scholarly journals Environmental Application of Biogenic Magnetite Nanoparticles to Remediate Chromium(III/VI)-Contaminated Water

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 260 ◽  
Author(s):  
Yumi Kim ◽  
Yul Roh
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Magnetite Nanoparticles ◽  
Environmental Remediation ◽  
Electrostatic Interactions ◽  
Physicochemical Characteristics ◽  
High Reactivity ◽  
Environmental Application ◽  
Surface Areas ◽  
Biogenic Magnetite

The physicochemical characteristics of biogenic minerals, such as high specific surface areas and high reactivity and the presence of a bacterial carrier matrix, make them promising for various applications. For instance, catalysts, adsorbents, oxidants, and reductants. The objective of this study is to examine the efficiency of biogenic magnetite nanoparticles (BMNs) that are produced by metal-reducing bacteria for removing chromium. Interactions between ionic chromium (Cr III/VI) and BMNs were examined under different pH values (ranging from pH 2 to pH 12) by using different doses of BMN (0–6 g/L). Chemically synthesized magnetite nanoparticles (CMNs) were used in the experiments for the purpose of comparing them to the BMNs. The results showed that the BMNs had higher Cr(VI) removal efficiency (100%) than the CMNs (82%) after a two-week reaction time. A lower pH and longer reaction time in the Cr-contaminated solution led to a higher Cr(VI) removal efficiency. The Cr(VI) removal efficiency by the BMNs in the Cr-contaminated groundwater was about 94% after a reaction time of two weeks. The BMNs that were coated with organic matter were more effective than the CMNs in leading to adsorption of Cr(III) with electrostatic interactions (82% versus 13%) and in preventing Fe(II) oxidation within the magnetite structure. These results indicate that the BMNs could be used to decontaminate ionic Cr in environmental remediation technologies.

scholarly journals The Era of Nanomaterials: A Safe Solution or a Risk for Marine Environmental Pollution?

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 441
Author(s):  
Maria Consiglia Esposito ◽  
Ilaria Corsi ◽  
Gian Luigi Russo ◽  
Carlo Punta ◽  
Elisabetta Tosti ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Environmental Remediation ◽  
Health Impact ◽  
High Reactivity ◽  
Raw Material ◽  
Design Framework ◽  
Environmental Matrices ◽  
Natural Ecosystems ◽  
Environmental Application ◽  
Environmentally Safe

In recent years, the application of engineered nanomaterials (ENMs) in environmental remediation gained increasing attention. Due to their large surface area and high reactivity, ENMs offer the potential for the efficient removal of pollutants from environmental matrices with better performances compared to conventional techniques. However, their fate and safety upon environmental application, which can be associated with their release into the environment, are largely unknown. It is essential to develop systems that can predict ENM interactions with biological systems, their overall environmental and human health impact. Until now, Life-Cycle Assessment (LCA) tools have been employed to investigate ENMs potential environmental impact, from raw material production, design and to their final disposal. However, LCA studies focused on the environmental impact of the production phase lacking information on their environmental impact deriving from in situ employment. A recently developed eco-design framework aimed to fill this knowledge gap by using ecotoxicological tools that allow the assessment of potential hazards posed by ENMs to natural ecosystems and wildlife. In the present review, we illustrate the development of the eco-design framework and review the application of ecotoxicology as a valuable strategy to develop ecosafe ENMs for environmental remediation. Furthermore, we critically describe the currently available ENMs for marine environment remediation and discuss their pros and cons in safe environmental applications together with the need to balance benefits and risks promoting an environmentally safe nanoremediation (ecosafe) for the future.

Effects of operational parameters on defluoridation efficiency using electrocoagulation process

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
M. Behbahani ◽  
M.R. Alavi Moghaddam ◽  
M. Arami
Keyword(s):  
Reaction Time ◽  
Anode Material ◽  
Removal Efficiency ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Operational Parameters ◽  
Applied Current ◽  
Initial Ph ◽  
Electrocoagulation Process ◽  
Electrode Connection

