scholarly journals Biological treatment of a synthetic dairy wastewater in a sequencing batch biofilm reactor: Statistical modeling using optimization using response surface methodology

2011 ◽  
Vol 17 (4) ◽  
pp. 485-495 ◽  
Author(s):  
A.A.L. Zinatizadeh ◽  
Y. Mansouri ◽  
A. Akhbari ◽  
S. Pashaei

In this study, the interactive effects of initial chemical oxygen demand (CODin), biomass concentration and aeration time on the performance of a lab-scale sequencing batch biofilm reactor (SBBR) treating a synthetic dairy wastewater were investigated. The experiments were conducted based on a central composite design (CCD) and analyzed using response surface methodology (RSM). The region of exploration for treatment of the synthetic dairy wastewater was taken as the area enclosed by the influent comical oxygen demand (CODin (1000, 3000 and 5000 mg/l)), biomass concentration (3000, 5000 and 7000 mg VSS/l) and aeration time (2, 8 and 18 h) boundaries. Two dependent parameters were measured or calculated as response. These parameters were total COD removal efficiency and sludge volume index (SVI). The maximum COD removal efficiencies (99.5%) were obtained at CODin, biomass concentration and aeration time of 5000 mg COD/l, 7000 mg VSS/l and 18 h, respectively. The present study provides valuable information about interrelations of quality and process parameters at different values of the operating variables.

2018 ◽  
Vol 78 (2) ◽  
pp. 379-389 ◽  
Author(s):  
Sonalika Sonal ◽  
Astha Singh ◽  
Brijesh Kumar Mishra

Abstract The aim of the present study was to investigate the performance of a novel coagulant, i.e. ZrOCl2, for the removal of anthraquinone-based reactive dye from aqueous solution. An ideal experimental setup was designed based on central composite design using response surface methodology to determine the individual and interactive effects of different operational variables (i.e. pH, coagulant dose and dye concentration) on treatment performance in terms of dye and chemical oxygen demand (COD) removal efficiencies. Total 92.58% dye and 85.33% COD removal were experimentally attained at optimized conditions at low coagulant dose, i.e. 156.67 mg/L for the dye concentration of 105.67 mg/L at pH 2. To validate the working pH of the metal coagulant, the static charge of ZrOCl2 was measured using Eh value. The performance of the coagulant was validated with experimental and predicted values in the selected data set, and R2 values for both responses were found to be 0.99 and 0.95 respectively, which shows the reliability of the experimental design. Further, the toxicity of the coagulant was assessed and no such toxicity was found even up to the concentration of 500 mg/L, proclaiming the disposal of sludge may not exhibit any threat to humans. Experimental results suggested that the ZrOCl2 could be used as an eco-friendly coagulant for dye wastewater treatment.


2005 ◽  
Vol 51 (11) ◽  
pp. 95-103 ◽  
Author(s):  
H. Dulkadiroglu ◽  
E.U. Cokgor ◽  
N. Artan ◽  
D. Orhon

This study investigates the effect of temperature and the sludge age on the performance of a moving bed sequencing batch biofilm reactor (MBSBBR) for COD removal and nitrification. The experiments are conducted in a lab-scale MBSBBR operated at three different temperatures (20, 15 and 10 °C) with a synthetic feed simulating domestic sewage characteristics. Evaluation of the results revealed that removal of organic matter at high rates and with efficiencies over 90% was secured at all operation conditions applied. The nitrification rate was significantly influenced by changes in temperature but complete nitrification occurred at each temperature. The nitrification rates observed at 20 and 15 °C were very close (0.241 mg NOX-N/m2 d, 0.252 mg NOX-N/m2 d, respectively), but at 10 °C, it decreased to 0.178 mg NOX-N/m2 d. On the other hand, the biomass concentration and sludge age increased while the VSS/TSS ratios that can be accepted as an indicator of active biomass fraction decreased with time. It is considered that, increasing biofilm thickness and diffusion limitation affected the treatment efficiency, especially nitrification rate, negatively.


