scholarly journals Fenton-Like Oxidation of Antibiotic Ornidazole Using Biochar-Supported Nanoscale Zero-Valent Iron as Heterogeneous Hydrogen Peroxide Activator

2020 ◽  
Vol 17 (4) ◽  
pp. 1324 ◽  
Author(s):  
Yanchang Zhang ◽  
Lin Zhao ◽  
Yongkui Yang ◽  
Peizhe Sun
Keyword(s):  
Oxidation Process ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
Mass Ratio ◽  
Promising Alternative ◽  
Nanoscale Zero Valent Iron ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
H2o2 System

Biochar (BC)-supported nanoscale zero-valent iron (nZVI-BC) was investigated as a heterogeneous Fenton-like activator to degrade the antibiotic ornidazole (ONZ). The characterization of nZVI-BC indicated that BC could enhance the adsorption of ONZ and reduce the aggregation of nZVI. Thus, nZVI-BC had a higher removal efficiency (80.1%) than nZVI and BC. The effects of parameters such as the nZVI/BC mass ratio, pH, H2O2 concentration, nZVI-BC dose, and temperature were systematically investigated, and the removal of ONZ followed a pseudo-second-order kinetic model. Finally, possible pathways of ONZ in the oxidation process were proposed. The removal mechanism included the adsorption of ONZ onto the surface of nZVI-BC, the generation of •OH by the reaction of nZVI with H2O2, and the oxidation of ONZ. Recycling experiments indicated that the nZVI-BC/H2O2 system is a promising alternative for the treatment of wastewater containing ONZ.

Improvement of As(III) removal with diatomite overlay nanoscale zero-valent iron (nZVI-D): adsorption isotherm and adsorption kinetic studies

2016 ◽  
Vol 17 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Nusavadee Pojananukij ◽  
Kitirote Wantala ◽  
Sutasinee Neramittagapong ◽  
Chitsan Lin ◽  
Duangkanok Tanangteerpong ◽  
...  
Keyword(s):  
Adsorption Isotherm ◽  
Kinetic Studies ◽  
Second Order ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
Kinetic Adsorption ◽  
Nanoscale Zero Valent Iron ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Nanoscale zero-valent iron coated on diatomite (nZVI-D) was successfully synthesized as a composite material. It is the combination of nZVI and diatomite which has been proved to be a promising material in arsenite or As(III) removal. The result showed that 25.5% of As(III) was removed using diatomite only but more than 95% of As(III) was removed using nZVI-D, at the same contact time of 60 min and pH 6. The experimental isotherm data for As(III) adsorption at different initial concentrations were analyzed using the Langmuir, Freundlich, and Dubinin–Radushkevich equations. Among these three, the equilibrium data fitted well with the Langmuir isotherm. The kinetic adsorption was also studied using the pseudo-first, second-order, and intraparticle diffusion equations. The data were well explained by the pseudo-second-order kinetic model. From the results of kinetic adsorption and the adsorption isotherm, it can be concluded that arsenite adsorption was controlled by the mass transfer and adsorption process.

Performance of Nano Zero-Valent Iron Derived from the Decomposition of Siderite in the Removal of Phosphate

2021 ◽  
Vol 21 (1) ◽  
pp. 623-631
Author(s):  
Yueling Zhao ◽  
Haibo Liu ◽  
Tianhu Chen ◽  
Dong Chen ◽  
Chen Chen ◽  
...  
Keyword(s):  
Orthogonal Experiment ◽  
Zero Valent Iron ◽  
Raw Material ◽  
Order Kinetic ◽  
Experimental Conditions ◽  
P Concentration ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Nano Zero Valent Iron

Natural siderite was selected as a raw material for preparing nano zero-valent iron (nZVI). The efficiency of the as-synthesized nZVI for PO3−4–P removal was investigated, and the effects of the annealing temperature, pH, initial PO3−4–P concentration, adsorption temperature and oxygen were investigated. The results indicated that after annealing at 550 °C, nZVI exhibited an average crystal size of 56.3 nm and a surface area of 14.1 m2/g. A decrease in pH and an increase in oxygen availability enhanced the removal efficiency. The adsorption process, which was spontaneous and exothermic according to the thermodynamic analysis, agreed well with the pseudo-second-order kinetic model. Based on the Langmuir equilibrium isotherms, the capacity of nZVI to adsorb phosphorus was determined to be 33.18 mg/L. The optimized conditions for the experimental conditions were defined by an orthogonal experiment as follows: initial P concentration 2 mg/L, initial pH 4, iron dose 2 g/L, adsorption time 60 min. The experimental results suggested that the as-prepared nZVI was a promising adsorbent for the removal of phosphate.

