scholarly journals Removal of iron and manganese from groundwater sources using nano-biosorbents

Author(s):  
Mohammad Akbari Zadeh ◽  
Allahyar Daghbandan ◽  
Behrouz Abbasi Souraki

Abstract Background The presence of iron (Fe) and manganese (Mn) ions in rocky beds leads to groundwater pollution. Moreover, their excessive concentration causes bad taste and color stains of water. Methods Tea leaves-derived char (TLC), rice straw-derived char (RSC), and nanosilica (NS) were used to adsorb Fe and Mn ions from water sources. The effects of parameters such as contact time, composition percentage, and particle size of biosorbents in a fixed-bed adsorption column were investigated. Results The study on the adsorption of Fe and Mn ions showed that the amount of adsorption increased significantly by decreasing the particle size. Furthermore, the combination of nano-biosorbents with nanosilica improved the adsorption. The Thomas and Adams–Bohart models adequately indicated the adsorption of Fe and Mn ions onto nano-biosorbents in the column mode. The TLC and RSC with NS are applicable for the removal of Fe and Mn ions from groundwater. Conclusions According to the BET analysis results, with more crushing of biosorbents by ball mill and placing them in the furnace, specific surface area of tea leaves and rice straw increased from 0.29 to 3.45 and from 3.70 to 10.99 m2/g, respectively. The absorption of iron and manganese from the aqueous solution increased with the percentage of nano-silica. According to breakthrough curves, under best conditions (the seventh mode), nano-biosorbents could remove 98.05% and 97.92% of iron and manganese ions, respectively. The maximum equilibrium capacity of the adsorption column (mg/g) was 256.56 for iron and 244.79 for manganese. Graphical abstract

2021 ◽  
Vol 891 ◽  
pp. 31-36
Author(s):  
Jirah Emmanuel T. Nolasco ◽  
Camille Margaret S. Alvarillo ◽  
Joshua L. Chua ◽  
Ysabel Marie C. Gonzales ◽  
Jem Valerie D. Perez

Continuous fixed-bed column studies were performed using nanocomposite beads made up of chitosan, polyethyleneimine, and graphene oxide as adsorbents for the removal of methyl orange (MO) in water. The effects of different operating parameters such as initial MO concentration (5, 10, and 15 ppm), bed height (10, 17.5, and 25 cm), and flow rate (27, 43, and 58 mL/min) were investigated using an upward-flow fixed-bed column set-up. The breakthrough curves generated were fitted with Adams-Bohart, Thomas, Yoon-Nelson, and Yan et al. models. The results showed that Yan et al. model agreed best with the breakthrough curves having an R2 as high as 0.9917. Lastly, design parameters for a large-scale adsorption column were determined via scale-up approach using the parameters obtained from column runs.


2007 ◽  
Vol 20-21 ◽  
pp. 635-638 ◽  
Author(s):  
Karol Campos ◽  
Eric Guibal ◽  
Francisco Peirano ◽  
M. Ly ◽  
Holger Maldonado

Mercury sorption on chitosan was investigated in batch and continuous systems. Chitosan sorption properties were determined through sorption isotherms. Langmuir and Freundlich equations were used for the modeling of isotherms at pH 5. In batch systems, maximum sorption capacities reached 550 mg Hg/g. Sorption kinetics have been studied as a function of sorbent particle size and stirring rate. Dynamic removal of mercury was tested in a fixed bed reactor investigating the following parameters: particle size, column size, flow velocity and metal ion concentration. Clark and Adams-Bohart models were evaluated for the simulation of breakthrough curves. This study shows that chitosan is an effective sorbent for the treatment and recovery of mercury from dilute effluents at near neutral pH.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6145
Author(s):  
Wondwosen Sime Geleta ◽  
Esayas Alemayehu ◽  
Bernd Lennartz

Millions of people across the globe suffer from health issues related to high fluoride levels in drinking water. The purpose of this study was to test modified pumice as an adsorbent for the purification of fluoride-containing waters. The adsorption of fluoride onto zirconium-coated pumice (Zr–Pu) adsorbent was examined in fixed-bed adsorption columns. The coating of zirconium on the surface of VPum was revealed by X-ray diffractometer (XRD), Inductively coupled plasma-optical emission spectroscopy (ICP-EOS), and X-ray fluorescence (XRF) techniques. The degree of surface modification with the enhanced porosity of Zr–Pu was evident from the recorded scanning electron microscope (SEM) micrographs. The Brunauer-Emmett-Teller (BET) analysis confirmed the enhancement of the specific surface area of VPum after modification. The Fourier transform infrared (FTIR) examinations of VPum and Zr–Pu before and after adsorption did not reveal any significant spectrum changes. The pH drift method showed that VPum and Zr–Pu have positive charges at pHPZC lower than 7.3 and 6.5, respectively. Zr–Pu yielded a higher adsorption capacity of 225 mg/kg (2.05 times the adsorption capacity of VPum: 110 mg/kg), at pH = 2 and volumetric flow rate (QO) of 1.25 mL/min. Breakthrough time increases with decreasing pH and flow rate. The experimental adsorption data was well-matched by the Thomas and Adams-Bohart models with correlation coefficients (R2) of ≥ 0.980 (Zr–Pu) and ≥ 0.897 (VPum), confirming that both models are suitable tools to design fixed-bed column systems using volcanic rock materials. Overall, coating pumice with zirconium improved the defluoridation capacity of pumice; hence, a Zr–Pu-packed fixed-bed can be applied for defluoridation of excess fluoride from groundwater. However, additional investigations on, for instance, the influences of competing ions are advisable to draw explicit conclusions.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7759
Author(s):  
Mieczysław Bałys ◽  
Ewelina Brodawka ◽  
Grzegorz Stefan Jodłowski ◽  
Jakub Szczurowski ◽  
Marta Wójcik

Carbonaceous adsorbents have been pointed out as promising adsorbents for the recovery of methane from its mixture with carbon dioxide, including biogas. This is because of the fact that CO2 is more strongly adsorbed and also diffuses faster compared to methane in these materials. Therefore, the present study aimed to test alternative carbonaceous materials for the gas separation process with the purpose of enriching biogas in biomethane and to compare them with the commercial one. Among them was coconut shell activated carbon (AC) as the adsorbent derived from bio-waste, rubber tire pyrolysis char (RPC) as a by-product of waste utilization technology, and carbon molecular sieve (CMS) as the commercial material. The breakthrough experiments were conducted using two mixtures, a methane-rich mixture (consisting of 75% CH4 and 25% CO2) and a carbon dioxide-rich mixture (containing 25% CH4 and 75% CO2). This investigation showed that the AC sample would be a better candidate material for the CH4/CO2 separation using a fixed-bed adsorption column than the commercial CMS sample. It is worth mentioning that due to its poorly developed micropore structure, the RPC sample exhibited limited adsorption capacity for both compounds, particularly for CO2. However, it was observed that for the methane-rich mixture, it was possible to obtain an instantaneous concentration of around 93% CH4. This indicates that there is still much potential for the use of the RPC, but this raw material needs further treatment. The Yoon–Nelson model was used to predict breakthrough curves for the experimental data. The results show that the data for the AC were best fitted with this model.


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