A study by response surface methodology (RSM) on optimization of phosphorus adsorption with nano spherical calcium carbonate derived from waste

2019 ◽  
Vol 79 (1) ◽  
pp. 188-197 ◽  
Author(s):  
Shuo Deng ◽  
Yinguang Chen
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Phosphorus Removal ◽  
Contact Time ◽  
Adsorption Process ◽  
Polynomial Regression ◽  
Logistic Growth ◽  
Optimum Level ◽  
Phosphorus Adsorption ◽  
Initial Ph

Abstract A nano spherical CaCO3 (NSC) derived from solid waste (precipitated from tris(α-chloropropyl) phosphate and triethyl phosphate mixed wastewater) was prepared as adsorbent for phosphorus removal from aqueous solution. Response surface methodology (RSM) was used to develop an approach for the evaluation of phosphorus adsorption process, and Box-Behnken design was performed to investigate the effects of various experimental parameters (temperature, contact time, initial pH and dosage of absorbent) on phosphorus adsorption. The model results of experimental data gave a high correlation coefficient (R2 = 0.9658), and a predictive model of quadratic polynomial regression equation and optimum level values were established successfully. It was found that the adsorption efficiency and adsorption capacity reached 97.05% and 123.79 mg/g, respectively, under conditions of temperature of 45 °C, initial pH 5.3, contact time of 11 h, and absorbent amount of 392 mg/L. X-ray diffraction (XRD) analysis testified new phase, Ca10(PO4)6CO3, was produced in the adsorption process. Apart from that, adsorption behavior fitted well with the Langmuir isotherm model and logistic growth model. The thermodynamic study indicated that phosphorus removal by NSC as adsorbent was a spontaneous, endothermic, and mainly chemical adsorption process.

scholarly journals Application of response surface methodology for modeling and optimization of Bacillus subtilis spores inactivation by the UV/persulfate process

2016 ◽  
Vol 17 (2) ◽  
pp. 342-351 ◽  
Author(s):  
Zahra Sabeti ◽  
Mahmood Alimohammadi ◽  
Samira Yousefzadeh ◽  
Hassan Aslani ◽  
Maryam Ghani ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Bacillus Subtilis ◽  
Response Surface ◽  
Contact Time ◽  
Microbial Reduction ◽  
Subtilis Spore ◽  
Log Reduction ◽  
Surface Models ◽  
Initial Ph ◽  
Cryptosporidium Parvum Oocysts

Stronger disinfection techniques are required to inactivate Bacillus subtilis spores as surrogate microorganisms for Cryptosporidium parvum oocysts. In this study, the effects of UV and persulfate separately and also in combination were investigated on B. subtilis spore inactivation. Central composite design and response surface methodology were used to optimize target microorganism reduction. Contact time, initial pH, and persulfate dosage were considered as input experimental variables. Based on the design of the experiments, first and second order response surface models have been developed to correspond to the output response of B. subtilis spore reduction. It can be concluded that microbial reduction by UV alone was more effective than persulfate, while the combined UV/persulfate process demonstrated the highest log reduction (4.1) under the following optimal conditions: 60 min contact time, pH = 7.8, and persulfate dosage of 30 mM. On the other hand, the optimal condition for UV treatment was a contact time of 60 min at a pH of 5.0, which led to a 3.19 log spore inactivation. Consequently, the UV/persulfate system can be introduced as an alternative disinfectant for the inactivation of B. subtilis spores.

Optimisation of medium composition for probiotic biomass production using response surface methodology

2013 ◽  
Vol 81 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Masumeh Anvari ◽  
Gholam Khayati ◽  
Shora Rostami
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Yeast Extract ◽  
Polynomial Regression ◽  
Probiotic Bacterium ◽  
Medium Composition ◽  
Bifidobacterium Animalis ◽  
Extract Concentration ◽  
Initial Ph ◽  
Probiotic Biomass

This study was aimed to optimise lactose, inulin and yeast extract concentration and also culture pH for maximising the growth of a probiotic bacterium,Bifidobacterium animalissubsp.lactisin apple juice and to assess the effects of these factors by using response surface methodology. A second-order central composite design was applied to evaluate the effects of these independent variables on growth of the microorganism. A polynomial regression model with cubic and quadratic terms was used for analysis of the experimental data. It was found that the effects involving inulin, yeast extract and pH on growth of the bacterium were significant, and the strongest effect was given by the yeast extract concentration. Estimated optimum conditions of the factors on the bacterial growth are as follows: lactose concentration=9·5 g/l; inulin concentration=38·5 mg/l; yeast extract concentration=9·6 g/l and initial pH=6·2.