Author(s):  
Gholam Khayati ◽  
Morteza Barati

The biological treatments are convenient and economical methods for improving the efficiency of industrial waste water treatment. Activated sludge is the most important biological wastewater treatment processes. Batch cultures for the treatment of whey with activated sludge were optimized through response surface methodology (RSM). A second-order central composite design was applied to evaluate the effects of three independent variables (aeration time, pH and percentage of sludge volume) on COD removal percent. Optimum conditions were estimated through RSM at 23.4 h aeration time, pH=6.8 and 5.6 (%v/v) sludge volume/ wastewater volume and to achieve 38.1% COD removal. 1 (g/L) addition of PAC reduction COD until 48.7%.


2017 ◽  
Vol 76 (8) ◽  
pp. 2015-2031 ◽  
Author(s):  
Senem Yazici Guvenc ◽  
Hanife Sari Erkan ◽  
Gamze Varank ◽  
Mehmet Sinan Bilgili ◽  
Guleda Onkal Engin

This study deals with chemical oxygen demand (COD), phenol and Ca+2 removal from paper mill industry wastewater by electrocoagulation (EC) and electro-Fenton (EF) processes. A response surface methodology (RSM) approach was employed to evaluate the effects and interactions of the process variables and to optimize the performance of both processes. Significant quadratic polynomial models were obtained (R2 = 0.959, R2 = 0.993 and R2 = 0.969 for COD, phenol and Ca+2 removal, respectively, for EC and R2 = 0.936, R2 = 0.934 and R2 = 0.890 for COD, phenol and Ca+2 removal, respectively). Numerical optimization based on desirability function was employed; in a 27.55 min trial, 34.7% of COD removal was achieved at pH 9 and current density 96 mA/cm2 for EC, whereas in a 30 min trial, 74.31% of COD removal was achieved at pH 2 and current density 96 mA/cm2 and H2O2/COD molar ratio 2.0 for EF. The operating costs were calculated to be 6.44 €/m3 for EC and 7.02 €/m3 for EF depending on energy and electrode consumption at optimum conditions. The results indicate that the RSM is suitable for the design and optimization of both of the processes. However, EF process was a more effective technology for paper mill industry wastewater treatment as compared with EC.


2021 ◽  
Author(s):  
Miriam Appiah-Brempong ◽  
Helen Michelle Korkor Essandoh ◽  
Nana Yaw Asiedu ◽  
Samuel Kwame Dadzie ◽  
Francis Yao Momade

Abstract There is a dearth in knowledge on artisanal tannery wastewater treatment as most studies are focused on treatment of wastewater generated from modern-day leather manufacturing industries. The extensive use of plant materials in artisanal tanneries introduces high loads of polyphenolic compounds in the wastewater rendering biological treatment of the wastewater ineffective. This study, therefore, employed coagulation-flocculation process to pre-treat artisanal tannery wastewater with the aim of applying the central composite design, a statistical approach in Response Surface Methodology (RSM) to model and optimize the removal of Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) and turbidity and to minimize Sludge Volume Index (SVI). Optimization process focused on the two most important influencing parameters: dosage of aluminium sulphate and initial pH of wastewater. Results revealed that optimal pH and aluminium sulphate dosage of 6.09 and 11.6g/L respectively could yield maximum removal efficiencies of 38.51% of COD, 76.05% of TSS and 79.64% of turbidity from the wastewater with a minimum SVI of 29.57mL/g. Further experiments conducted to validate these results showed a good agreement between the experimental and predicted results signifying the suitability of RSM for optimization of the coagulation treatment process. This is the first reported study on optimization of coagulation-flocculation treatment of artisanal tannery wastewater. Results of this study can be used practically for efficient pre-treatment of artisanal tannery wastewater.


