Nano platelets kaolinite for the adsorption of toxic metal ions in the environment

2019 ◽  
Author(s):  
Chem Int

Contamination of water reservoirs with different toxic metal ions from industrial activities has emerged as one of major issues in recent years. The adsorption of Pb(II) ions from aqueous solution onto Nano platelets kaolinite has been investigated. The adsorption studies were determined as a function of pH, contact time, initial metal ion concentration, adsorbent dosage and temperature. Nano platelets kaolinite prepared from raw Jordanian kaolin clay showed size in the range of 12-80 nm. Maximum adsorption capacity as determined by Langmuir isotherm model is 175.44 mg/g for Pb(II). Thermodynamic parameters, ΔGo, ΔHo and ΔSo were revealed that the adsorption process is spontaneous and endothermic process. The results showed that Nano platelets kaolinite can be efficiently used as a low-cost alternative and eco-friendly adsorbent for the removal of toxic heavy metals from wastewater.

2020 ◽  
Vol 11 (4) ◽  
pp. 11891-11904

In the present study, batch mode adsorption was carried out to investigate the adsorption capacity of dried bael flowers (Aegle marmelos) for the adsorptive removal of Cu(II) ions from aqueous solutions by varying agitation time, initial metal concentration, the dose of adsorbent, temperature, and initial pH of the Cu(II) ion solution. The percentage removal of 98.7% was observed at 50 ppm initial metal ion concentration, 0.5 g/100.00 cm3 adsorbent dosage, within the contact time of 120 minutes at 30 ºC in the pH range of 4 – 7. The sorption processes of Cu(II) ions was best described by pseudo-second-order kinetics. Langmuir isotherm had a good fit with the experimental data with 0.97 of correlation coefficient (R2), and the maximum adsorption capacity obtained was 23.14 mg g-1 at 30 ºC. The results obtained from sorption thermodynamic studies suggested that the adsorption process is exothermic and spontaneous. SEM analysis showed tubular voids on the adsorbent. FTIR studies indicated the presence of functional groups like hydroxyl, –C-O, –C=O, and amide groups in the adsorbent, which can probably involve in metal ion adsorption. Therefore, dried bael flowers can be considered an effective low-cost adsorbent for treating Cu(II) ions.


This study showed that kaolinite clay modified with Moringa oleifera pods is a promising low cost adsorbent for the removal of metals from aqueous solution because the resultant composite has higher adsorption capacities, and hence a better metal ions removal efficiency. The efficiencies of these adsorbents for the removal of Pb (II) and Cd (II) ions from aqueous solutions were studied as a function of pH, time, adsorbate concentration and adsorbent dose. Adsorption results showed that pH did significantly affect removal of heavy metal ions between pH 3 and 6. Increasing contact time and initial metal ion concentration increased the sorption capacity of the adsorbent for the metal ions. Adsorbent dosage indicated mainly surface phenomena involving sharing of electrons between the adsorbent surface and the metal ion species. The adsorption of metal ions from aqueous solutions of both metal ions at different initial metal ion concentrations reduced the initial adsorption rates of the adsorption of Pb (II) and Cd (II) by unmodified and modified kaolinite clay.


2019 ◽  
Vol 31 (10) ◽  
pp. 2240-2244
Author(s):  
Vihar Patel ◽  
Akshit A. Patel ◽  
Bharat Dixit ◽  
Ritu Dixit

Removal of dyes colour and Cu(II) metal ion from aqueous solution using acetone-formaldehyde-salicyclic acid (AFSA) resin has been carried out. The results revealed that AFSA resin acts as a cheap substitute to commercial adsorbent like activated carbons. The effects of pH, adsorbent dose, contact time, and initial dye and Cu(II) metal ion concentration on the adsorption efficiencies were investigated. Isotherm studies were conducted using Langmuir and Freundlich models, and thermodynamic studies were also performed. Adsorption of dyes was found to obey the Langmuir isotherm model and have endothermic process. The maximum adsorption capacities calculated from the Langmuir isotherm were found to be 88.18 and 2.9 mg/g for methyl orange dyes


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
P. Sujatha ◽  
V. Kalarani ◽  
B. Naresh Kumar

