scholarly journals Response surface methodological approach for optimizing removal of ciprofloxacin from aqueous solution using thermally activated persulfate/aeration systems

2017 ◽  
Vol 19 (3) ◽  
pp. 389-395 ◽  
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Methodological Approach ◽  
Persulfate Oxidation ◽  
Thermally Activated ◽  
Initial Ph ◽  
Ph Range ◽  
Optimized Conditions ◽  
Mn3o4 Nanoparticles ◽  
Activated Persulfate

Being used in large quantities for some decades, antibiotics have been of little notice since their existence in the environment. Present study aims at investigating the optimization of Ciprofloxacin removal (CIP) in Thermally Activated Persulfate (TAP)/Aeration systems by Central Composite Design (CCD). The effect of operating parameters including initial pH, CIP concentration, Persulfate concentration and temperature on the removal process was investigated in order to find out the optimum conditions. Typically, high temperature, high Persulfate dose, and low initial CIP concentration increased the removal efficiency of CIP. At the tested pH range of 3–11, the highest removal occurred at pH 3.93. Finally, the effects of Mn3O4 Nanoparticles, N2 gas, and COD reduction in optimal condition were studied. Mn3O4 Nanoparticles and N2 gas in optimized conditions increased the removal efficiency from 93.41 to 90.1, respectively. The results showed that Thermally Activated Persulfate oxidation was the efficient process for the treatment of aqueous solution containing Ciprofloxacin due to the production of Sulfate radicals.

scholarly journals Efficient Sequestration of Hexavalent Chromium by Graphene-Based Nanoscale Zero-Valent Iron Composite Coupled with Ultrasonic Pretreatment

2021 ◽  
Vol 18 (11) ◽  
pp. 5921
Author(s):  
Haiyan Song ◽  
Wei Liu ◽  
Fansheng Meng ◽  
Qi Yang ◽  
Niandong Guo
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Inhibitory Effect ◽  
Ultrasonic Cavitation ◽  
Zero Valent Iron ◽  
Ultrasonic Pretreatment ◽  
Nanoscale Zero Valent Iron ◽  
Passivation Layers ◽  
Initial Ph ◽  
Two Phases

Nanoscale zero-valent iron (nZVI) has attracted considerable attention for its potential to sequestrate and immobilize heavy metals such as Cr(VI) from an aqueous solution. However, nZVI can be easily oxidized and agglomerate, which strongly affects the removal efficiency. In this study, graphene-based nZVI (nZVI/rGO) composites coupled with ultrasonic (US) pretreatment were studied to solve the above problems and conduct the experiments of Cr(VI) removal from an aqueous solution. SEM-EDS, BET, XRD, and XPS were performed to analyze the morphology and structures of the composites. The findings showed that the removal efficiency of Cr(VI) in 30 min was increased from 45.84% on nZVI to 78.01% on nZVI/rGO and the removal process performed coupled with ultrasonic pretreatment could greatly shorten the reaction time to 15 min. Influencing factors such as the initial pH, temperature, initial Cr(VI) concentration, and co-existing anions were studied. The results showed that the initial pH was a principal factor. The presence of HPO42−, NO3−, and Cl− had a strong inhibitory effect on this process, while the presence of SO42− promoted the reactivity of nZVI/rGO. Combined with the above results, the process of Cr(VI) removal in US-nZVI/rGO system consisted of two phases: (1) The initial stage is dominated by solution reaction. Cr(VI) was reduced in the solution by Fe2+ caused by ultrasonic cavitation. (2) In the following processes, adsorption, reduction, and coprecipitation coexisted. The addition of rGO enhanced electron transportability weakened the influence of passivation layers and improved the dispersion of nZVI particles. Ultrasonic cavitation caused pores and corrosion at the passivation layers and fresh Fe0 core was exposed, which improved the reactivity of the composites.

Degradation of carbon tetrachloride in aqueous solution in the thermally activated persulfate system

2015 ◽  
Vol 286 ◽  
pp. 7-14 ◽  
Author(s):  
Minhui Xu ◽  
Xiaogang Gu ◽  
Shuguang Lu ◽  
Zhaofu Qiu ◽  
Qian Sui ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Carbon Tetrachloride ◽  
Thermally Activated ◽  
Activated Persulfate

scholarly journals Oxidative Degradation of Amoxicillin in Aqueous Solution by Thermally Activated Persulfate

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Juanjuan Zhao ◽  
Yujiao Sun ◽  
Fachao Wu ◽  
Minjian Shi ◽  
Xurui Liu
Keyword(s):  
Aqueous Solution ◽  
Reaction Temperature ◽  
Oxidative Degradation ◽  
Water Remediation ◽  
Order Kinetic ◽  
Production Chain ◽  
First Order ◽  
Thermally Activated ◽  
Pseudo First Order ◽  
Activated Persulfate

Antibiotic residues and antibiotic resistance genes (ARGs) pose a great threat to public health and food security via the horizontal transfer in the food production chain. Oxidative degradation of amoxicillin (AMO) in aqueous solution by thermally activated persulfate (TAP) was investigated. The AMO degradation followed a pseudo-first-order kinetic model at all tested conditions. The pseudo-first-order rate constants of AMO degradation well-fitted the Arrhenius equation when the reaction temperature ranged from 35°C to 60°C, with the apparent activate energy of 126.9 kJ·mol−1. High reaction temperature, high initial persulfate concentration, low pH, high Cl− concentration, and humic acid (HA) concentration increased the AMO degradation efficiency. The EPR test demonstrated that both ·OH and SO4·− were generated in the TAP system, and the radical scavenging test identified that the predominant reactive radical species were SO4·− in aqueous solution without adjusting the solution pH. In groundwater and drinking water, AMO degradation suggested that TAP could be a reliable technology for water remediation contaminated by AMO in practice.

