scholarly journals Response Surface Methodology: Photocatalytic Degradation Kinetics of Basic Blue 41 Dye Using Activated Carbon with TiO2

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1068
Author(s):  
Emmanuel Kweinor Tetteh ◽  
Elorm Obotey Ezugbe ◽  
Dennis Asante-Sackey ◽  
Edward Kwaku Armah ◽  
Sudesh Rathilal

Water decontamination still remains a major challenge to some developing countries not having centralized wastewater systems. Therefore, this study presents the optimization of photocatalytic degradation of Basic Blue 41 dye in an aqueous medium by an activated carbon (AC)-TiO2 photocatalyst under UV irradiation. The mesoporous AC-TiO2 synthesized by a sonication method was characterized by X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy for crystal phase identification and molecular bond structures, respectively. The efficiency of the AC-TiO2 was evaluated as a function of three input variables viz. catalyst load (2–4 g), reaction time (15–45 min) and pH (6–9) by using Box-Behnken design (BBD) adapted from response surface methodology. Using color and turbidity removal as responses, a 17 run experiment matrix was generated by the BBD to investigate the interaction effects of the three aforementioned input factors. From the results, a reduced quadratic model was generated, which showed good predictability of results agreeable to the experimental data. The analysis of variance (ANOVA), signposted the selected models for color and turbidity, was highly significant (p < 0.05) with coefficients of determination (R2) values of 0.972 and 0.988, respectively. The catalyst load was found as the most significant factor with a high antagonistic impact on the process, whereas the interactive effect of reaction time and pH affected the process positively. At optimal conditions of catalyst load (2.6 g), reaction time (45 min), and pH (6); the desirability of 96% was obtained by a numerical optimization approach representing turbidity removal of 93% and color of 96%.

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Nichaonn Chumuang ◽  
Vittaya Punsuvon

The present study was performed to optimize a heterogeneous calcium methoxide (Ca(OCH3)2) catalyzed transesterification process assisted with tetrahydrofuran (THF) as a cosolvent for biodiesel production from waste cooking oil. Response surface methodology (RSM) with a 5-level-4-factor central composite design was applied to investigate the effect of experimental factors on the percentage of fatty acid methyl ester (FAME) conversion. A quadratic model with an analysis of variance obtained from the RSM is suggested for the prediction of FAME conversion and reveals that 99.43% of the observed variation is explained by the model. The optimum conditions obtained from the RSM were 2.83 wt% of catalyst concentration, 11.6 : 1 methanol-to-oil molar ratio, 100.14 min of reaction time, and 8.65% v/v of THF in methanol concentration. Under these conditions, the properties of the produced biodiesel satisfied the standard requirement. THF as cosolvent successfully decreased the catalyst concentration, methanol-to-oil molar ratio, and reaction time when compared with biodiesel production without cosolvent. The results are encouraging for the application of Ca(OCH3)2 assisted with THF as a cosolvent for environmentally friendly and sustainable biodiesel production.


2021 ◽  
Vol 9 (2) ◽  
pp. 470-479

The removal percentage of color from institutional wastewater was studied using an electrocoagulation process with different electrode combination at the anode and cathode. This was done by considering operational parameters such as pH at (3, 6 and 9), current at (0.03A, 0.06A and 0.09A) and reaction time at (20, 40 and 60 minutes). When electrode combined in the form of Al-Al (anode-Cathode/Cathode-Anode) and Fe-Fe (anode-Cathode/Cathode-Anode) the percentage removal of color was up to 95.50% and 97.24% respectively. On the other hand around 98.03% and 91.95% of color was removed when Al-Fe (Anode-Cathode) and Fe-Al (Anode-Cathode) combined at pH 9 and 60 minutes of reaction time respectively. Central composite design from response surface methodology was used up to analysis the statistical and mathematical data based on experimental results such as the model was significant for all electrode combinations. Similarly a quadratic model was used for further study of operational effects on the removal (%) of color from institutional wastewater. The value of coefficient of the determination (R2) also indicated the model was a good fit as well as optimization was done by Response Surface Methodology.


2019 ◽  
Vol 19 (4) ◽  
pp. 882
Author(s):  
Mohamad Shahrul Fizree Idris ◽  
Nur Hanis Adila Azhar ◽  
Fazira Firdaus ◽  
Siti Efliza Ashari ◽  
Siti Fairus Mohd Yusoff

Hydrogenated liquid natural rubber (HLNR) was synthesized from liquid natural rubber (LNR) by thermolysis of p-toluenesulfonyl hydrazide (TSH). The HLNR structure was characterized by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies. Thermogravimetric analysis (TGA) showed that the HLNR had higher decomposition temperature compared to LNR. A response surface methodology (RSM) based on a central composite rotatable design (CCRD) with five-level-three-factors was used to optimize the main important reaction parameters, such as the TSH:LNR weight ratio (1–3), reaction temperature (110–150 °C), and reaction time (1–8 h). A quadratic model was developed using this multivariate statistical analysis. Optimum conditions for the non-catalytic hydrogenation of LNR using TSH were obtained; an LNR hydrogenation percentage of 83.47% at a TSH:LNR weight ratio of 1.41, a reaction temperature of 118.11 °C, and a reaction time of 3.84 h were predicted. The R2 value of 0.9949 indicates that the model provides data that are well matched with those from the experiment.


