scholarly journals Application of a multiple criteria analysis for the selection of appropriate radical based processes in treatment of car wash wastewater

2020 ◽  
Vol 26 (2) ◽  
pp. 200115-0
Author(s):  
Elif DURNA ◽  
Nevim GENÇ
Keyword(s):  
Operating Cost ◽  
Operating Conditions ◽  
Cod Removal ◽  
Optimum Operating ◽  
Combined Processes ◽  
Preference Order ◽  
Effective Parameters ◽  
Pareto Analysis ◽  
Car Wash ◽  
Car Wash Wastewater

In this study, the treatment of car wash wastewater was investigated by radical based hybrid/combined processes. Proposed processes, (Microwave (MW) + persulfate (PS) + Electrocoagulation (EC)), (ozone (O3) + PS + EC) and (MW + PS + O3), were optimized with Taguchi orthogonal array technique for maximum COD removal. The COD removal under optimum conditions was obtained to be 84%, 64.9% and 61.4%, for (MW + PS+ EC), (O3 + PS+ EC) and (MW + PS+ O3) processes, respectively. Operating costs for (MW + PS + EC), (O3 + PS + EC) and (MW + PS + O3) processes have been calculated as 0.2614, 0.1335 and 0.2653 €/L wastewater under optimum operating conditions. Pareto analysis showed that MW time and PS dose are very effective parameters but especially ozone related parameters have no significant effect on COD removal. Processes were evaluated with the PROMETHEE approach in terms of treatment efficiency, operating cost, sludge formation, and preferability criteria to determine the most suitable among the three alternative processes. As a result, the preference order of the processes for the treatment of car wash wastewater with radical based treatment processes was found as (MW + EC + PS) > (MW + O3 + PS) > (O3 + EC + PS).

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.

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 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.

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 Removal of COD and BOD from biologically treated municipal wastewater by electrochemical treatment

2013 ◽  
Vol 5 (2) ◽  
pp. 475-481 ◽  
Author(s):  
Arun Kumar Sharma ◽  
A. K. Chopra
Keyword(s):  
Municipal Wastewater ◽  
Operating Cost ◽  
Operating Time ◽  
Sewage Treatment Plant ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Initial Ph ◽  
Treated Municipal Wastewater ◽  
Maximum Removal

The present investigation observed the effect of current density (CD), operating time (OT), inter electrode distance (IED), electrode area (EA), initial pH and settling time (ST) using Fe-Fe electrode combination on the removal of chemical oxygen demand (COD) and biochemical oxygen demand (BOD) from biologically treated municipal wastewater (BTMW) of Sewage Treatment Plant (STP). The maximum removal of COD (92.35%) from BTMW was found with the optimum operating conditions of CD (2.82 A/m2), OT (40 mins.), IED (0.5 cm), EA (160 cm2), initial pH (7.5) and ST (60 min.), while the maximum removal of BOD (84.88%) was found with the ST (30 min.) at the same operating conditions. There was no need of pH adjustment of the BTMW during ET as the optimal removal efficiency was close to the pH of 7.5. Under optimal operating conditions, the operating cost was found to be 54.29 Rs./m3 / 1.08 US$/m3 in terms of the electrode consumption (78.48 x 10-5 kg Al/m3 ) and energy consumption (108.48 Kwh/m3).

scholarly journals Mineralization of Hazardous Waste Landfill Leachate using Photo-Fenton Process

2018 ◽  
Vol 65 ◽  
pp. 05012 ◽  
Author(s):  
Pradeep Kumar Singa ◽  
Mohamed Hasnain Isa ◽  
Yeek-Chia Ho ◽  
Jun-Wei Lim
Keyword(s):  
Reaction Time ◽  
Operating Conditions ◽  
Cod Removal ◽  
Molar Ratio ◽  
Optimum Operating ◽  
Fenton Process ◽  
Batch Mode ◽  
Fenton Reagents ◽  
Uv Lamp ◽  
Fenton Oxidation Process