Characterization of natural- and organobentonite by XRD, SEM, FT-IR and thermal analysis techniques and its adsorption behaviour in aqueous solutions

Clay Minerals ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 31-44 ◽  
Author(s):  
G. A. Ikhtiyarova ◽  
A. S. Özcan ◽  
Ö. Gök ◽  
A. Özcan
Keyword(s):  
Surface Area ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Textile Dye ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Thermal Analysis Techniques

AbstractIn this study, natural bentonite was modified with hexadecyltrimethylammonium (HDTMA) bromide to obtain organobentonite (HDTMA-bentonite). Bentonite and HDTMA-bentonite were then characterized using XRD, XRF, SEM, FT-IR, thermogravimetric (TG) analysis, elemental analysis and Brunauer-Emmett-Teller (BET) surface area techniques. The HDTMA+ cation was found to be located on the surface and enters the interlayer spaces of smectite according to the XRD and SEM results. FT-IR spectra indicated the existence of HDTMA functional groups on the bentonite surface. The BET surface area significantly decreased after the modification due to the coverage of the pores of natural bentonite. After the characterization, the adsorption of a textile dye, Reactive Blue 19 (RB19), onto bentonite and HDTMA-bentonite was investigated. The maximum adsorption capacity of HDTMA-bentonite for RB19 was 502 mg g-1 at 20°C. The adsorption process followed a pseudo-second-order kinetic model and it was exothermic and physical in nature.

Characterization of Durian Seed Starch/PVOH Composite Hydrogel as a Potential Adsorbent for Removal of Hazardous Dyes

2014 ◽  
Vol 931-932 ◽  
pp. 286-290 ◽  
Author(s):  
W. Pimpa ◽  
C. Pimpa
Keyword(s):  
Adsorption Capacity ◽  
Synthetic Dyes ◽  
Order Kinetic ◽  
Solution Ph ◽  
Environment Friendly ◽  
Composite Hydrogels ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Durian Seed

The intention of this study was to prepare the environment friendly durian seed starch/polyvinyl alcohol (DSS/PVOH) composite hydrogels modified by chemical cross-linking with glutaraldehyde and to assess the adsorption potential of the DSS/PVOH composite hydrogels for the removal of the synthetic dyes from aqueous solution. The hydrogels were characterized by swelling behavior and scanning electron microscope (SEM). The effect of DSS content and initial dye solution pH on the adsorption capacity was studied conducting batch experiment system. The DSS/PVOH composite hydrogels consisting 3% DSS has optimum adsorption capacity of 3.411 mg/g (for methylene blue under the condition of pH 7) and 3.274 mg/g (for acid orange 8 under the condition of pH 2.5) at 24 h of contact time. The adsorptions were well fitted by the pseudo-second order kinetic model. It was indicated that the mechanism of removal predominant is effective for low dye concentrations, below 10 mg/l.

scholarly journals Preparation and Characterization of a Novel Amidoxime-Modified Polyacrylonitrile/Fly Ash Composite Adsorbent and Its Application to Metal Wastewater Treatment

2022 ◽  
Vol 19 (2) ◽  
pp. 856
Author(s):  
Yan Sun ◽  
Xiaojun Song ◽  
Jing Ma ◽  
Haochen Yu ◽  
Gangjun Liu ◽  
...  
Keyword(s):  
Fly Ash ◽  
Adsorption Process ◽  
Single Layer ◽  
Nitrogen Adsorption ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
High Degree

The polyacrylonitrile/fly ash composite was synthesized through solution polymerization and was modified with NH2OH·HCl. The amidoxime-modified polyacrylonitrile/fly ash composite demonstrated excellent adsorption capacity for Zn2+ in an aqueous medium. Fourier transform-Infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption, X-ray diffraction, and scanning electron microscopy were used to characterize the prepared materials. The results showed that the resulting amidoxime-modified polyacrylonitrile/fly ash composite was able to effectively remove Zn2+ at pH 4–6. Adsorption of Zn2+ was hindered by the coexisting cations. The adsorption kinetics of Zn2+ by Zn2+ followed the pseudo-second order kinetic model. The adsorption process also satisfactorily fit the Langmuir model, and the adsorption process was mainly single layer. The Gibbs free energy ΔG0, ΔH0, and ΔS0 were negative, indicating the adsorption was a spontaneous, exothermic, and high degree of order in solution system.

