scholarly journals Fabrication and Evaluation of Bimetallic Materials for Removal of Cr6+

2022 ◽  
Vol 2160 (1) ◽  
pp. 012011
Author(s):  
Tingting Wang ◽  
Zhiyong Han ◽  
Xiaobin Lv

Abstract Adsorption technology is an effective way for removal of heavy metals ions and other organic pollutants in water treatment. In recent years, bimetallic adsorbents with high performance and low cost have attracted more and more attention. In this study, nano zero valent iron was prepared. On this basis, Fe/Cu Bimetallic materials were prepared. The effects of Cu conversion, initial concentration, time, and pH value on Cr6+ removal rate and amount were systematically tested. The results show that under the conditions of initial concentration (50mg/L), time (60min) and pH (3), the Fe/Cu material with copper conversion of 3% has the best effect on the removal of Cr6+ in wastewater. Thus, this study is expected to provide important reference data for the effective removal of Cr6+ in water.

Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 462 ◽  
Author(s):  
Xi Liu ◽  
Xiaofei Liu ◽  
Pinxuan Huang ◽  
Fang Wei ◽  
Guangyao Ying ◽  
...  

Immunoaffinity columns (IACs) are most popularly used for mycotoxin clean-up in complex matrices prior to chromatographic analysis. But, their high cost has limited their wide application and the regeneration of IACs for multiple instances of reuse is important. This study aimed to investigate the feasibility of regeneration and reuse of IACs for purification of ochratoxin A (OTA) in spiked raw malt and dried ginger samples followed by high performance liquid chromatography-fluorescence detection. After each use, the IACs were filled with phosphate buffer saline (PBS) as the preservation solution and stored at 8 °C overnight for regeneration and reuse until the recovery rate was <70%. The results showed that matrix type, preparation procedure, and pH value of sample extraction exhibited major effects on the reuse of IACs for OTA clean-up. While, after modifying the sample preparation procedure using water as the diluent and the solution at a pH of 7 to 8, the IACs could be used eight and three times for the spiked raw malt and dried ginger samples with OTA after regeneration. Regarding the traditional procedure recommended in Chinese Pharmacopoeia (2015 edition), the IACs could be used for three and two times for the spiked raw malt and dried ginger samples with OTA, respectively. Therefore, the corresponding experimental cost could be reduced to one-eighth and one-third of the original cost. This is the first study on the regeneration and reuse of IACs for OTA clean-up in complex Chinese herbal medicines, providing a green and economical tool for a large number of samples analysis with low cost.


2019 ◽  
Vol 6 (7) ◽  
pp. 190351 ◽  
Author(s):  
Shuangxi Zhou ◽  
Zhiling Du ◽  
Xiuwen Li ◽  
Yunhai Zhang ◽  
Yide He ◽  
...  

In this study, natural manganese oxides (MnO x ), an environmental material with high redox potential, were used as a promising low-cost oxidant to degrade the widely used dyestuff methylene blue (MB) in aqueous solution. Although the surface area of MnO x was only 7.17 m 2 g −1 , it performed well in the degradation of MB with a removal percentage of 85.6% at pH 4. It was found that MB was chemically degraded in a low-pH reaction system and the degradation efficiency correlated negatively with the pH value (4–8) and initial concentration of MB (10–50 mg l −1 ), but positively with the dosage of MnO x (1–5 g l −1 ). The degradation of MB fitted well with the second-order kinetics. Mathematical models were also built for the correlation of the kinetic constants with the pH value, the initial concentration of MB and the dosage of MnO x . Furthermore, several transformation products of MB were identified with HPLC-MS, which was linked with the bond energy theory to reveal that the degradation was initiated with demethylation.


2019 ◽  
Vol 15 (No. 1) ◽  
pp. 30-37 ◽  
Author(s):  
Mohib Ullah ◽  
Ruqia Nazir ◽  
Muslim Khan ◽  
Waliullah Khan ◽  
Mohib Shah ◽  
...  

The removal of toxic metals like lead (Pb) and cadmium (Cd) is very urgent keeping their hazardous effects in view. In this work, seeds of Albizia lebbeck and Melia azedarach trees were converted into activated carbon adsorbents and applied for the adsorptive removal of Pb and Cd metals from an aqueous solution. The as prepared adsorbents were characterised by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The removal efficiencies of both metals were strongly dependent on their initial concentration, contact time, pH, temperature and the quantity of adsorbents. 0.2 g of both adsorbents removed respectively 75 and 62% Pb and 77 and 66% Cd from from 100 ml of a 40 mg/l concentrated solution in 120 min at pH 5 and a temperature of 20°C. Both the Freundlich and Langmuir isotherms were well fitted to the experimental data. We believe that this work will provide a convenient way to synthesise low cost activated carbon adsorbents for the remediation of highly toxic metals from wastewater to safeguard our environment for future generations.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0,enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.


2014 ◽  
Vol 955-959 ◽  
pp. 2453-2457
Author(s):  
Hui Yang ◽  
Meng Zhao ◽  
Ji Gang Yang ◽  
Xin Chai ◽  
Yue Xu

This document studies test methods on modification of activated carbon by potassium permanganate to adsorb Cu2+. Ensure all factors’ effects on Cu2+ removal. Use potassium permanganate solution to modify activated carbon, investigate main factors’ effects on Cu2+ removal and analyze mechanism by changing potassium permanganate solution concentration, adsorption time, activated carbon’s additive amount and temperature. The results show that modification of activated carbon by 0.03mol/L potassium permanganate solution (0.03K-GAC) can adsorb Cu2+ best. 0.03K-GAC’s removal rate on Cu2+ is 98% when the initial concentration of Cu2+ is 50mg/L, the additive amount of 0.03K-GAC is 2.0g, the pH value is 5.5, the temperature is 25°C and the adsorption time is 4h. Modification of activated carbon by potassium permanganate has good adsorbability on Cu2+. Potassium permanganate solution concentration, adsorption time and additive amount can influence the adsorption of Cu2+ by activated carbon. However, temperature’s influence on the effect of adsorption is non-significant.