scholarly journals Removal of Pharmaceutical Micropollutants with Integrated Biochar and Marine Microalgae

2020 ◽  
Vol 9 (1) ◽  
pp. 4
Author(s):  
Amin Mojiri ◽  
Maedeh Baharlooeian ◽  
Reza Andasht Kazeroon ◽  
Hossein Farraji ◽  
Ziyang Lou
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Response Surface Methodology ◽  
Cell Viability ◽  
Response Surface ◽  
Contact Time ◽  
Marine Microalgae ◽  
Chaetoceros Muelleri ◽  
Mean Squared Errors ◽  
High Concentrations

Using microalgae to remove pharmaceuticals and personal care products (PPCPs) micropollutants (MPs) have attracted considerable interest. However, high concentrations of persistent PPCPs can reduce the performance of microalgae in remediating PPCPs. Three persistent PPCPs, namely, carbamazepine (CBZ), sulfamethazine (SMT) and tramadol (TRA), were treated with a combination of Chaetoceros muelleri and biochar in a photobioreactor during this study. Two reactors were run. The first reactor comprised Chaetoceros muelleri, as the control, and the second reactor comprised Chaetoceros muelleri and biochar. The second reactor showed a better performance in removing PPCPs. Through the response surface methodology, 68.9% (0.330 mg L−1) of CBZ, 64.8% (0.311 mg L−1) of SMT and 69.3% (0.332 mg L−1) of TRA were removed at the initial concentrations of MPs (0.48 mg L−1) and contact time of 8.1 days. An artificial neural network was used in optimising elimination efficiency for each MP. The rational mean squared errors and high R2 values showed that the removal of PPCPs was optimised. Moreover, the effects of PPCPs concentration (0–100 mg L−1) on Chaetoceros muelleri were studied. Low PPCP concentrations (<40 mg L−1) increased the amounts of chlorophyll and proteins in the microalgae. However, cell viability, chlorophyll and protein contents dramatically decreased with increasing PPCPs concentrations (>40 mg L−1).

scholarly journals Response surface methodology approach for the optimisation of adsorption of hydrolysed polyacrylamide from polymer-flooding wastewater onto steel slag: a good option of waste mitigation

2017 ◽  
Vol 76 (4) ◽  
pp. 776-784 ◽  
Author(s):  
Mijia Zhu ◽  
Jun Yao ◽  
Zhonghai Qin ◽  
Luning Lian ◽  
Chi Zhang
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Contact Time ◽  
Interactive Effect ◽  
Steel Slag ◽  
Oxygen Demand ◽  
Polymer Flooding ◽  
High Concentration ◽  
Adsorbent Dosage

Wastewater produced from polymer flooding in oil production features high viscosity and chemical oxygen demand because of the residue of high-concentration polymer hydrolysed polyacrylamide (HPAM). In this study, steel slag, a waste from steel manufacturing, was studied as a low-cost adsorbent for HPAM in wastewater. Optimisation of HPAM adsorption by steel slag was performed with a central composite design under response surface methodology (RSM). Results showed that the maximum removal efficiency of 89.31% was obtained at an adsorbent dosage of 105.2 g/L, contact time of 95.4 min and pH of 5.6. These data were strongly correlated with the experimental values of the RSM model. Single and interactive effect analysis showed that HPAM removal efficiency increased with increasing adsorbent dosage and contact time. Efficiency increased when pH was increased from 2.6 to 5.6 and subsequently decreased from 5.6 to 9.3. It was observed that removal efficiency significantly increased (from 0% to 86.1%) at the initial stage (from 0 min to 60 min) and increased gradually after 60 min with an adsorbent dosage of 105.2 g/L, pH of 5.6. The adsorption kinetics was well correlated with the pseudo-second-order equation. Removal of HPAM from the studied water samples indicated that steel slag can be utilised for the pre-treatment of polymer-flooding wastewater.

Electrocoagulation and nanofiltration integrated process application in purification of bilge water using response surface methodology

2016 ◽  
Vol 74 (3) ◽  
pp. 564-579 ◽  
Author(s):  
Ceyhun Akarsu ◽  
Yasin Ozay ◽  
Nadir Dizge ◽  
H. Elif Gulsen ◽  
Hasan Ates ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Cod Removal ◽  
Positive Sign ◽  
Aluminum Electrode ◽  
Integrated Process ◽  
Bilge Water ◽  
Cod Removal Efficiency ◽  
Initial Ph