scholarly journals Effect of structural differences of pumice on synthesis of pumice-supported nFe0: removal of Cr (VI) from water

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Bilsen Tural ◽  
Erdal Ertaş ◽  
Mehmet Güzel ◽  
Servet Tural
Keyword(s):  
Iron Content ◽  
Second Order ◽  
Zero Valent Iron ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Support Material ◽  
Solution Ph ◽  
Nanoscale Zero Valent Iron ◽  
Pseudo Second Order

AbstractIn this study, pumice from different regions of Turkey (Diyarbakir, Southeast Turkey and Bitlis, East Turkey) has been supplied and used as supporting material for nanoscale zero-valent iron (nFe0). Native Bitlis pumice (NBP)-supported nanoscale zero-valent iron (BP-nFe0) and native Diyarbakir pumice (NDP)-supported nanoscale zero-value iron (DP-nFe0) were synthesized under the same conditions. Native pumice (NDP, NBP) and pumice-supported nFe0 (DP-nFe0 and BP-nFe0) adsorbents were morphologically and structurally characterized by SEM, EDX, XRF and BET. When using NBP as support material, the iron content of the BP-nFe0 increased 1.9-fold from 1.99 to 3.83%. However, iron content of NDP (2.08%) increased approximately 29 times after it is used as a support material in synthesis of DP-nFe0 (60%). The removal potential of native pumice (NBP and NDP) and iron-modified pumice (BP-nFe0 and DP-nFe0) samples was investigated to remove Cr(VI) ions. The parameters of solution pH, initial metal concentration, contact time and the amount of adsorbent in the removal of chromium (VI) ions were investigated. Langmuir, Freundlich, Temkin, Dubinin–Radushkevich and Jovanovic isotherm models were used to evaluate the adsorption equilibrium data. The equilibrium adsorption was found so as to be well described by the Langmuir isotherm model for all the adsorbents studied. The maximum adsorption capacity of Cr(VI) ions for NDP, NBP, DP-nFe0 and BP-nFe0 was 10.82, 14.30, 161.29 and 17.39 mg/g, respectively. The rate of Cr(VI) removal was subjected to kinetic analysis using pseudo-first-order, pseudo-second-order, intraparticle diffusion and Elovich models. Kinetic studies suggest that adsorption of NDP, NBP, DP-nFe0 and BP-nFe0 described more favorably by the pseudo-second-order kinetic model. The results showed that NDP is a much better support material for nFe0 when compared to NBP.

scholarly journals REMOVAL OF TETRACYCLINE FROM AQUEOUS SOLUTIONS USING NANOSCALE ZERO VALENT IRON AND FUNCTIONAL PUMICE MODIFIED NANOSCALE ZERO VALENT IRON

2017 ◽  
Vol 25 (3) ◽  
pp. 223-233 ◽  
Author(s):  
Ulker Asli GULER
Keyword(s):  
Aqueous Solutions ◽  
Reduction Process ◽  
Zero Valent Iron ◽  
Maximum Adsorption Capacity ◽  
Mass Ratio ◽  
Order Model ◽  
First Order ◽  
Nanoscale Zero Valent Iron ◽  
Equilibrium Data ◽  
Pseudo Second Order

Nanoscale zero valent iron (nzvi) and functional pumice modified nanoscale zero valent iron (P-nzvi) were successfully synthesized and used for the removal of tetracycline (TC). These materials were characterized by SEM, TEM, XRD, FTIR, BET. Different factors such as the mass ratio, dosage of adsorbent, ph, initial TC concentration and temperature were investigated. Based on these results; a possible removal mechanism was proposed including TC adsorption and TC reduction via oxidation of Fe0 to Fe3+. In addition, isotherm and thermodynamic parameters were applied to the equilibrium data. The maximum adsorption capacity of TC by nzvi and P-nzvi was 105.46 mg/g and 115.13 mg/g, respectively. Adsorption and reduction kinetics were examined for the TC removal process. The pseudo-second-order model and pseudo-first-order model was observed for adsorption and reduction process, respectively. Finally, more than 90% of TC from aqueous solutions was removed by nzvi and P-nzvi.