2012 ◽  
Vol 476-478 ◽  
pp. 1926-1929
Author(s):  
Xiao Cai Yu ◽  
Dong Dong Hu ◽  
Qian Du ◽  
Xv Zheng ◽  
Ji Yao Guo

Nanoscale titanium dioxide (TiO2) has been fabricated through a sound sol-gel method at room temperature with Tetra-n-butyl Titanate as the precursor, and the particles are characterized by XRD and TEM techniques. The results manifest that the as-prepared TiO2 is amorphous with the anatase structure and its size is around 33.2nm. Five factors, including dosage of TiO2, initial concentration of diesel, pH value, photocatalytic degradation reaction time and the presence of H2O2, are considered in the diesel degradation experiments. An orthogonal test is carried out to optimize the photocatalytic degradation of diesel pollutants based on the single-factor experiments. It reveals that when the dosage of TiO2 is 1.0g/L, the initial concentration of diesel is 0.5g/L, pH value is 6, the reaction time is 4h and the H2O2 dosage is 0.09%, the removal rate of diesel pollutants can up to 88%. Besides, the influence of each factor on removing diesel can be arranged in decreasing order: initial concentration of diesel> photocatalytic reaction time> pH value> TiO2 dosage> H2O2 dosage.


2012 ◽  
Vol 476-478 ◽  
pp. 2001-2004
Author(s):  
Xiao Cai Yu ◽  
Peng Fei Zhu ◽  
Kui Sheng Song ◽  
Dong Dong Hu ◽  
Qian Du

The Fe3+-doped nano-TiO2 catalyst with various amounts of dopant Fe3+ irons was prepared by a sol-gel method. The products were characterized by XRD and SEM. The photocatalytic degradation of ammonia nitrogen in aquaculture wastewater was investigated by using Fe3+-doped nano-TiO2 under UV irradiation. In the experiment, the effect of Fe3+/TiO2 dosage, the ratio of dopant Fe3+, ammonia-N initial concentration, pH value, H2O2 volume concentration, and reaction time, respectively, on the removal of ammonia-N was investigated. The experimental results can be stated as follows: when the ratio of dopant Fe3+ was 0.25% wt, the dosage of Fe3+/TiO2 was 0.7 g/L, the initial concentration of ammonia-N was 10 mg/L, H2O2 volume fraction was 4 %, respectively, if the reaction time may last 4 h, the removal rate of ammonia-N was expected to reach 97.17 %.


2012 ◽  
Vol 724 ◽  
pp. 472-475
Author(s):  
Xuan Liang ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Qiang Mei

Low cost industrial and agricultural by-products are promising materials for water pollution treatment such as removal of heavy metals. This work deals with removal of silver ions from solutions using expanded rice husk (ERH), nature diatomite (ND) and nature bentonite (NB). Firstly the influence of pH value of the solution on adsorption capacity for silver ions was studied, and then the effect of initial silver concentration on adsorbents adsorption capacity was investigated. The silver ions removal percentage increases with initial pH and achieves a maximum value of nearly 94% at pH= 5.0 ± 0.5 for ERH. The maximum adsorption capacity is 18.6 mg/g for ERH.


2012 ◽  
Vol 209-211 ◽  
pp. 2058-2062
Author(s):  
Yong Bing Huang ◽  
Jing Dong ◽  
Xian Juan Li ◽  
Li Li Wang ◽  
Ye Li ◽  
...  

Ferrum manganese composite materials (1-3μm) had been successfully synthesized by low-cost ferruginous manganese ore in wet granulation to treat the arsenic wastewater effectively. The experiment showed when the cement content was 10%, the amount of saw dust was 5% and roasting temperature was 250°C, the composite materials was able to meet the demand of the particles strength and the removal rates of As(Ⅲ) and As(Ⅴ) were up to 85.25% and 80.13% respectively. The analysis for the materials of adsorption effect factors indicated as pH value increased, the removal rate reduced. The temperature was in an opposite way. Within 0-40min, the adsorption of arsenic became better and better. After 60min, the process basically reached the adsorption equilibrium. In addition, the removal rate also reduced following with the increasing dosing quantity of SO42- and HPO42-. Especially the HPO42- influenced it heavily. Therefore, it was important to control the content of HPO42- for the arsenic removal.


2014 ◽  
Vol 12 (1) ◽  
pp. 477-486 ◽  
Author(s):  
Abbas H. Sulaymon ◽  
Ahmed A. Mohammed ◽  
Tariq J. Al-Musawi

Abstract This study aims to evaluate the ability of abundant low-cost garden grass to remove cadmium and chromium ions from aqueous solutions. Batch biosorption studies were carried out to examine the biosorption capacity, pH value, temperature, agitation speed, and metal ions concentration. The biosorption process revealed that the garden grass was an effective biosorbent of cadmium and chromium. The maximum chromium and cadmium removal rate was 90 and 80% at pH 4, respectively. FTIR spectroscopy analysis showed that the hydroxyl, amine, and carboxyl groups were the major groups responsible for the biosorption process. The maximum biosorption capacity was 18.19 and 19.4 mg/g for cadmium and chromium, respectively. The biosorption isotherm data fitted well the Langmuir model. Kinetic data were adequately fitted by the pseudo-second-order kinetic model.


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