Marine pollution has been considered an increasing problem because of the increase in sea transportation day by day. Therefore, a large volume of bilge water which contains petroleum, oil and hydrocarbons in high concentrations is generated from all types of ships. In this study, treatment of bilge water by electrocoagulation/electroflotation and nanofiltration integrated process is investigated as a function of voltage, time, and initial pH with aluminum electrode as both anode and cathode. Moreover, a commercial NF270 flat-sheet membrane was also used for further purification. Box–Behnken design combined with response surface methodology was used to study the response pattern and determine the optimum conditions for maximum chemical oxygen demand (COD) removal and minimum metal ion contents of bilge water. Three independent variables, namely voltage (5–15 V), initial pH (4.5–8.0) and time (30–90 min) were transformed to coded values. The COD removal percent, UV absorbance at 254 nm, pH value (after treatment), and concentration of metal ions (Ti, As, Cu, Cr, Zn, Sr, Mo) were obtained as responses. Analysis of variance results showed that all the models were significant except for Zn (P &gt; 0.05), because the calculated F values for these models were less than the critical F value for the considered probability (P = 0.05). The obtained R2 and Radj2 values signified the correlation between the experimental data and predicted responses: except for the model of Zn concentration after treatment, the high R2 values showed the goodness of fit of the model. While the increase in the applied voltage showed negative effects, the increases in time and pH showed a positive effect on COD removal efficiency; also the most effective linear term was found as time. A positive sign of the interactive coefficients of the voltage–time and pH–time systems indicated synergistic effect on COD removal efficiency, whereas interaction between voltage and pH showed an antagonistic effect.

Optimization of the Fermentation Conditions for 1-Deoxynojirimycin Production by Streptomyces lawendulae Applying the Response Surface Methodology

2011 ◽  
Vol 7 (3) ◽  
Author(s):  
Zhao-Jun Wei ◽  
Le-Chun Zhou ◽  
Hua Chen ◽  
Gui-Hai Chen
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Starch Content ◽  
Ultra Violet ◽  
Soluble Starch ◽  
High Yield ◽  
Yield Strain ◽  
Fermentation Time ◽  
Ethyl Sulfate ◽  
Initial Ph

Moranoline (1-Deoxynojirimycin, DNJ) is a piperidine alkaloid, and shows high inhibit activities to glucoamylase and ?-glucosidase. One DNJ high-yield strain of Streptomyces lawendulae was obtained after isolated form soil and mutated with the ultra violet (UV) and ethyl sulfate (DES), which named as TB-412, and can produce DNJ with 35.925 mg/L. Response surface methodology (RSM) was applied to optimize the parameters of DNJ yield from S. lawendulae TB-412. The effects of independent variables of fermentation, including time, temperature, initial pH and the soluble starch content were investigated. The statistical analysis showed that the fermentation time, pH and the soluble starch content, and the quadratics of time, temperature, pH and the soluble starch content, as well as the interactions between fermentation time and pH, and time and the soluble starch content, showed significant effects on DNJ yield. The optimal process parameters for DNJ production within the experimental range of the variables researched was at 11d, 27 °C, pH 7.5, and 8% soluble starch content. At this condition, the DNJ yield was predicted to be 42.875 mg/L.

scholarly journals Biosorption of lead ions by exopolysaccharide producing Azotobacter sp.

2021 ◽  
Vol 42 (1) ◽  
pp. 40-50
Author(s):  
P. Dhevagi ◽  
◽  
S. Priyatharshini ◽  
A. Ramya ◽  
M. Sudhakaran ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Response Surface ◽  
Functional Groups ◽  
Contact Time ◽  
Sewage Water ◽  
Energy Dispersive ◽  
X Ray ◽  
Scanning Electron

Aim: Removal of lead from wastewater using Azotobacter species and optimisation of various parameters to maximise the adsorption of lead by response surface methodology as a tool. Methodology: The bacterial isolate UBI-7 recovered from sewage water irrigated soil was examined for its biosorption potential towards lead. The lead removal efficiency of Azotobacter salinestris was studied with respect to metal concentration (50-250 mg l-1), contact time (24-120 hrs), and pH (4-8).Using response surface methodology, these factors were optimized and R2 value obtained was 0.9710 for lead ions, which indicates the validity of the model. Observation with Fourier Transform Infrared (FTIR), Scanning Electron Microscope imaging (SEM) and Energy Dispersive X-ray Spectroscopic analysis (EDX) were carried out to confirm lead biosorption by Azotobacter salinestris. Results: The lead tolerant bacterium isolated from sewage water irrigated soil (UBI-7) was recognized as Azotobacter salinestris by 16S rRNA based gene sequence analysis. The highest removal percentage of Pb (61.54) was 50 mg l-1 in 72 hrs equilibration period. Interaction effect between different levels of Pb and different contact time of the solution were found to be significant. Lead biosorption by the organism was confirmed by the changes in stretching intensities of functional groups as well as appearance of strong OH stretching at 3291.69 cm-1. Images obtained from Scanning Electron Microscope and Energy Dispersive X-ray Spectroscopic studies of the bacteria (UBI-7) before and after biosorption clearly indicated lead adsorption. Interpretation: Current study proves that the functional groups of Azotobacter salinestris are involved in lead biosorption from aqueous solution which was confirmed through FTIR.EDX analysis also elucidated the lead absorption by the bacterial cells. Hence, this could be effectively utilized for decontamination of lead from the polluted environment. Key words: Azotobacter salinestris, Biosorption, Lead, Response surface methodology

