scholarly journals Degradation of UV Filter Ethyl 4-Aminobenzoate (Et-PABA) Using a UV-Activated Persulfate Oxidation Process

2019 ◽  
Vol 9 (14) ◽  
pp. 2873
Author(s):  
Ruirui Han ◽  
Qiang Wu ◽  
Chihao Lin ◽  
Lingfeng Zhang ◽  
Zhicai Zhai ◽  
...  
Keyword(s):  
Oxidation Process ◽  
Removal Rate ◽  
Inhibitory Effect ◽  
Aminobenzoic Acid ◽  
Degradation Mechanisms ◽  
Broad Application ◽  
Initial Concentration ◽  
Persulfate Oxidation ◽  
Activated Persulfate ◽  
Application Prospects

In this paper, the ultraviolet/persulfate (UV/PDS) combined oxidation process was used to remove the ethyl 4-aminobenzoate (Et-PABA), one of the typical 4-aminobenzoic acid (PABA)-type UV filters. The effects of various factors on the removal of Et-PABA using the UV/PDS process were investigated, and the degradation mechanisms of Et-PABA were explored. The results showed that the UV/PDS process can effectively remove 98.7% of Et-PABA within 30 min under the conditions: UV intensity of 0.92 mW·cm−2, an initial concentration of Et-PABA of 0.05 mM, and a PDS concentration of 2 mM. The removal rate of Et-PABA increased with the increase in PDS dosage within the experimental range, whereas humic acid (HA) had an inhibitory effect on Et-PABA removal. Six intermediates were identified based on HPLC–MS and degradation pathways were then proposed. It can be foreseen that the UV/PDS oxidation process has broad application prospects in water treatment.

Study on the Alage Removal by Microwave Irradiation

2010 ◽  
Vol 113-116 ◽  
pp. 87-90
Author(s):  
Qing Jie Xie
Keyword(s):  
Activated Carbon ◽  
Microwave Irradiation ◽  
Removal Efficiency ◽  
Oxidation Process ◽  
Removal Rate ◽  
Treatment Efficiency ◽  
Dynamic Reaction ◽  
Initial Concentration ◽  
First Order ◽  
Pollutants Removal

The microwave irradiation (MI) was found that it had significantly treatment efficiency for pollutants removal. It was developed to treat the alage in this paper. The granular activated carbon (GAC) was used as catalyst. The effect of the acting time, MI power, GAC amount and the initial concentration on alage removal were studied. The results showed: with the increasing of the acting time, MI power, GAC amount the alage removal rate were increased, but the effect of the initial concentration to alage removal was opposite; the optimum value of acting time, MI power and GAC amount were 5min, 450W and 3g respectively with the alage removal efficiency reached up to 100%. It also showed that with the alage removed under the MI the COD, SS were removed too. It was discovered that the oxidation process was basically in conformity with the first-order dynamic reaction(ln(C/C0)＝-0.9371t+0.6744（R2=0.9472）).

Influence of chloride ions on organic contaminants decolorization through the Fe0-activated persulfate oxidation process: efficiency and intermediates

2019 ◽  
Vol 80 (3) ◽  
pp. 563-574 ◽  
Author(s):  
Feng Ding ◽  
Yong Xie ◽  
Tengyan Wu ◽  
Na Liu
Keyword(s):  
Organic Contaminants ◽  
Oxidation Process ◽  
Operating Cost ◽  
Oxygen Demand ◽  
Transformation Products ◽  
Chloride Ions ◽  
Process Efficiency ◽  
Persulfate Oxidation ◽  
By Products ◽  
Activated Persulfate

Abstract This study was conducted to evaluate the influence of chloride ions (Cl−) on organic contaminants decolorization by the Fe0-activated persulfate process (PS/Fe0), as well as the generation of transformation products. Orange II (OII) was chosen as the target pollution. The results indicated that Cl− influenced the OII decolorization by PS/Fe0 system, resulting in the generation of chlorine-containing by-products. OII containing Cl− solution can be efficiently decolorized by PS/Fe0 process, and the decolorization efficiencies changed depending on Cl− concentration due to the reaction between Cl− and sulfate radicals (SO4–•). The operating cost for 94% color and 64% chemical oxygen demand (COD) removal of the OII dye was estimated at 0.73 USD/m3. The chlorine-containing by-products, such as chlorobenzene, 3,5-dichloro-benzene-1,2-diol, and 2,3-dichloro-2,3-dihydro-1,4-naphthoquinone, were generated during the reaction. The results further indicated that increasing both PS concentration and temperature enhanced OII decolorization and reduced the generation of chlorine-containing intermediates. The addition of ultrasound can further decrease the generation of chlorine-containing intermediates under high-temperature conditions. The proposed pathways of decolorization of OII containing Cl− also indicated that SO4–• dominated the OII degradation, while the presence of Cl− led to the generation of chlorine-containing intermediates.

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.

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