Thermally activated persulfate oxidation of NAPL chlorinated organic compounds: effect of soil composition on oxidant demand in different soil-persulfate systems

2017 ◽  
Vol 75 (8) ◽  
pp. 1794-1803 ◽  
Author(s):  
Jialu Liu ◽  
Zhehua Liu ◽  
Fengjun Zhang ◽  
Xiaosi Su ◽  
Cong Lyu
Keyword(s):  
Organic Compounds ◽  
Mineral Content ◽  
Removal Rate ◽  
Soil Types ◽  
Soil Composition ◽  
Persulfate Oxidation ◽  
Chlorinated Volatile Organic Compounds ◽  
Thermally Activated ◽  
Soil Components ◽  
Activated Persulfate

This study investigates the interaction of persulfate with soil components and chlorinated volatile organic compounds (CVOCs), using thermally activated persulfate oxidation in three soil types: high sand content; high clay content; and paddy field soil. The effect of soil composition on the available oxidant demand and CVOC removal rate was evaluated. Results suggest that the treatment efficiency of CVOCs in soil can be ranked as follows: cis-1,2-dichloroethene > trichloroethylene > 1,2-dichloroethane > 1,1,1-trichloroethane. The reactions of soil components with persulfate, shown by the reduction in soil phase natural organics and mineral content, occurred in parallel with persulfate oxidation of CVOCs. Natural oxidant demand from the reaction of soil components with persulfate exerted a large relative contribution to the total oxidant demand. The main influencing factor in oxidant demand in paddy-soil-persulfate systems was natural organics, rather than mineral content as seen with sand and clay soil types exposed to the persulfate system. The competition between CVOCs and soil components for oxidation by persulfate indicates that soil composition exhibits a considerable influence on the available oxidant demand and CVOC removal efficiency. Therefore, soil composition of natural organics and mineral content is a critical factor in estimating the oxidation efficiency of in-situ remediation systems.

Destruction of EDTA by Bimetallic Al-Fe/O2 Process under Aqueous Room Temperature and Pressure Conditions

2013 ◽  
Vol 800 ◽  
pp. 555-559
Author(s):  
Xin Liu ◽  
Jin Hong Fan ◽  
Lu Ming Ma
Keyword(s):  
Aqueous Solution ◽  
Benzoic Acid ◽  
Removal Efficiency ◽  
Room Temperature ◽  
Ethylenediaminetetraacetic Acid ◽  
Oxidative Degradation ◽  
Hydroxybenzoic Acid ◽  
Mass Ratio ◽  
Initial Ph ◽  
Temperature And Pressure

Oxidative degradation of ethylenediaminetetraacetic acid (EDTA) in aqueous solution at room temperature and pressure by the bimetallic Al-Fe/O2 process, which was verified by the addition of benzoic acid as ·OH scavenger and the detection of para-hydroxybenzoic acid, was investigated. The results showed that the removal efficiency of EDTA, TOC and TN could be about 98%, 77.5% and 43% respectively after 3h reaction when the initial pH was 5. The effects of initial pH, concentration of EDTA, mass ratio of Al0 and Fe0 and Al-Fe loading were also investigated. Significantly, the bimetallic Al-Fe process exhibited higher reactivity than monometallic Fe0/Al0 process for the degradation of EDTA when the mass ratio of Al0 and Fe0 ranged from 0.11 to 2.97.

scholarly journals Performance Comparison of Fe2+ Activated Persulfate and Electro-Persulfate Process in Acid Blue 25 Removal from Aqueous Solution Operating: Conditions and Reaction Velocity

2020 ◽  
Author(s):  
Zeinab Ghorbani
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Ferrous Sulfate ◽  
Electrochemical Process ◽  
Sodium Persulfate ◽  
Sulfate Concentration ◽  
Reaction Velocity ◽  
Acid Blue 25 ◽  
Acid Blue ◽  
Activated Persulfate

The purpose of this study was to compare the performance of Fe2+ activated persulfate and electro-persulfate process in Acid Blue 25 removal from aqueous solution. For this reason, the effects of different parameters including pH, dye, sodium persulfate and ferrous sulfate concentrations were investigated. The removal efficiency of 92% at the time of 60 min was obtained at pH= 3, dye concentration= 50 mg/L, sodium persulfate concentration= 500 mg/L and Fe (II) sulfate concentration= 100 mg/L for Fe2+ activated persulfate system and the removal efficiency of 95% at pH= 5, dye concentration = 200 mg/L, sodium persulfate concentration = 500 mg/L and ferrous sulfate concentration = 100 mg/L for electro-persulfate system by means of graphite materials as the neutral electrodes. COD removal efficiency in Fe2+ activated persulfate and electro-persulfate in the mentioned conditions were 90% and 89% in 180 minutes, respectively. Moreover, the result of process kinetics showed that using electrochemical process improved the reaction velocity from 0.0016 to 0.0487 mg/L/min. The comparison between these two-process showed that using electrochemical process improved dye removal efficiency by 4 times.

Ultrasound assisted, thermally activated persulfate oxidation of coal tar DNAPLs

2016 ◽  
Vol 318 ◽  
pp. 497-506 ◽  
Author(s):  
Libin Peng ◽  
Li Wang ◽  
Xingting Hu ◽  
Peihui Wu ◽  
Xueqing Wang ◽  
...  
Keyword(s):  
Coal Tar ◽  
Persulfate Oxidation ◽  
Thermally Activated ◽  
Ultrasound Assisted ◽  
Activated Persulfate
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