Competitive adsorption of Ni(II) and Cu(II) ions from aqueous solution by vermiculite-alginate composite: batch and fixed-bed column studies

Author(s):  
Ebrahim Allahkarami ◽  
Nona Soleimanpour Moghadam ◽  
Bahareh Jamrotbe ◽  
Amirreza Azadmehr
2019 ◽  
Vol 19 (7) ◽  
pp. 1929-1937 ◽  
Author(s):  
Nguyen Chi Thanh ◽  
Boonchai Wichitsathian ◽  
Chatpet Yossapol ◽  
Watcharapol Wonglertarak ◽  
Borano Te

Abstract Arsenic-polluted water is a global concern and puts millions of people at risk of developing cancer. The improvement of aqueous solution coexisting with arsenite and arsenate using iron mixed porous clay pellets was investigated in batch and fixed-bed column systems. Batch studies showed that the removal rate occurred in two main phases with an equilibrium time of 52 h. The pseudo-second-order model well described the experimental data. Isotherm data were well fitted by the Langmuir–Freundlich model. The removal efficiency was significantly reduced in alkaline solution and the presence of phosphate ions. The column study revealed that the breakthrough time and saturation time increased with lower feeding flow rate, higher bed height, and lower initial adsorbate concentration. The Thomas model provided good performance for predicting the column experimental data.


2017 ◽  
Vol 76 (7) ◽  
pp. 1895-1906 ◽  
Author(s):  
Sowmya Vilvanathan ◽  
S. Shanthakumar

The biosorption capability of Chrysanthemum indicum to remove nickel ions from aqueous solution in a fixed-bed column was examined in this study. Native C. indicum flower waste was improved for its biosorptive potential by pyrolysis to obtain its biochar form and, thereby, both raw (CIF-R) and biochar (CIF-BC) forms of the flower were used for Ni(II) removal. Fixed bed column studies were conducted to examine the influence of bed height (1.0–3.0 cm), flow rate (1.0–5.0 mL min−1) and initial metal ion concentration (25–75 mg L−1). The breakthrough curves (Cout/Cin vs time) were modelled using different dynamic adsorption models, viz. Adams-Bohart, Thomas and Yoon-Nelson model. Interpretation of the data revealed a favorable correlation with the Thomas model with higher R2 values and closer model-predicted and experimental biosorption capacity values. The equilibrium uptake capacity of CIF-R and CIF-BC for Ni(II) were found to be 14.02 and 29.44 mg g−1, respectively. Further, the column was regenerated using HCl as eluent, to desorb the adsorbed Ni(II) ions. The experimental results implied and affirmed the suitability of the biosorbents for nickel ion biosorption with its nature being favorable, efficient, and environmentally friendly.


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