scholarly journals Performance of Laterite Soil Grains as Adsorbent in the Removal of Chromium

2015 ◽  
Vol 10 (1) ◽  
pp. 270-280 ◽  
Author(s):  
I Syama ◽  
Arun Thalla ◽  
D Manu

The present study aims to examine the efficiency of laterite grains (LG) and acid activated laterite grains (AALG) as an adsorbent for removal hexavalent chromium and ferric ion from synthetic wastewater, under laboratory conditions. Adsorption of hexavalent chromium and ferric ion from synthetic wastewater is examined by batch and column studies wherein it is found to be dependent on pH, Contact time, adsorbent dosage and initial adsorbate concentration. Percentage removal enhances with the increase in adsorbent dosage and with low pH, the optimal removal is achieved at pH=2. AALG is found to investigate possibility of improvement in removal efficiency of hexavalent chromium. The removal efficiency of AALG is found to be significantly higher than the efficiency obtained from LG, at pH=7. An adsorbent dosage 2g of LG is found to be optimum for removal of ferric ion with low initial concentration of 2.5 mg/L. The equilibrium adsorption data obtained from batch studies were fitted with Langmuir and freundlich isotherm for both hexavalent chromium and ferric ions. The percentage removal obtained from batch adsorption studies were found to be higher than that obtained by column studies for both the adsorbates.

Author(s):  
L. Salami ◽  
D. O. Olumuyiwa ◽  
E. A. Alfred ◽  
O. S. Olakanmi

Dumpsite leachate has the potential to pollute ground and surface water as well as vegetation within the vicinity of the dumpsite.  Its treatment therefore needs adequate attention. The aim of this work is to study the adsorption of Soluos dumpsite leachate treatment using Musa sapientum peel as biosorbent with a view of establishing the adsorption isotherm model. Musa sapientum peels sourced from Ayetoro market in Epe area of Lagos State, Nigeria were used to prepare the adsorbent. Batch adsorption was carried out with various dosage of the prepared absorbent in leachate collected from Soluos dumpsite in Lagos. The adsorption data obtained were fitted into Linear, Freundlich, Langmuir, Temkin and Hasley isotherm models. The results showed that the concentration of total dissolved solids (TDS) in the dumpsite leachate decreased as the adsorbent dosage increased. At adsorbent dosage of 10 g/L, the concentration of TDS in the leachate was 485.7 mg/L which was less than the 500 mg/L stipulated by National Environmental Standard and Regulatory Agency (NAESRA) for the discharge of wastewater. The coefficient of determination (R2) values for Linear, Freundlich and Hasley, Langmuir and Temkin isotherm models were 0.9944, 0.9936, 0.8562 and 0.9723 respectively. Linear isotherm model was jettisoned because the plot did not pass through the origin and Freundlich isotherm model was ignored as a result of N value which was less than unity hence Hasley isotherm model was adopted in this work. A good correlation existed between the experimental and predicted values, having a R2 value of 0.9965 which further validated the Hasley isotherm model as the best adsorption model for the treatment of Soluos dumpsite leachate using Musa sapientum peel as biosorbent. It was concluded that Musa sapientum peel as biosorbent can be used for treatment of Soluos dumpsite leachate.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Tamirat Dula ◽  
Khalid Siraj ◽  
Shimeles Addisu Kitte

This study reports on the adsorption of Hexavalent Chromium from aqueous solutions using activated carbon prepared from bamboo (Oxytenanthera abyssinica) waste by KOH activation heating in an electrical furnace at 1073 K for 3 hrs. Batch adsorption experiments were also carried out as a function of pH, contact time, initial concentration of the adsorbate, adsorbent dosage, and temperature of the solution. Kinetic studies of the data showed that the adsorption follows the pseudo-second-order kinetic model. Thermodynamic parameters showed that adsorption on the surface of BWAC was feasible, spontaneous in nature, and exothermic between temperatures of 298 and 318 K. The equilibrium data better fitted the Freundlich isotherm model for studying the adsorption behavior of Hexavalent Chromium by BWAC. IR spectrum for loaded and unloaded BWAC was obtained using FT-IR spectrophotometer. Adsorption efficiency and capacity of Hexavalent Chromium were found to be 98.28% at pH 2 and 59.23 mg/g at 300 K.


