scholarly journals Batch versus column modes for the adsorption of radioactive metal onto rice husk waste: conditions optimization through response surface methodology

2017 ◽  
Vol 76 (5) ◽  
pp. 1035-1043 ◽  
Author(s):  
Abida Kausar ◽  
Haq Nawaz Bhatti ◽  
Munawar Iqbal ◽  
Aisha Ashraf

Batch and column adsorption modes were compared for the adsorption of U(VI) ions using rice husk waste biomass (RHWB). Response surface methodology was employed for the optimization of process variables, i.e., (pH (A), adsorbent dose (B), initial ion concentration (C)) in batch mode. The B, C and C2 affected the U(VI) adsorption significantly in batch mode. The developed quadratic model was found to be validated on the basis of regression coefficient as well as analysis of variance. The predicted and actual values were found to be correlated well, with negligible residual value, and B, C and C2 were significant terms. The column study was performed considering bed height, flow rate and initial metal ion concentration, and adsorption efficiency was evaluated through breakthrough curves and bed depth service time and Thomas models. Adsorption was found to be dependent on bed height and initial U(VI) ion concentration, and flow rate decreased the adsorption capacity. Thomas models fitted well to the U(VI) adsorption onto RHWB. Results revealed that RHWB has potential to remove U(VI) ions and batch adsorption was found to be efficient versus column mode.

2021 ◽  
Author(s):  
Utkarsh Upadhyay ◽  
Sarthak Gupta ◽  
Ankita Agarwal ◽  
Inkollu Sreed ◽  
Kayamkulathethu Latitha Anitha

Abstract Over the years, researchers have continuously searched for ways to achieve adsorption of heavy metal ions from the industrial effluents at lowest possible cost, which has resulted into the development of innumerous special type of low cost adsorbents, called biosorbents. While potential of many biosorbents have been explored in laboratory setup, very few studies have tried to scale up the biosorption process and predict the performance of these biosorbents in a large scale industrial setup. In this work, performance of laboratory synthesized dolochar has been investigated for adsorption of Cd2+ ions in a large scale process with the application of Aspen Adsorption. Moreover, the optimum values of the operating parameters (namely, flow rate, bed height and inlet metal ion concentration) that would result into maximum amount of cadmium ion adsorption (high exhaustion capacity) in minimum time (less exhaustion time) for a fixed mass of dolochar (1200 kg) have been calculated via the application of Response Surface Methodology. It was found out that, at optimum values of bed height (3.48 m), flow rate (76.31 m3/day) and inlet concentration (10 ppm), the optimized value of exhaustion capacity and exhaustion time for cadmium ion adsorption in dolochar packed bed is equal to 1.85 mg/g and 11.39 hours, respectively. The validity of these simulation experiments can be proven by the fact that the obtained exhaustion capacity of dolochar packed beds always remained in close proximity of the experimentally obtained value of adsorption capacity of the dolochar in batch process mode (equal to 2.1 mg/g).


2021 ◽  
Vol 235 (3) ◽  
pp. 281-294
Author(s):  
Abida Kausar ◽  
Haq Nawaz Bhatti ◽  
Munawar Iqbal

Abstract Sugarcane bagasse waste biomass (SBWB) efficacy for the adsorption of Zr(IV) was investigated in batch and column modes. The process variables i.e. pH 1–4 (A), adsorbent dosage 0.0–0.3 g (B), and Zr(IV) ions initial concentration 25–200 mg/L (C) were studied. The experiments were run under central composite design (CCD) and data was analysed by response surface methodology (RSM) methodology. The factor A, B, C, AB interaction and square factor A2, C2 affected the Zr(IV) ions adsorption onto SBWB. The quadratic model fitted well to the adsorption data with high R2 values. The effect of bed height, flow rate and Zr(IV) ions initial concentration was also studied for column mode adsorption and efficiency was evaluated by breakthrough curves as well as Bed Depth Service and Thomas models. Bed height and Zr(IV) ions initial concentration enhanced the adsorption of capacity of Zr(IV) ions, whereas flow rate reduced the column efficiency.