A novel magnetic biochar from sewage sludge: synthesis and its application for the removal of malachite green from wastewater

2016 ◽  
Vol 74 (8) ◽  
pp. 1971-1979 ◽  
Author(s):  
Jing Zhang ◽  
Mao Liu ◽  
Tao Yang ◽  
Kai Yang ◽  
Hongyu Wang
Keyword(s):  
Sewage Sludge ◽  
Malachite Green ◽  
Strontium Hexaferrite ◽  
Order Kinetic ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Magnetic Biochar ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this study, a novel magnetic sludge biochar (MSBC) from sewage sludge was created by the assembly of strontium hexaferrite (SrFe12O19) onto the surface of sewage sludge biochar (SBC) under high-temperature and oxygen-free conditions. The characterization of MSBC was achieved by Fourier transform infrared spectroscopy, X-ray diffraction and vibrating sample magnetometry, and the adsorption properties of the MSBC towards malachite green (MG) from aqueous solution were systematically investigated. The influence of variables (different mass ratio of SBC and SrFe12O19, initial MG concentration, absorbent dosage, pH and contact time) was also studied in detail. The optimal adsorption amount of MG (388.65 mg MG/g) was obtained with 500 mg MG/L, 2.0 g MSBC/L for 40 min under pH of 7.0, with different mass ratios of SBC and SrFe12O19 (1:4, 1:2, 3:4 and 1:1), when the mass ratio of SBC and SrFe12O19 was 3:4 at room temperature, and the Langmuir model was more suitable than the Freundlich model for equilibrium data. Meanwhile, the kinetic models showed that the overall adsorption process was better described by a pseudo-second-order kinetic model. The results indicated that the MSBC was a novel, efficient, magnetically separable adsorbent for the removal of the dye from wastewater.

scholarly journals Conversion of coconut waste into cost effective adsorbent for Cu(II) and Ni(II) removal from aqueous solutions

2020 ◽  
Vol 26 (4) ◽  
pp. 200250-0
Author(s):  
Abdul Rahman Abdul Rahim ◽  
Iswarya ◽  
Khairiraihanna Johari ◽  
Nasir Shehzad ◽  
Norasikin Saman ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Process ◽  
Agricultural Waste ◽  
Physicochemical Characterization ◽  
Cost Effective ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption

Desiccated coconut waste (DCW) is an agricultural waste that originates from the coconut milk processing industry. In this study, it was utilized for the removal of copper (Cu(II)) and nickel (Ni(II)) via adsorption process. The physicochemical characterization of the DCW adsorbent shows that the adsorbent have a surface area of 6.63 m<sup>2</sup>/g, have high elemental carbon content and existences of important functional groups on its surface. The adsorptive capability of DCW adsorbent in removing the heavy metal were conducted in batch studies. DCW adsorbent performed highest Ni(II) and Cu(II) adsorption capacity at pH 6, where equilibrium is achieved at 450 minutes. The kinetic analysis showed the adsorption agreed with pseudo-second order kinetic model, indicating the Cu(II) and Ni(II) adsorption were a chemical adsorption, limited by the film diffusion. The DCW adsorbent still retained its effective adsorption capacity after 2 adsorption-desorption cycles, which is one of the excellent criteria of a good adsorbent for an adsorption process.

scholarly journals Efficient removal of tetracycline with KOH-activated graphene from aqueous solution

2017 ◽  
Vol 4 (11) ◽  
pp. 170731 ◽  
Author(s):  
Jie Ma ◽  
Yiran Sun ◽  
Fei Yu
Keyword(s):  
Ionic Strength ◽  
High Specific Surface Area ◽  
Order Kinetic ◽  
Liquid Ratio ◽  
Promising Alternative ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Solid Liquid ◽  
Coexisting Ions

Activated graphene absorbents with high specific surface area (SSA) were prepared by an easy KOH-activated method, and were applied in absorbing antibiotics, such as tetracycline (TC). After activation, many micropores were introduced to graphene oxide sheets, leading to higher SSA and many new oxygen-containing functional groups, which gave KOH-activated graphene excellent adsorption capacity (approx. 532.59 mg g −1 ) of TC. Further study on the adsorption mechanism showed that the Langmuir isotherm model and the pseudo-second-order kinetic model fitted with experiment data. To further understand the adsorption process, the effects of solid–liquid ratio, pH, ionic strength and coexisting ions were also investigated. The results revealed that, compared with pH and ionic strength, solid–liquid ratio and coexisting ions (Cu 2+ , CrO 4 2− ) had more significant influence over the adsorption performance. The findings provide guidance for application of KOH-activated graphene as a promising alternative adsorbent for antibiotics removal from aqueous solutions.

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