Field Of Remediation Research Articles

S defect-rich MoS2 aerogel with hierarchical porous structure: Efficient photocatalysis and convenient reuse for removal of organic dyes

To avoid the difficulty of separating solids from liquids when reusing powder photocatalysts, 3D stereoscopic photocatalysts were constructed. In this study, three-dimensional S defect-rich MoS2 hierarchical aerogel was prepared by chemical cross-linking of functional ultrathin 2D MoS2. Its phase, micro-morphology and structure were characterized, and it was used in the study of photocatalytic degradation of organic pollutants. Of the samples tested, MS@CA-3 (i.e., defect-rich 3D MoS2 aerogel with a loading of 30 mg of defect-rich MoS2) exhibited the best photocatalytic activity due to its suitable load, good light transmission, and a degradation rate of up to 91.0% after 3 h. In addition, MS@CA-3 aerogel offers high recyclability and structural stability, and the degradation rate of the organic pollutant methylene blue decreases only 9.8% after more than ten cycles of photocatalytic degradation. It combines the high catalytic performance of S defect-rich 2D MoS2 and the convenient reusability of hierarchical porous aerogel. This study provides valuable data and a reference for the practical promotion and application of photocatalytic technology in the field of environmental remediation.

Removal of Cr(VI) from aqueous solution using ball mill modified biochar: multivariate modeling, optimization and experimental study

Chromium (Cr(VI)) pollution has attracted wide attention due to its high toxicity and carcinogenicity. Modified biochar has been widely used in the removal of Cr(VI) in water as an efficient and green adsorbent. However, the existing biochar prepared by chemical modification is usually complicated in process, high in cost, and has secondary pollution, which limits its application. It is urgent to explore modified biochar with simple process, low cost and environmental friendliness. Therefore, ball milling wheat straw biochar (BM-WB) was prepared by ball milling technology in this paper. The adsorption characteristics and mechanism of Cr(VI) removal by BM-WB were analyzed by functional group characterization, adsorption model and response surface method. The results showed that ball milling effectively reduced the particle size of biochar, increased the specific surface area, and more importantly, enhanced the content of oxygen-containing functional groups on the surface of biochar. After ball milling, the adsorption capacity of Cr(VI) increased by 3.5–9.1 times, and the adsorption capacity reached 52.21 mg/g. The adsorption behavior of Cr(VI) follows the pseudo-second-order kinetics and Langmuir isotherm adsorption model rate. Moreover, the Cr(VI) adsorption process of BM-WB is endothermic and spontaneous. Under the optimized conditions of pH 2, temperature 45 °C, and adsorbent dosage 0.1 g, the removal rate of Cr(VI) in the solution can reach 100%. The mechanism of Cr(VI) adsorption by BM-WB is mainly based on electrostatic attraction, redox and complexation. Therefore, ball milled biochar is a cheap, simple and efficient Cr(VI) removal material, which has a good application prospect in the field of remediation of Cr(VI) pollution in water.

Study on the Inhibition of Hydrogen Evolution Reaction by Electrocatalytic Reduction of Carbon Dioxide Using Elsholtzia Harchowensis Biochar

With the widespread application of plant remediation technology in the field of soil remediation, there was an increasing stock of hyperaccumulating plant tissues containing heavy metals, but there was currently a lack of effective disposal methods. In the preliminary research process, researchers used the copper hyperaccumulating plant Elsholtzia Harchowensis to prepare biochar material electrodes and successfully used them in the electrocatalytic reduction of carbon dioxide (CO2) process. Due to the previous research being conducted in aqueous solutions, the hydrogen evolution reaction (HER) on the working electrode surface has a certain impact on the Faraday efficiency (FE) of carbon-containing products. In order to further improve the electrocatalytic reduction performance of biochar materials, this study was based on B- and N-doped biochar prepared from Elsholtzia Harchowensis as raw material. The influence mechanisms of electrode surface hydrophobicity and electrolyte components (PC/water) on the CO2RR and HER were studied, respectively. After dropwise coating PTFE on the surface of Cu/C-BN material, the hydrophobicity of Cu/C-BN-PT material was improved, and the effect on the active sites of the catalyst was relatively small without changing the structure and elemental characteristics of the original electrode. In a 1.0 M KHCO3 solution, the Faraday efficiency of H2 in Cu/C-BN-PT material decreased by 20.1% compared to Cu/C-BN at −0.32 V (vs. RHE), indicating that changing the hydrophilicity of the material can significantly inhibit the HER. In a solution of PC/water at a ratio of 9:1 (V:V), the FE of converting CO2 to methane (CH4) at −0.32 V (vs. RHE) reached 12.0%, and the FE of carbon monoxide (CO) reached 64.7%. The HER was significantly inhibited, significantly improving the selectivity of electrocatalytic CO2.