2012 ◽  
Vol 518-523 ◽  
pp. 369-375 ◽  
Author(s):  
Yue Hong Yang ◽  
Dun Tao Shu ◽  
Ting Dong Fu ◽  
Huai Yu Zhang

The purpose of this study was to investigate the adsorption of Cu(II) on phosphogypsum, a waste material from the manufacture of phosphoric acid by wet process. The removal capacity of phosphogypsum for Cu(II) ions was studied as a function of solution pH, contact time, adsorbent dosage and adsorbate concentration. Before batch adsorption study, phosphogypsum was pre-conditioned by calcine without water. The Langmuir and Freundlich theories were used to describe the Cu(II) adsorption process, and the Freundlich isotherm showed the best fit to the process. The adsorptions of Cu(II) followed pseudo-second-order kinetics. Maximum adsorption capacity of lime-preconditioned phosphogypsum was found to be 2.824 mg/g. The results showed that the phoshogypsum is a suitable adsorbent for the removal of Cu(II) ions from aqueous solutions.


Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 357-368 ◽  
Author(s):  
Malihe Sarabadan ◽  
Hadis Bashiri ◽  
Seyed Mahdi Mousavi

AbstractA zeolite-montmorillonite (zeolite-Mt) nano-adsorbent was prepared by calcination at 600°C. The synthesized nano-adsorbent was tested for removal of a toxic and cationic dye (crystal violet) from water, and it was characterized by various techniques. The effects of variables such as pH, temperature, adsorbent dosage and initial dye concentration on the removal efficiency of the dye were investigated by response surface methodology (RSM). Experimental conditions were optimized by RSM to achieve the maximum dye removal efficiency. Optimum conditions for maximum removal of dye were obtained at pH 9, temperature of 25°C, adsorbent dosage of 2 g L−1 and initial dye concentration of 40 mg L−1. Under these conditions, the maximum removal efficiency obtained was 99.9%. Various isotherms were applied to study adsorption equilibrium, and of these, the Freundlich isotherm provided the best fit. In addition, the fractal-like integrated kinetic Langmuir model was the most appropriate among several kinetic models. The thermodynamic parameters were also determined. The zeolite-Mt prepared under optimum conditions displayed a greater adsorption capacity than activated carbon (manufactured by Merck) and than various other adsorbents.


2015 ◽  
Vol 21 (4) ◽  
pp. 465-476
Author(s):  
Jun Tan ◽  
Xiaoyan Wei ◽  
Yuxia Ouyang ◽  
Rui Liu ◽  
Ping Sun ◽  
...  

The effectiveness of insoluble xanthate (ISX) and crosslinked starch-graft-polyacrylamide-co-sodium xanthate (CSAX) for Cu(II) removal from wastewater was evaluated. The two types of xanthates were characterized by SEM, XRD, FTIR, and elemental analysis. Also, the factors influencing adsorption behaviors of copper ions from aqueous solutions were investigated. The results indicated CSAX had higher absorption capacity for Cu(II) than ISX because it contained more N and S. While as far as the removal efficiency was concerned, ISX was better than CSAX for its strong ligand-CSS- groups. The removal efficiency of Cu(II) onto CSAX and ISX increased with the increase in pH. The mechanism for Cu(II) adsorption was ionic exchange for ISX whereas both ion exchange and physical adsorption contributed to adsorption by CSAX. The adsorption kinetics of ISX and CSAX for Cu(II) were favorably described by the pseudo-second-order kinetic model, and the adsorption isotherms were described well with the Freundlich isotherm model. The study with synthetic wastewater showed CSAX was a worthwhile alternative to the traditional ISX only when the wastewater contained both Cu(II) and turbidity.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Patience Mapule Thabede ◽  
Ntaote David Shooto ◽  
Thokozani Xaba ◽  
Eliazer Bobby Naidoo

