Optimization of leachate treatment using persulfate/H2O2 based advanced oxidation process: case study: Deir El-Balah Landfill Site, Gaza Strip, Palestine

2015 ◽  
Vol 73 (1) ◽  
pp. 102-112 ◽  
Author(s):  
Ahmed H. Hilles ◽  
Salem S. Abu Amr ◽  
Rim A. Hussein ◽  
Anwar I. Arafa ◽  
Olfat D. El-Sebaie
Keyword(s):  
Reaction Time ◽  
Advanced Oxidation Process ◽  
Gaza Strip ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Leachate Treatment ◽  
Operating Variables ◽  
Treatment Processes ◽  
N Removal

The objective of this study was to investigate the performance of employing H2O2 reagent in persulfate activation to treat stabilized landfill leachate. A central composite design (CCD) with response surface methodology (RSM) was applied to evaluate the relationships between operating variables, such as persulfate and H2O2 dosages, pH, and reaction time, to identify the optimum operating conditions. Quadratic models for the following two responses proved to be significant with very low probabilities (<0.0001): chemical oxygen demand (COD) and NH3-N removal. The obtained optimum conditions included a reaction time of 116 min, 4.97 g S2O82−, 7.29 g H2O2 dosage and pH 11. The experimental results were corresponding well with predicted models (COD and NH3-N removal rates of 81% and 83%, respectively). The results obtained in the stabilized leachate treatment were compared with those from other treatment processes, such as persulfate only and H2O2 only, to evaluate its effectiveness. The combined method (i.e., /S2O82−/H2O2) achieved higher removal efficiencies for COD and NH3-N compared with other studied applications.

scholarly journals Car Wash Wastewater Treatment Using an Advanced Oxidation Process: A Rapid Technique for the COD Reduction of Water Pollutant Sources

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Reza Davarnejad ◽  
Kasra Sarvmeili ◽  
Meysam Sabzehei
Keyword(s):  
Reaction Time ◽  
Current Density ◽  
Advanced Oxidation Process ◽  
Volume Ratio ◽  
Operating Conditions ◽  
Molar Ratio ◽  
Optimum Operating ◽  
Car Wash ◽  
Water Pollutant ◽  
Car Wash Wastewater

In this paper, a car wash wastewater (CW) was treated by an economic and eco-friendly method called electro-Fenton (EF) technique. The experiments were conducted to investigate the effect of five important variables including reaction time, current density, pH, H2O2/Fe2+ molar ratio and H2O2/Car wash wastewater (mL/L) on the quality characteristics of wastewater such as COD, BOD5, TOC, TSS, heavy metals, EC, surfactants and hardness. By applying Box-Behnken design (BBD) and response surface methodology (RSM), the optimum operating conditions were obtained. The optimum conditions for COD [as a main factor in a wastewater (according to the environmental protocols)] removal of 68.72% were experimentally found at reaction time of 75.80 min, current density of 58.81 mA/cm2, pH of 3.02, volume ratio of H2O2/CW of 1.62 mL/L, H2O2/Fe2+ molar ratio of 3.66.

Evaluating photo-degradation of COD and TOC in petroleum refinery wastewater by using TiO2/ZnO photo-catalyst

2016 ◽  
Vol 74 (6) ◽  
pp. 1312-1325 ◽  
Author(s):  
Dheeaa al deen Atallah Aljuboury ◽  
Puganeshwary Palaniandy ◽  
Hamidi Bin Abdul Aziz ◽  
Shaik Feroz ◽  
Salem S. Abu Amr
Keyword(s):  
Reaction Time ◽  
Treatment Time ◽  
Removal Rate ◽  
Air Flow ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Removal Rates ◽  
Operational Conditions ◽  
Photo Catalyst