The aim of this study is to examine the effect of operational parameters on fluoride removal using electrocoagulation method. For this purpose, various operational parameters including initial pH, initial fluoride concentration, applied current, reaction time, electrode connection mode, anode material, electrolyte salt, electrolyte concentration, number of electrodes and interelectrode distance were investigated. The highest defluoridation efficiency achieved at initial pH 6. In the case of initial fluoride concentration, maximum removal efficiency (98.5%) obtained at concentration of 25mg/l. The increase of applied current and reaction time improved defluoridation efficiency up to 99%. The difference of fluoride removal efficiencies between monopolar and bipolar series and monopolar parallel were significant, especially at reaction time of 5 min. When aluminum used as anode material, higher removal efficiency (98.5%) achieved compared to that of iron anode (67.7%). The best electrolyte salt was NaCl with the maximum defluoridation efficiency of 98.5% compared to KNO3 and Na2SO4. The increase of NaCl had no effect on defluoridation efficiency. Number of electrodes had little effect on the amounts of Al3+ ions released in the solution and as a result defluoridation efficiency. Almost the same fluoride removal efficiency obtained for different interelectrode distances.

scholarly journals Treatment of oilfield wastewater by combined process of micro-electrolysis, Fenton oxidation and coagulation

2017 ◽  
Vol 76 (12) ◽  
pp. 3278-3288 ◽  
Author(s):  
Zhenchao Zhang
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Treatment Process ◽  
Cod Removal ◽  
Fenton Oxidation ◽  
Oily Wastewater ◽  
Optimum Conditions ◽  
Combined Process ◽  
Cod Removal Efficiency ◽  
Optimized Conditions

Abstract In this study, a combined process was developed that included micro-electrolysis, Fenton oxidation and coagulation to treat oilfield fracturing wastewater. Micro-electrolysis and Fenton oxidation were applied to reduce chemical oxygen demand (COD) organic load and to enhance organic components gradability, respectively. Orthogonal experiment were employed to investigate the influence factors of micro-electrolysis and Fenton oxidation on COD removal efficiency. For micro-electrolysis, the optimum conditions were: pH, 3; iron-carbon dosage, 50 mg/L; mass ratio of iron-carbon, 2:3; reaction time, 60 min. For Fenton oxidation, a total reaction time of 90 min, a H2O2 dosage of 12 mg/L, with a H2O2/Fe2+ mole ratio of 30, pH of 3 were selected to achieve optimum oxidation. The optimum conditions in coagulation process: pH, cationic polyacrylamide dosage, mixing speed and time is 4.3, 2 mg/L, 150 rpm and 30 s, respectively. In the continuous treatment process under optimized conditions, the COD of oily wastewater fell 56.95%, 46.23%, 30.67%, respectively, from last stage and the total COD removal efficiency reached 83.94% (from 4,314 to 693 mg/L). In the overall treatment process under optimized conditions, the COD of oily wastewater was reduced from 4,314 to 637 mg/L, and the COD removal efficiency reached 85.23%. The contribution of each stage is 68.45% (micro-electrolysis), 24.07% (Fenton oxidation), 7.48% (coagulation), respectively. Micro-electrolysis is the uppermost influencing process on COD removal. Compared with the COD removal efficiency of three processes on raw wastewater under optimized conditions: the COD removal efficiency of single micro-electrolysis, single Fenton oxidation, single coagulation is 58.34%, 44.88% and 39.72%, respectively. Experiments proved the effect of combined process is marvelous and the overall water quality of the final effluent could meet the class III national wastewater discharge standard of petrochemical industry of China (GB8978-1996).

Removal of phenol from steel wastewater by combined electrocoagulation with photo-Fenton

2018 ◽  
Vol 78 (6) ◽  
pp. 1260-1267 ◽  
Author(s):  
Mohammad Malakootian ◽  
Mohammad Reza Heidari
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Current Density ◽  
Steel Industry ◽  
High Efficiency ◽  
Oxygen Demand ◽  
Optimal Conditions ◽  
Suitable Alternative ◽  
Steel Mills ◽  
Real Wastewater

Abstract Phenol and its derivatives are available in various industries such as refineries, coking plants, steel mills, drugs, pesticides, paints, plastics, explosives and herbicides industries. This substance is carcinogenic and highly toxic to humans. The purpose of the study was to investigate the removal of phenol from wastewater of the steel industry using the electrocoagulation–photo-Fenton (EC-PF) process. Phenol and chemical oxygen demand (COD) removal efficiency were investigated using the parameters pH, Fe2+/H2O2, reaction time and current density. The highest removal efficiency rates of phenol and COD were 100 and 98%, respectively, for real wastewater under optimal conditions of pH = 4, current density = 1.5 mA/cm2, Fe2+/H2O2 = 1.5 and reaction time of 25 min. Combination of the two effective methods for the removal of phenol and COD, photocatalytic electrocoagulation photo-Fenton process is a suitable alternative for the removal of organic pollutants in industry wastewater because of the low consumption of chemicals, absence of sludge and other side products, and its high efficiency.

