Heat-Activated Persulfate Oxidation of Chlorinated Solvents in Sandy Soil

Heat-activated persulfate oxidative treatment of chlorinated organic solvents containing chlorinated ethenes and ethanes in soil was investigated with different persulfate dosages (20 g/L, 40 g/L, and 60 g/L) and different temperatures (30°C, 40°C, and 50°C). Chlorinated organic solvents removal was increased as persulfate concentration increase. The persulfate dosage of 20 g/L with the highest OE (oxidant efficiency) value was economically suitable for chlorinated organic solvents removal. The increasing temperature contributed to the increasing depletion of chlorinated organic solvents. Chlorinated ethenes were more easily removed than chlorinated ethanes. Moreover, the persulfate depletion followed the pseudo-first-order reaction kinetics (kps=0.0292 [PS]0+0.0008,R2=0.9771). Heat-activated persulfate appeared to be an effective oxidant for treatment of chlorinated hydrocarbons.

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The effect of temperature on tacticity for bulk thermal polymerization of styrene

e-Polymers ◽

10.1515/epoly.2008.8.1.466 ◽

2008 ◽

Vol 8 (1) ◽

Cited By ~ 2

Author(s):

Farshid Ziaee ◽

Mehdi Nekoomanesh ◽

Hamid Salehi Mobarakeh ◽

Hassan Arabi

Keyword(s):

Thermal Polymerization ◽

Effect Of Temperature ◽

Polymerization Temperature ◽

Deuterated Chloroform ◽

Methylene Carbon ◽

Aromatic Carbon ◽

First Order ◽

Different Temperatures ◽

Increasing Temperature ◽

Better Than

AbstractThree types of polystyrenes were prepared at different temperatures of 50, 150 and 250°C by bulk thermal polymerization of styrene below 20 percent of conversion. The assignment of all stereosequences at pentad level of quaternary aromatic carbon and hexad level of methylene carbon of the polystyrenes were done using 13C Liquid NMR in deuterated chloroform at similar conditions. Bernoullian and first-order Markov statistics were calculated and the results were compared with experimental NMR results. It is shown that first-order Markov statistics fit slightly better than Bernoullian statistics for the assigned carbons. The results indicated that by increasing polymerization temperature the probability of meso addition (Pm) in polystyrene chains was enhanced. Pm was calculated for polystyrenes prepared at 50, 150 and 250°C and corresponding values were 0.378, 0.398 and 0.402 respectively. It was shown that by increasing temperature the polymerization is directed toward the Bernoullian propagation. By increasing the NMR acquisition temperature from 20 to 65°C higher resolution especially in quaternary aromatic carbon was achieved and the related peak was splitted to 16 peaks corresponding to a heptad level compared to 10 peaks in 20°C.

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Kinetics and Thermodynamics of Dispersed Oil Sorption by Kapok Fiber

Ecological Chemistry and Engineering S ◽

10.1515/eces-2019-0053 ◽

2019 ◽

Vol 26 (4) ◽

pp. 759-772

Author(s):

Check Shyong Quek ◽

Norzita Ngadi ◽

Muhammad Abbas Ahmad Zaini

Keyword(s):

Hydraulic Retention Time ◽

Droplet Size Distribution ◽

Physicochemical Characteristics ◽

Pseudo First Order Reaction ◽

Kapok Fiber ◽

First Order ◽

Dispersed Oil ◽

Different Temperatures ◽

Original Amount ◽

Oil Droplet Size

Abstract This work was aimed at evaluating the sorption of dispersed oil by kapok fiber. The physicochemical characteristics of kapok fiber were investigated using BET, SEM, FTIR, XRD, contact angle and elemental analysis. The oil droplet size distribution at different temperatures was analysed using a Coulter counter, and its relationship with sorption was investigated. The effects of dosage, hydraulic retention time and temperature, on the sorption performance were studied. The result indicates that the sorption of dispersed oil by kapok fiber is spontaneous, endothermic and agreed with the pseudo-first-order reaction kinetics. The amount of oil that could be removed is about 28.5 %, while that of water is less than 1 % of the original amount (0.5 dm3). Kapok is a promising natural hydrophobic fiber for dispersed oil removal from oily wastewater.

