To enhance the Cd2+ adsorption capacity on coconut shell-derived biochar by chitosan modifying: performance and mechanism

Author(s):  
Guanhai Mo ◽  
Jiang Xiao ◽  
Xiang Gao
2013 ◽  
Vol 739 ◽  
pp. 142-147
Author(s):  
Guo Li He ◽  
Hong Hong Yi ◽  
Xiao Long Tang ◽  
Fen Rong Li ◽  
Yun Dong Li ◽  
...  

Selecting effective xenon adsorbents is important for preventing significant global nuclear proliferation. The adsorption capacity of coconut shell activated carbons (SAC),zeolite 10X,zeolite 5A, zeolite 13X were researched and the Xenon adsorption of the coconut shell activated carbon modified by KOH(SAC/KOH-1 and SAC/KOH-2) were compared in this paper. The factors of temperature and flow rate that influenced the dynamic adsorption of xenon by 10X were discussed. The order of the Xenon adsorption capacity is as follows: zeolite 10X, SAC/KOH-2, SAC/KOH-1, SAC, zeolite 13X, zeolite 5A.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Azrina Aziz ◽  
Mohamad Nasran Nasehir Khan ◽  
Mohamad Firdaus Mohamad Yusop ◽  
Erniza Mohd Johan Jaya ◽  
Muhammad Azan Tamar Jaya ◽  
...  

This research aims to optimize preparation conditions of coconut-shell-based activated carbon (CSAC) and to evaluate its adsorption performance in removing POP of dichlorodiphenyltrichloroethane (DDT). The CSAC was prepared by activating the coconut shell via single-stage microwave heating under carbon dioxide, CO2 flow. The total pore volume, BET surface area, and average pore diameter of CSAC were 0.420 cm3/g, 625.61 m2/g, and 4.55 nm, respectively. The surface of CSAC was negatively charged shown by the zeta potential study. Response surface methodology (RSM) revealed that the optimum preparation conditions in preparing CSAC were 502 W and 6 min for radiation power and radiation time, respectively, which corresponded to 84.83% of DDT removal and 37.91% of CSAC’s yield. Adsorption uptakes of DDT were found to increase with an increase in their initial concentration. Isotherm study revealed that DDT-CSAC adsorption system was best described by the Langmuir model with monolayer adsorption capacity, Qm of 14.51 mg/g. The kinetic study confirmed that the pseudo-second-order model fitted well with this adsorption system. In regeneration studies, the adsorption efficiency had slightly dropped from 100% to 83% after 5 cycles. CSAC was found to be economically feasible for commercialization owing to its low production cost and high adsorption capacity.


2020 ◽  
Vol 32 (8) ◽  
pp. 2084-2090
Author(s):  
Lam Van Tan ◽  
Hong-Tham Nguyen Thi ◽  
To-Uyen Dao Thi ◽  
Nguyen Thi Thuy Hong

A straw-activated carbon has been successfully synthesized with the high BET surface area, at 494.9240 m2/g, which is perfectly suitable for the adsorption of cephalexin antibiotic from aqueous water. It is noted that the adsorption capacity of straw-activated carbon is demonstrated by the effect of initial concentration, contact time, pH solution and dosage. The straw-activated carbon exhibited improved decontaminant efficiency towards cephalexin antibiotics. Quick and improved sorption could be attributable to the distinctive structural and compositional merits as well as the synergetic contribution of functional groups to surface material. Most interestingly, the adsorption capacity achieved at pH 6 was ~98.52%. A mechanism adsorption has been proposed to demonstrate adsorption of the straw-activated carbon (AC-S). By comparison with other studies, it is confirmed that AC-S in this study obtained a higher removal efficiency than other adsorbent materials, suggesting that straw-activated carbon may be an appropriate candidate to treat cephalexin from wastewater media


2011 ◽  
Vol 255-260 ◽  
pp. 2981-2986
Author(s):  
Xiao Yan Ma ◽  
Nai Yun Gao ◽  
Jun Li ◽  
Chen Chen

Three kinds of granular carbon made from different materials of coal, coconut shell and jujube seed were evaluated for adsorption of 2-methylisoborneol in drinking water by equilibrium isotherm simulation. Results showed that Freundlich isotherm can more suitable to describe the adsorption of these three kinds of carbon. For coal-based, coconut shell and jujube seed carbon, the largest adsorption capacity of 2-MIB were 2225.0,3152.8 and 1E-07(ng/g)(L/ng)n respectively in pure water, and in raw water they were 559.6,612.5 and 6E-28(ng/g)(L/ng)n respectively, about one-fifth of those in pure water. Among the selected carbons, coconut shell carbon had the largest adsorption capacity, followed by coal-based and jujube seed carbon which can hardly absorb 2-MIB.


