Effect of common inorganic ions on aniline degradation in groundwater by activated persulfate with ferrous iron

2015 ◽  
Vol 16 (3) ◽  
pp. 667-674 ◽  
Author(s):  
Yan Zhao ◽  
Yongsheng Zhao ◽  
Qin Li ◽  
Rui Zhou ◽  
Xu Chen
Keyword(s):  
Removal Efficiency ◽  
Ferrous Iron ◽  
Advanced Oxidation Processes ◽  
Inorganic Ions ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Inhibitory Effects ◽  
Oxidation Processes ◽  
Coexisting Ions ◽  
Activated Persulfate

Aniline is widespread in groundwater and of great toxicity. Advanced oxidation processes, such as the ferrous iron (Fe2+)-activated persulfate process, have been proven to be effective for organic pollutants. However, few studies have focused on the effects of coexisting ions on the degradation of aniline. In this study, the degradation efficiency of aniline and the effects of common inorganic ions (CO32−, PO43−, HCO3−, SO42−, NO3−, Na+, K+, Mg2+, and Ca2+) on aniline degradation were examined. Under the optimum operating conditions, 86.33% aniline degradation (C0 = 11 mmol/L) was observed within 60 min. The effects of cations on aniline degradation were negligible. Anions decreased the removal efficiency of aniline because of the radicals generated by the reaction between sulfate radical or hydroxyl radical and these anions. As the concentrations of PO43−, CO32−, SO42−, HCO3−, and NO3− increased from 0 mmol/L to 5 mmol/L, the removal efficiency of aniline decreased to 19.72%, 24.56%, 66.76%, 68.76%, and 82.42%, respectively. The order of inhibitory effects was PO43− > CO32− > >SO42− > HCO3− > >NO3−.

Kinetic study of dye removal using TiO2 supported on polyethylene terephthalate by advanced oxidation processes through neural networks

2019 ◽  
Vol 79 (6) ◽  
pp. 1134-1143 ◽  
Author(s):  
Ada Azevedo Barbosa ◽  
Ramon Vinicius Santos de Aquino ◽  
Naiana Santos da Cruz Santana Neves ◽  
Renato Falcão Dantas ◽  
Marta Maria Menezes Bezerra Duarte ◽  
...  
Keyword(s):  
Kinetic Study ◽  
Polyethylene Terephthalate ◽  
Advanced Oxidation Processes ◽  
Dye Removal ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Order Model ◽  
Oxidation Processes ◽  
First Order ◽  
Pseudo First Order

Abstract This work investigated the efficiency of polyethylene terephthalate (PET) as support material for TiO2 films in the photocatalytic degradation of red Bordeaux and yellow tartrazine dyes. The optimum operating conditions were determined by a factorial design, which resulted after 180 min of treatment in degradations of 99.5% and 99.1% for the UVC/H2O2/TiO2Sup and solar/H2O2/TiO2Sup systems, respectively. For the kinetic study, the experimental data fitted to the pseudo-first-order model and the calculated kinetic constants (k) values were 0.03 min−1 for the UVC/H2O2/TiO2Sup system and 0.0213 min−1 for the system solar/H2O2/TiO2Sup. It was verified that TiO2 supported in the PET remained with high degradation efficiency even after five cycles of reuse, indicating a good stability of the photocatalyst in the support. A significant reduction of TOC content was also observed along the reaction time. The phytotoxicity bioassay with Lactuca sativa demonstrated that after treatment with UVC/H2O2/TiO2Sup and solar/H2O2/TiO2SUP, an increase in IC50 and consequently lower toxicity was observed.

scholarly journals Performance Analysis of Various Advanced Oxidation Processes on COD Removal from Raw Petroleum Refinery Effluent

2021 ◽  
Vol 43 (7) ◽  
pp. 504-512
Author(s):  
Sri Martini ◽  
Sharmeen Afroze ◽  
Mira Setiawati
Keyword(s):  
Advanced Oxidation Processes ◽  
Petroleum Refinery ◽  
Light Exposure ◽  
Advanced Oxidation ◽  
Operating Conditions ◽  
Cod Removal ◽  
Optimum Operating ◽  
Oxidation Processes ◽  
Refinery Effluent ◽  
Petroleum Refinery Effluent