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Permanganatic oxidation of neomycine sulphate salt in basic media: a kinetic study

Journal of Drug Delivery and Therapeutics ◽

10.22270/jddt.v9i1.2201 ◽

2019 ◽

Vol 9 (1) ◽

pp. 159-164

Author(s):

Narayan V. Lawale ◽

Bhagwan Singh Dobhal ◽

Sandip Singh Gaur ◽

Rajendra Pardeshi

Keyword(s):

Kinetic Study ◽

Order Reaction ◽

First Order Reaction ◽

Pseudo First Order Reaction ◽

Reaction Conditions ◽

First Order ◽

Alkaline Permanganate ◽

Different Temperatures ◽

Alkaline Conditions ◽

Pseudo First Order

Permanganatic oxidation of Neomycine sulphate salt has been studied at different temperatures using spectrophotometer under alkaline conditions. The effect of variation of substrate Neomycine sulphate salt (NS), oxidant (KMnO4) and NaOH was studied under pseudo first order reaction conditions. The effect of different salts and solvents on oxidation of NS was also studied. The reaction was found to be first order with respect to oxidant, substrate and NaOH.. Keywords: Neomycine sulphate salt (NS), KMnO4 , permanganatic oxidation, alkaline permanganate

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Degradation Behaviors of Trichloroethylene by Permanganate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1051.588 ◽

2014 ◽

Vol 1051 ◽

pp. 588-593

Author(s):

Yi Chu Huang ◽

Shun Yi Huang ◽

Shin Shian Chen ◽

Chen Yao Ma ◽

Hung Chieh Chen

Keyword(s):

Batch Reactor ◽

Order Rate Constant ◽

Pseudo First Order Reaction ◽

First Order ◽

High Oxidation ◽

Speed Up ◽

Chlorinated Organic ◽

Degradation Behaviors ◽

Pseudo First Order ◽

Chlorinated Organic Pollutants

Surfactant-enhanced permanganate oxidation (SEPO) technology utilizes the surfactant to mobilize and/or solubilize the dense-non-aqueous-phase liquids (DNAPLs) and then exploits the high oxidation capacity of permanganate (MnO4-) to oxidize them. SEPO technology has been shown as an effective way to remediate the aquifers contaminated with chlorinated organic pollutants such as trichloroethylene (TCE). Experiments were carried out with a series of continuous stir batch reactor to quantify the kinetic parameters of which MnO4- oxidizes the aqueous TCE in the presence of surfactant. It was found that TCE followed the observed pseudo-first-order reaction with respect to MnO4- whether the surfactants were present or not. In the absence of surfactants, the observed pseudo-first-order rate constant (kobs) and half-life (t1/2) were 0.12-0.25 min-1 and 2.5-7.1 min for MnO4-, respectively. For the Tween80 concentration less than its critical micelle concentration (CMC), the kobs value was 0.14 min-1 and the t1/2 was 2.6 min for MnO4-. As the Tween80 concentration exceeded its CMC, the kobs values increased to 0.32-0.37 min-1 and the t1/2 reduced to 0.44-0.46 min. The results showed that combination of permanganate with a proper type of surfactant can speed up the removal of contaminants in aquifers.

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Kinetic Analysis of Catalytic Reductive Dechlorination of Chlorobenzene in Aqueous Solutions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.777.65 ◽

2013 ◽

Vol 777 ◽

pp. 65-70 ◽

Cited By ~ 1

Author(s):

Hong Yi Zhou ◽

Si Liang ◽

Si Si Zeng ◽

Shuang Jian Lei

Keyword(s):