scholarly journals Investigation of metal doped mesoporous TiO2 nanostructures for environmental remediation

2021 ◽  
Author(s):  
Santhi K ◽  
Harish S ◽  
Navaneethan M ◽  
S Ponnusamy
Keyword(s):  
Environmental Remediation ◽  
Surface Composition ◽  
Anatase Phase ◽  
Environmental Application ◽  
Tem Analysis ◽  
Xrd Pattern ◽  
Sn Doping ◽  
Good Crystallinity ◽  
Lower Temperature ◽  
Metal Doped

Abstract In the recent past, metal oxides have attracted the researchers because of their applications in energy and environmental application domains. In the present work, hydrothermal technique used to prepared the Sn doped TiO2 nanoparticles and the effect of Sn concentration has been investigated. The structural, morphological, surface composition, optical and photocatalytic behavior were studied. XRD pattern revealed that doping of Sn makes easy transformation of rutile from anatase phase at lower temperature, providing tetragonal structure of rutile of TiO2. TEM analysis showed the formation of nanoparticles with spherical like morphology with good crystallinity. UV-Vis spectra, it is observed that optical absorption edge gets red shifted upon Sn doping and the band gap is found to be 2.6 eV. The photocatalytic activity of the synthesized nanoparticles has been investigated under visible light irradiation. Experimental results suggested that 0.5 wt % of Sn doped nanoparticles have shown to exhibit improved photocatalytic properties.

scholarly journals Antiviral Effects of Gelatin Stabilized Ferrous Sulfide Nanoparticles

2021 ◽  
Author(s):  
Ting Tong ◽  
Shuangfei Deng ◽  
Xiaotong Zhang ◽  
Liurong Fang ◽  
Jiangong Liang ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Low Cost ◽  
Antiviral Effect ◽  
High Reactivity ◽  
Host Cells ◽  
Antiviral Effects ◽  
Ferrous Sulfide ◽  
Effective Inhibition ◽  
Co Precipitation ◽  
First Time

Abstract Ferrous sulfide nanoparticles (FeS NPs) are widely applied to environmental remediation, catalysis, energy storage and medicine because of their high reactivity, large specific surface area and low cost, arousing great interest of researchers. However, there is no literature reported on its application in the antiviral field. In the study, gelatin stabilized FeS nanoparticles (Gel-FeS NPs) were synthesized by co-precipitation of Fe2+ and S2‒ in the aqueous phase with continuous stirring under anaerobic conditions. The as-prepared Gel-FeS NPs were good stabilization and dispersibility with the size distribution of 77.7 ± 16.4 nm, as determined by UV-Vis spectrometer, TEM, FTIR, XRD and XPS. We reported for the first time the virucidic and antiviral activity of Gel-FeS NPs. The Gel-FeS NPs with good dispersibility and biocompatibility were synthesized, and they exhibited effective inhibition on the proliferation of PRRSV by blocking the PRRSV outside the host cells. Moreover, the Fe2+ from degraded ferrous sulfide still displayed an antiviral effect, demonstrating the advantage as an antiviral nanomaterial of Gel-FeS NPs compared to other nanomaterials. This work highlighted the antiviral effect of Gel-FeS NPs, broaden the applications of iron-based nanoparticles for combating the virus.

Interfacial reactions between impurities and slag onset of Si purification by slag addition

2021 ◽  
Vol 119 (1) ◽  
pp. 101
Author(s):  
Yaqiong Li ◽  
Yunlong Yu ◽  
Lifeng Zhang ◽  
Zhengtao Li
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Interfacial Reactions ◽  
Refining Process ◽  
Short Reaction Time ◽  
Impurity Removal ◽  
Slag Refining ◽  
Al Distribution ◽  
Distribution Behavior

The interfacial reactions between impurities (Al and Ti) and slag onset of Si purification by 51 mol% SiO2–34 mol% CaO–15 mol% MgO slag addition were studied to enhance impurity removal efficiency from Si. The Al distribution behavior at the Si/Slag interface was investigated; a short reaction time (10 s) resulted in the formation of successive SiO2–CaO–MgO–Al2O3 layers in the slag with a thickness of 10 µm; increasing the reaction time (60 s) resulted in the entire ternary slag being changed into SiO2–CaO–MgO–Al2O3 quaternary slag due to the diffusion of Al2O3. It was shown that the highest impurity removal rate of Al could be achieved at the onset of the slag refining process. Based on the Ti distribution at the Si/slag interface, the slag refinement with 51 mol% SiO2–34 mol% CaO–15 mol% MgO had no effect on Ti removal.