The aim of this study is to investigate the performance of combined solar photo-catalyst of titanium oxide/zinc oxide (TiO2/ZnO) with aeration processes to treat petroleum wastewater. Central composite design with response surface methodology was used to evaluate the relationships between operating variables for TiO2 dosage, ZnO dosage, air flow, pH, and reaction time to identify the optimum operating conditions. Quadratic models for chemical oxygen demand (COD) and total organic carbon (TOC) removals prove to be significant with low probabilities (<0.0001). The obtained optimum conditions included a reaction time of 170 min, TiO2 dosage (0.5 g/L), ZnO dosage (0.54 g/L), air flow (4.3 L/min), and pH 6.8 COD and TOC removal rates of 99% and 74%, respectively. The TOC and COD removal rates correspond well with the predicted models. The maximum removal rate for TOC and COD was 99.3% and 76%, respectively at optimum operational conditions of TiO2 dosage (0.5 g/L), ZnO dosage (0.54 g/L), air flow (4.3 L/min), reaction time (170 min) and pH (6.8). The new treatment process achieved higher degradation efficiencies for TOC and COD and reduced the treatment time comparing with other related processes.

scholarly journals Enzymatic Transesterification of Waste Frying Oil from Local Restaurants in East Colombia Using a Combined Lipase System

2020 ◽  
Vol 10 (10) ◽  
pp. 3566
Author(s):  
Mary Angélica Ferreira Vela ◽  
Juan C. Acevedo-Páez ◽  
Nestor Urbina-Suárez ◽  
Yeily Adriana Rangel Basto ◽  
Ángel Darío González-Delgado
Keyword(s):  
Reaction Time ◽  
Methyl Esters ◽  
Enzyme Concentration ◽  
Operating Conditions ◽  
Frying Oil ◽  
Biodiesel Production ◽  
Optimum Operating ◽  
Waste Frying Oil ◽  
Production Chain ◽  
Enzymatic Transesterification

The search for innovation and biotechnological strategies in the biodiesel production chain have become a topic of interest for scientific community owing the importance of renewable energy sources. This work aimed to implement an enzymatic transesterification process to obtain biodiesel from waste frying oil (WFO). The transesterification was performed by varying reaction times (8 h, 12 h and 16 h), enzyme concentrations of lipase XX 25 split (14%, 16% and 18%), pH of reaction media (6, 7 and 8) and reaction temperature (35, 38 and 40 °C) with a fixed alcohol–oil molar ratio of 3:1. The optimum operating conditions were selected to quantify the amount of fatty acid methyl esters (FAMEs) generated. The highest biodiesel production was reached with an enzyme concentration of 14%, reaction time of 8 h, pH of 7 and temperature of 38 °C. It was estimated a FAMEs production of 42.86% for the selected experiment; however, best physicochemical characteristics of biodiesel were achieved with an enzyme concentration of 16% and reaction time of 8 h. Results suggested that enzymatic transesterification process was favorable because the amount of methyl esters obtained was similar to the content of fatty acids in the WFO.

scholarly journals Process Analysis of PMMA Dental Resins Scraps Depolimerization: Optimization of Reaction Time and Temperature

2021 ◽  
Author(s):  
Paulo Bisi dos Santos Jr. ◽  
Haroldo Jorge da Silva Ribeiro ◽  
Armando Costa Ferreira ◽  
Caio Campos Ferreira ◽  
Lucas Pinto Bernar ◽  
...  
Keyword(s):  
Refractive Index ◽  
Reaction Time ◽  
Liquid Phase ◽  
Kinematic Viscosity ◽  
Process Analysis ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Dental Resins ◽  
Liquid Products ◽  
The Cross

