Effects of common dissolved anions on the reduction of para-chloronitrobenzene by zero-valent iron in groundwater

2011 ◽  
Vol 63 (7) ◽  
pp. 1485-1490 ◽  
Author(s):  
C. Le ◽  
J. H. Wu ◽  
S. B. Deng ◽  
P. Li ◽  
X. D. Wang ◽  
...  
Keyword(s):  
Humic Acid ◽  
Groundwater Remediation ◽  
Reduction Rate ◽  
Zero Valent Iron ◽  
Iron Surface ◽  
Contaminated Groundwater ◽  
Carbonate Complex ◽  
Ion Concentrations ◽  
Batch Tests ◽  
Inner Sphere Complexes

Batch tests were conducted to evaluate the influences of several common dissolved anions in groundwater on the reduction of para-chloronitrobenzene (p-CNB) by zero-valent iron (ZVI). The results showed that p-CNB reduction was enhanced by both Cl− and SO42−. HCO3− could either improve or inhibit p-CNB reduction, depending on whether the mixing speed was intense enough to rapidly eliminate Fe–carbonate complex deposited on ZVI surface. Above a concentration of 100 mg L−1, NO3− increased the p-CNB reduction rate. The reduction rate by ClO4− decreased because the ClO4− competed with p-CNB for electrons. The p-CNB reduction was inhibited by PO43−, SiO32− and humic acid, in the order humic acid < PO43− < SiO32−, since these ions could form inner-sphere complexes on iron surface. The reaction even ceased when the ion concentrations were greater than 4, 0.5, and 30 mg L−1, respectively. The results indicated that common dissolved anions in groundwater should be taken into account when ZVI is applied for contaminated groundwater remediation.

scholarly journals Review on remediation of contaminated groundwater by Fe0-PRB technology

2021 ◽  
Vol 237 ◽  
pp. 01019
Author(s):  
Xiaohui Zhang ◽  
Xiaodong Wang ◽  
Xianfeng Sun
Keyword(s):  
Groundwater Remediation ◽  
Preparation Method ◽  
Zero Valent Iron ◽  
Contaminated Groundwater ◽  
Pilot Test ◽  
Application Technology ◽  
Remediation Technology ◽  
Test Stage ◽  
Working Principle ◽  
At Home

PRB technology is a new groundwater remediation technology, which is currently in the pilot test stage in China. Zero-valent iron is one of the most commonly used fillers in permeable reaction walls. In this paper, the principle and structure of PRB technology, the working principle of zero-valent iron in PRB, the preparation method and the optimization and improvement of application technology, the application examples at home and abroad and the prospect of PRB technology are introduced.

scholarly journals Improved Affinity of Nanoscale Zero Valent Iron toward Hydrophobic Organic Solvent using Poly(1-vinylpyrrolidone-co-vinyl acetate)

2020 ◽  
Vol 42 (9) ◽  
pp. 431-441
Author(s):  
Jeongmin Hong ◽  
Hayeon Yang ◽  
Taeyeon Cha ◽  
Younggyo Seo ◽  
Yuhoon Hwang
Keyword(s):  
Particle Size ◽  
Porous Media ◽  
Vinyl Acetate ◽  
Soil Remediation ◽  
Organic Contaminants ◽  
Nitrate Reduction ◽  
Groundwater Remediation ◽  
Reduction Rate ◽  
Zero Valent Iron ◽  
Nanoscale Zero Valent Iron

Objectives : Levels of organic contaminants in excess of the standard minimum have been detected in many commercial and residential sites, and the severity of soil and groundwater pollution is increasing. In particular, non-aqueous phase liquids (NAPLs) are hydrophobic organic pollutants that do not mix with water and are difficult to remove with existing soil remediation technology. These pollutants slowly dissolve into the groundwater over long periods of time, thus contaminating the groundwater. With the increasing need to remove NAPLs for soil and groundwater remediation, widespread interest has focused on the use of nanoscale zero valent iron (nZVI). However, nZVI has the disadvantage of reduced subsurface mobility. Hence, in the present study, the nZVI surface is modified with poly(1-vinylpyrrolidone-co-vinyl acetate) (PVP/VA), which has both hydrophilic and hydrophobic groups, to improve the mobility and selectivity of nZVI for the removal of NAPL.Methods : The PVP/VA modified nZVI is synthesized through the reaction of FeSO4･7H2O and NaBH4 in the presence of PVP/VA. To confirm the dispersibility of the prepared material, a precipitation experiment is performed using a visible light spectrometer, and the mobility through a sand-filled column is evaluated. In addition, the variation in particle size and characteristics according to the presence of PVP/VA is examined via transmission electron microscopy. The nitrate reduction ability of nZVI with PVP/VA is also evaluated to reveal changes in reactivity depending upon the degree of dispersion. To confirm the selective mobility towards NAPL, trichloroethylene and dodecane are used to evaluate the mobility with and without PVP/VA. Finally, the ratio of nZVI passing through the sponge layer absorbing dodecane is evaluated to determine the selective mobility towards NAPL in the porous medium.Results and Discussion : Although the dispersibility of the PVP/VA-nZVI is not significantly changed, the particle size is significantly decreased. Both the mobility in porous media and the nitrate reduction rate are improved via PVP/VA modification. The affinity for hydrophobic contaminants and the selective migration of PVP/VA-nZVI towards the NAPL layer are also improved. The high affinity for the NAPL was also shown by the column with NAPL layer.Conclusions : Surface-modification with PVP/VA, which has both hydrophilic and hydrophobic ends, enabled the synthesis of nZVI with a smaller and more uniform particle size, thus providing high mobility in porous media and high reactivity towards contaminants. The combined hydrophilicity and hydrophobicity of PVP/VA is shown to increase the affinity of nZVI towards NAPL and, thus, promote its migration to the NAPL layer. Thus, it is anticipated that the efficiency of soil remediation can be improved by promoting the movement of nZVI towards the target NAPL layer.