The primary objective of the present study is to evaluate the optimization conditions such as kinetic and equilibrium isotherm models involved in the removal of Ni(II) from the aqueous solutions byTrichoderma viride. The biosorbent was characterized by FTIR and SEM. The optimum biosorption conditions were determined as a function of pH, biomass dosage, contact time, initial metal ion concentration, and temperature. The maximum Ni(II) biosorption was obtained at pH 4.5. The equilibrium data were better fit by the Langmuir isotherm model than by the Freundlich isotherm. The kinetic studies indicate that the biosorption process of the metal ion Ni(II) has followed well the pseudo-second-order model. The sum of the square errors (SSE) and chi-square (χ2) tests were also carried out to find the best fit kinetic model and adsorption isotherm. The maximum biosorption capacity (qm) ofT.viridebiomass was found to be 47.6 mg/g for Ni(II) ion. Therefore, it can be concluded thatT.viridebiomass was effective and low-cost potential adsorbent to remove the toxic metal Ni(II) from aqueous solutions. The recovery process of Ni(II) fromT.viridebiomass was found to be higher than 98% by using 0.25 M HNO3. Besides the application of removal of toxic metal Ni(II) from aqueous solutions, the biosorbentT.viridecan be reused for five consecutive sorption-desorption cycles was determined.


2021 ◽  
Vol 12 (2) ◽  
pp. 1884-1898

Natural water gets contaminated with heavy metal ions because of industrial effluents' discharge into the aquatic environment. As these heavy metal ions cause various health hazards, they should be removed from the aqueous solution. Heavy metal ion concentration in the aqueous solution is very less, so conventional metal removal and recovery processes cannot be applied here. The adsorption method is a great alternative to all these processes as it is a cost-effective and easy method. The use of natural, low-cost materials as adsorbents is eco-friendly also. However, metal uptake capacity of low-cost materials is very less. So, modification is required for low-cost materials to increase their efficiency. In the present review, different modification procedures adopted by different researchers have been discussed. Different low-cost materials used are sawdust, fruit and vegetable wastes, soil, minerals, etc. The modifying agents are heat, acids, bases, and other chemicals. Nevertheless, most of the studies are limited to batch tests only. Future research should be carried out on the extension of batch tests to column study for the large-scale treatment of contaminated water, and the cost of modification procedures and their impact on the environment should also be assessed.


2020 ◽  
Vol 32 (4) ◽  
pp. 727-732
Author(s):  
Harish Sharma ◽  
Rajesh Kumar ◽  
Mahesh Chandra Vishwakarma ◽  
Sushil Kumar Joshi ◽  
Narender Singh Bhandari

In present study, Pyras pashia leaves were used as low cost biosorbent to study biosorption of Cu(II), Pb(II) and Cd(II) ions from contaminated wastewater. In the employed batch methods pH, contact time, metal ion concentration, temperature, biosorbent doses were taken as study parameters. The pH was varied from pH 1-9 to study the influence of pH on biosorption of metal ions by Pyras pashia. The optimum pH for the removal of Cu(II), Pb(II) and Cd(II) is observed at pH 5. The biosorption equilibrium time was varied between 15-75 min. Langmuir, Freundlich and Temkin isotherms were employed to study the biosorption. The biosorption parameter fits well with Langmuir isotherm. The biosorption of metal ions was increased with increasing biosorbent dose and contact time while increase in pH, metal ion concentration and temperature decrease the biosorption. Thermodynamic data suggest that the bisorption process was spontaneous, feasible and endothermic.


2019 ◽  
Author(s):  
Chem Int

An easy route for preparation emulsion of kaolinite (Al2Si2O5.4H2O) from Sweileh sand deposits, west Amman, Jordan by hydrochloric acid under continuous stirring for 4 h at room temperature was performed and nano kaolinite powder was used as an adsorbent for the removal of Cu(II), Zn(II) and Ni(II) ions. Nano kaolinite was characterized by XRD, FT-IR and SEM techniques. Effect of pH, adsorbent dose, initial metal ion concentration, contact time and temperature on adsorption process was examined. The negative values of ΔGo and the positive value of ΔHo revealed that the adsorption process was spontaneous and endothermic. The Langmuir isotherm model fitted well to metal ions adsorption data and the adsorption capacity. The kinetic data provided the best correlation of the adsorption with pseudo-second order kinetic model. In view of promising efficiency, the nano kaolinite can be employed for heavy metal ions adsorption.


2017 ◽  
Vol 56 (6) ◽  
pp. 1461-1470 ◽  
Author(s):  
Subhajit Dash ◽  
Haribandhu Chaudhuri ◽  
Radha Gupta ◽  
Udayabhanu G. Nair ◽  
Ashis Sarkar

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