2015 ◽  
Vol 16 (3) ◽  
pp. 783-793 ◽  
Author(s):  
Sajida Rasheed ◽  
Luiza. C. Campos ◽  
Jong. K. Kim ◽  
Qizhi Zhou ◽  
Imran Hashmi

A response surface methodology (RSM) applying central composite design with rotatable full factorial (14 non-center and six center points) was used to discern the effect of granular activated carbon (GAC), sand and pH on total trihalomethanes (TTHMs) and humic acid (HA) removal from drinking water. Results showed efficient TTHMs and HA removal by GAC while a sand column showed little effect for TTHMs but was significant for total organic carbon (TOC) removal. With GAC and a sand column of 4 cm, a pH increase from 6 to 8 caused an increase in TTHM removal from 79.8 to 83.6% while a decrease in HA removal from 26.6 to 6.6% was observed. An increase in GAC column depth from 10 to 20 cm caused a slight increase in TTHM removal from 99.4 to 99.7%, while TOC removal was increased from an average of 38.85% to 57.4% removal. The developed quadratic model for TTHM removal (p = 0.048) and linear model for TOC removal (p = 0.039) were significant. GAC column depth (p &lt; 0.0117) and column depth2 (p &lt; 0.039) were the most significant factors. A 98% TTHMs, 30%TOC and 51% residual chlorine removal were optimized at 9 cm GAC and 4 cm sand column depth at pH 8 with desirability factor (D) 0.64.


Author(s):  
Omar Abed Habeeb ◽  
Ramesh Kanthasamy ◽  
Gomaa A. M. Ali ◽  
Rosli Mohd Yunus

The main point of this study is to investigate the optimal conditions for preparation of activated carbon from wood sawdust (ACWSD) for removal of hydrogen sulfide (H2S) from wastewater. The response surface methodology (RSM) was employed to prepare the ACWSD by chemical activation with potassium hydroxide (KOH). The threepreparation  variables impact of activation temperature (724 – 1000 °C), KOH: precursor (wt%) impregnation ratio (IR) (2:1 – 4:1) and activation time (60 – 120 min) on removal efficiency (RE, %) of H2S and activated carbon yield (ACY, %) were investigated. The preparation parameters were correlated by developing a quadratic model depend on the central composite design (CCD) to the two responses. The analysis of variance (ANOVA) was identified the most influential variable on each experimental design responses. The results showed that the temperature of 854 °C, chemical impregnation ratio of 2.95 wt% and activation time of 80 min were the optimum conditions for preparation of ACWSD with responses of RE and ACY of 72.88 % and 31.89 %, respectively. It is concluded that the ACWSD was appeared to be a favorable substance for removal of dissolved H2S from synthetic wastewater.


2018 ◽  
Vol 9 (2) ◽  
pp. 163-172
Author(s):  
Mijia Zhu ◽  
Xianqing Yin ◽  
Wu Chen ◽  
Zhengji Yi ◽  
Heyong Tian

Abstract The removal of sulphate ions constitutes one of the main challenges in mining, metallurgical and other industries. This work evaluated sulphate removal from aqueous solutions by an electrocoagulation (EC)/raw straw activated carbon (RSAC) adsorption coupled process. The process parameters affecting sulphate removal efficiency were investigated: current density (0–100 mA/cm2), RSAC dosage (0–0.8 g/L), initial pH (4–9) and reaction time (0–40 min). A central composite design coupled with response surface methodology (RSM) was used to construct a mathematic model of EC/RSAC process that considers three key variables, namely current density, RSAC dosage and reaction time. Under optimum conditions (current density of 75 mA/cm2, dosage of 0.46 g/L and reaction time of 19.2 min), the removal efficiency of sulphate reached 95.2%. The RSM predictive value was 94.08% with a small deviation (1.12%). Thus, the fundamental data and results can provide some useful information for further studies and applications of the EC/RSAC coupled system in sulphate-containing wastewater treatment.


Author(s):  
Abrar Muslim ◽  
Marwan Marwan ◽  
Ramli Saifullah ◽  
Muhammad Yahya Azwar ◽  
Darmadi Darmadi ◽  
...  

2019 ◽  
pp. 49-59
Author(s):  
Nu Linh Giang Ton ◽  
Thi Hoai Nguyen ◽  
Quoc Hung Vo

Avocado peel has been considered as a potential source of natural antioxidants in which phenolics are among the most important compounds. Therefore, this study aims to optimize the extraction process of phenolics using response surface methodology and evaluate the corresponding antioxidant activity. From the quadratic model, the optimal condition was determined including the ethanol concentration 54.55% (v/v), the solvent/solute ratio 71.82/1 (mL/g), temperature 53.03 oC and extraction time 99.09 min. The total phenolic content and the total antioxidant capacity at this condition with minor modifications were 26,74 ± 0,04 (mg GAE/g DW) and 188.06 ± 1.41 (mg AAE/g DW), respectively. The significant correlation between total phenolic content and total antioxidant capacity was also confirmed. Key words: response surface methodology, central composite rotatable design, total phenolic content, total antioxidant capacity, avocado peel


Sign in / Sign up

Export Citation Format

Share Document