Objectives : This comparative study investigated various methods of advanced oxidation processes (AOPs) that were separately conducted for treating raw petroleum refinery effluent regarding chemical oxygen demand (COD) removal.Methods : Fenton, photo-Fenton, TiO2, ZnO, TiO2/Ultra violet (UV), and ZnO/UV were performed individually for measuring the effect of light irradiation, treatment time, pH, catalysts dosage, and light source on the profile of COD values.Results and Discussion : The experimental data of this work showed that the dependency on the light exposure in heterogeneous photo-catalytic reaction using TiO2 and ZnO is higher than that of homogeneous photo-Fenton technique. The optimum operating conditions in heterogeneous system occurred at 100 min of oxidation time, pH 5, and catalyst dosage 1 g/L that resulted in 21.8, 20.68, 60.9, and 55.17% of COD removal for TiO2, ZnO, TiO2/UV, and ZnO/UV, respectively. In contrast, both Fenton and photo-Fenton experienced their highest performance at pH 4 by obtaining 44.2 and 59.77% of COD removal, respectively. Eventually, kinetic study indicated that COD degradation can be well expressed by second-order pattern that reached higher correlation coefficient values by 0.999 and 0.998 for TiO2/UV and TiO2, respectively.Conclusions : Overall, it could be assumed that AOPs are reliable techniques to purify raw and complex raw industrial effluents.

Comparative Study of Advance Oxidation Processes for Treatment of Pesticide Wastewater

2019 ◽  
pp. 261-323
Author(s):  
Augustine Chioma Affam ◽  
Malay Chaudhuri
Keyword(s):  
Energy Efficiency ◽  
Comparative Study ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Cost Effective ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Oxidation Processes ◽  
Toc Removal ◽  
The Cost

This study compared the amount of catalyst and energy efficiency required for operation of five advanced oxidation processes (Fenton, UV photo-Fenton, solar photo-Fenton, UV/TiO2/H2O2, and FeGAC/H2O2) for degradation of the pesticides chlorpyrifos cypermethrin and chlorothalonil wastewater. Under optimum operating conditions, degradation in terms of COD and TOC removal and biodegradability (BOD5/COD ratio) index (BI) were observed to be (1) Fenton – 69.03% (COD), 55.61% (TOC), and 0.35 (BI); (2) UV photo-Fenton – 78.56% (COD), 63.76% (TOC), and 0.38 (BI); (3) solar photo-Fenton – 74.19% (COD), 58.32% (TOC), and 0.36 (BI); (4) UV/TiO2/H2O2 – 53.62% (COD), 21.54% (TOC), and 0.26 (BI); and (5) FeGAC/H2O2 – 96.19% (COD), 85.60% (TOC), and 0.40 (BI). The cost was $39.9/kg TOC (Fenton), $34.1/kg TOC (UV photo-Fenton), $30.1/kg TOC (solar photo-Fenton), $239/kg TOC (UV/TiO2/H2O2), and $0.74/kg TOC (FeGAC/H2O2). The FeGAC/H2O2 process was found to be most efficient and cost effective for pretreatment of the pesticide wastewater for biological treatment.

scholarly journals Modeling and Optimization for Production of Rice Husk Activated Carbon and Adsorption of Phenol

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Y. S. Mohammad ◽  
E. M. Shaibu-Imodagbe ◽  
S. B. Igboro ◽  
A. Giwa ◽  
C. A. Okuofu
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Rice Husk ◽  
Adsorption Process ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Process Variables ◽  
Adsorbent Dosage ◽  
Pretreatment Temperature

Modeling of adsorption process establishes mathematical relationship between the interacting process variables and process optimization is important in determining the values of factors for which the response is at maximum. In this paper, response surface methodology was employed for the modeling and optimization of adsorption of phenol onto rice husk activated carbon. Among the action variables considered are activated carbon pretreatment temperature, adsorbent dosage, and initial concentration of phenol, while the response variables are removal efficiency and adsorption capacity. Regression analysis was used to analyze the models developed. The outcome of this research showed that 99.79% and 99.81% of the variations in removal efficiency and adsorption capacity, respectively, are attributed to the three process variables considered, that is, pretreatment temperature, adsorbent dosage, and initial phenol concentration. Therefore, the models can be used to predict the interaction of the process variables. Optimization tests showed that the optimum operating conditions for the adsorption process occurred at initial solute concentration of 40.61 mg/L, pretreatment temperature of 441.46°C, adsorbent dosage 4 g, adsorption capacity of 0.9595 mg/g, and removal efficiency of 97.16%. These optimum operating conditions were experimentally validated.

scholarly journals The removal of organic compounds from landfill leachate using ozone-based advanced oxidation processes

2018 ◽  
Vol 45 ◽  
pp. 00046
Author(s):  
Jacek Leszczyński ◽  
Jolanta Walery Maria
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Compounds ◽  
Removal Efficiency ◽  
Landfill Leachate ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Uv Absorbance ◽  
Leachate Treatment ◽  
Oxidation Processes ◽  
Ozone Dose