Green Synthesis of Silver Nanoparticles using Lawsonia inermis for Enhanced Degradation of Organic Pollutants in Wastewater Treatment

<p>In response to the growing demand for eco-friendly and efficient catalysts in wastewater treatment, this study introduces a novel, biosynthesized silver nanoparticle (AgNP) using leaf extract from Lawsonia inermis, a widely available plant. We employed a unique concentration mixture of 0.015 mg/mL leaf extract and 2.0 mM silver nitrate to achieve optimal results under atmospheric conditions. Comprehensive characterization was conducted through X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and ultraviolet-visible absorption spectroscopy. Remarkably, these Lawsonia inermis-synthesized AgNPs (LI-AgNPs) demonstrated superior catalytic degradation of organic pollutants, such as 4-nitrophenol, methylene blue, eosin yellow, and methyl orange. Among them, 4-nitrophenol was reduced most efficiently, following pseudo-first order kinetics. The LI-AgNPs exhibited unprecedented catalytic potential, evidenced by a sharp decline in methyl orange absorption and the emergence of a new hydrazine compound signal at 280 nm. With a catalytic loading as low as 0.2 mg/mL, we achieved an astounding 82.5% dye removal. This innovative approach advances the field of environmental remediation</p>

Co(1-nSr)TiO3 (n=0, 0.05, 0.1) nano perovskites: Novel photocatalysts synthesized by sol-gel and cold-evaporated sol-gel methods for CO remediation from polluted air

The cobalt-based perovskite photocatalysts doped with three strontium levels, Co(1-nSr)TiO3 (n = 0, 0.05, 0.1), were synthesized using sol-gel (SG) and cold-evaporated sol-gel (CESG) methods and their photocatalytic performance were compared in the field of photocatalytic CO remediation from polluted air. The photocatalytic samples were evaluated by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, solid-state UV spectroscopy, scanning electron microscopy (SEM), Transmission electron microscope (TEM), and BET surface area to evaluate physicochemical properties and their correlation with activity. The results showed that the cold-evaporated synthesis reduced the bandgap and increased the photocatalytic activity. The cold-evaporated synthesis technique enhanced the bandgap range by 15% through 0.05% Sr doping (from 3.3eV at CoTiO3 to 2.85 eV at Co(1-0.05Sr)TiO3, where wavelength activity decreased from 375.97 nm (UV region) to 435.33 nm (visible region). The optimum photocatalyst, Co(1-0.05Sr)TiO3 (CESG) exhibited 62.6% CO oxidation under the visible region. The result demonstrated that the CESG synthesis method increases the surface area, decreases the particle size, narrows and uniforms particle size distribution, and changes the crystal structure compared to the SG method. It is concluded that the CESG method is a promising method to synthesize photocatalysts that are activated under visible light for environmental protection.

Poly(2,6-dimethyl-1,4-phenylene) oxide/atactic poly(styrene) fibers with nanoporous crystalline phase

The preparation of poly(2,6-dimethyl-1,4-phenylene) oxide/atactic poly(styrene) (PPO/PS) fibers with nanoporous crystalline (NC) phase through guest-induced crystallization of melt-spun amorphous fibers is for the first time reported. These NC PPO/PS fibers display exceptional capacity to absorb volatile organic compounds from dissolved in water at very low concentrations. The equilibrium uptakes and sorption kinetics of perchloroethylene (PCE) exhibit significantly higher values and faster rates compared to the corresponding amorphous fibers. Furthermore, it is noteworthy that the equilibrium uptakes of NC PPO/PS fibers are considerably higher compared to NC PPO films. The fast pollutant uptake exhibited by these innovative NC PPO/PS fibers makes them highly promising potential applications in the field of water pollutant remediation.

Hydrogen Nanobubbles Generated In Situ from Nanoscale Zerovalent Iron with Water to Further Enhance Selenite Sequestration.

