Adsorption kinetics and mechanisms of copper ions on activated carbons derived from pinewood sawdust by fast H3PO4 activation

2018 ◽  
Vol 25 (8) ◽  
pp. 7907-7915 ◽  
Author(s):  
Xinyuan Gao ◽  
Long Wu ◽  
Qing Xu ◽  
Wei Tian ◽  
Zhanyong Li ◽  
...  
2018 ◽  
Vol 230 ◽  
pp. 61-63 ◽  
Author(s):  
Li Dawei ◽  
Wang Yu ◽  
Zhou Jiaojiao ◽  
Wang Jicheng ◽  
Liu Xiaoyang ◽  
...  

2021 ◽  
Author(s):  
khaled Mostafa ◽  
H. Ameen ◽  
A. Ebessy ◽  
A. El-Sanabary

Abstract Our recently tailored and fully characterized poly (AN)-starch nanoparticle graft copolymer having 60.1 G.Y. % was used as a starting substrate for copper ions removal from waste water effluent after chemical modification with hydroxyl amine via oximation reaction. This was done to change the abundant nitrile groups in the above copolymer into amidoxime one and the resultant poly (amidoxime) resin was used as adsorbent for copper ions. The resin was characterized qualitatively via rapid vanadium ion test and instrumentally by FT-IR spectra and SEM morphological analysis to confirm the presence of amidoxime groups. The adsorption capacity of the resin was done using the batch technique, whereas the residual copper ions content in the filtrate before and after adsorption was measured using atomic adsorption spectrometry. It was found that the maximum adsorption capacity of poly (amidoxime) resin was 115.2 mg/g at pH 7, 400ppm copper ions concentration and 0.25 g adsorbent at room temperature. The adsorption, kinetics and isothermal study of the process is scrutinized using different variables, such as pH, contact time, copper ion concentration and adsorbent dosage. Different kinetics models comprising the pseudo-first-order and pseudo-second-order have been applied to the experimental data to envisage the adsorption kinetics. It was found from kinetic study that pseudo-second-order rate equation was better than pseudo-first-order supporting the formation of chemisorption process. While, in case of isothermal study, the examination of calculated correlation coefficient (R2) values showed that the Langmuir model provide the best fit to experimental data than Freundlich one.


Author(s):  
L.M. Grishchenko ◽  
V.E. Diyuk ◽  
G.G. Tsapyuk ◽  
R. Mariychuk ◽  
O.V. Mischanchuk ◽  
...  

2020 ◽  
Vol 32 (10) ◽  
pp. 2653-2659
Author(s):  
Tumma Prasanna Kumar Reddy ◽  
Sayana Veerababu ◽  
Malireddy Venkata Sai Mohan Reddy ◽  
Kunta Ravindhranath

Three different activated carbons as effective adsorbents were prepared by digesting the stems of Cordia dichotoma, Albizia thompsonii and Polyalthia cerasoides plants in conc. H2SO4 for Cu2+ removal from wastewater. The sorption natures of these sorbents are optimized with respect to various physico-chemical characteristics for the maximum Cu2+ removal using simulated waters. Cordia dichotoma (CDAC), Albizia thompsonii (ATAC) and Polyalthia cerasoides (PCAC) activated carbons show good sorption capacities of values: 97.0, 76.8 and 66.7 mg/g, respectively in a wide pH ranges. Unlike that of other two activated carbons, Cordia dichotoma activated carbon is effective even in acid conditions, indicting its direct applicability to Cu-based industrial effluents which are generally acidic in nature. Interference of two fold excess of co-ions is minimal. The established extraction conditions for the removal of more than 95.0% from 10 ppm Cu2+ solution at room temperature (303 K) using CDAC as sorbent are: pH: 3-9; time of equilibration: 1 h; sorbent dosage: 0.100 g/100 mL; with ATAC: pH: 6-9; time of equilibration: 1.5 h and sorbent dosage: 0.125 g/100 mL; and with PCAC: pH: 6-9; time of equilibration: 2.0 h and sorbent dosage 0.50 g/100 mL. Spent adsorbents can be regenerated and reused until four cycles with minimal loss of adoption capacities. Thermodynamic studies revealed that the sorption is spontaneous and endothermic in nature. Further, the ΔH value for CDAC is 30.156 KJ/mol; it indicates the strong chemisorption and may be through reduction to Cu+/Cu and/or complex formation between Cu2+ and functional groups of the adsorbent. The ΔH values of other two activated carbons, ATAC and PCAC, indicated that the sorption is mainly physical with strong inclination towards chemical nature. Positive ΔS values of all the three sorbents, emphasizes the disorder or randomness at the solid-liquid interface and hence favourable conditions for more penetration of Cu2+ into the surface layers of the adsorbent and hence, more removal of Cu2+ ions. The negative ΔG values indicate that the sorption forces are good enough to cross the potential barrier at the solid-liquid interface and hence the process is spontaneous. The prepared three activated carbons were also successfully applied to industrial effluent and polluted lake samples.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2558 ◽  
Author(s):  
Zhansheng Wu ◽  
Xinhui Wei ◽  
Yongtao Xue ◽  
Xiufang He ◽  
Xia Yang

Activated carbons (ACs) based on apricot shells (AS), wood (W), and walnut shells (WS) were applied to adsorb atrazine in co-solutions. To study the effect of Bisphenol A (BPA) on the adsorption behavior of atrazine, the adsorption performance of ACs for BPA in single solution was studied. The results demonstrated that the adsorption kinetics of BPA fitted the pseudo-second-order model, the adsorption isotherms of BPA followed the Langmuir model. Meanwhile, the adsorption kinetics of atrazine fitted the pseudo-second-order kinetics model and the isotherm was consistent with the Freundlich model both in single solution and co-solution. In addition, competitive adsorption was observed when atrazine coexisted with BPA or humic acid. For the adsorption capacity, the adsorption amount of ASAC, WAC, and WSAC for atrazine obviously decreased by 18.0%, 30.0%, and 30.3% in the presence of BPA, respectively, which was due to the π−π interactions, hydrophobic interactions, and H-bonds, resulting in the competitive adsorption between atrazine and BPA. This study contributes to the further understanding of the adsorption behavior for atrazine in co-solution.


2010 ◽  
Vol 156-157 ◽  
pp. 1215-1218 ◽  
Author(s):  
Qing Ruo Xie ◽  
Zhang Fa Tong ◽  
Li Wen Zheng ◽  
Xiao Guang Chen

A new process was investigated which combines both fast pyrolysis carbonization and CS activated carbons with H3PO4 activation (CSAC). ACs were obtained as by-product from the preparation process of bio-oil with fast pyrolysis under different temperatures (T=727–973 K), in which the reaction ended in a very short duration. A two-step process of reaction is proposed to govern carbonization and activation: firstly fast pyrolysis reaction removing disorganized material was associated with considerable weight loss but with low generation of porosity, pyrolysis/carbonization under the flow of N2 is suggested to ensure fluidization of CS powders and bed material, enhance decomposition of raw material, initiates controlled gasification at different temperatures. Then H3PO4 activation process dominated at 573 K, which leads to considerable evolution of porosity. In this research, the adsorption characteristics were determined from N2 adsorption isotherms and subsequent analysised by the BET-and BJH-methods. As a result, the iodine adsorption number of AC was 1310 mg/g and the SSA of AC was 1421.38 m2/g .


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