In this study, the application of ozonation and ozonation with hydrogen peroxide processes for landfill leachate treatment was investigated. The effluents were characterized by COD 710 mgO2/dm3 and BOD5 72 mg O2/dm3. According to the adopted indicators, the determined BOD/COD ratio of 0.1 in raw leachates indicates a stabilized landfill. Ozone was applied at doses of 0.15 - 0.6 gO3/dm3, and hydrogen peroxide at such doses to keep the weight ratios of H2O2/O3 0.4 - 1.6. The maximum COD and UV absorbance removal was respectively 29% and 51% by applying a high ozone dose of 0.6 gO3/dm3. After oxidation, the ratio of BOD/COD was increased from 0.1 up to 0.3. It has been shown that by using hydrogen peroxide in ozonation, organic compounds expressed as COD can be efficiently removed from the effluents. The best conditions for the H2O2/O3 process were obtained with a H2O2/O3 ratio of 0.8 and ozone dose of 0.6 gO3/dm3. Under these conditions, the removal efficiency of COD was 46%.

scholarly journals Experimental Investigation of the Decarburization Behavior of Medical Waste Incinerator Fly Ash (MWIFA)

Processes ◽  
2018 ◽  
Vol 6 (10) ◽  
pp. 186 ◽  
Author(s):  
Guoxia Wei ◽  
Hanqiao Liu ◽  
Fang Liu ◽  
Tongtong Zeng ◽  
Guisheng Liu ◽  
...  
Keyword(s):  
Fly Ash ◽  
Removal Efficiency ◽  
Tween 80 ◽  
Medical Waste ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Waste Incinerator ◽  
Pump Speed ◽  
Flotation Column ◽  
Micro Bubble

The objective of the research was to compare the flotation performance of medical waste incinerator fly ash (MWIFA) by considering two methods: the cyclonic-static micro-bubble flotation column (FCSMC) method and conventional flotation cell (CFC) method. The results indicated that for FSCMC, the optimum parameters were kerosene = 3.5 g/kg·ash, methyl isobutyl carbinol (MIBC) = 0.2 g/kg·ash, Tween 80 = 7.5% of kerosene concentration, slurry concentration = 100 g/L, and pump speed = 380 r/min. The optimized conditions resulted in a higher dioxin removal efficiency (90.98%), carbon removal efficiency (91.88%) and lower loss on ignition (LOI) (4.96%). The data obtained from the CFC under different optimum operating conditions were 88.65%, 90.63% and 5.68%, respectively. FSCMC was proven to be more efficient for the flotation of MWIFA than CFC.

Removal of Iron from Metallurgical Grade Silicon with Pressure Leaching

2011 ◽  
Vol 675-677 ◽  
pp. 873-876 ◽  
Author(s):  
Ke Qiang Xie ◽  
Zhan Liang Yu ◽  
Wen Hui Ma ◽  
Yang Zhou ◽  
Yong Nian Dai
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Removal Efficiency ◽  
Acid Concentration ◽  
Operating Conditions ◽  
Raw Material ◽  
Optimum Operating ◽  
Pressure Leaching ◽  
Metallurgical Grade Silicon ◽  
Grade Silicon

In this paper, removal of iron from metallurgical grade silicon with pressure leaching is carried out. We investigated the factors such as the concentration of hydrochloric, particle size of raw material ground, temperature, pressure and reaction time, which influenced on the removal of iron. The results show that the optimum operating conditions for pressure leaching in hydrochloride are: acid concentration 4 mol/L, diameter for raw material less than 50 μm, leaching temperature 160 0C，leaching pressure 2.0 MPa, leaching time 2.0 h. The content of iron residual in MG-Si powder was reduced to about 200 ppmw. The removal efficiency of iron is up to 90.90 %.

scholarly journals Optimization of the Spent Activated Carbon Regeneration with the Radical Based Advanced Oxidation Processes: Preference of the Most Suitable Process by PROMETHEE Approach

2021 ◽  
Author(s):  
Nevim Genç ◽  
Elif Durna ◽  
Esin KACIRA
Keyword(s):  
Activated Carbon ◽  
Advanced Oxidation Processes ◽  
Operating Cost ◽  
Advanced Oxidation ◽  
Operating Conditions ◽  
Regeneration Process ◽  
Adsorptive Capacity ◽  
Optimum Conditions ◽  
Oxidation Processes ◽  
Regeneration Processes