In this work, the cross-linked PMMA-based dental resins scraps were submitted to pyrolysis to recover MMA (Methylmethacrylate). The thermal degradation of cross-linked PMMA-based dental resins scraps was analyzed by TG/DTG to guide the operating conditions in pilot scale. The pyrolysis experiments carried out in a reactor of 143L, at 345, 405, and 420°C, 1.0 atmosphere. The reaction liquid products obtained at 345°C, physicochemical characterized for density, kinematic viscosity, and refractive index. The chemical composition of liquid products obtained at 345°C, 30, 40, 50, 60, 70, 80, and 110 minutes, at 405°C, 50, 70, and 130 minutes, and at 420°C, 40, 50, 80, 100, 110, and 130 minutes determined by GC-MS. The experiments show that liquid phase yields were 55.50%, 48.73%, and 48.20% (wt.), at 345, 405, and 420°C, respectively, showing a smooth sigmoid behavior, decreasing with increasing temperature, while that of gas phase were 31.69%, 36.60%, and 40.13% (wt.), respectively, increasing with temperature. The liquid products density, kinematic viscosity, and refractive index obtained at 30, 40, 50, 60, 70, 80, and 110 minutes, varied between 0.9227 and 0.9380 g/mL, 0.566 and 0.588 mm2/s, and 1.401 and 1.414, respectively, showing percentage deviations between 0.74 and 2.36%, 7.40 and 10.86%, and 0.00 and 0.92%, respectively, compared to standard values for density, kinematic viscosity, and refractive index of pure MMA at 20 °C. The GC-MS identified in the reaction liquid products at 345, 405, and 420°C, 1.0 atm, esters of carboxylic acids, alcohols, ketones, and aromatics, showing concentrations of MMA between 83.454 and 98.975% (area.). For all the depolymerization experiments, the concentrations of MMA in the liquid phase, between 30 and 80 minutes, reach purities above 98% (area.), decreasing drastically with increasing reaction time after 100 minutes, thus making it possible to depolymerize the cross-linked PMMA-based dental resins scraps by pyrolysis to recover MMA. The optimum operating conditions to achieve high MMA concentrations, as well as elevated yields of liquid reaction products were 345 °C and 80 minutes.

Taguchi Approach and ANOVA in Optimization of the Dissolution of Colemanite in CO2 and SO2- Water Systems

2020 ◽  
Vol 10 (2) ◽  
pp. 88-97
Author(s):  
Zafer Ekinci ◽  
Esref Kurdal ◽  
Meltem Kizilca Coruh
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Gas Flow ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Process Conditions ◽  
Liquid Ratio ◽  
Positive Effects ◽  
Controllable Factors

Background: Turkey is approximately 72% of the world’s boron sources. Colemanite, tincal, ulexite and pandermite are among the most significant in Turkey. Boron compounds and minerals are widely used in many industrial fields. Objective: The main purpose of this study was to investigate the control of impurities in the boric acid production process using colemanite by carrying out the reaction with a mixture of CO2 and SO2 - water, and determining the appropriate process conditions to develop a new process as an alternative to the use of sulfuric acid. Due to worrying environmental problems, intensive studies are being carried out globally to reduce the amount of CO2 and SO2 gases released to the atmosphere. Methods: The Taguchi method is an experimental design method that minimizes the product and process variability by selecting the most appropriate combination of the levels of controllable factors compared to uncontrollable factors. Results: It was evaluated the effects of parameters such as reaction temperature, solid-to liquid ratio, SO2/CO2 gas flow rate, particle size, stirring speed and reaction time. The optimum conditions determined to be reaction temperature of 45°C; a solid–liquid ratio of 0.083 g.mL−1; an SO2/CO2 ratio of 2/2 mL.s−1; a particle size of -0.354+0 .210 mm; a mixing speed of 750 rpm and a reaction time of 20 min. Conclusion: Under optimum operating conditions, 96.8% of colemanite was dissolved. It is thought that the industrial application of this study will have positive effects on the greenhouse effect by contributing to the reduction of CO2 and SO2 emissions that cause global warming.