Author(s):  
Hind Yaacoubi ◽  
Zuo Songlin

Abstract The objective of this research is to study the retention of two acidic anthraquinone dyes by Coconut-shell-based activated carbon. Ultimately, this work allows the valorization of this new material as an adsorbent. The effect of ammonia modification on the adsorption capacity of activated carbon towards remazol brilliant blue R19 (RB19) and acid blue 25 (AB25), has been studied. Coconut-shell-based activated carbon material was modified under ammonia flow at 900 and 1000 °C. The adsorption rates and isotherms of RB19 and AB25 on the resultant materials were then tested. The results show that ammonia modification remarkably increases the adsorption capacities of the activated carbons to RB19 and AB25, by a factor of 2–3 after treatment at 1000 °C (From 0.22 mmol g−1 and 1.04 mmol g−1 to 0.76 mmol g−1 and 2.19 mmol g−1 on AC and AC-O-N-1000, respectively). The increased adsorption capacity is attributed to the introduction of basic nitrogen-containing functional groups and enhanced pore development by ammonia modification. The collected experimental kinetic and isotherm data are well compatible with the intraparticle diffusion kinetic model and the Langmuir isotherm model. According to these results, the adsorption affinity is homogeneous in terms of surface functional groups and the surface bears a finite number of identical adsorption sites.


2013 ◽  
Vol 594-595 ◽  
pp. 240-244
Author(s):  
Nor Adilla Rashidi ◽  
Suzana Yusup ◽  
Azry Borhan

The objective of this research is to synthesize the microporous activated carbon and test its applicability for CO2gas capture. In this study, coconut shell-based and commercial activated carbon is used as the solid adsorbent. Based on the findings, it shows that the gas adsorption capacity is correlated to the total surface area of the materials. In addition, reduction in the adsorption capacity with respect to temperature proves that the physisorption process is dominant. Higher carbon dioxide (CO2) adsorption capacity in comparison to nitrogen (N2) capacity contributes to higher CO2/N2selectivity, and confirms its applicability in the post-combustion process. Utilization of abundance agricultural wastes and one-step physical activation process is attractive as it promotes a cleaner pathway for activated carbon production, and simultaneously, reduces the total operating cost.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Le Phuong Hoang ◽  
Huu Tap Van ◽  
Thi Thuy Hang Nguyen ◽  
Van Quang Nguyen ◽  
Phan Quang Thang

Coconut shell activated carbon loaded with cobalt ferrite (CoFe2O4) composites (CAC/CoFe2O4) was synthesized via the single-step refluxing router method to manufacture adsorbents. The adsorbents were then applied to remove Rhodamine B (RhB) from aqueous environments via adsorption. The properties of coconut shell activated carbon (CAC) and CAC/CoFe2O4 were investigated through the usage of electron microscopic methods (SEM: Scanning Electron Microscopy, EDS: Energy Dispersive X-ray), powder X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). A series of batch experiments were implemented to evaluate the influences of various experimental parameters (initial pH, RhB concentration, contact time, and dosage of CAC/CoFe2O4) on the adsorption process. It was found that CoFe2O4 was successfully attached to activated carbon particles and had the suitable adsorption capacity for RhB at a molar ratio of 1 : 2:200 corresponding to the Co : Fe:CAC order. The removal efficiency and adsorption of RhB were optimal at a pH level of 4. The maximum adsorption capacity was 94.08 mg/g at an initial concentration of 350 mg/L and adsorbent dosage of 0.05 g/25 mL. Freundlich and Langmuir's models fitted well with the results obtained from the experimental data. The pseudo-second-order model also suited the most for RhB adsorption with the most remarkable correlation coefficient (R2 = 0.934). The adsorption process was controlled by a chemisorption mechanism through electrostatic attraction, hydrogen bonding interactions, and π-π interactions.


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