scholarly journals Process Optimization at an Industrial Scale in the adsorptive removal of Cd2+ ions using Dolochar via Response Surface Methodology

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).

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.


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 (11) ◽  
pp. 2325 ◽  
Author(s):  
Mubeen Isam ◽  
Lavania Baloo ◽  
Shamsul Rahman Mohamed Kutty ◽  
Saba Yavari

The removal of Pb (II) and Cu (II) ions by using marine red macroalgae (Gracilaria changii) as a biosorbent material was evaluated through the batch equilibrium technique. The effect of solution pH on the removal of metal ions was investigated within the range of 2–7. The response surface methodology (RSM) technique involving central composite design (CCD) was utilised to optimise the three main sorption parameters, namely initial metal ion concentration, contact time, and biosorbent dosage, to achieve maximum ion removal. The models’ adequacy of response was verified by ANOVA. The optimum conditions for removal of Pb (II) and Cu (II) were as follows: pH values of 4.5 and 5, initial concentrations of 40 mg/L, contact times of 115 and 45 min, and biosorbent dosage of 1 g/L, at which the maximum removal percentages were 96.3% and 44.77%, respectively. The results of the adsorption isotherm study showed that the data fitted well with the Langmuir’s model for Pb (II) and Cu (II). The results of the adsorption kinetic study showed that the data fitted well with the pseudo-second order model for Pb (II) and Cu (II). In conclusion, red alga biomass exhibits great potential as an efficient low-cost sorbent for removal of metal ions.


Author(s):  
K. Narasimhulu ◽  
Y. Pydi Setty

This chapter refers to the study of the biosorption of Ni(II) and Cd(II) in packed bed bioreactor by Pseudomonas putida. The conventional treatment methods of Nickel and Cadmium were elaborated and compared with biosorption. The methods for optimization of process conditions for biosorption of Ni(II) and Cd(II) in packed bed bioreactor by Pseudomonas putida were explained. The optimum conditioned were determined to be flow rate of 300 mL/h, initial metal ion concentration of 100 mg/L and bed height of 20 cm with weight of biosorbent of 12 g, and it was found that the Agar immobilized Pseudomonas putida showed maximum percent biosorption and bed saturation occurred at 20 minutes. Optimization results of Ni(II) and Cd(II) by Pseudomonas putida from the Design Expert software were obtained as bed height of 19.93 cm, initial metal ion concentration of 103.85 mg/L, and flow rate of 310.57 mL/h. The percent biosorption of Ni(II) and Cd(II) is 87.2% and 88.2% respectively. The predicted optimized parameters are in agreement with the experimental results. Experiments were carried out at established optimum conditions of bed height of 20.77 cm, flow rate of 309.09 mL/h, and initial metal ion concentration of 109.23 mg/L and results of biosorption of Ni(II) and Cd(II) were reproduced and they were in agreement with the predicted results. Based the experimental results, it was observed that the Pseudomonas putida was the best choice to remove Nickel and Cadmium ions from wastewater in a continuous column system.


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%.


2006 ◽  
Vol 72 (6) ◽  
pp. 4020-4027 ◽  
Author(s):  
Adrian Hetzer ◽  
Christopher J. Daughney ◽  
Hugh W. Morgan

ABSTRACT This study reports surface complexation models (SCMs) for quantifying metal ion adsorption by thermophilic microorganisms. In initial cadmium ion toxicity tests, members of the genus Geobacillus displayed the highest tolerance to CdCl2 (as high as 400 to 3,200 μM). The thermophilic, gram-positive bacteria Geobacillus stearothermophilus and G. thermocatenulatus were selected for further electrophoretic mobility, potentiometric titration, and Cd2+ adsorption experiments to characterize Cd2+ complexation by functional groups within and on the cell wall. Distinct one-site SCMs described the extent of cadmium ion adsorption by both studied Geobacillus sp. strains over a range of pH values and metal/bacteria concentration ratios. The results indicate that a functional group with a deprotonation constant pK value of approximately 3.8 accounts for 66% and 80% of all titratable sites for G. thermocatenulatus and G. stearothermophilus, respectively, and is dominant in Cd2+ adsorption reactions. The results suggest a different type of functional group may be involved in cadmium biosorption for both thermophilic strains investigated here, compared to previous reports for mesophilic bacteria.


2017 ◽  
pp. 285-293
Author(s):  
Vesna Vasic ◽  
Aleksandar Jokic ◽  
Marina Sciban ◽  
Jelena Prodanovic ◽  
Jelena Dodic ◽  
...  

The present work studies the effect of operating parameters (pH, feed flow rate, and transmembrane pressure) on microfiltration of distillery stillage. Experiments were conducted in the presence of a Kenics static mixer as a turbulence promoter, and its influence on the flux improvement and specific energy consumption was examined. Response surface methodology was used to investigate the effect of selected factors on microfiltration performances. The results showed that response surface methodology is an appropriate model for mathematical presentation of the process. It was found that the use of a static mixer is justified at the feed flow rates higher than 100 L/h. In contrast, the use of a static mixer at low values of feed flow rate and transmembrane pressure has no justification from an economic point of view.


2016 ◽  
Vol 74 (9) ◽  
pp. 1999-2009 ◽  
Author(s):  
Sayed Mohammad Bagher Hosseini ◽  
Narges Fallah ◽  
Sayed Javid Royaee

This study evaluates the advanced oxidation process for decolorization of real textile dyeing wastewater containing azo and disperse dye by TiO2 and UV radiation. Among effective parameters on the photocatalytic process, effects of three operational parameters (TiO2 concentration, initial pH and aeration flow rate) were examined with response surface methodology. The F-value (136.75) and p-value <0.0001 imply that the model is significant. The ‘Pred R-Squared’ of 0.95 is in reasonable agreement with the ‘Adj R-Squared’ of 0.98, which confirms the adaptability of this model. From the quadratic models developed for degradation and subsequent analysis of variance (ANOVA) test using Design Expert software, the concentration of catalyst was found to be the most influential factor, while all the other factors were also significant. To achieve maximum dye removal, optimum conditions were found at TiO2 concentration of 3 g L−1, initial pH of 7 and aeration flow rate of 1.50 L min−1. Under the conditions stated, the percentages of dye and chemical oxygen demand removal were 98.50% and 91.50%, respectively. Furthermore, the mineralization test showed that total organic compounds removal was 91.50% during optimum conditions.


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