for much dispersion of the elements of interest in the surface. these elements may be concentrated in non-magnetic and magnetic part of calcrete. based on the current research, mineralogica...

In heap bioleaching, acidophilic extremophiles contribute to enhanced metal extraction from mineral sulphides through the oxidation of Fe(II) and/or reduced inorganic sulphur compounds (RISC), such as elemental sulphur or mineral sulphides, or the degradation of organic compounds derived from the ore, biota or reagents used during mineral processing. The impacts of variable solution acidity and...

A laboratory investigation was developed to confirm and to quantify the reductions in absorbable organic halide (AOX) discharge when sodium sulphide was added during elemental chlorine-free (ECF) bleaching of sugarcane bagasse pulp. After the chlorine dioxide bleaching stage, the pulp was sent directly into the extraction stage without washing. FTIR was employed to determine the breakage of che...

The utilization of several inorganic and organic sulphur compounds by three strains of Clostridium perfringens and the production of hydrogen sulphide from these compounds was investigated. Sulphate, sulphite, thiosulphate and sulphide cannot supply sulphur to the organism, neither do they have any effect, when added in non-toxic concentrations, on the growth in media containing utilizable orga...

In previous and in work to be published, it has been shown that iron sulphide material, produced by sulphate-reducing bacteria (SRB), is an excellent adsorbent for a wide range of heavy metals. The material adsorbs between 100 and 400 mg g~1 and residual levels in solutions can be of the order of pg per litre. Further, strongly magnetic forms of this material can now be produced which can be e!...