This study was conducted to evaluate the COD removal efficiency of Photo-Fenton oxidation process. The reagents used in the Photo-Fenton process are catalyst Fe2+ and H2O2 as oxidizing agent. A 16W UV lamp was used to carry out the experiments. All the experiments were performed in batch mode to investigate the influence of operating conditions viz., Fenton reagents dosage, molar ratio and reaction time. The maximum COD removal observed was 68% under optimum operating conditions. The operating conditions H2O2/Fe2+ molar ratio = 3 and reaction time = 90 minutes were found to optimum. The dosages of Fenton reagents i.e. hydrogen peroxide and Fe2+ were optimum at 0.09 mol/L and 0.03 mol/L respectively.

High-Rate Nitrification in a Biological Fluidized Bed

1990 ◽  
Vol 22 (1-2) ◽  
pp. 431-442 ◽  
Author(s):  
P. F. Cooper ◽  
S. C. Williams
Keyword(s):  
Fluidized Bed ◽  
Operating Cost ◽  
Operating Conditions ◽  
High Rate ◽  
Optimum Operating ◽  
Secondary Effluent ◽  
Below Ground ◽  
Demonstration Plant ◽  
Technical Evaluation ◽  
Volumetric Loading

The use of a Biological Fluidized Bed (BFB) was evaluated in a large demonstration plant for nitrification of a secondary effluent at Horley STW (South of London). The BFB was operated over a range of flows from 250→600 m3/d using effluents containing 25mg NH3-N/ℓ, 18mg BOD/ℓ to define the optimum operating conditions. It was possible to reduce from 27 down to 3mg NH3-N/ℓ in a contact time of only 38 mins (a volumetric loading of 1 kg NH3-N/m3.d). The unit was then operated under diurnal flow. A 20m deep below-ground downflow-bubble-contact oxygenator was used which was capable of dissolving 60mg 02/ℓ. Following the technical evaluation, an economic comparison was made between using the add-on nitrifying BFB against the option of extending an existing activated sludge plant. The BFB had a lower capital cost but higher operating cost. The BFB was shown to be cost competitive.

scholarly journals Effect of some effective parameters on COD Removal from Nam Son Landfill Leachate by electrocoagulation

2017 ◽  
Vol 55 (5) ◽  
pp. 540
Author(s):  
Son Thanh Le ◽  
Khai Cao Le ◽  
Linh Tuan Doan ◽  
Anh Thi Doan
Keyword(s):  
Operating Time ◽  
Operating Conditions ◽  
Cod Removal ◽  
Current Intensity ◽  
Optimum Operating ◽  
Electrolysis Time ◽  
Leachate Treatment ◽  
Treatment Performance ◽  
Iron Electrodes ◽  
Removal Efficiencies

Leachate becomes ahead of wastewaters as being the most difficult to treat due to its complex and widely variable composition. In this research, the leachate treatment performance by electrocoagulation (EC) was studied. The samples of leachate were taken from Nam Son landfill in Hanoi. The effects of factors namely current intensity, electrolysis time, initial pH and anode materials on the EC performance were investigated via chemical oxygen demand (COD) removal efficiencies. The input leachate properties were obtained as COD, NH4+ and pH in the range of around 6247 ± 295, 1270 ± 38 mg/l and 8 ± 0.1, respectively. Mono-polar electrocoagulation unit was carried out in a batch system for leachate treatment with iron electrodes and approximately 1.8 litter of leachate. Firstly, with the increase in current (1 to 4A), the COD removal efficiencies increased from 50.00 to 78.57% (pH = 8 and operating time = 40 min). Secondly, by the increase in operating time, the treatment performance also went up significantly in first 40 min, then nearly level-off at above 73 % (pH=8, current intensity = 3A). In addition, the effect of pH in range of 5 to 10 on the electrocoagulation process was studied and showed the highest treatment efficiencies in neutral and mild alkaline medium, especially between 6 < pH < 8. Finally, the electrode materials made of iron and aluminum was investigated and the result indicated that when the iron anodes were replaced by aluminum, the COD removal efficiency experienced a considerable decline, from 70 to 37.93% (pH = 8 and operating time = 40 min). In combination of all experiments, the optimum operating conditions were achieved as iron electrodes, current intensity of 3A, electrolysis time of 40 min, the raw pH with iron electrodes, resulting the maximum COD removal efficiencies of 73.21%. As a result, the electrocoagulation can be applied to leachate pre-treatment.

