scholarly journals Precipitation Methods Using Calcium-Containing Ores for Fluoride Removal in Wastewater

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 511 ◽  
Author(s):  
Li Wang ◽  
Ye Zhang ◽  
Ning Sun ◽  
Wei Sun ◽  
Yuehua Hu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Hydrochloric Acid ◽  
Removal Rate ◽  
Ecological Environment ◽  
Fluoride Removal ◽  
Action Mechanism ◽  
Reaction Conditions ◽  
Fluoride Ions ◽  
Simulated Wastewater ◽  
Oscillation Rate

F-containing wastewater does great harm to human health and the ecological environment and thus needs to be treated efficiently. In this paper, the new calcium-containing precipitant calcite and aided precipitant fluorite were adopted to purify F-containing wastewater. Relevant reaction conditions, such as reaction time, oscillation rate, dosage of hydrochloric acid, calcite dosage and the assisting sedimentation performance of fluorite, and action mechanism are analyzed. The experiment showed that the removal rate of fluoride in simulated wastewater reached 96.20%, when the reaction time, the dosage of calcite, the dosage of 5% dilute hydrochloric acid, and the oscillation rate was 30 min, 2 g/L, 21.76 g/L, and 160 r/min, respectively. Moreover, the removal rate of fluoride in the actual F-containing smelting wastewater reaches approximately 95% under the optimum condition of calcite dosage of 12 g/L, reaction time of 30 min, and oscillation rate of 160 r/min. The addition of fluorite significantly improves the sedimentation performance of the reactive precipitates. The experimental results showed that calcite and fluorite can effectively reduce the concentration of fluoride ions in F-containing wastewater and solve the problem of slow sedimentation of reactive precipitates.

Study on Pretreatment of Dye Wastewater by Fenton Oxidation Process

2012 ◽  
Vol 627 ◽  
pp. 378-381
Author(s):  
Bi Rong Wang
Keyword(s):  
Reaction Time ◽  
Oxidation Process ◽  
Removal Rate ◽  
Fenton Oxidation ◽  
Dye Wastewater ◽  
Dyeing Wastewater ◽  
Reaction Conditions ◽  
Fenton Oxidation Process

Fenton pretreatment has been used for treating dye wastewater. The effects of the dos of H2O2 and FeSO4, reaction time and pH on the removal COD were investigated. It was found that, when the reaction conditions are as follows: COD 2850 mg/L dyeing wastewater, the dosage of H2O2 is 140mmol/L, FeSO4 17.02 mmol/L, pH 7.6, and reaction time 1.0 h, the CODcr of dye wastewater removal rate of up to 70%. Fenton pretreatment process of dye wastewater has a broad prospect.

Preparation and Electrospinning of Acidified-Oxidized Potato Starch

2012 ◽  
Vol 535-537 ◽  
pp. 2340-2344 ◽  
Author(s):  
Hong Jie Wang ◽  
Xin Jin ◽  
Wen Yu Wang ◽  
Chang Fa Xiao ◽  
Lin Tong
Keyword(s):  
Reaction Time ◽  
Hydrochloric Acid ◽  
Optimum Condition ◽  
Potato Starch ◽  
Ammonium Persulfate ◽  
Modified Starch ◽  
Oxidizing Agent ◽  
Reaction Conditions ◽  
Native Starch ◽  
Optimum Reaction

This paper investigates the preparation and electrospinning of acidified-oxidized potato starch. In this article, acidified-oxidized potato starch was prepared by adding ammonium persulfate as an oxidizing agent and hydrochloric acid as a catalyst. The effect of reaction time, temperature, the concentration of hydrochloric acid and the content of ammonium persulfate on the viscosity and content of carboxyl were discussed. The optimum reaction conditions were as follows: 1.5 hours ,50°C, 0.5mol/l HCl, 2.5% (NH4)2S2O8. And then, the acidified-oxidized potato starch prepared at the optimum condition was dissolved in dimethyl sulfoxide (DMSO) to be electrospinned by contrast to native starch. Electrospinning of 5wt%-21wt% of modified starch in DMSO produced beads, beaded fibers, and smooth fibers, depending on the concentration range. Smooth fibers were observed until the concentration reached 19wt%, while native starch was 5wt%.

The Treatment of H-GL Dye Wastewater by Fenton Oxidation

2012 ◽  
Vol 518-523 ◽  
pp. 2274-2277
Author(s):  
Wen Yao Yan ◽  
Yu Hong Chai
Keyword(s):  
Reaction Time ◽  
Fenton Oxidation ◽  
Dye Wastewater ◽  
Reaction Conditions ◽  
Decolorization Rate ◽  
Initial Ph ◽  
Simulated Wastewater ◽  
Dark Blue

Abstract. Investigation on the degradation of dye simulated wastewater containing disperse H-GL dark blue was conducted under Fenton oxidation scheme. Reaction conditions such as the dosage of H2O2 and Fe2+, initial pH, initial dye concentration and reaction time were studied in terms of decolorization efficiencies. Up to 94.5% decolorization rate was attained after 30 min using H2O2 36 mg L-1 and Fe2+ 75mg L-1 at a pH of 3.