scholarly journals Zero-Valent Iron Nanoparticles for Soil and Groundwater Remediation

2020 ◽  
Vol 17 (16) ◽  
pp. 5817
Author(s):  
Alazne Galdames ◽  
Leire Ruiz-Rubio ◽  
Maider Orueta ◽  
Miguel Sánchez-Arzalluz ◽  
José Luis Vilas-Vilela
Keyword(s):  
Contaminated Soils ◽  
Groundwater Remediation ◽  
Iron Nanoparticles ◽  
Environmental Issues ◽  
High Specific Surface Area ◽  
Zero Valent Iron ◽  
Pilot Studies ◽  
High Effectiveness ◽  
Nanosized Materials ◽  
Zero Valent Iron Nanoparticles

Zero-valent iron has been reported as a successful remediation agent for environmental issues, being extensively used in soil and groundwater remediation. The use of zero-valent nanoparticles have been arisen as a highly effective method due to the high specific surface area of zero-valent nanoparticles. Then, the development of nanosized materials in general, and the improvement of the properties of the nano-iron in particular, has facilitated their application in remediation technologies. As the result, highly efficient and versatile nanomaterials have been obtained. Among the possible nanoparticle systems, the reactivity and availability of zero-valent iron nanoparticles (NZVI) have achieved very interesting and promising results make them particularly attractive for the remediation of subsurface contaminants. In fact, a large number of laboratory and pilot studies have reported the high effectiveness of these NZVI-based technologies for the remediation of groundwater and contaminated soils. Although the results are often based on a limited contaminant target, there is a large gap between the amount of contaminants tested with NZVI at the laboratory level and those remediated at the pilot and field level. In this review, the main zero-valent iron nanoparticles and their remediation capacity are summarized, in addition to the pilot and land scale studies reported until date for each kind of nanomaterials.

Zero‐Valent Iron (ZVI) for Groundwater Remediation

2021 ◽  
pp. 282-309
Author(s):  
Naresh K. Sethy ◽  
Zeenat Arif ◽  
K.S. Sista ◽  
Pradeep Kumar ◽  
P.K. Mishra ◽  
...  
Keyword(s):  
Groundwater Remediation ◽  
Zero Valent Iron

Effects of Natural Organic Matter on TCE Removal in Groundwater by Zero-Valent Iron: Batch Study

2013 ◽  
Vol 807-809 ◽  
pp. 486-489
Author(s):  
Tong Zhou Liu ◽  
Pin Hua Rao
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Early Stage ◽  
Organic Contaminant ◽  
Zero Valent Iron ◽  
Contaminant Removal ◽  
Inhibitory Effects ◽  
Batch Study

An investigation on the effects of humic acid (representing NOM) on TCE (a typical organic contaminant) removal by Fe0in batch settings was carried out. Inhibitory effects of humic acid on Fe0towards TCE removal were observed. At early stage of the experiments, humic acid might partition with TCE, and the adsorption or deposition of humic acid onto Fe0surface would further facilitated TCE immobilization. Once the reduction reactive sites on Fe0surfaces were covered by accumulated humic acid and the partition of TCE to humic acid became saturated, TCE removal in Fe0was observed retarded.

Combining physical containment with optimal withdrawal for contaminated groundwater remediation

1987 ◽  
Vol 10 (4) ◽  
pp. 200-204 ◽  
Author(s):  
David P. Ahlfeld ◽  
John M. Mulvey ◽  
George F. Pinder
Keyword(s):  
Groundwater Remediation ◽  
Contaminated Groundwater

Remediation of MTBE-contaminated groundwater by integrated circulation wells and advanced oxidation technologies

2017 ◽  
Vol 18 (2) ◽  
pp. 399-407 ◽  
Author(s):  
Bassam Tawabini ◽  
Mohammed Makkawi
Keyword(s):  
Groundwater Remediation ◽  
Treatment Time ◽  
Shallow Groundwater ◽  
Advanced Oxidation ◽  
Shallow Aquifer ◽  
Contaminated Groundwater ◽  
Butyl Ether ◽  
Tertiary Butyl ◽  
Industrial Facilities ◽  
Environmental Threats

Abstract The proximity of shallow groundwater systems to sources of contamination usually exposes them to severe environmental threats. Hazardous pollutants that leak from gas stations, landfills, and industrial facilities may eventually reach the underneath shallow groundwater aquifers, posing risks to human health and the environment. Cleaning contaminated groundwater sources has always been a challenge to the local authorities. This is even more challenging when dealing with difficult pollutants such as methyl tertiary butyl ether (MTBE) due its high solubility in water, poor biodegradability, and poor adsorption onto solids. This study aims to assess the efficiency of a pilot groundwater remediation system to treat a shallow aquifer contaminated with MTBE. The in-house designed and fabricated pilot system combines the technology of circulation wells and UV-based advanced oxidation technology for the breakdown and removal of MTBE from water. An ultraviolet/hydrogen peroxide (UV/H2O2) process was used in this study to remove MTBE from water. The concentration of MTBE was reduced from approximately 1,400 μg/L to as low as 34 μg/L within 30 minutes, with a treatment efficiency of about 98%. The study also assesses the effects of the UV intensity and the treatment time needed to remove the target pollutant.

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