scholarly journals Optimization and Modeling of Microcystin-LR Degradation by TiO2 Photocatalyst Using Response Surface Methodology

2020 ◽  
Author(s):  
Negar Jafari ◽  
Afshin Ebrahimi ◽  
Karim Ebrahimpour ◽  
Ali Abdolahnejad
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Contact Time ◽  
High Performance ◽  
Operating Variables ◽  
Effective Removal ◽  
Positive Effect ◽  
Harmful Effects ◽  
Maximum Removal

Introduction: Microcystin-leucine arginine (MC-LR) is a toxin with harmful effects on the liver, kidney, heart, and gastrointestinal tract. So, effective removal of MC-LR from water resources is of great importance. The aim of this study was to remove microcystin-LR (MC-LR) from aqueous solution by Titanium Dioxide (TiO2). Materials and Methods: In the present study, TiO2, as a semiconductor, was used for photodegradation of MC-LR under ultraviolet light (UV). The Response Surface Methodology was applied to investigate the effects of operating variables such as pH (A), contact time (B), and catalyst dose (B) on the removal of MC-LR. The MC-LR concentration was measured by high-performance liquid chromatography (HPLC). Results: The results showed that single variables such as A, B, and C had significant effects on MC-LR removal (pvalue < 0.05). In other words, increase of the contact time and catalyst dose had a positive effect on enhancing the removal efficiency of MC-LR, but the effect of pH was negative. The analysis of variance showed that BC, A2, and C2 variables had a significant effect on the MC-LR removal (pvalue < 0.05). Finally, the maximum removal efficiency of MC-LR was 95.1%, which occurred at pH = 5, contact time = 30 minutes, and catalyst dose = 1 g/l. Conclusion: According to the findings, TiO2, as a photocatalyst, had an appropriate effect on degradation of the MC-LR.

scholarly journals ADSORPTION OF MALACHITE GREEN DYE USING SPENT COFFEE GROUND BIOCHAR: OPTIMISATION USING RESPONSE SURFACE METHODOLOGY

2020 ◽  
Vol 83 (1) ◽  
pp. 27-36
Author(s):  
Mardawani Mohamad ◽  
Rizki Wannahari ◽  
Rosmawani Mohammad ◽  
Noor Fazliani Shoparwe ◽  
Kwan Wei Lun ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Adsorption Capacity ◽  
Response Surface ◽  
Malachite Green ◽  
Contact Time ◽  
Quadratic Model ◽  
Adsorbent Dosage ◽  
Coffee Grounds ◽  
Spent Coffee Ground ◽  
Coffee Ground

Used coffee grounds usually end up as landfill. However, the unique structural properties of its porous surface make coffee grounds can be transformed into biochar and performed as an alternative low cost adsorbent. Malachite green (MG) is a readily water soluble dye which is used extensively in textile and aquaculture industries. The mordant complex structures of MG generate destructive effects to animals and environment. In this study, adsorption of malachite green using spent coffee ground biochar as adsorbent was investigated. The experiments were designed in two methods: classical and optimisation by response surface methodology. Three parameters were studied, which are adsorbent dosage, contact time and pH while the responses in this study are malachite green removal (%) and adsorption capacity (mg/g). Optimisation studies were performed using response surface methodology. Quadratic model was chosen for both response and studied using central composite design. The correlation coefficient, R2 for the quadratic model of malachite green removal (%) and adsorption capacity (mg/g) were 0.95 and 0.99, respectively. The optimum malachite green removal (%) predicted was found at 99.27%, by using 0.12 g of adsorbent dosage, 43.05 minutes of contact time and pH of 9.45 at desirability of 1.0. The optimum adsorption capacity (mg/g) predicted was found at 118.01 mg/g, by using 0.02 g of adsorbent dosage, 60 minutes of contact time and pH of 10.24 at desirability of 0.98. So, it was concluded that the spent coffee ground biochar can be used as an effective adsorbent for malachite green removal from aqueous solution.

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