The Study of Phosphorus Removal by Electrocoagulation with Iron-Anodes

2011 ◽  
Vol 183-185 ◽  
pp. 417-421
Author(s):  
Yong Bo Lin ◽  
Yang Yang ◽  
Shuai Wang
Keyword(s):  
Reaction Time ◽  
Total Phosphorus ◽  
Current Density ◽  
Phosphorus Removal ◽  
Removal Rate ◽  
Electrolysis Time ◽  
Optimal Conditions ◽  
Reaction Conditions ◽  
Electrode Distance ◽  
Initial Ph

Determined to adopt iron as anodes, and Ti-base board with coating as cathodes. To optimize the reaction conditions of phosphorus removal by electrocoagulation (EC), testing the effect of current density, electrode distance, initial pH and electrolysis time on the phosphorus removal. According to the results, the optimal conditions for the phosphorus removal in the EC treatment were obtained, i.e., 20 mA/cm2 of current density, 2cm of distance and 10min of reaction time were optimum. Under these conditions, phosphorus removal by electrocoagulation reached to 95.07%, 10min later the change of total phosphorus (TP) removal rate is not obvious. By the end of this test, phosphorus removal by electrocoagulation reached to 99.68%.

Persulfuric Acid Oxidation Mechanism of Acid Red B Wastewater

2011 ◽  
Vol 233-235 ◽  
pp. 399-402 ◽  
Author(s):  
Lin Bo Li ◽  
Wei Lei ◽  
Tao Hong
Keyword(s):  
Reaction Time ◽  
Azo Dye ◽  
Removal Rate ◽  
Oxidation Mechanism ◽  
Acid Oxidation ◽  
Reaction Conditions ◽  
Promotion Effect ◽  
Optimum Reaction ◽  
Catalytic Mechanisms ◽  
Cod Removal Rate

In this paper, azo dye Acid Red B (ARB) simulation of wastewater was treated with persulfuric acid. By conducting the comparative experiments of the catalysts and analyzing their catalytic mechanisms, the promotion effect of catalysts on the reaction was ranked as: AgNO3>Ag2SO4>CoCl2>CoSO4>FeSO4>FeCl2; in addition, optimum reaction conditions were attained: ARB concentration of 200mg/L, the reaction time 1h, temperature 25°C, oxidant dosage 15mL/L and 6.5×10-5mol/L with catalyst of AgNO3, under which the decolorization rate of ARB was up to 100%, and COD removal rate was up to 72%.

Synthesis of organic soluble poly(substituted-aniline) from 2-methyl-6-ethylaniline tar

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744091 ◽  
Author(s):  
Yuan Liu ◽  
Shu-Bai Li ◽  
Pei Yao ◽  
Qi-Meng Zhang
Keyword(s):  
Reaction Time ◽  
Hydrochloric Acid ◽  
Acid Concentration ◽  
Structural Information ◽  
Oxidative Polymerization ◽  
Chemical Oxidative Polymerization ◽  
Reaction Conditions ◽  
Ft Ir ◽  
Solubility Of Polymers ◽  
Soluble Poly

Organic soluble poly(substituted-aniline) was synthesized by chemical oxidative polymerization from 2-methyl-6-ethylaniline tar. The structural information of samples was characterized using FT-IR and SEM techniques. The influences of acid concentration, mole ratio of oxidants to tar, reaction time and temperature were investigated. The solubility of polymers was also studied. The results indicate that the conductivity of poly(substituted-aniline) could reach 2.51 [Formula: see text] S ⋅ cm[Formula: see text] under the reaction conditions with 1 mol./L hydrochloric acid, mole ratio of oxidants to tar = 1, and at 10[Formula: see text]C for 3 h. The polymers show better solubility than polyaniline in most organic solvents.