Gas nanobubbles used for water treatment and recovery give rise to great concern for their unique advantages of less byproducts, higher efficiency, and environmental friendliness. Nanoscale zerovalent iron (nZVI), which has also been widely explored in the field of environmental remediation, can generate gas hydrogen by direct reaction with water. Whether nanoscale hydrogen bubbles can be produced to enhance the pollution removal of the nZVI system is one significant concern involved. Herein, we report direct observations of in situ generation of hydrogen nanobubbles (HNBs) from nZVI in water. More importantly, the formed HNBs can enhance indeed the reduction of Se(IV) beyond the chemical reduction ascribed to Fe(0), especially in the anaerobic environment. The possible mechanism is that HNBs enhance the reducibility of the system and promote electron transport in the solution. This study demonstrates a unique function of HNBs combined with nZVI for the pollutant removal and a new approach for in situ HNB generation for potential applications in the fields of in situ remediation agriculture, biotechnology, medical treatment, health, etc.

Genome analysis of Shewanella putrefaciens 4H revealing the potential mechanisms for the chromium remediation.

Microbial remediation of heavy metal polluted environment is ecofriendly and cost effective. Therefore, in the present study, Shewanella putrefaciens stain 4H was previously isolated by our group from the activated sludge of secondary sedimentation tank in a dyeing wastewater treatment plant. The bacterium was able to reduce chromate effectively. The strains showed significant ability to reduce Cr(VI) in the pH range of 8.0 to 10.0 (optimum pH 9.0) and 25-42 ℃ (optimum 30 ℃) and were able to reduce 300mg/L of Cr(VI) in 72h under parthenogenetic anaerobic conditions. In this paper, the complete genome sequence was obtained by Nanopore sequencing technology and analyzed chromium metabolism-related genes by comparative genomics The genomic sequence of S. putrefaciens 4H has a length of 4,631,110bp with a G + C content of 44.66% and contains 4015 protein-coding genes and 3223, 2414, 2343genes were correspondingly annotated into the COG, KEGG, and GO databases. The qRT-PCR analysis showed that the expression of chrA, mtrC, and undA genes was up-regulated under Cr(VI) stress. This study explores the Chromium Metabolism-Related Genes of S. putrefaciens 4H and will help to deepen our understanding of the mechanisms of Cr(VI) tolerance and reduction in this strain, thus contributing to the better application of S. putrefaciens 4H in the field of remediation of chromium-contaminated environments.

High-efficiency decontamination of pharmaceutical wastewater: Synergistic effects from NaGdF4:Tm,Yb@Mn-MOFs composite photocatalysts

Water pollution caused by antibiotics poses a serious threat to human health and ecosystems. Rapid and efficient removal of antibiotic pollution in water by photocatalysts is one of the effective means to protect the environment and public health. Herein, a wide-spectral responsive upconversion NaGdF4:Yb,Tm@Mn-MOFs core-shell nanostructures were built by coating hexagonal NaGdF4:Yb,Tm cores with amino-functionalized manganese carboxylate MOFs (Mn-MOFs) shells, which exhibited good water dispersibility. Mn-MOFs catalysts is mainly concentrated in the ultraviolet region, while NaGdF4:Yb,Tm nanoparticles can transform infrared light into visible light or even higher energy ultraviolet light, which is harvested by the Mn-MOFs. The optimized nanostructures were tested under simulated solar light (After 120 min irradiation) in the degradation of tetracycline, oxytetracycline hydrochloride and tetracycline hydrochloride, while their degradation rates reached 70%, 72% and 75%, respectively. The better photocatalytic mechanism for antibiotics than its individual components was elucidated, which provides a potential strategy to broaden the full spectrum absorption of the wide bandgap semiconductors and apply for the field of environmental remediation.

