scholarly journals Humic acid degradation by fenton-like process using Fe2+ and Mn4+

2018 ◽  
Vol 13 (2) ◽  
pp. 388-399 ◽  
Author(s):  
Antover Panazzolo Sarmento ◽  
Alisson Carraro Borges ◽  
Antonio Teixeira de Matos ◽  
Lincoln Lucílio Romualdo
Keyword(s):  
Reaction Time ◽  
Humic Acid ◽  
Desirability Function ◽  
Relative Concentration ◽  
Fenton Process ◽  
Optimum Conditions ◽  
Pareto Chart ◽  
Surface Method ◽  
Efficient Alternative ◽  
Central Composite

Abstract This study investigates the Humic Acid (HA) degradation in aqueous solution by a Fenton-Like process using Fe2+ and Mn4+ as a catalyst. The effect of the independent factors: pH, [H2O2], [Fe2+], [Mn4+] and t (reaction time) at the efficiency of HA degradation were evaluated, aiming at obtaining the optimum conditions. The statistic arrangement adopted was the Central Composite Design, and the response variable was the HA relative concentration after the treatments. The inferences were made using variance analysis, the Pareto chart, the response surface method and the desirability function. The variables which were more significant at the HA degradation were: [Fe2+] (linear and square effects), pH (square effect) and the interactions between [Fe2+] vs [H2O2] and [Fe2+] vs t. The addition of Mn4+ did not provide a significant improvement to the efficiency of HA degradation. Nevertheless, it was observed that the conventional Fenton process proved to be an efficient alternative for the HA degradation. The optimal and most economical condition is pH 5, [H2O2] of 6.17 mmol L−1, [Fe2+] of 0.54 mmol L−1, reaction time of 120 min and no added Mn4+.

scholarly journals Sulfamethoxazole and Trimethoprim Degradation by Fenton and Fenton-Like Processes

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1655 ◽  
Author(s):  
Antover Panazzolo Sarmento ◽  
Alisson Carraro Borges ◽  
Antonio Teixeira de Matos ◽  
Lincoln Lucílio Romualdo
Keyword(s):  
Reaction Time ◽  
Fenton Reaction ◽  
Desirability Function ◽  
Relative Concentration ◽  
Optimum Conditions ◽  
Degradation Model ◽  
Pareto Chart ◽  
Linear Effect ◽  
Ph Values ◽  
Antibiotic Degradation

In this work, the degradation of sulfamethoxazole (SMX) and trimethoprim (TMP) via Fenton and Fenton-like processes was evaluated using Mn2+ as supporting catalyst in the Fenton reaction. The optimum conditions of degradation were also evaluated. Besides that, the effect of independent factors pH, [H2O2], [Fe2+], [Mn2+] and reaction time (t) on the efficiency of the SMX and TMP degradation were assessed. Box–Behnken was the experimental design adopted, delineating the relative concentration (C/Co) of antibiotics after treatments as response variable. The inferences were conducted using variance analysis, Pareto chart, response surface methodology, and desirability function. Due to the lack of adjustment of the SMX degradation model, there are no more inferences about it. The significant variables (p ≤ 0.05) on TMP degradation were: reaction time quadratic and linear effect, [Fe2+] linear effect, [Mn2+] linear effect, interaction pH vs. [Mn2+]. The Mn2+ addition aided TMP degradation in environments with lower pH values. However, the addition may harm the efficiency of the antibiotic degradation at higher pH. The optimum condition for TMP degradation in the conventional process (without the addition of Mn2+) is: pH 5, [H2O2] equal to 4.41 mmol L−1, [Fe2+] equal to 0.81 mmol L−1 and 90 min reaction time.

Extraction Study of Nitro Humic Acid from Lignite by Dry and Wet Process

2013 ◽  
Vol 483 ◽  
pp. 119-123
Author(s):  
Yang Yuan ◽  
Ji Ping Liu ◽  
Zhuo Chen ◽  
Hong Cheng Li
Keyword(s):  
Nitric Acid ◽  
Reaction Time ◽  
Humic Acid ◽  
Reaction Temperature ◽  
Production Condition ◽  
Weight Ratio ◽  
Optimum Conditions ◽  
Dry Process ◽  
Wet Process ◽  
Extraction Study

Nitro humic acid was extracted from lignite of Guizhou Anshun, which production condition and process were studied. The results show that the optimum conditions of dry process are concentration of nitric acid of 40%, reaction temperature of 95°C, reaction time of 5 min. The optimum conditions of wet process production are concentrations of nitric acid of 20% ~ 25%, the solid-liquid ratio of 1:1.25 (weight ratio), reaction temperature of 80 ~ 85°C, and reaction time of 30 min.