Abstract In this study, regeneration of spent granular activated carbon (GAC) with reactive dye by hydroxyl and sulfate radical based advanced oxidation processes (Microwave (MW) + Persulfate (PS)), (Fe(II) + PS), and (O3 + H2O2) were evaluated. The adsorption of the dye to the GAC surface was characterized by chemisorption and Langmuir isotherm. Regeneration processes have been optimized by the Response Surface Methodology to determine the operating conditions that will provide the highest adsorptive capacity. The optimum conditions of (MW + PS), (Fe (II) + PS), and (O3 + H2O2) processes were (process PS anion of 45.52 g/L, pH of 11.4, MW power of 126 W, duration of 14.56 min), ( Fe (II) of 3.58 g/L, PS anion of 73.5 g/L, duration of 59.8 min, pH of 10.9) and (H2O2 of 2.8 mole/L, ozone dose of 98%, duration of 32.8 min, pH of 5.3), respectively. For (MW + PS), (Fe (II) + PS), and (O3 + H2O2) processes, the adsorptive capacity under optimum conditions were found as 4.36, 8.89 and 8.12 mg dye / g GAC respectively. For (Fe (II) + PS) and (O3 + H2O2) processes these values are approximately equal to the adsorptive capacity of raw GAC (8.01 mg dye / g GAC). The predicted values of the adsorption capacities by the obtained models were in good agreement with the actual experimental results. PROMETHEE approach was used in the preference of the appropriate regeneration process. The adsorptive capacity of regenerated GAC, operating cost of the regeneration process, change in the adsorptive capacity during the regeneration cycle and carbon mass loss criteria were taken into account. The order of preference of regeneration processes was determined as (Fe (II) + PS)> (MW + PS)> (O3 + H2O2) considering all criteria.

scholarly journals Synthesis and Scaling up of Fe3+ by Sol-gel Method Doped on Ceramic Foam for Decolorization of Reactive Red Dyeing Wastewater

2016 ◽  
pp. 47-58
Author(s):  
Pongsak Khaowin ◽  
Prukraya Pongyeela ◽  
Pichayapan Kongpanna ◽  
Juntima Chungsiriporn
Keyword(s):  
Removal Efficiency ◽  
Sol Gel ◽  
Operating Conditions ◽  
Color Removal ◽  
Ceramic Foam ◽  
Optimum Operating ◽  
Disperse Dyes ◽  
Flow Rates ◽  
Gel Method ◽  
Sol Gel Method

Wastewater from the Batiktextile industry contains large amounts of dyestuff together with significant amounts of suspended solids (SS), dispersing agents, salts and trace amounts of me-tals. Since this can lead to severe environmental problems, proper wastewater treatment pro-cesses are essential. The synthesis of Fe3+by sol-gel method doped on a ceramic foam for reac-tive red and disperse dyes removal from synthetic dye wastewater. Inthis research, the effect of color concentration, amount of catalyst and volumetric flow rates for industrial scale were studied.The Fe3+catalyst was prepared by sol-gel method in which 3M of FeCl3was used as a pre-cursor. The synthesized catalyst was characterized by the EDX spectrum from an X-ray spectro-meter. The surface morphology of the catalyst was investigated using a scanning electron microscope (SEM). To determine optimum operating conditions for catalytic testing, variations of disperse and reactive red concentrations (10 to 200 mg L-1) were used. The results indicated that the highest color removal efficiency (up to 96%) was observed when using Fe3+catalyst; 4 piecesper literof solution, and initial pH of 6.0. These conditions were then scaled up for a continuous packed bed column study. It was found that the optimal operating conditions obtained from the mathematical model for reactive red wastewater were: concentration of reactive red in the syn-thetic wastewater20 to 80 mg L-1; amounts of catalyst 432.5 to 1,730 mg and volumetric flow rates of wastewater20 to 200 mL min-1. Up to 84.85% of color removal efficiency was achieved.

Enhanced Degradation of Reactive Black 5 from Aqueous Solution over TiO2 Nanoparticles under UV Light Irradiation: Optimization, Experimental & Theoretical Approaches

2020 ◽  
Vol 8 (3) ◽  
pp. 1232-1241
Keyword(s):  
Tio2 Nanoparticles ◽  
Removal Efficiency ◽  
Uv Light ◽  
Operating Conditions ◽  
Light Irradiation ◽  
Optimum Operating ◽  
P Value ◽  
Reactive Black 5 ◽  
Theoretical Approaches ◽  
Uv Light Irradiation

In this study, the elimination of dye from contaminated water was considered by the photocatalytic process with TiO2. The effects of operational parameters like TiO2 dosage, initial dye concentration, pH, contact time and temperature on the rate of dye decomposition are studied. TiO2 nanoparticles were characterized by XRD, FESEM, and FTIR. The Response Surface Methodology was carried out to investigate the composition effect of input independent factors and removal efficiency (one dependent output response). The F-value (315.9), P-value (2.2 × 10−16), multiple R2 (0.9858), adjusted R2 (0.9827), and lack of fit (0.494) show that the reduced second-order model is greatly significant for dye removal by TiO2 nanoparticles. The efficacy of the process at the optimum operating conditions, pH=11, TiO2 dose (0.7 g/l), reaction time (67.5 minutes), Temperature (40 ℃), and initial dye concentration (55 mg/l) was 86.6%. By using regression coefficients derived from the model and the Solver “Add-ins”, higher removal efficiency was accounted to be 90%. The results showed that the TiO2 nanoparticles under UV light irradiation are very proper for reducing the concentration of pollutants in textile wastewater effluent.

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