Adsorption of Pb2+, Cu2+ and Cr3+ on Yongnian Bentonite

2014 ◽  
Vol 1056 ◽  
pp. 16-19
Author(s):  
Shu Li Ding ◽  
Dan Dan Hou ◽  
Bo Hui Xu ◽  
Yu Zhuang Sun

The Bentonite from Yongnian is Ca-Bentonite, Montmorillonite Content 52%, Colloidal Value 57ml/15g, Eca2+/CEC 53.60%. the Adsorption Characteristics of Pb2+, Cu2+ and Cr3+ onto Bentonite under Conditions of Constant Temperature and Ph have been Studied. the Results Show that the Adsorption Capacities of Heavy Metal Ions onto Bentonite from Yongnian Follow the Order of Pb2+> Cu2+> Cr3+. it is Found that the Adsorption Process of Bentonite Accords with the Langmuir Isotherm Model. the Maximum Adsorption of 3 Kinds of Metal Ions onto Bentonite is in Order of Cr3+>Cu2+>Pb2+.

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 112
Author(s):  
Kayee Chan ◽  
Kohki Morikawa ◽  
Nobuyuki Shibata ◽  
Anatoly Zinchenko

DNA–chitosan (DNA–CS) hydrogel was prepared by in situ complexation between oppositely charged DNA and chitosan polyelectrolytes via electrostatic cross-linking to study its adsorption characteristics. The DNA–chitosan hydrogel matrix contains (i) cationic (NH3+) and anionic (PO4–) sites for electrostatic binding with ionic species, (ii) -OH and -NH2 groups and heteroaromatic DNA nucleobases for chelation of heavy metal ions, and (iii) DNA double-helix for recognition and binding to small organic molecules of various structures and polarities. DNA–CS hydrogels efficiently bind with Hg2+, Pb2+, Cd2+, and Cu2+ metal cations of significant environmental concern. Adsorption capacities of DNA–CS hydrogels for studied metal ions depend on hydrogel composition and pH of solution and reach ca. 50 mg/g at neutral pHs. Hydrogels with higher DNA contents show better adsorption characteristics and notably higher adsorption capacity to Hg2+ ions. Because of the co-existence of cationic and anionic macromolecules in the DNA–CS hydrogel, it demonstrates an affinity to both anionic (Congo Red) and cationic (Methylene Blue) dyes with moderate adsorption capacities of 12.6 mg/g and 29.0 mg/g, respectively. DNA–CS hydrogel can also be used for adsorptive removal of pharmaceuticals on conditions that their molecules are sufficiently hydrophobic and have ionogenic group(s). Facile preparation and multitarget adsorption characteristics of DNA–CS hydrogel coupled with sustainable and environmentally friendly characteristics render this system promising for environmental cleaning applications.


2010 ◽  
Vol 6 (1) ◽  
pp. 56-60
Author(s):  
Anis Shofiyani ◽  
Gusrizal Gusrizal

Effect of pH and determination of adsorption capacity of Cu(II), Ni(II) and Pb(II) heavy metal ions on adsorbent prepared from Eichhornia crassipes (eceng gondok) biomass has been investigated. The influence of media acidity on the adsorption characteristics was carried out by determining ions adsorbed at various pH in the range of 2-10, while an adsorption isotherm model of Langmuir was used to estimate the capacity of adsorption. Results showed that Cu(II) was optimally adsorbed at the range pH of 5-6, Ni(II) at 2-4, while Pb(II) reached an optimum adsorption at pH 2-3. The adsorption data of Cu(II), Ni(II) and Pb(II) for the adsorbent folowed quite well Langmuir isotherm model, confirmed that such chemisorptions involved on that process. The ions adsorption capacities (am) were 27.47, 16.69, and 15.04 mg/g for Pb(II), Cu(II), and Ni(II), respectively.   Keywords: adsorption, heavy metal, Eichhornia crassipes, pH, capacity


Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3703 ◽  
Author(s):  
Shen Song ◽  
Zhao Liu ◽  
Ji Zhang ◽  
Caizhen Jiao ◽  
Ling Ding ◽  
...  