scholarly journals Optimization of Voltammetric Determination of Dysprosium (III) Using Plackett-Burman and RSM-CCD Experimental Designs

2020 ◽  
Vol 17 (4) ◽  
pp. 1198
Author(s):  
Santhy Wyantuti ◽  
Zulida Setyorini ◽  
Safri Ishmayana ◽  
Yeni Hartati ◽  
M Firdaus
Keyword(s):  
Electrical Current ◽  
Differential Pulse ◽  
Current Response ◽  
Optimum Conditions ◽  
Surface Method ◽  
Two Factors ◽  
Pulse Voltammetry ◽  
Central Composite ◽  
Significant Factors

This study was aimed to develop an optimized Dy determination method using differential pulse voltammetry (DPV). The Plackett-Burman (PB) experimental design was used to select significant factors that affect the electrical current response, which were further optimized using the response surface method-central composite design (RSM-CCD). The type of electrolyte solution and amplitude modulation were found as two most significant factors, among the nine factors tested, which enhance the current response based on PB design. Further optimization using RSM-CCD shows that the optimum values for the two factors were 0.1046 M and 0.1082 V respectively. When the optimum conditions were applied for Dy determination good recovery and precision were achieved with values of 91.58%, and 99.80%, respectively. The detection limit and quantification limit of the method were 1.4322 mg/L and of 4.7741 mg/L, respectively.

scholarly journals Assessment of coagulation pretreatment of leachate by response surface methodology

2017 ◽  
Vol 76 (9) ◽  
pp. 2321-2327 ◽  
Author(s):  
Ridha Lessoued ◽  
Fatiha Souahi ◽  
Leonor Castrillon Pelaez
Keyword(s):  
Experimental Data ◽  
Response Surface ◽  
Simple Technique ◽  
Operating Parameters ◽  
Optimum Conditions ◽  
Turbidity Removal ◽  
Surface Method ◽  
Model Predictions ◽  
Initial Ph ◽  
Central Composite

Abstract Coagulation-flocculation is a relatively simple technique that can be used successfully for the treatment of old leachate by poly-aluminum chloride (PAC). The main objectives of this study are to design the experiments, build models and optimize the operating parameters, dosage m and pH, using the central composite design and response surface method. Developed for chemical organic matter (COD) and turbidity responses, the quadratic polynomial model is suitable for prediction within the range of simulated variables as it showed that the optimum conditions were m of 5.55 g/L at pH 7.05, with a determination coefficient R² at 99.33%, 99.92% and adjusted R² at 98.85% and 99.86% for both COD and turbidity. We confirm that the initial pH and PAC dosage have significant effects on COD and turbidity removal. The experimental data and model predictions agreed well and the removal efficiency of COD, turbidity, Fe, Pb and Cu reached respectively 61%, 96.4%, 97.1%, 99% and 100%.

scholarly journals Degradation of Total organic carbon (TOC) and Chemical oxygen demand (COD) in Petroleum wastewater by solar Photo-Fenton process.

2017 ◽  
Vol 19 (3) ◽  
pp. 430-438 ◽  
Keyword(s):  
Free Energy ◽  
Wastewater Treatment ◽  
Reaction Time ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Oil Refinery ◽  
Fenton Process ◽  
Optimum Conditions ◽  
Fenton Reagent ◽  
Acidic Conditions

The aim of this study is to investigate the performance of solar photo-Fenton process (H2O2/Fe2+/Solar) to treat petroleum wastewater from Sohar oil Refinery, Oman. The effect of operating conditions such as pH, reaction time, Fenton ratio, and Fenton reagent concentrations are investigated. The obtained optimum conditions include H2O2 dosage (1 g L-1), Fe+2 dosage (0.08 g L-1), pH (3) and reaction time (180 min). TOC and COD removal rates are 64 % and 78 %, respectively. However, the photolytic process was less efficient in the petroleum wastewater treatment, achieving an 11.5% and 9% of COD and TOC removals, respectively. The solar photo-Fenton process has well efficient for petroleum wastewater treatment in the acidic conditions and more economic by free energy.