Enhanced removal of nitrobenzene with lignosulfonate modified zero valent iron: removal kinetic, reaction mechanism, and application feasibility

The reductive capacity of zero valent iron (ZVI) is extremely restricted by the surface passivation. To address this issue, ball-milling lignosulfonate modified ZVI (LS-ZVI) was prepared and used to determine the reactivity, electron utilization efficiency and application feasibility towards nitrobenzene (ArNO2) removal. The results showed that LS-ZVI could completely remove ArNO2 within 40 min with aniline conversion percentage of ∼95%, while ArNO2 reduction by ZVI was negligible within 180 min. Electrochemical evidence, H2 production, and characterization analysis collectively illuminated that the enhanced ArNO2 reduction by LS-ZVI was attributed to the increased Fe0 exposure that endowed it with excellent electron transfer ability. The inhibited H2 production indicated that the electron utilization efficiency of LS-ZVI towards ArNO2 was close to 100%. Moreover, ArNO2 removal was slightly inhibited under higher solution pH. Except for the obvious inhibitory effect of high concentration NO3−, the effects of co-existing ions (Cl−, NO3−, SO42−, Ca2+, and Mg2+) were little. The presence of Ni(II) had a negligible effect on ArNO2 removal, while high concentration of Cd(II) and Cr(VI) could obviously inhibit ArNO2 reduction. In addition, the excellent reusability of LS-ZVI and the complete ArNO2 removal in groundwater suggested the feasibility of LS-ZVI in practical field remediation.

Adsorptive Removal of Selected Toxic Metals from Pharmaceutical Wastewater using Fe<sup>3</sup>O<sup>4</sup>/ZnO Nanocomposite

Pharmaceutical wastewater is a major source of environmental contamination, often containing toxic metals that pose significant threats to ecosystems and public health. This study explores the potential of magnetite/zinc oxide (Fe3O4/ZnO) nanocomposites prepared using a sol-gel method for the removal of lead, cadmium, and copper ions from pharmaceutical wastewater. The nanocomposite was characterized using X-ray diffraction (XRD), High-resolution scanning electron microscopy (HRSEM)/energy dispersive spectroscopy (EDS) and Fourier transmission infrared spectroscopy (FTIR). The XRD analysis of the nanocomposite identified 2θ (theta), of 31.7º, 34.4º, 36.2º, 47.5º, 56.6º, 62.8º, 66.3º, and 67.9º which correspond to the crystal planes of (100), (002), (101), (102), (110), (103), (200), and (112), respectively. The diffraction peaks associated with Fe3O4 at 2θ of 18.02º, 29.4º, and 43.3º, related to the crystal planes of (111), (220), and (400), respectively of the Fe3O4 phase. The HRSEM image of the nanocomposite exhibited spherical-shaped structures of Fe3O4/ZnO, and some irregular shapes. The effects of the contact time, dosage and temperature on the removal percentage of toxic metal ions were studied. Freundlich and Langmuir isotherm constants and correlation coefficients were determined and the equilibrium process was better described by the Langmuir isotherm. The adsorption process followed a second order kinetics and the thermodynamic parameters showed that the involved process was spontaneous. These findings contribute to the advancement of environmentally friendly technologies for the pharmaceutical industry and the broader field of wastewater remediation.

P-n Junction catalysis in action: Boosting norfloxacin photodegradation with ZIF-67-based Co3O4 wrapped in MoS2 with surface functionalized graphene quantum-dot

The primary challenge in photocatalytic application is to address the inefficiency in exploiting the photo-induced charge carriers. The dynamic behaviors of photogenerated carriers can be controlled through an internal electric field by building a p-n heterojunction. In this respect, p-n heterojunctions constructed from zeolitic imidazolate frameworks (ZIFs) with further surface functionalization are uniquely active and can increase the charge separation due to a favorable band structure. Thus, the present work demonstrates the preparation of an excellent visible-light absorbing photocatalyst based on a Co3O4 from ZIF-67 wrapped with MoS2 and functionalized with graphene quantum dots (GQDs), which is evaluated for the photodegradation of norfloxacin. Under visible light irradiation, the as-designed GQDs-functionalized MoS2@Co3O4 p-n heterojunction photocatalyst outperforms the individual MoS2 and Co3O4 semiconductors. The remarkable degradation efficiency is mostly due to the formation of a p-n heterojunction between MoS2 and the ZIF-67-based Co3O4. The photocatalytic mechanism of the as-designed system is deduced from reactive species trapping studies. This study sheds light on the design of a photocatalytic system based on ZIF-67, and on the effect of surface functionalization, thereby expanding the potential practical application of these materials in the field of environmental remediation.

