scholarly journals Humulus scandens-Derived Biochars for the Effective Removal of Heavy Metal Ions: Isotherm/Kinetic Study, Column Adsorption and Mechanism Investigation

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3255
Author(s):  
Xingang Bai ◽  
Luyang Xing ◽  
Ning Liu ◽  
Nana Ma ◽  
Kexin Huang ◽  
...  

Humulus scandens was first adopted as a biomass precursor to prepare biochars by means of a facile molten salt method. The optimized biochar exhibits a high specific surface area of ~450 m2/g−1, a rich porous structure and abundant oxygen functional groups, which demonstrate excellent adsorption performance for heavy metal ions. The isotherm curves fit well with the Langmuir models, indicating that the process is governed by the chemical adsorption, and that the maximum adsorption capacity can reach 748 and 221 mg/g−1 for Pb2+ and Cu2+, respectively. In addition, the optimized biochar demonstrates good anti-interference ability and outstanding removal efficiency for Cu2+ and Pb2+ in simulated wastewater. The mechanism investigation and DFT calculation suggest that the oxygen functional groups play dominant roles in the adsorption process by enhancing the binding energy towards the heavy metal ions. Meanwhile, ion exchange also serves as the main reason for the effective removal.

2011 ◽  
Vol 64 (6) ◽  
pp. 1325-1332 ◽  
Author(s):  
Syed Ashraf ◽  
Angela Cluley ◽  
Ckarlos Mercado ◽  
Anja Mueller

In wastewater treatment, the removal of heavy metals is difficult due to the limited affinity of heavy metal ions to ion exchange resins. Here imprinting polymerization is used to develop resins with high capacity and selectivity for heavy metal ions for water treatment. A random copolymer of methacrylate and methacrylamide was found to be most effective for the removal of hydrophilic metal complexes, like CdCl2, ZnCl2, and the metalloid NaH2AsO4, particularly when the porosity of these resins is increased. For hydrophobic complexes imprinting emulsion polymerization was developed and data for the effective removal of mercury dithizonate will be described. Complete removal for up to 80 ppm of cadmium and mercury with only 200 mg of imprinted resin was obtained; competition and co-imprinting experiments are described as well.


2020 ◽  
Vol 54 (1 (251)) ◽  
pp. 83-85
Author(s):  
M.L. Yeritsyan ◽  
K.M. Yeritsyan ◽  
V.M. Mavisakalyan ◽  
A.M. Arustamyan ◽  
R.P. Mkhitaryan

The reaction between urea and melamine was studied. The reaction resulted in tris-carbamide derivative of melamine. During the reaction between the melamine derivative and the glycoside group of chitosan the sim-triazine functional groups were formed, which are included in the structure of synthesized derivative of chitosan. The synthesized derivative of chitosan was tested. It is recommended to use this chitosan derivative as an absorbent for the separation of heavy metal ions such as Cd2+, Hg1+, Hg2+, Co2+, Ag1+, As3+, As5+, etc. from the aqueous solutions of salts.


2014 ◽  
Vol 14 (4) ◽  
pp. 2937-2946 ◽  
Author(s):  
K. Rajakumar ◽  
S. Dinesh Kirupha ◽  
S. Sivanesan ◽  
Rajamaniccam L. Sai

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Abate Ayele ◽  
Yakob Godebo Godeto

Heavy metals generated mainly through many anthropogenic processes, and some natural processes have been a great environmental challenge and continued to be the concern of many researchers and environmental scientists. This is mainly due to their highest toxicity even at a minimum concentration as they are nonbiodegradable and can persist in the aquatic and terrestrial environments for long periods. Chromium ions, especially hexavalent ions (Cr(VI)) generated through the different industrial process such as tanneries, metallurgical, petroleum, refractory, oil well drilling, electroplating, mining, textile, pulp and paper industries, are among toxic heavy metal ions, which pose toxic effects to human, plants, microorganisms, and aquatic lives. This review work is aimed at biosorption of hexavalent chromium (Cr(VI)) through microbial biomass, mainly bacteria, fungi, and microalgae, factors influencing the biosorption of chromium by microorganisms and the mechanism involved in the remediation process and the functional groups participated in the uptake of toxic Cr(VI) from contaminated environments by biosorbents. The biosorption process is relatively more advantageous over conventional remediation technique as it is rapid, economical, requires minimal preparatory steps, efficient, needs no toxic chemicals, and allows regeneration of biosorbent at the end of the process. Also, the presence of multiple functional groups in microbial cell surfaces and more active binding sites allow easy uptake and binding of a greater number of toxic heavy metal ions from polluted samples. This could be useful in creating new insights into the development and advancement of future technologies for future research on the bioremediation of toxic heavy metals at the industrial scale.


2019 ◽  
Vol 9 (3) ◽  
pp. 547 ◽  
Author(s):  
Min Wang ◽  
Zhuqing Wang ◽  
Xiaohong Zhou ◽  
Shikun Li

In this study, we prepared a novel calcium alginate-disodium ethylenediaminetetraacetate dihydrate hybrid aerogel (Alg-EDTA) by chemical grafting and vacuum-freeze-drying to remove heavy metal ions from wastewater. Experimental results show that the as-prepared Alg-EDTA adsorbent has a high affinity for heavy metal ions, such as Cd2+, Pb2+, Cu2+, Cr3+, and Co2+, and can adsorb >85% of metal ions from the corresponding solution. Alg-EDTA also exhibits high selectivity toward Cd2+, and the maximum adsorption capacity for Cd2+ reached 177.3 mg/g, which exceeds the adsorption capacity of most reported Cd2+-adsorbents. Adsorbent regeneration can be achieved by a simple acid-washing process, and adsorption performance of Alg-EDTA remains stable after repeated use. All these findings indicate that Alg-EDTA has a promising prospect in the treatment of heavy metal ions wastewater.


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