Synthesis of Coal-Water Slurry Dispersant Based on Humic Acid

2011 ◽  
Vol 347-353 ◽  
pp. 1466-1469 ◽  
Author(s):  
Guang Hua Zhang ◽  
Hao Hao ◽  
Jun Feng Zhu
Keyword(s):  
Reaction Time ◽  
Humic Acid ◽  
Acrylic Acid ◽  
Active Ingredient ◽  
Orthogonal Experiment ◽  
Reaction System ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
Water Slurry ◽  
Coal Water Slurry

This paper focused on the preparation of the grafted modification of humic acid (HA) that was used in coal water slurry (CWS). By means of orthogonal experiment, the grafted humic acid was synthesized with acrylic acid (AA) copolymerized with humic acid, using potassium persulfate as the initiator in the reaction system. The structure of copolymer was characterized by ATR-FTIR. And then, the viscosity, liquidity, and stability of CWS used the dispersant based on the modified humic acid were determined through the CWS viscometer and tests of stability. The optimum conditions of synthesis are that the mass ratio of AA and HA is 0.35:1, dosage of initiator is 5%, reaction temperature of is 75°C, reaction time is 2.0h. Besides, when the dosage of active ingredient of the dispersant for CWS was 0.12%, the viscosity of CWS achieved lower.

scholarly journals Leaching and solvent extraction purification of zinc from Mehdiabad complex oxide ore

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Faraz Soltani ◽  
Hossna Darabi ◽  
Reza Aram ◽  
Mahdi Ghadiri
Keyword(s):  
Solvent Extraction ◽  
Environmental Pollution ◽  
Central Composite Design ◽  
Complex Oxide ◽  
Hydrometallurgical Process ◽  
Purification Process ◽  
Optimum Conditions ◽  
Leaching Experiments ◽  
Central Composite ◽  
Sulphuric Acid Concentration

AbstractAn integrated hydrometallurgical process was used for the zinc leaching and purification from a zinc ore containing 9.75 wt% zinc. The zinc minerals in the ore were hemimorphite, willemite, and calcophanite. Main gangue minerals were quartz, goethite, hematite, and calcite. Central composite design (CCD) method was used to design leaching experiments and the optimum conditions were found as follows: 30% of solid fraction, 22.05% sulphuric acid concentration, and the leaching temperature of 45 °C. The PLS containing 35.07 g/L zinc, 3.16 g/L iron, and 4.58 g/L manganese impurities was produced. A special purification process including Fe precipitation and Zn solvent extraction was implemented. The results showed that after precipitation of iron, Zn extraction of 88.5% was obtained with the 2 stages extraction system composed of 30 vol% D2EHPA as extractant. The overall Zn recovery from the ore was 71.44%. Therefore, an appropriate solution containing 16.6 g/L Zn, 0.05 g/L Fe, and 0.11 g/L Mn was prepared for the electro-winning unit without using the roasting and calcination steps (conventional method), which result in environmental pollution.

scholarly journals Chemical Removal of Cu and Zn from Swine Feces before Soil Application

Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 377
Author(s):  
Moo-Joon Shim ◽  
Seung-Mok Lee
Keyword(s):  
Reaction Time ◽  
H2so4 Solution ◽  
Optimum Conditions ◽  
Liquid Ratio ◽  
Optimal Method ◽  
Zn Concentration ◽  
Swine Feces ◽  
Removal Efficiencies ◽  
Cu And Zn ◽  
Oxalic Acids

Cu and Zn are known to be abundant in swine feces; hence, concentrations of these metals need to be lowered before swine feces are applied to land in order to prevent potential environmental problems. The main objective of this study was to develop an appropriate chemical process to remove Cu and Zn from swine feces using acid extractions. The removal efficiencies of Cu and Zn decreased in the order of H2SO4 > HNO3 > organic acids (citric and oxalic acids). Owing to the highest removal efficiencies of Cu and Zn by using H2SO4, it was selected for further elimination of Cu and Zn from swine feces. By using H2SO4, the optimal concentration, solid-to-liquid ratio, and reaction time were 2%, 1:50, and 8 h, respectively. At the optimum conditions, Cu concentration was decreased from 198 mg/kg to 40.1 mg/kg and Zn concentration from 474 mg/kg to 80.0 mg/kg, with removal rates of 79.7% and 83.1%, respectively. The low Cu removal efficiency, resulting from the strong complexation between Cu and organic matter of swine feces, was improved by the increase in the reaction time and H2SO4 solution concentrations. However, about half of the total nitrogen (TN) was also removed by using H2SO4, indicating that the swine feces treated with H2SO4 may have poor value as fertilizer. Additional studies are required to find an optimal method to maintain TN concentrations while simultaneously removing Cu and Zn.

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