scholarly journals Facile construction of Fe, N and P co-doped carbon spheres by carbothermal strategy for the adsorption and reduction of U(vi)

RSC Advances ◽  
2020 ◽  
Vol 10 (57) ◽  
pp. 34859-34868
Author(s):  
Zhimin Dong ◽  
Zhibin Zhang ◽  
Runze Zhou ◽  
Yayu Dong ◽  
Yuanyuan Wei ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Removal Efficiency ◽  
Environmental Remediation ◽  
Carbon Sphere ◽  
Carbon Spheres ◽  
Practical Applications ◽  
Magnetic Carbon ◽  
Co Doped

The constructed novel magnetic carbon sphere co-doped by N, P, Fe (Fe/P-CN) exhibits high U(vi) removal efficiency, excellent magnetic separation and reusability, evidencing the potential practical applications in environmental remediation.

scholarly journals Unravelling the Environmental Application of Biochar as Low-Cost Biosorbent: A Review

2020 ◽  
Vol 10 (21) ◽  
pp. 7810 ◽  
Author(s):  
Antía Fdez-Sanromán ◽  
Marta Pazos ◽  
Emilio Rosales ◽  
María Angeles Sanromán
Keyword(s):  
Low Cost ◽  
Value Added ◽  
Physicochemical Characteristics ◽  
The Novel ◽  
Key Factors ◽  
Biomass Waste ◽  
Environmental Application ◽  
Adsorption Mechanisms ◽  
Points Of Interest ◽  
Interesting Approach

In this age, a key target for enhancing the competitiveness of the chemical, environmental and biotechnology industries is to manufacture high-value products more efficiently and especially with significantly reduced environmental impact. Under this premise, the conversion of biomass waste to a high-value added product, biochar, is an interesting approach under the circular economy principles. Thus, the improvements in the biochar production and its new and innovative uses are hot points of interest, which are the focus of vast efforts of the scientific community. Biochar has been recognized as a material of great potential, and its use as an adsorbent is becoming a reliable strategy for the removal of pollutants of different streams, according to its high adsorption capacity and potential to eliminate recalcitrant compounds. In this review, a succinct overview of current actions developed to improve the adsorption capability of biochar, mainly of heavy metal and organic pollutants (dyes, pharmaceuticals and personal care products), is summarized and discussed, and the principal adsorption mechanisms are described. The feedstock and the production procedure are revealed as key factors that provide the appropriate physicochemical characteristics for the good performance of biochar as an adsorbent. In addition, the modification of the biochar by the different described approaches proved their feasibility and became a good strategy for the design of selective adsorbents. In the last part of this review, the novel prospects in the regeneration of the biochar are presented in order to achieve a clean technology for alleviating the water pollution challenge.

scholarly journals Microorganism Assisted Synthesized Nanoparticles for Catalytic Applications

Energies ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 190 ◽  
Author(s):  
Xiaojiao Fang ◽  
Yin Wang ◽  
Zegao Wang ◽  
Zaixing Jiang ◽  
Mingdong Dong
Keyword(s):  
Energy Consumption ◽  
Environmental Remediation ◽  
Heterogeneous Catalysts ◽  
Catalytic Efficiency ◽  
High Energy ◽  
Surface Areas ◽  
Novel Approach ◽  
Toxic Agents ◽  
Wide Range ◽  
Catalytic Applications

Metal and metalloid nanoparticles (NPs) have attracted substantial attention from research communities over the past few decades. Traditional methodologies for NP fabrication have also been intensely explored. However, drawbacks such as the use of toxic agents and the high energy consumption involved in chemical and physical processes hinder their further application in various fields. It is well known that some bacteria are capable of binding and concentrating dissolved metal and metalloid ions, thereby detoxifying their environments. Bioinspired fabrication of NPs is environmentally friendly and inexpensive and requires only low energy consumption. Some biosynthesized NPs are usually used as heterogeneous catalysts in environmental remediation and show higher catalytic efficiency because of their enhanced biocompatibility, stability and large specific surface areas. Therefore, bacteria used as nanofactories can provide a novel approach for removing metal or metalloid ions and fabricating materials with unique properties. Even though a wide range of NPs have been biosynthesized, and their synthetic mechanisms have been proposed, some of these mechanisms are not known in detail. This review focuses on the synthesis and catalytic applications of NPs obtained using bacteria. The known mechanisms of bioreduction and prospects in the design of NPs for catalytic applications are also discussed.

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