The aim of the present study was to utilise pristine and magnetite-sucrose functionalized Nigella Sativa seeds as the adsorbents for the uptake of chromium(VI) and lead(II) ions from synthetic wastewater. Prestine Nigella Sativa seeds were labelled (PNS) and magnetite-sucrose functionalized Nigella Sativa seeds (FNS). The PNS and FNS composites were characterized by Fourier-transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). The FTIR analysis of both adsorbents revealed the presence of vibrations assigned to 1749 and 1739 cm-1 (-C=O) for ketonic group for both adsorbents. The amide (-NH) peak was observed at 1533 and 1527 cm-1 on FNS and PNS composites, respectively, whilst the carboxyl group (-COOH) were observed at 1408 cm-1 on both adsorbents. The XRD results of FNS and PNS composites showed a combination of spinel structure and y -Fe2O3 phase confirming the formation of iron oxide. The influence of operational conditions such as initial concentration, temperature, pH, and contact time was determined in batch adsorption system. The kinetic data of Cr(VI) and Pb(II) ions on both adsorbents was described by pseudo-first-order (PFO) model which suggested physisorption process. The sorption rate of Cr(VI) ions was quicker, it attained equilibrium in 20 min, and the rate of Pb(II) ions was slow in 90 min. Freundlich isotherm described the mechanism of Pb(II) ions adsorption on PNS and FNS composites. Langmuir best fitted the uptake of Cr(VI) ions on PNS and FNS. The results for both adsorbents showed that the removal uptake of Pb(II) ions increased when the initial concentration was increased; however, Cr(VI) uptake decreased when the initial concentration increased. The adsorption of Cr(VI) and Pb(II) ions on both adsorbents increased with temperature.


2021 ◽  
Vol 15 (1) ◽  
pp. 1-8
Author(s):  
Angelica Macalalad ◽  
◽  
Quennie Rose Ebete ◽  
Dominic Gutierrez ◽  
Madelaine Ramos ◽  
...  

The present study is focused on the use of activated carbon derived from water hyacinth (WH-AC) as adsorbent for the removal of Cr(VI) from aqueous solution. The optimized WH-AC was found to be mesoporous and considered as granular. The surface area of 11.564 m2/g was found to have a good adsorption capacity. The adsorption data of the optimized WH-AC followed a pseudo-second order kinetics and the Freundlich isotherm model. Based on the correlation coefficient obtained from pseudo-second-order kinetic model, the R2 values were all above 0.99, which is closer to unity of one (1) indicating that it followed a chemisorption process. The adsorption capacity of WH-AC increased from 1.98 to 4.68 mg/g when adsorbate concentration increased from 20 to 50 mg/l. The overall study proved that the adsorption by activated carbon derived from water hyacinth can be an alternative and efficient technique in hexavalent chromium removal.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1161
Author(s):  
Somayeh Rahdar ◽  
Abbas Rahdar ◽  
Mostafa Sattari ◽  
Laleh Divband Hafshejani ◽  
Athanasia K. Tolkou ◽  
...  

