Response surface methodological approach for the optimization of adsorption process in the removal of Cr(VI) ions by Cu2(OH)2CO3 nanoparticles

Potential of cobalt ferrite nanoparticles (CoFe2O4) for remediation of hexavalent chromium from synthetic and printing press wastewater

“…At lower pH, available adsorbate species compete with Cr(VI) ions and occupy the available adsorbent sites which negatively affects the efficiency of nanoparticles. As pH of wastewater was increased, removal of these species took place via precipitation and the larger number of adsorption sites were left unoccupied, resulting in higher removal of Cr(VI) ions from printing press wastewater at higher pH [30]. As removal of metallic species by precipitation method was not the aim of the present study, so adsorption experiments for printing press wastewater were carried out at pH 2.0 to avoid precipitation.…”

Efficient simultaneous removal of Cu(II) and Cr2O72− from aqueous solution by a renewable amphoteric functionalized mesoporous silica

“…Due to the widespread presence of copper and chromium in industrial applications such as electroplating, metal finishing, metal polishing, smelting and refining etc., Cu(II) and Cr 2 O 7 2À are becoming the abundant harmful ions in the liquid effluents [4][5][6]. Their levels in the aqueous solution are much higher than the maximum acceptable level of 0.05 mg/L for Cu(II) and 0.1 mg/L for Cr 2 O 7 2À , which are set by the US Environmental Protection Agency (EPA) [7,8]. The excessive Cu(II) and Cr 2 O 7 2À existed in aqueous solution will seriously destroy ecological systems and human bodies through accumulation and circulation in the environment and food chain [9,10].…”

Response surface methodology approach for optimization of methyl orange adsorptive removal by magnetic chitosan nanocomposite

“…The multivariate techniques are fast, effective, and provide optimization of more than one variable simultaneously [31][32][33]. CCD, as a type of RSM method, is an independent, rotatable, orthogonal and quadratic design [24].…”