scholarly journals Enhancing the Decolorization of Methylene Blue Using a Low-Cost Super-Absorbent Aided by Response Surface Methodology

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4430
Author(s):  
Nor Hakimin Abdullah ◽  
Mazlan Mohamed ◽  
Norshahidatul Akmar Mohd Shohaimi ◽  
Azwan Mat Lazim ◽  
Ahmad Zamani Abdul Halim ◽  
...  

The presence of organic dyes from industrial wastewater can cause pollution and exacerbate environmental problems; therefore, in the present work, activated carbon was synthesized from locally available oil palm trunk (OPT) biomass as a low-cost adsorbent to remove synthetic dye from aqueous media. The physical properties of the synthesized oil palm trunk activated carbon (OPTAC) were analyzed by SEM, FTIR-ATR, and XRD. The concurrent effects of the process variables (adsorbent dosage (g), methylene blue (MB) concentration (mg/L), and contact time (h)) on the MB removal percentage from aqueous solution were studied using a three-factor three-level Box–Behnken design (BBD) of response surface methodology (RSM), followed by the optimization of MB adsorption using OPTAC as the adsorbent. Based on the results of the analysis of variance (ANOVA) for the three parameters considered, adsorbent dosage (X1) is the most crucial parameter, with an F-value of 1857.43, followed by MB concentration (X2) and contact time (X3) with the F-values of 95.60 and 29.48, respectively. Furthermore, the highest MB removal efficiency of 97.9% was achieved at the optimum X1, X2, and X3 of 1.5 g, 200 mg/L, and 2 h, respectively.

2021 ◽  
Vol 12 (4) ◽  
pp. 4567-4583

Tunics corm saffron (TCS) is a low-cost adsorbent that removes methylene blue (MB) from an aqueous solution. The TCS was characterized using FTIR and SEM analysis. The influence of MB adsorption variables such as TCS dose (0.4–2.4 g L−1), contact time (0–120 min), MB dye concentration (100–500 mg L−1) was optimized Box–Behnken design (BBD) combined with response surface methodology (RSM) modeling. All three variables among the main parameters significantly affected the removal efficiency by applying the quadratic regression analysis. The results showed that the predicted values for MB adsorption were close to the experimental values and were in good agreement. Besides, the r2 value (r2=0.970) indicates that the regression can predict response for the adsorption process in the studied range. The optimum BBD-RSM for MB removal of 89.48 % was recorded at a TCS dose of 1.78 g L−1, contact time of 56 min, MB dye concentration of 176 mg L–1 at solution pH of 5.4 temperature 21 °C. Excellent regeneration of TCS to remove MB in sixth consecutive adsorption-desorption cycles. This work highlights that TCS offers tremendous potential as a low-cost for organic dyes removal from wastewaters.


2017 ◽  
Vol 43 (2) ◽  
pp. 37-43 ◽  
Author(s):  
Yusuf Uzun ◽  
Tekin Şahan

Abstract Removal of mercury(II) (Hg(II)) from aqueous media by a new biosorbent was carried out. Natural Polyporus squamosus fungus, which according to the literature has not been used for the purpose of Hg(II) biosorption before, was utilized as a low-cost biosorbent, and the biosorption conditions were analyzed by response surface methodology (RSM). Medium parameters which were expected to affect the biosorption of Hg(II) were determined to be initial pH, initial Hg(II) concentration (Co), temperature (T (°C)), and contact time (min). All experiments were carried out in a batch system using 250 mL fl asks containing 100 mL solution with a magnetic stirrer. The Hg(II) concentrations remaining in fi ltration solutions after biosorption were analyzed using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Based on the RSM results, the optimal conditions were found to be 5.30, 47.39 mg/L, 20°C and 254.9 min for pH, Co, T (°C), and contact time, respectively. Under these optimal conditions, the maximum biosorbed amount and the biosorption yield were calculated to be 3.54 mg/g and 35.37%, respectively. This result was confi rmed by experiments. This result shows that Polyporus squamosus has a specifi c affi nity for Hg ions. Under optimal conditions, by increasing the amount of Polyporus squamosus used, it can be concluded that all Hg ions will be removed


2021 ◽  
Vol 4 (1) ◽  
pp. 25-30
Author(s):  
Farah Amni Daud ◽  
Norhisyam Ismail ◽  
Rozidaini Mohd Ghazi

The release of dyes in form of wastewater causes serious environmental problems such as retards photosynthesis, inhibit growth of aquatic biota by blocking out sunlight and utilizing dissolved oxygen. In this study, activated carbon derived from foxtail palm (Wodyetia bifurcata) empty fruit bunch (EFB) was used as an adsorbent to remove methylene blue in aqueous solution. The preparation process of activated carbon consisted of H2SO4 impregnation followed by carbonization at 300ºC for 24 hours. The optimization adsorption process was carried out using Response Surface Methodology (RSM) via Box-Behnken design. Three important operating variables namely dye concentration, contact time and adsorbent dosage were studied. The optimum conditions obtained were 100 ppm of methylene blue, 13 h of contact time and 2 g of activated carbon with the highest percentage of methylene blue removal of 99.9%. Based on the study, activated carbon derived from foxtail palm EFB showed good potential as an adsorbing agent.


2021 ◽  
Vol 7 (2) ◽  
pp. 27-33
Author(s):  
N. F. M. Salleh ◽  
F. F. Asmori ◽  
N. M. Shukri ◽  
S. F. M. Hanafiah

Imperata Cylindrica (IC) is a solid waste that is readily available throughout the year known as one of the most important weed in the world and frequently causes major disposal issues. As a result, using IC as a low-cost adsorbent is beneficial from both, economic and environmental standpoint to remove colors from wastewater of textile industry. This work studies the reaction optimization of methylene blue (MB) removal using IC by response surface methodology (RSM). The RSM experiments were designed with 4 independent variables (initial adsorbent dosage, initial pH, initial dye concentration, and initial temperature) and 1 response variable (percent removal of MB). According to the pareto figure, the initial pH demonstrated the greatest impact on the percent removal of MB. The RSM data predicted the optimum condition of MB removal up to 86.61% using IC, by utilizing adsorbent dosage of 1.458 g/L, at 42 oC, initial pH of 6.8 and MB concentration of 235 ppm. The chacterization analysis revealed the physicochemical properties of IC in the adsoprtion process.


2017 ◽  
Vol 76 (4) ◽  
pp. 776-784 ◽  
Author(s):  
Mijia Zhu ◽  
Jun Yao ◽  
Zhonghai Qin ◽  
Luning Lian ◽  
Chi Zhang

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.


2020 ◽  
Vol 83 (1) ◽  
pp. 27-36
Author(s):  
Mardawani Mohamad ◽  
Rizki Wannahari ◽  
Rosmawani Mohammad ◽  
Noor Fazliani Shoparwe ◽  
Kwan Wei Lun ◽  
...  

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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