Dyes are known as one of the most dangerous industrial pollutants which can cause skin diseases, allergy, and provoke cancer and mutation in humans. Therefore, one of the important environmental issues is the effective removal of dyes from industrial wastewater. In the current work, BaFe12O19/CoFe2O4@polyethylene glycol (abbreviated as BFO/CFO@PEG) nanocomposite was synthesized and evaluated regarding its capacity for adsorptive removal of a model dye Acid Blue 92 (denoted as AB92) from aqueous solutions. The characteristics of the prepared nanocomposite was determined by tests such as X-ray diffraction (XRD), scanning electron microscope (SEM), vibration sample magnetization (VSM), and Fourier transform infrared spectroscopy (FTIR). The effects of conditional parameters including pH (2–12), initial concentration of dye (20–100 mg/L), adsorbent dosage (0.02–0.1 g/L) and contact time (0-180 min) on the adsorption of dye were investigated and then optimized. The results indicated that with the increase of the adsorbent dosage from 0.02 to 0.1 g/L, the removal efficiency increased from 74.1% to 78.6%, and the adsorbed amount decreased from 148.25 to 31.44 mg/g. The maximum removal efficiency (77.54%) and adsorption capacity (31.02 mg/g) were observed at pH 2. Therefore, the general optimization conditions revealed that the maximum adsorption efficiency of dye was obtained in condition of initial concentration of 20 mg/L, contact time of 1 h and pH of solution equal 2. The adsorption isotherm and kinetic data were evaluated using a series of models. The pseudo-second order kinetic model and Freundlich isotherm model show the best fitting with experimental data with R2∼0.999.


2010 ◽  
Vol 7 (4) ◽  
pp. 1454-1462 ◽  
Author(s):  
T. Mugugan ◽  
A. Ganapathi ◽  
R. Valliappan

The dye, Grey BL was adsorbed on an adsorbent prepared from mature leaves of the Pungan tree (Pongamia glabra). A batch adsorption study was carried out with variable adsorbate concentration, adsorbent amount and pH. Ninety three percent of the dye could be removed by 2 g of the derris leaf powder from 1 L of an aqueous solution containing 25 mg of the dye at 300 K. The adsorption followed pseudo first order kinetics with a mean rate constant of 3.73 ×10-3min-1and an intraparticle diffusion rate constant of 6.36 x10-2mg g-1min-0.5. A possible mechanism of adsorption was suggested on the basis of concurrently operating surface adsorption and pore diffusion. The experimental data yielded excellent fits with Langmuir and Freundlich isotherm equations. The Langmuir monolayer capacity had a mean value of 8.27 mg g-1. The results indicated that the dye, Grey BL, strongly interacts with a biomass-based adsorbent, the Derris (Pongamia glabra) leaf powder.


Author(s):  
Khadija Qureshi ◽  
Kashif Hussain Mangi ◽  
Zulfiqar Ali Solangi ◽  
Zulfiqar Ali Bhatii ◽  
Mukhtiar Ali ◽  
...  

Arsenic is a carcinogenic element capable to get into water bodies and drinking water supplies from natural deposits and industrial practices. Its presence in drinking underground water is highly toxic to human health. The study is focused on the development of indigenous Iron-Coated Pottery Granules (ICPG) to remove As from groundwater of Hala City. The developed ICPG was agitated with local clay white flour and water. A low-cost adsorbent namely ICPG was synthesized for the expulsion of As from underground water. The ICGP was characterized with SEM and FTIR techniques. Furthermore, the impact of physical parameters including adsorbate concentration, dosage, mixing time, pH, and contact time on As removal efficiency was investigated in batch experiments. The maximum removal efficiency was achieved with an adsorbent dosage of 0.5 grams at pH =7 for a contact time of 90 minutes when agitated at a speed of 150 r/min. The arsenic removal efficiency was found highly dependent on contact time increase and optimum pH (maximum removal achieved at strong adsorption of As at pH 4–7), however, the rise of adsorbate concentration resulted in the decrement in the efficiency after certain range. Batch adsorption study of underground water sample collected from Hala, Sindh, Pakistan was performed with satisfactory results, i.e. 94 arsenic removal from water. All the water samples were analyzed through atomic absorption Spectrophotometer. The investigation has indicated that ICPG is an exceptionally favourable material for As removal from drinking underground water and can be applied to handle the arsenic issue in most of the regions of Sindh province.


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