Optimization of Continuously Stirred Tank Bioreactor Design for Cost Minimization: Effect of Microbial Species and Operating Conditions

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Erin E Powell ◽  
Gordon A Hill
Keyword(s):  
Culture Medium ◽  
Operating Cost ◽  
Oxygen Demand ◽  
Design Strategy ◽  
Aeration Rate ◽  
Operating Conditions ◽  
Stirred Tank ◽  
Optimum Operating ◽  
Stirred Tank Bioreactor ◽  
Microbial Species

The operation of continuously stirred tank bioreactors (CSTBs) at minimum cost is a major concern of operators. In this work, a CSTB design strategy is presented where impeller stirring speed and aeration rate are optimized to meet the oxygen demand of growing cells, simultaneously minimizing the capital and operating cost. The operating cost is limited to the cost of utilities. The optimization scheme assumes a given fermentor tank size, and that the properties of the culture medium and the oxygen respiratory requirements of the microorganisms being cultivated are known. It is possible to choose between two different turbine impellers during the design process. The equations, constraints, and the CSTB design strategy employed by the program are described. The effect of microbial species, ions in the culture medium, impeller style, as well as changing CSTB size and biomass input density on the optimum operating conditions, is examined. The mass transfer coefficient, gas holdup, mixing speed, and aeration rate are all reported at optimized cost conditions. A study of the effects of various parameters on the CSTB design are shown.

scholarly journals A Model for Optimal Treatment of Cassava Wastewater Using Anaerobic Baffled Reactor

2021 ◽  
Vol 18 (2) ◽  
pp. 129-134
Author(s):  
A.O. Ibeje ◽  
E. Onukwugha
Keyword(s):  
Experimental Data ◽  
Wastewater Treatment ◽  
Aspect Ratio ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Utilization Rate ◽  
Treatment Processes ◽  
Cyanide Inhibition ◽  
Cassava Wastewater ◽  
Influent Flow

The major components of the effluents from cassava processing industries are cyanide and starch. However it is suspected that cyanide inhibits the treatment of cassava wastewater. The experimental data were successfully fitted to a polynomial model which was used to optimize the treatment processes at a laboratory scale. The Monod and Michealis-menten models for cassava wastewater treatment was successfully calibrated and validated in an ABR system. For Michealis-Menten model, the maximum substrate utilization rate is estimated in the range: 2866.88 to 1432.84 mgl-1 and for Monod’s model, it is estimated in the range: 493 to 1242 mgl-1, which is more realistic, hence validating the empirical model as more accurate than the former, which is theoretical. The result revealed that the inhibitor constant decreased from 9.9989 to 1.6101mgl-1 as the number of baffles increased from 3 to 10. To reach a maximum COD removal efficiency of 99%, it was found that the aspect ratio of 10, 20 baffles, cyanide inhibition constant of 30 mg/l and influent flow rate of 0.8 l/min, are the required optimum operating conditions of the anaerobic baffled reactors.

scholarly journals Demulsification Treatment of Spent Metalworking Fluids by Metal Cations: The Synergistic Effect and Efficiency Evaluation

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1807
Author(s):  
Yanqing Zhang ◽  
Lingxue Wu ◽  
Xiaochen Zhang ◽  
Baoxin Ge ◽  
Yuanfeng Qi
Keyword(s):  
Reaction Time ◽  
Synergistic Effect ◽  
Metal Ions ◽  
Metal Ion ◽  
Operating Cost ◽  
Operating Conditions ◽  
Metalworking Fluids ◽  
Optimum Operating ◽  
Efficiency Evaluation ◽  
Automobile Parts

