Owing to the unique microporous structure and high specific surface area, porous carbon could act as a good carrier for functional materials. In this paper, polyacrylonitrile (PAN)-based porous carbon materials (PPC-0.6-600, PPC-0.8-600, PPC-0.6-800 and PPC-0.8-800) were prepared by heating KOH at 600°C and 800oC for the removal of Cr(VI) from aqueous solution. The adsorbent was characterized b...

EXTENDED ABSTRACT The removal of chromium from water and wastewater has caused increased research interest in recent years. Chromium exists in the environment mainly in one of two valence states: a) trivalent Cr(III), and b) hexavalent Cr(VI) form. Cr(VI) enters the environment primarily through industrial processes including the production of steel and metal alloys, chrome plating, dyes and pi...

Single Cr(VI) reduction and coupled reduction/stabilization (R/S) processes were evaluated at pilot scale to determine their effectiveness to treat chromite ore processing residue (COPR). Sodium sulfide was used as the reducing agent and cement, gypsum and lime were tested as the stabilizing agents. The pilot experiments were performed in a helical ribbon blender mixer with batches of 250 kg of...

A microporous bisphenol A diglycidyl ether (DGEBA) epoxified-polyethersulfone (PES) blend membrane (EPES membrane) was prepared through dry-wet phase inversion. This study attempts to correlate the changes in membrane physical and chemical properties when the EPES membranes were exposed to different durations of dry-phase inversion, towards the separation efficiency of carcinogen chromium (VI)....

The influence of Fe(III) starting material on the ability of magnetically recoverable biogenic magnetites produced by Geobacter sulfurreducens to retain metal oxyanion contaminants has been investigated. The reduction/removal of aqueous Cr(VI) was used to probe the reactivity of the biomagnetites. Nanomagnetites produced by the bacterial reduction of schwertmannite powder were more efficient at...

Arachis hypogea shells (ground nut shells), a lignocellulosic waste biomass, was evaluated for sequestering of Cr(VI) from synthetic wastewater. Arachis hypogea shells (AHS) were used in three different forms, viz.natural (AHSN), immobilized in the form of beads (AHSB), and in the form of activated carbon (AHSC). Batch experiments were performed for the removal of hexavalent chromium. Effects o...

The synthesis of NiO nanoparticles was done by sol-gel method. Nickel Acetate Tetrahydrate ((CH3COO)2 –Ni·4H2O) was dissolved in ethanol with constant stirring to obtain a clear and light greenish sol. Oxalic acid solution was used to obtain a thick green gel, then dried in an oven to get dried gel and was then grinded into fine powders and calcined for different time periods to obtain nanocrys...

Nanoscale iron particles decorated graphene sheets synthesized via sodium borohydride reduction of graphene oxide, showed enhanced magnetic property, surface area and Cr(vi) adsorption capacity compared to bare iron nanoparticles.