Removing heavy metal ions from industrial wastewater is one of the most important and difficult areas of the water treatment industry. In this study, Bacterial Cellulose/Polyvinyl Alcohol/Graphene Oxide/Attapulgite (BC/PVA/GO/APT) composites were successfully prepared via a repeated freeze-thaw method using bacterial cellulose, polyvinyl alcohol as the skeleton, and graphene oxide, attapulgite as fillers. The capacities of adsorbing Cu2+ and Pb2+ ions in solution were investigated. FTIR, XRD, SEM, BET, and TG-DSC analyses showed that the BC/PVA/GO/APT hydrogel has a better hydrophilicity, a larger specific surface area and a better thermal stability than traditional materials. We found that the adsorption of Cu2+ and Pb2+ ions can be accurately predicted by the Freundlich kinetic model, and the optimal adsorption capacities of these ions were found to be 150.79 mg/g and 217.8 mg/g respectively. Thermodynamic results showed that the adsorption process is spontaneous and exothermic. BC/PVA/GO/APT composites are suggested to be an ideal adsorption material for removing heavy metal ions from industrial wastewater.


RSC Advances ◽  
2021 ◽  
Vol 11 (28) ◽  
pp. 17080-17091
Author(s):  
Xinggang Chen ◽  
Zhuang Tian ◽  
Haina Cheng ◽  
Gang Xu ◽  
Hongbo Zhou

The Cu2+ first bound to the outer mannan and finally entered the cytoplasm. During the whole adsorption process, the number of adsorption sites in the outer and middle cell walls was the largest, and then gradually decreased.


Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 315 ◽  
Author(s):  
Musa Yahaya Pudza ◽  
Zurina Zainal Abidin ◽  
Suraya Abdul Rashid ◽  
Faizah Md Yasin ◽  
A. S. M. Noor ◽  
...  

The materials and substances required for sustainable water treatment by adsorption technique, are still being researched widely by distinguished classes of researchers. Thus, the need to synthesize substances that can effectively clean up pollutants from the environment cannot be overemphasized. So far, materials in bulk forms that are rich in carbon, such as biochar and varieties of activated carbon have been used for various adsorptive purposes. The use of bulk materials for such purposes are not efficient due to minimal surface areas available for adsorption. This study explores the adsorption task at nano dimension using carbon dots (CDs) from tapioca. The properties of carbon structure and its influence on the adsorptive efficacy of carbon nanoparticles were investigated by energy-dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HrTEM), and atomic force microscopy (AFM). The results implied carbon present in CDs are good adsorbents for effective adsorption of heavy metal ions (lead) with removal efficiency of 80.6% in aqueous environment. The adsorption process as explored by both Langmuir and Freundlich isotherms have proven favorability of the adsorption process. Langmuir form two and three have correlation coefficients R2 at 0.9922 and 0.9912, respectively. The Freundlich isotherm confirms CDs as having defined surface heterogeneity and the exponential distribution of active sites. The adsorption of lead unto CDs obeyed the second order kinetic model with coefficient of determination, R2 of 0.9668 and 0.9996 at an initial lead concentration of 20 mg/L and 100 mg/L, respectively. The findings validated the efficiency of CDs derived from tapioca as an excellent material for further utilization in the environmental fields of wastewater pollution detection and clean up, bio-imaging, and chemical sensing applications.


2020 ◽  
Vol 99 ◽  
pp. 106072 ◽  
Author(s):  
Lihua Liu ◽  
Siyan Liu ◽  
Hongliang Peng ◽  
Zhengchi Yang ◽  
Lu Zhao ◽  
...  

2011 ◽  
Vol 308-310 ◽  
pp. 178-181
Author(s):  
Xin Liang Liu ◽  
Li Jun Wang ◽  
Yong Li Chen ◽  
Nan Chen ◽  
Shuang Fei Wang

The bagasse fibers were activated by alkalize and etherified. 1,2-ethanediamine and carbon disulfide were used to modify the etherify fiber to get the chelate-fiber contained sulfur and nitrogen. The FTIR was used to characterize the xanthated aminating-fiber (XAF). The mechanism of sorption properties for heavy metal ions were studied. As the results shown, the optimal process to prepare the XAF was that the reaction time, concentration of NaOH and dosage of CS2 was 60min, 12% and 2mL, respectively. The chelate-fiber containing sulfur and nitrogen possessed high adsorption capacities for Cu(II) and the mechanism of sorption fitted the pseudo-second-order model well.


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