In this paper, various metal ions were utilized for the demulsification of spent metalworking fluids discharged from an automobile parts workshop. Five types of metal ions, i.e., Fe3+, Al3+, Fe2+, Ca2+ and Mg2+, combined with coagulant were systematically evaluated, and the synergistic effect as well as the optimum operating conditions were studied. The results indicated that the Ca2+ as well Mg2+ possessed hardly efficiency for the demulsification, on the contrary, Fe2+ reduced the yield of the by-product sludge and lowered the SV30 ratio, and Al3+ boosted the CODCr removal. Furthermore, Fe3+ and Al3+ had a significant synergistic effect to achieve a better transmittance and a higher CODCr/SV30 ratio which revealed that more CODCr was removed, as well as less by-product sludge was generated. For a better demulsification of spent metalworking fluids, the optimum operating conditions were gathered as follows: the dosage of metal ions was 0.08 mol/L with Al3+:Fe3+ ratio was 1.5:1, the reaction pH was 6.00, the reaction time was 18.00 min and the temperature was 323.00 K. Based on this, the CODCr removal, the SV30 ratio and the transmittance and CODCr/SV30 ratio of the spent metalworking fluids were 80.21%, 40.00%, 95.20% and 128.33 mg/mL, respectively. This combined metal ion demulsification method possessed an advantageous minimization of spent metalworking fluids, which greatly benefited the automobile parts workshops in cutting down the operating cost in environmental protection.

scholarly journals Inorganic carbon removal from refinery wastewater by using TiO2/ZnO/Fenton photocatalyst

2018 ◽  
Vol 20 (2) ◽  
pp. 216-225
Keyword(s):  
Inorganic Carbon ◽  
Treatment Time ◽  
Removal Rate ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Refinery Wastewater ◽  
Operational Conditions ◽  
Operating Variables ◽  
Solar Photocatalyst ◽  
Quadratic Models

The aim of this study is to investigate the performance of the solar photocatalyst of TiO2/ZnO/Fenton process to treat the refinery wastewater and remove inorganic carbon (IC) which potentially toxic to human, aquatic and microorganism life. Central composite design with response surface methodology was used to evaluate the relationships between operating variables for TiO2 dosage, ZnO dosage, Fe2+ dosage, H2O2 dosage, and pH to identify the optimum operating conditions. Quadratic models for inorganic carbon (IC) removal and residual iron prove to be significant with low probabilities (<0.0001). The (IC) removal rates and residual iron correspond well with the predicted models. The maximum removal rate for IC and residual iron was 92.3% and 0.013, respectively at optimum operational conditions of a TiO2 dosage (0.3 g/l), ZnO dosage (0.58 g/l), Fe2+ dosage (0.02 g/l), H2O2 dosage (2.7 g/l), and pH (7). The treatment process achieved higher degradation efficiencies for IC and reduced the treatment time comparing with other related processes.

An attempt to understand dissolved air flotation using multivariate data analysis

1995 ◽  
Vol 31 (3-4) ◽  
pp. 191-201 ◽  
Author(s):  
Milos Krofta ◽  
Banda Herath ◽  
David Burgess ◽  
Larry Lampman
Keyword(s):  
Municipal Wastewater ◽  
Suspended Solid ◽  
Operating Conditions ◽  
Effluent Water ◽  
Dissolved Air Flotation ◽  
Multivariate Technique ◽  
Operating Variables ◽  
Treatment Processes ◽  
Air Flotation ◽  
Dissolved Air

In order to optimize the dissolved air flotation (DAF) process, a mathematical relationship should be established between the operating variables and the quality of the effluent water. In this study, operating parameters, including influent wastewater characteristics, were related to suspended solid (SS), COD, BOD5 and turbidity of the effluent via an empirical mathematical model. The data presented in this study were obtained from a pilot plant DAF study carried out on municipal wastewater at Lee, Massachusetts to determine the operating conditions for the wastewater clarification. Response surface methodology was used to determine optimal conditions and to study the variations of flotation behaviour with varying operating conditions. The multivariate technique used in this study is an extremely valuable tool to analyze data obtained from actual wastewater treatment processes where the characteristics of the wastewater are constantly changing. Without such a tool it may not be possible to draw valid conclusions. In addition, this technique requires comparatively fewer experiments when compared to traditional methods. Addition of more flocculant and recycle water over what is required actually decreases the effluent water quality. Tests carried out with the same DAF unit at Little Rock, Arkansas and Birmingham, Alabama have confirmed the accuracy of the predictions from the model.

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