Oxidation Chlorination of Thiophene in Coking Benzene

2011 ◽  
Vol 130-134 ◽  
pp. 1066-1069 ◽  
Author(s):  
Min Yan Ling ◽  
Hou He Chen
Keyword(s):  
Hydrochloric Acid ◽  
Potassium Permanganate ◽  
Sulfur Compound ◽  
Removal Rate ◽  
Reaction Conditions ◽  
Potassium Permanganate Solution ◽  
Preliminary Results

Thiophene is a typical thiophenenic sulfur compound that exists in coking benzene. In this paper, investigate oxidation chlorination of thiophene in coking benzene. Potassium permanganate was combined with hydrochloric acid for a new KMnO4/HCl system of oxidation desulfurization. The preliminary results show that the thiophene in the benzene cannot be deep oxidized desulfurization alone potassium permanganate solution even at acetum. The thiophene in the coking benzene could be mostly converted by using KMnO4/HCl system. In suitable reaction conditions thiophene’s removal rate can reach more than 93%.

scholarly journals Preparation and Characterization of High-Efficiency Magnetic Heavy Metal Capture Flocculants

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1732
Author(s):  
Yuanyuan Yu ◽  
Yongjun Sun ◽  
Jun Zhou ◽  
Aowen Chen ◽  
Kinjal J. Shah
Keyword(s):  
Heavy Metal ◽  
Reaction Time ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Monomer Concentration ◽  
Synthesis Process ◽  
Response Surface Optimization ◽  
Metal Capture ◽  
Total Monomer Concentration

In this study, a high-efficiency magnetic heavy metal flocculant MF@AA was prepared based on carboxymethyl chitosan and magnetic Fe3O4. It was characterized by SEM, FTIR, XPS, XRD and VSM, and the Cu(II) removal rate was used as the evaluation basis for the preparation process. The effects of AMPS content, total monomer concentration, photoinitiator concentration and reaction time on the performance of MF@AA flocculation to remove Cu(II) were studied. The characterization results show that MF@AA has been successfully prepared and exhibits good magnetic induction characteristics. The synthesis results show that under the conditions of 10% AMPS content, 35% total monomer concentration, 0.04% photoinitiator concentration, and 1.5 h reaction time, the best yield of MF@AA is 77.69%. The best removal rate is 87.65%. In addition, the response surface optimization of the synthesis process of MF@AA was performed. The optimal synthesis ratio was finally determined as iron content 6.5%, CMFS: 29.5%, AM: 53.9%, AMPS: 10.1%. High-efficiency magnetic heavy metal flocculant MF@AA shows excellent flocculation performance in removing Cu(II). This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove Cu(II) in wastewater.

Study on the Synthesis of Isoamyl Acetate Catalyzed by Strong Acidic Cation Exchange Resin

2011 ◽  
Vol 396-398 ◽  
pp. 2411-2415 ◽  
Author(s):  
Ping Lan ◽  
Li Hong Lan ◽  
Tao Xie ◽  
An Ping Liao
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Cation Exchanger ◽  
Cation Exchange Resin ◽  
Isoamyl Acetate ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Reaction Conditions ◽  
Optimum Reaction

Isoamyl acetate was synthesized from isoamylol and glacial acetic acid with strong acidic cation exchanger as catalyst. The effects of reaction conditions such as acid-alcohol ratio, reaction time, catalyst dosage to esterification reaction have been investigated and the optimum reaction conditions can be concluded as: the molar ratio of acetic acid to isoamylol 0.8:1, reaction time 2h, 25 % of catalyst (quality of acetic acid as benchmark). The conversion rate can reach up to 75.46%. The catalytic ability didn’t reduce significantly after reusing 10 times and the results showed that the catalyst exhibited preferably catalytic activity and reusability.

scholarly journals Synthesis of propylene carbonate from urea and 1,2-propylene glycol over metal carbonates

2011 ◽  
Vol 17 (3) ◽  
pp. 323-331 ◽  
Author(s):  
Jiancheng Zhou ◽  
Wu Dongfang ◽  
Birong Zhang ◽  
Yali Guo
Keyword(s):  
Reaction Time ◽  
Propylene Glycol ◽  
Propylene Carbonate ◽  
Reaction Temperature ◽  
Reaction Conditions ◽  
Lead Carbonate ◽  
Synthetic Process ◽  
Metal Carbonates ◽  
Optimal Reaction ◽  
Mixed Carbonate

A series of single-metal carbonates and Pb-Zn mixed-metal carbonates were prepared as catalysts for alcoholysis of urea with 1,2-propylene glycol (PG) for the synthesis of propylene carbonate (PC). The mixed carbonates all show much better catalytic activities than the single carbonates, arising from a strong synergistic effect between the two crystalline phases, hydrozincite and lead carbonate. The mixed carbonate with Pb/Zn=1:2 gives the highest yield of PC, followed by the mixed carbonate with Pb/Zn=1:3. Furthermore, Taguchi method was used to optimize the synthetic process for improving the yield of PC. It is shown that the reaction temperature is the most significant factor affecting the yield of PC, followed by the reaction time, and that the optimal reaction conditions are the reaction time at 5 hours, the reaction temperature at 180 oC and the catalyst amount at 1.8 wt%, resulting in the highest PC yield of 96.3%.

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