scholarly journals Operating Cost Reduction of In-line Coagulation/Ultrafiltration Membrane Process Attributed to Coagulation Condition Optimization for Irreversible Fouling Control

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1076 ◽  
Author(s):  
Sung Yoo
Keyword(s):  
Cost Reduction ◽  
Operating Cost ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Minor Effect ◽  
Membrane Process ◽  
Charge Neutralization ◽  
Jar Test ◽  
Condition Optimization

This study examined the optimum coagulation conditions for reducing irreversible fouling during the in-line coagulation/ultrafiltration (UF) membrane process and assessed the decrease in operating cost. The coagulation conditions that generated charge-neutralization, sweep-flocculation, and under-dosing mechanisms were obtained by a jar-test, and a pilot-scale in-line coagulation/UF membrane process was operated under the coagulation conditions. Charge-neutralization and sweep-flocculation mechanisms reduced irreversible fouling effectively, and the under-dosing mechanism was able to reduce irreversible fouling only when flocs of a certain size or larger were formed. This revealed that floc size was a more important factor in reducing irreversible fouling than floc structure, and once initial cake layers were created by flocs of a fixed size, the structure of formed cake layers had only a minor effect on irreversible fouling. Regarding reduction in operating cost, 0.5 mg/L and 3 h, which were necessary to produce an under-dosing mechanism, were deemed the optimum coagulant dosage and coagulant injection time, respectively, to reduce irreversible fouling. In order to analyze the operating cost reduction effect, a pilot plant was operated under optimum operating conditions, and the total operating cost was approximately 11.2% lower than without in-line coagulation.

scholarly journals Influence of operating conditions on the electrolytic treatment for the removal of color, TSS, hardness and alkalinity using Al-Al electrode combination

2014 ◽  
Vol 6 (1) ◽  
pp. 279-285 ◽  
Author(s):  
Arun Kumar Sharma ◽  
A. K. Chopra
Keyword(s):  
Municipal Wastewater ◽  
Operating Cost ◽  
Operating Time ◽  
Sewage Treatment Plant ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Electrode Combination ◽  
Initial Ph ◽  
Maximum Removal ◽  
Electrolytic Treatment

The present investigation observed the effect of current density (CD), operating time (OT), inter electrode distance (IED), electrode area (EA), initial pH and settling time (ST) using Al-Al electrode combination on the removal of color, total suspended solids (TSS), hardness (HR) and alkalinity (ALK) from biologically treated municipal wastewater (BTMW) of Sewage Treatment Plant (STP), Jagjeetpur, Haridwar, India. The maximum removal of color (99.86%), TSS (98.7%), HR (78.9%) and ALK (43.69 %) from BTMW was found with the optimum operating conditions of CD (2.65 A/m2), OT (40 mins.), IED (0.5 cm), EA (160 cm2), initial pH (7.5) and ST (60 min.). However, the maximum removal of ALK was found with the optimum operating conditions of CD (1.68 A/m2), OT (40 mins.), IED (1.0 cm), EA (80 cm2), initial pH (7.5) and ST (90 min.) The electrolytic treatment ( ET) brought down the concentration of HR and ALK to the desirable limit of the BIS standards of drinking water. There was no need of pH adjustment of the BTMW during ET as the optimal removal efficiency was close to the pH of 7.5. Under optimal operating conditions, the operating cost was found to be 1.01 $/m3 in terms of the electrode consumption (23.71x 10-5 kg Al/m3) and energy consumption (101.76 Kwh/m3). The study revealed that BTMW can be effectively treated with the Al-Al electrode combination for color, TSS, HR and ALK removal.

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