Nanoscale Zero-Valent Iron Modified by Bentonite with Enhanced Cr(VI) Removal Efficiency, Improved Mobility, and Reduced Toxicity

Abstract

The aggregation of nanoscale zero-valent iron (nZVI) particles and their limited transport ability in environmental media hinder their application in environmental remediation. In this study, the Cr(VI) removal efficiency, transport performance, and toxicity of nZVI and bentonite-modified nZVI (B-nZVI) were investigated. Compared with nZVI, B-nZVI improved the removal efficiency of Cr(VI) by 10%, and also significantly increased the transport in quartz sand and soil. Increasing the flow rate can enhance the transport of nZVI and B-nZVI in the quartz sand columns. The transport of the two materials in different soils was negatively correlated with the clay composition. Besides, modification of nZVI by bentonite could reduce toxicity to luminous bacteria (Photobacterium phosphereum T3) and ryegrass (Lolium perenne L.). Compared with Fe-EDTA, the transfer factors of nZVI and B-nZVI were 65.0% and 66.4% lower, respectively. This indicated that although iron nanoparticles accumulated in the roots of ryegrass, they were difficult to be transported to the shoots. The results of this study indicate that B-nZVI has a strong application potential in in situ environmental remediation.

Oxidative stress and toxicity produced by arsenic and chromium in broiler chicks and application of vitamin E and bentonite as ameliorating agents

“…Bentonite is a clay mineral collection of fine particles with high opening volume and particular active sites ( 17 , 79 ). Bentonite is a widely used porous adsorbent aluminum phyllosilicate clay with high adsorption capability, chemical and mechanical solidity, and unique inter-lamellar structural properties ( 80 , 81 ). The metal ion belongings, preliminary concentration, adsorbent quantity, and operational circumstances (contacting time, pH, temperature, etc.)…”

“…Metals like arsenic, chromium etc., interfere with various body processes and are toxic to many organs and tissues ( 82 ), thus leading to the generation of ROS, consequently creating oxidative stress in the body ( 46 ). Bentonite absorbs these toxic substances and acts as an ameliorating agent ( 80 , 83 ). In the present study, bentonite administration improved arsenic and chromium-treated broiler chicks compared to the control group.…”

Cr(VI) Reduction and Fe(II) Regeneration by Penicillium oxalicum SL2-Enhanced Nanoscale Zero-Valent Iron

“…After 7 days of incubation on potato dextrose agar medium at 30 °C in the dark, spores were harvested and resuspended in sterile 0.05% Triton-X solution and then filtered through sterilized glass wool with a diameter of 5 to 10 μm. nZVI particles were prepared via liquid-phase reduction method as in our previous research …”

“…nZVI particles were prepared via liquid-phase reduction method as in our previous research. 27 The synergistic removal efficiency of Cr(VI) by P. oxalicum SL2 and nZVI was first investigated. A spore suspension (10 8 spores mL −1 ; 1.0%, v/v) was inoculated into potato dextrose liquid medium and preincubated for 48 h. Mycelial pellets were collected by filtration through a 0.25 mm sieve (approx.…”

Removal of Antibiotics from Aqueous Solutions by Bentonite Supported-Nanoscale Zero-Valent Iron

“…1.35 g of FeCl3•6H2O, 0.28 g of bentonite, and 0.5 g of PVP were dissolved in a three-necked flask with 100 mL of ethanol-water solution. The solution was mixed with a mechanical stirrer for 10 min in N2 environment and 100 mL of 0.2 M KBH4 was added dropwise with a constant pressure separating funnel [123]. It was found that nZVI particles prepared by the reduction of Fe 3+ ions with NaBH4 are homogeneously dispersed on the bentonite surface.…”