2020 ◽  
Vol 26 (2) ◽  
pp. 200105-0
Author(s):  
Kaushal Naresh Gupta ◽  
Rahul Kumar

This paper discusses the isolation of xylene vapor through adsorption using granular activated carbon as an adsorbent. The operating parameters investigated were bed height, inlet xylene concentration and flow rate, their influence on the percentage utilization of the adsorbent bed up to the breakthrough was found out. Mathematical modeling of experimental data was then performed by employing a response surface methodology (RSM) technique to obtain a set of optimum operating conditions to achieve maximum percentage utilization of bed till breakthrough. A fairly high value of R2 (0.993) asserted the proposed polynomial equation’s validity. ANOVA results indicated the model to be highly significant with respect to operating parameters studied. A maximum of 76.1% utilization of adsorbent bed was found out at a bed height of 0.025 m, inlet xylene concentration of 6,200 ppm and a gas flow rate of 25 mL.min-1. Furthermore, the artificial neural network (ANN) was also employed to compute the percentage utilization of the adsorbent bed. A comparison between RSM and ANN divulged the performance of the latter (R2 = 0.99907) to be slightly better. Out of various kinetic models studied, the Yoon-Nelson model established its appropriateness in anticipating the breakthrough curves.


Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 325 ◽  
Author(s):  
Subrata Biswas ◽  
Manisha Bal ◽  
Sushanta Behera ◽  
Tushar Sen ◽  
Bhim Meikap

A novel biochar alginate composite adsorbent was synthesized and applied for removal of Zn2+ ions from aqueous solution. Kinetics, equilibrium and thermodynamic studies showed the suitability of the adsorbent. From a Langmuir isotherm study, the maximum monolayer adsorption capacity of the composite adsorbent was found to be 120 mg/g. To investigate the effect of process variables like initial Zn2+ concentration (25–100 mg/L), adsorbent dose (0.4–8 g/L) and temperature (298–318 K) on Zn2+ adsorption, response surface methodology (RSM) based on a three independent variables central composite design of experiments was employed. A quadratic model equation was developed to predict the relationship between the independent variables and response for maximum Zn2+ removal. The optimization study reveals that the initial Zn2+ concentration and adsorbent dose were the most effective parameters for removal of Zn2+ due to higher magnitude of F-statistic value which effects to a large extent of Zn2+ removal. The optimum physicochemical condition for maximum removal of Zn2+ was determined from the RSM study. The optimum conditions are 43.18 mg/L initial metal ion concentration, 0.062 g adsorbent dose and a system temperature of 313.5 K. At this particular condition, the removal efficiency of Zn2+ was obtained as 85%.


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


2021 ◽  
Vol 11 (4) ◽  
pp. 1739
Author(s):  
Muhammad Ajaz Ahmed ◽  
Jae Hoon Lee ◽  
Joon Weon Choi

A synergistic combination of dioxane, acetic acid, and HCl was investigated for lignin extraction from pine wood biomass. After initial screening of reagent combination, response surface methodology (RSM) was used to optimize the lignin yield with respect to the variables of time 24–72 h, solids loading 5–15%, and catalyst dose 5–15 mL. A quadratic model predicted 8.33% of the lignin yield, and it was further confirmed experimentally and through the analysis of variance (ANOVA). Lignin at optimum combination exhibited features in terms of derivatization followed by reductive cleavage (DFRC) with a value of (305 µmol/gm), average molecular weights of 4358 and polydispersity of 1.65, and 2D heteronuclear single quantum coherence nuclear magnetic resonance spectrum (2D-HSQC NMR) analysis showing relative β-O-4 linkages (37.80%). From here it can be suggested that this fractionation can be one option for high quality lignin extraction from lignocellulosic biomass.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3150
Author(s):  
Mengwei Xu ◽  
Chao Huang ◽  
Jing Lu ◽  
Zihan Wu ◽  
Xianxin Zhu ◽  
...  

Magnetic MXene composite Fe3O4@Ti3C2 was successfully prepared and employed as 17α-ethinylestradiol (EE2) adsorbent from water solution. The response surface methodology was employed to investigate the interactive effects of adsorption parameters (adsorption time, pH of the solution, initial concentration, and the adsorbent dose) and optimize these parameters for obtaining maximum adsorption efficiency of EE2. The significance of independent variables and their interactions were tested by the analysis of variance (ANOVA) and t-test statistics. Optimization of the process variables for maximum adsorption of EE2 by Fe3O4@Ti3C2 was performed using the quadratic model. The model predicted maximum adsorption of 97.08% under the optimum conditions of the independent variables (adsorption time 6.7 h, pH of the solution 6.4, initial EE2 concentration 0.98 mg L−1, and the adsorbent dose 88.9 mg L−1) was very close to the experimental value (95.34%). pH showed the highest level of significance with the percent contribution (63.86%) as compared to other factors. The interactive influences of pH and initial concentration on EE2 adsorption efficiency were significant (p < 0.05). The goodness of fit of the model was checked by the coefficient of determination (R2) between the experimental and predicted values of the response variable. The response surface methodology successfully reflects the impact of various factors and optimized the process variables for EE2 adsorption. The kinetic adsorption data for EE2 fitted well with a pseudo-second-order model, while the equilibrium data followed Langmuir isotherms. Thermodynamic analysis indicated that the adsorption was a spontaneous and endothermic process. Therefore, Fe3O4@Ti3C2 composite present the outstanding capacity to be employed in the remediation of EE2 contaminated wastewaters.