Flexible crystalline zinc doped silica nanofibers with superior wettability and remediation for oily wastewater

Construction of ceramic fibrous membranes with good mechanical property and separation performance for the remediation of surfactant stabilized emulsions at high-temperature or complex environment is on great demand, yet still a challenge. Herein, the zinc ions doped silica (ZSO) nanofibrous membranes with expectable flexibility and superior selective wettability is prepared via a facile sol–gel electrospinning technique. The doping of zinc ions in silica nanofibers induced the obvious variation in crystalline and surface roughness structure, which were directly relevant to the mechanical properties and wettability of the resultant ZSO nanofibrous membranes. The advantageous features favored the ZSO membranes with excellent surfactant stabilized oil-in-water emulsion separation performance, including the separation efficiency of >98 %, the permeation flux of ∼3900 L m−2 h−1 driven by gravity, outstanding chemical stability, and good reusability within 10 cycles. In addition, the rationally designed micro-/nano-structured composite ceramic fibrous membranes displayed significant improvements on structural stability, mechanical property, and prominent separation performance towards emulsions at high temperature (∼95 °C) and nanoparticle-containing wastewater. The clarification of the relationship among crystalline structure, surface roughness, mechanical properties, and application performance would facilitate the fabrication of filtration materials used in the fields of oil-spill cleanup, seawater destination, and wastewater remediation.

Plasma treatment enhanced piezo-photocatalytic performance of Bi2WO6 for efficient degradation of tetracycline hydrochloride

Photocatalysis is limited by the high recombination rate of photogenerated e- and h+, but the piezoelectric effect can enhance the separation efficiency of charge carriers, so that the combining piezoelectric catalysis with photocatalysis is a highly promising approach for improving catalytic performance. In this study, aim to enhance piezo-photocatalytic performance, plasma treatment was applied to modify the surface of Bi2WO6 to form oxygen vacancies. After plasma treatment, Bi2WO6 exhibited a larger specific surface area, thinner thickness, narrower band gap, etc. These improvements have been confirmed to enhance the piezoelectric response of Bi2WO6, facilitate band bending and further improve the absorption of visible light, accelerate the separation of charge carriers, thus enhanced the piezo-photocatalytic activity. Consequently, utilization of plasma treatment had improved greatly the piezo-photocatalytic performance of Bi2WO6 for the degradation of tetracycline hydrochloride. Impressively, plasma treatment promoted the generation of 1O2 during the piezo-photocatalytic reaction, emphasizing the advantages of utilizing plasma treatment for improving the performance of piezo-photocatalysts. This work highlights the use of plasma treatment to increase active sites and induce vacancy defects on the surface of catalysts, which exhibit excellent piezo-photocatalytic degradation performance and show great potential in the field of environmental remediation.

Micro/nanomotors for neuromodulation.

Micro-nanomotors (MNMs) are micro/nanoscale intelligent devices with vast potential in the fields of drug delivery, precision medicine, biosensing, and environmental remediation. Their primary advantage lies in their ability to convert various forms of external energy (such as magnetic, ultrasonic, and light energy) into their own propulsive force. Additionally, MNMs offer high controllability and modifiability, enabling them to navigate in the microscopic world. Importantly, recent research has harnessed the unique advantages of MNMs to synergize their capabilities in neuromodulation. This mini-review presents the significant progress and pioneering achievements in the use of MNMs for neuromodulation, with the aim of inspiring readers to explore the broader biomedical applications of these MNMs. Through continuous innovation and diligent exploration, MNMs show promise to have a profound impact on the field of biomedicine.

Synergistic self-driven and heterogeneous effect of a biomass-derived urchin-like Mn3O4/C3N4 Janus micromotor catalyst for efficient degradation of carbamazepine.

It is well known that obtaining efficient carbamazepine degradation materials or rapid carbamazepine-removal methods is still a challenge in the field of environmental remediation. Hence, the present study aimed to concurrently address these issues by combining a self-driven, heterostructured and low-cost biomass-templated urchin-like Janus micromotor catalyst for highly efficient carbamazepine degradation. The catalyst could autonomously move in a circle-like motion pattern via O2 bubbles generated from the Mn3O4-catalyzed decomposition of H2O2 with a velocity of 223.5 ± 7.0 μm s-1 in 1% H2O2. Benefiting from the well-structured heterojunction at the interface of C3N4 and Mn3O4, carbamazepine (CBZ) was degraded by 61% in 100 min under sunlight irradiation. In addition, density functional theory calculation results proved that the formation of the heterojunction structure promoted the generation of photo-generated carriers. Thus, the presented method provides a promising pathway for the rational construction and preparation of movable catalysts for the efficient removal of organic pollutants from wastewater.