Rate Constant ◽

Organic Contaminants ◽

Room Temperature ◽

Solution Ph ◽

First Order ◽

Effective Removal ◽

Chlorinated Organic ◽

Ph Range ◽

Increasing Temperature

Deposition of Pd on the surface of zero-valent iron (Pd/Fe) further enhances the ability of the metal to reductively dechlorinate organic contaminants. This work determined the dechlorination of chlorobenzene in water by Pd/Fe and evaluated the effects of Pd loading in Fe, Pd/Fe dosage, solution pH and temperature on the reaction. Pseudo-first-order rate constants were obtained to analyze the reaction kinetics. Chlorobenzene was nearly completely dechlorinated within 60 min by Pd/Fe at room temperature. Benzene was the end product of the reaction, along with the release of chloride into water. The rate constant of chlorobenzene dechlorination increased with increasing Pd loading in Fe and Pd/Fe dosage within the tested ranges of 0.005 - 0.020% and 2.0 - 6.0 g/75 mL, respectively. The rate constant increased with decreasing solution pH over the tested pH range of 4.5 - 6.5, indicating the role of protons in dechlorination. The reaction was considered to occur primarily on the surface of Pd where protons were reduced to hydrogen species and chlorobenzene was subsequently dechlorinated by the hydrogen species. The rate of chlorobenzene dechlorination increased with increasing temperature. The estimated activation energy of the reaction was 47.94 kJ/mol within the temperature range of 15 - 40°C, indicating that the dechlorination of chlorobenzene by Pd/Fe readily occurs at room temperature. Pd/Fe may be a potential reductant for effective removal of chlorinated organic contaminants from water.

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A Comparative Electrochemical and Morphological Investigation on the Behavior of NiCr and CoCr Dental Alloys at Various Temperatures

Metals ◽

10.3390/met11020256 ◽

2021 ◽

Vol 11 (2) ◽

pp. 256

Author(s):

Florentina Golgovici ◽

Mariana Prodana ◽

Florentina Gina Ionascu ◽

Ioana Demetrescu

Keyword(s):

Low Temperatures ◽

Artificial Saliva ◽

Electrochemical Stability ◽

Morphological Investigation ◽

Dental Alloys ◽

Ion Release ◽

Icp Ms ◽

Different Temperatures ◽

Good Concordance ◽

Increasing Temperature

The purpose of our study is to compare the behavior of two reprocessed dental alloys (NiCr and CoCr) at different temperatures considering the idea that food and drinks in the oral cavity create various compositions at different pH levels; the novelty is the investigation of temperature effect on corrosion parameters and ion release of dental alloys. Electrochemical stability was studied together with morphology, elemental composition and ions release determination. The results obtained are in good concordance: electrochemistry studies reveal that the corrosion rate is increasing by increasing the temperature. From SEM coupled with EDS, the oxide film formed on the surface of the alloys is stable at low temperatures and a trend to break after 310K. ICP-MS results evidence that in accordance with increasing temperature, the quantities of ions released from the alloys immersed in artificial saliva also increase, though they still remain small, less than 20 ppm.

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Oxidative degradation of gentamicin present in water by an electro-Fenton process and biodegradability improvement

Open Chemistry ◽

10.1515/chem-2019-0110 ◽

2019 ◽

Vol 17 (1) ◽

pp. 1017-1025

Author(s):

Mohamed Réda Arhoutane ◽

Muna Shueai Yahya ◽

Miloud El Karbane ◽

Kacem El Kacemi

Keyword(s):

Chemical Oxygen Demand ◽

Biological Process ◽

Oxidative Degradation ◽

Oxygen Demand ◽

Polluted Water ◽

Applied Current ◽

Pseudo First Order Reaction ◽

First Order ◽

Appropriate Treatment ◽

By Products

AbstractIn the context of environmental protection, where there is a need to develop effective operations for carrying out appropriate treatment of polluted water by pharmaceuticals. Therefore, the present study aims at evaluating the degradation for gentamicin through electro-Fenton (EF) operation, through taking into consideration the effect of several parameters of experimental in the process, namely, the concentration of initial gentamicin, the applied current and the Fe+2 (II) quantities. The (EF) operation employed involves a carbon-felt as cathode and platinum as anode at pH 3. Studies for the gentamicin kinetics is monitored by HPLC giving a pseudo-first order reaction following by a chemical oxygen demand, with a reached degree of mineralization 96% after of four hours of treatment through current 100 mA/cm2 with 0.1 mM of Fe+2. We find that the degradation for molecule of gentamicin is accompanied by an augmentation of the biodegradability, assesse through the Biochemical Oxygen Demand (BOD5) on chemical oxygen demand (COD) ratio, that augmentation from 0 to 0.41 before treatment after 30 min for EF treatment, showing that there is potential for conjugation of the EF process and the biological process. Furthermore, the by-products have been identified on the basis of HPLC-MS/MS results.

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