2009 ◽  
Vol 52 (6) ◽  
pp. 1541-1553 ◽  
Author(s):  
Dayane Rosalyn Izidoro ◽  
Agnes de Paula Scheer ◽  
Maria-Rita Sierakowsk

In this work, the rheological behaviour of emulsions (mayonnaises) stabilized by green banana pulp using the response surface methodology was studied. In addition, the emulsions stability was investigated. Five formulations were developed, according to design for constrained surfaces and mixtures, with the proportion, respectively: water/soy oil/green banana pulp: F1 (0.10/0.20/0.70), F2 (0.20/0.20/0.60), F3 (0.10/0.25/0.65), F4 (0.20/0.25/0.55) and F5 (0.15/0.225/0.625) .Emulsions rheological properties were performed with a rotational Haake Rheostress 600 rheometer and a cone and plate geometry sensor (60-mm diameter, 2º cone angle), using a gap distance of 1mm. The emulsions showed pseudoplastic behaviour and were adequately described by the Power Law model. The rheological responses were influenced by the difference in green banana pulp proportions and also by the temperatures (10 and 25ºC). The formulations with high pulp content (F1 and F3) presented higher shear stress and apparent viscosity. Response surface methodology, described by the quadratic model,showed that the consistency coefficient (K) increased with the interaction between green banana pulp and soy oil concentration and the water fraction contributed to the flow behaviour index increase for all emulsions samples. Analysis of variance showed that the second-order model had not significant lack-of-fit and a significant F-value, indicating that quadratic model fitted well into the experimental data. The emulsions that presented better stability were the formulations F4 (0.20/0.25/0.55) and F5 (0.15/0.225/0.625).


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Mahdis Mosayebi ◽  
Mahdi Kashaninejad ◽  
Leila Najafian

Roasting sunflower kernels is a key process in production of nuts. In this study, the effect of roasting conditions, including hot air temperature (120–160°C), infrared (IR) power (400–600 W) and roasting time (3–10 min) on energy and specific energy consumption, color parameters (L∗, a∗, b∗, ΔE, BI, SI, WI, and h°), texture, moisture content, chemical properties (pH and total phenolic contents, peroxide value (PV), and sensory properties of sunflower kernel were investigated. In addition, the best models for the responses were obtained, and the proper roasting conditions were determined using response surface methodology (RSM). A quadratic model was proposed for color change (L∗, ΔE, SI, and WI), moisture and total phenol contents, linear relation for a∗, b∗, h°, and 2FI for BI, texture, PV, and pH. Roasting at 425.7 W IR power and 124.3°C for 3.7 min was found to be convenient or proper roasting conditions.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Xiao Guan ◽  
Lv Li ◽  
Jing Liu ◽  
Sen Li

We investigated the process intensification of ultrasonic-microwave-assisted technology for hordein extraction from barley. Response surface methodology was utilized to optimize the extraction conditions and to analyze the interaction between four selected variables: temperature, microwave power, ultrasonic power, and extraction time. The validated extraction yield of hordein reached 8.84% at 78°C, microwave power 298 W, and ultrasonic power 690 W after 20 min as optimum conditions. Compared with traditional water-bath extraction (4.7%), the ultrasonic-microwave-assisted technology effectively increased the hordein extraction yield and shortened the extraction time. According to the obtained quadratic model (R2 = 0.9457), ultrasonic power and extraction time were the first two significant factors. However, temperature limited the effects of other factors during extraction. SDS-PAGE and scanning electron microscopy were used to identify the hordein extract and to clarify the difference between the two hordein fractions extracted with new and traditional methods, respectively. Ultrasonic-microwave-assisted technology provided a new way to improve hordein extraction yield from barley and could be a good candidate for industrial application of process intensification.


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