A review on sustainable iron oxide nanoparticles: syntheses and applications in organic catalysis and environmental remediation

In this review paper, recent developments of iron oxide nanoparticles are highlighted and discussed in the field of organic catalysis and environmental remediation.

Advancements in Nanotechnology for Heavy Metal Remediation in Wastewater Treatment: Challenges and Opportunities

The exploration of the cutting edge of wastewater treatment, concentrating on the ever-changing field of heavy metal remediation uses of nanotechnology is a major requisite for sustainability. The investigation covers a wide range of nanotechnology topics, such as photocatalysis, adsorption, catalysis, and novel nanomembranes, providing a thorough grasp of its crucial function in water treatment. Examining specific nanomaterials such as nanoparticles, nanotubes, and nanofibers, the study evaluates their applications, highlighting their unique contributions to heavy metal removal. However, the paper meticulously dissects the challenges hindering the widespread use of nanoparticles in wastewater treatment, with a keen focus on graphene oxide nano-sheets, magnetic nanoparticles, polymeric hydrogels, and activated carbon. Novel techniques incorporating nanotechnology for heavy metal removal are also explored. The conclusion provides a synthesis of findings and offers recommendations for overcoming existing challenges, paving the way for an enhanced integration of nanotechnology in wastewater treatment practices. This paper serves as a vital resource for researchers, practitioners, and policymakers engaged in advancing sustainable and effective solutions for heavy metal remediation in wastewater treatment systems.

Advancements in removing common antibiotics from wastewater using nano zero valent iron.

The pollutants such as heavy metals, organic matter, and nitrates in soil and water pose challenges to environmental remediation technology. Nano zero valent iron has shown enormous potential in the field of environmental remediation due to its excellent adsorption performance. By using carbon based materials, rock minerals, biomolecules, etc., as supporting materials for nZVI, and through structural and performance modifications, its performance has been successfully optimized, reducing defects such as aggregation and easy oxidation of the material. This article compares and summarizes the modification effects of different loadings on nZVI, and comprehensively reviews the latest progress, preparation methods, and application of nZVI particles in soil and water remediation. Specifically, this article explores in detail the impact and mechanism of nZVI particles in commonly used antibiotics contaminated environments. Firstly, the combination methods of different types of materials with zero valent iron, as well as the synthesis methods and application scenarios of nZVI, were integrated. Secondly, the interaction mechanism between pollutants and nZVI was introduced in detail, including adsorption, redox reactions, and co-precipitation. Subsequently, environmental factors that affect repair efficiency were emphasized, such as pH value, coexisting components, oxygen, contact time, and temperature. Finally, the challenges faced by the application of nZVI in actual polluted soil and water bodies, as well as the prospects for its long-term efficacy and safety evaluation, are proposed to promote further development in the future.

Enhanced Fe(ii)/Fe(iii) cycle by boron enabled efficient Cr(vi) removal with microscale zero-valent iron.

Recently, researchers have been paying much attention to zero-valent iron (ZVI) in the field of pollution remediation. However, the depressed electron transport from the iron reservoir to the iron oxide shell limited the wide application of ZVI. This study was aimed at promoting the performance of microscale ZVI (mZVI) for hexavalent chromium (Cr(vi)) removal by accelerating iron cycle with the addition of boron powder. It was found that the addition of boron powder enhanced the Cr(vi) removal rate by 2.1 times, and the proportion of Cr(iii) generation after Cr(vi) removal process also increased, suggesting that boron could promote the reduction pathway of Cr(vi) to Cr(iii). By further comparing the Cr(vi) removal percentage of Fe(iii) with or without the boron powder, we found that boron powder could promote the percentage removal of Cr(vi) with Fe(iii) from 10.1% to 33.6%. Moreover, the presence of boron powder could decrease the potential gap values (ΔEp) between Fe(iii) reduction and Fe(ii) oxidation from 0.668 V to 0.556 V, further indicating that the added boron powder could act as an electron sacrificial agent to promote the reduction process of Fe(iii) to Fe(ii), and thus enhancing the reduction of Cr(vi) with Fe(ii). This study shed light on the promoted mechanism of Cr(vi) removal with boron powder and provided an environmentally friendly and efficient approach to enhance the reactivity of the mZVI powder, which would benefit the wide application of mZVI technology in the environmental remediation field.