Surface Modification of Hydrophobic Resin with Tricaprylmethylammonium Chloride for the Removal of Trace Hexavalent Chromium

Abstract

Chromium(VI) is one of the most toxic contaminants in the environment, even at low concentration. The conventional chemical precipitation process for Cr(VI) wastewater treatment becomes less effective at low Cr(VI) concentration. By a two-step solvent–nonsolvent method, tricaprylmethylammonium chloride (Aliquat 336) can be immobilized onto the surface of porous Amberlite XAD resin with good stability, giving Aliquat 336-modified resins (AMRs). Furthermore, the exposure of the cationic ammonium functional group facilitates the adsorption and stripping efficiency of Cr(VI). The amount of immobilized tricaprylmethylammonium chloride was 2.0 mmol/g of resin. A kinetic study showed that the adsorption of Cr(VI) was under film-diffusion control followed by intraparticle-diffusion control. The Cr(VI) adsorption capacity was as high as 1.37 mmol/g. More than 99% of the adsorbed Cr(VI) could be stripped during regeneration. For stability and reusability, the AMRs maintaine da high level of Cr(VI) adsorption even after four cycles of adsorption/stripping. The experimental results for actual wastewater demonstrated that the AMRs can be used effectively for the treatment of trace Cr(VI)-containing wastewater.

Palladium nanoparticles supported on amine-functionalized SiO2 for the catalytic hexavalent chromium reduction

“…Hexavalent chromium (Cr(VI)) is well-known as an extremely serious and ubiquitous environmental pollutant produced in wastewaters by several industrial processes such as metal electroplating, leather tanning, pigment production, and wood preservation [1][2][3][4]. Cr(VI) is considered to be the third most common pollutant at hazardous waste sites and the second most abundant heavy metal contaminant [5].…”

Recent Advances in Silica-Based Materials for the Removal of Hexavalent Chromium: A Review

“…18,19 Adsorption is a fundamental and economically viable process for the treatment of Cr(VI) from wastewater because of its several advantages such as high removal efficiency, low energy demand, less chemical investment, and reusability. Adsorption of Cr(VI) from the aqueous streams to the surface of the adsorbent occur due the electrostatic interaction or via a chemical reaction.…”

Selected applications of calixarene derivatives

“…53,54 The trivalent form Cr(III) is important for mammals in maintaining glucose, lipid and protein metabolisms, however the hexavalent form, Cr(VI) is toxic, e.g. it can diffuse as Cr 2 O 7 2-or HCr 2 O 7 -through human cell membranes, resulting in oxidized biological molecules.…”