2018 ◽  
Vol 2017 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Reza Shokoohi ◽  
Zahra Torkshavand ◽  
Hassan Zolghadnasab ◽  
Mohammad Yousef Alikhani ◽  
Meisam Sedighi Hemmat

Abstract Detergents are considered one of the important pollutants in hospital wastewater. Achieving efficient and bio-friendly methods for the removal of these pollutants is considered as a concern for environmental researchers. This study aims at studying the efficiency of a moving bed biofilm reactor (MBBR) system for removing linear alkyl benzene sulfonate (LAS) from hospital wastewater with utilization of response surface methodology (RSM). The present study was carried out on a reactor with continuous hydraulic flow using media k1 at pilot scale to remove detergent from hospital wastewater. The effect of independent variables including contact time, percentage of media filling and mixed liquor suspended solids (MLSS) concentration of 1000-3000 mg/l on the system efficiency were assessed. Methylene blue active substances (MBAS) and chemical oxygen demand (COD) 750-850 mg/l were used by closed laboratory method in order to measure the concentration of LAS. The results revealed that the removal efficiency of LAS detergent and COD using media k1, retention time of 24 hours, and MLSS concentration of around 3,000 mg/l were 92.3 and 95.8%, respectively. The results showed that the MBBR system as a bio-friendly compatible method has high efficiency in removing detergents from hospital wastewater and can achieve standard output effluent in acceptable time.


Author(s):  
SHANKAR B. UMA ◽  
Lakshmi Chandana M.V.V. ◽  
SRIDEVI V ◽  
LAKSHMI L. NEELIMA CHANDRA ◽  
◽  
...  

2021 ◽  
Vol 14 ◽  
pp. 117862212110281
Author(s):  
Ahmed S. Mahmoud ◽  
Nouran Y. Mohamed ◽  
Mohamed K. Mostafa ◽  
Mohamed S. Mahmoud

Tannery industrial effluent is one of the most difficult wastewater types since it contains a huge concentration of organic, oil, and chrome (Cr). This study successfully prepared and applied bimetallic Fe/Cu nanoparticles (Fe/Cu NPs) for chrome removal. In the beginning, the Fe/Cu NPs was equilibrated by pure aqueous chrome solution at different operating conditions (lab scale), then the nanomaterial was applied in semi full scale. The operating conditions indicated that Fe/Cu NPs was able to adsorb 68% and 33% of Cr for initial concentrations of 1 and 9 mg/L, respectively. The removal occurred at pH 3 using 0.6 g/L Fe/Cu dose, stirring rate 200 r/min, contact time 20 min, and constant temperature 20 ± 2ºC. Adsorption isotherm proved that the Khan model is the most appropriate model for Cr removal using Fe/Cu NPs with the minimum error sum of 0.199. According to khan, the maximum uptakes was 20.5 mg/g Cr. Kinetic results proved that Pseudo Second Order mechanism with the least possible error of 0.098 indicated that the adsorption mechanism is chemisorption. Response surface methodology (RSM) equation was developed with a significant p-value = 0 to label the relations between Cr removal and different experimental parameters. Artificial neural networks (ANNs) were performed with a structure of 5-4-1 and the achieved results indicated that the effect of the dose is the most dominated variable for Cr removal. Application of Fe/Cu NPs in real tannery wastewater showed its ability to degrade and disinfect organic and biological contaminants in addition to chrome adsorption. The reduction in chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), total phosphorus (TP), total nitrogen (TN), Cr, hydrogen sulfide (H2S), and oil reached 61.5%, 49.5%, 44.8%, 100%, 38.9%, 96.3%, 88.7%, and 29.4%, respectively.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Jalilzadeh ◽  
Ramin Nabizadeh ◽  
Alireza Mesdaghinia ◽  
Aliakbar Azimi ◽  
Simin Nasseri ◽  
...  

A systematic model for chemical oxygen demand (COD) removal using the ANAMMOX (Anaerobic AMMonium OXidation) process was provided based on an experimental design. At first, the experimental data was collected from a combined biological aerobic/anaerobic reactor. For modelling and optimization of COD removal, the main parameters were considered, such as COD loading, ammonium, pH, and temperature. From the models, the optimum conditions were determined as COD 97.5 mg/L, ammonium concentration equal to 28.75 mg-N/L, pH 7.72, and temperature 31.3°C. Finally, the analysis of the optimum conditions, performed by the response surface method, predicted COD removal efficiency of 81.07% at the optimum condition.


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