scholarly journals Activated Carbon Microsphere from Sodium Lignosulfonate for Cr(VI) Adsorption Evaluation in Wastewater Treatment

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 236 ◽  
Author(s):  
Keyan Yang ◽  
Jingchen Xing ◽  
Pingping Xu ◽  
Jianmin Chang ◽  
Qingfa Zhang ◽  
...  

In this study, activated carbon microsphere (SLACM) was prepared from powdered sodium lignosulfonate (SL) and polystyrene by the Mannich reaction and ZnCl2 activation, which can be used to remove Cr(VI) from the aqueous solution without adding any binder. The SLACM was characterized and the batch experiments were conducted under different initial pH values, initial concentrations, contact time durations and temperatures to investigate the adsorption performance of Cr(VI) onto SLACM. The results indicated that the SLACM surface area and average pore size were 769.37 m2/g and 2.46 nm (the mesoporous material), respectively. It was found that the reduced initial pH value, the increased temperature and initial Cr(VI) concentration were beneficial to Cr(VI) adsorption. The maximum adsorption capacity of Cr(VI) on SLACM was 227.7 mg/g at an initial pH value of 2 and the temperature of 40 °C. The adsorption of SLACM for Cr(VI) mainly occurred during the initial stages of the adsorption process. The adsorption kinetic and isotherm experimental data were thoroughly described by Elovich and Langmuir models, respectively. SL could be considered as a potential raw material for the production of activated carbon, which had a considerable potential for the Cr(VI) removal from wastewater.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 241 ◽  
Author(s):  
Jian Guo ◽  
Yaqin Song ◽  
Xiaoyang Ji ◽  
Lili Ji ◽  
Lu Cai ◽  
...  

The aim of this study was to optimize the adsorption performance of activated carbon (AC), derived from the shell of Penaeus vannamei prawns, on heavy metal ions. Inexpensive, non-toxic, and renewable prawn shells were subjected to carbonization and, subsequently, KOH-activation to produce nanoporous K-Ac. Carbonized prawn shells (CPS) and nanoporous KOH-activated carbon (K-Ac) from prawn shells were prepared and characterized by FTIR, XRD, BET, SEM, and TEM. The results showed that as-produced K-Ac samples were a porous material with microporous and mesoporous structures and had a high specific surface area of 3160 m2/g, average pore size of about 10 nm, and large pore volume of 2.38 m3/g. Furthermore, batches of K-Ac samples were employed for testing the adsorption behavior of Cd2+ in solution. The effects of pH value, initial concentration, and adsorption time on Cd2+ were systematically investigated. Kinetics and isotherm model analysis of the adsorption of Cd2+ on K-Ac showed that experimental data were not only consistent with the Langmuir adsorption isotherm, but also well-described by the quasi-first-order model. Finally, the adsorption behaviors of as-prepared K-Ac were also tested in a ternary mixture of heavy metal ions Cu2+, Cr6+, and Cd2+, and the total adsorption amount of 560 mg/g was obtained.



2016 ◽  
Vol 11 (4) ◽  
pp. 784-795 ◽  
Author(s):  
Abolghasem Alighardashi ◽  
Shooza Shahali

Excessive nitrate in the water impose a danger to human health and contribute to eutrophication. The present continuous fixed bed pilot study was carried out using granular activated carbon made from walnut shell for removal of nitrate from aqueous solution and natural groundwater. The carbon was characterized using SEM, FTIR and BET. The BET specific surface area and average pore size before nitrate adsorption were 1434.6 m2g−1 and 2.08 nm, respectively, and after were 633.28 m2g−1 and 2.04 nm, respectively. Optimum removal of nitrate was achieved at a contact time of 2 min, pH of 6.5 and a nitrate concentration of 200 mg/l. The hydraulic loading rate was calculated to be 10 m3/h.m2 and the maximum adsorption capacity using the Langmuir adsorption isotherm model (R2 = 0.99) was 10 mg NO3/g. These experiments were also carried out using groundwater and the removal of nitrate decreased from 68% to 60% because of competition with other cations and anions.



2016 ◽  
Vol 74 (12) ◽  
pp. 2751-2761 ◽  
Author(s):  
Yan Shu ◽  
Kelin Li ◽  
Jinfeng Song ◽  
Bing Li ◽  
Chunfang Tang

In this study, Salix matsudana activated carbon (SAC) was prepared by phosphoric acid activation, and the adsorption characteristics of Cd(II) and Pb(II) on SAC in single- and double-component solutions were investigated. In both systems, the adsorption capacities of both ions on SAC increased with the increasing initial pH value and temperature in the solutions, and the adsorption equilibrium was approached at 10 min. The adsorption process was spontaneous, endothermic, and depicted well by the pseudo-second-order adsorption model, and the equilibrium adsorption fitted reasonably well with the Langmuir isotherm. The maximum adsorption capacity (Qm) of Cd(II) and Pb(II) was 58.48 and 59.01 mg/g, respectively, in the single-element systems. However, it reduced to 25.32 and 31.09 mg/g, respectively, in the double-element system. The physicochemical property analysis showed that the specific surface area, total pore volume, and average pore diameter of SAC was 435.65 m2/g, 35.68 mL/g, and 3.86 nm, respectively. The SAC contained groups of -OH, C = O, and P = O. Results suggest that SAC had a good performance for the adsorption of Cd(II) and Pb(II) from solution, and the adsorption selectivity sequence was Pb(II) > Cd(II).



Author(s):  
Erman Taer ◽  
R. Taslim ◽  
Sugianto Sugianto ◽  
M. Paiszal ◽  
Mukhlis Mukhlis ◽  
...  

Activated carbon monoliths (ACMs) with average pore diameters in the meso- and micropore regions were successfully produced from biomass material. ACM synthesis uses chemical activation with KOH and ZnCl<sub>2</sub> activating agents. The carbon and activating agent mass ratios were 1:1, 1:3, 1:5 and 1:7. Both activating materials produced an ACM with an average pore diameter of 3.2 nm. The specific capacitance, specific surface area, energy and power were as high as 63 F/g, 650 m<sup>2</sup>/g, and 0.23 Wh/kg for KOH and 73 F/g, and 522 m<sup>2</sup>/g, and 19 W/kg for ZnCl<sub>2</sub> activating agents, respectively. For comparison, we also studied the physical and electrochemical properties of ACM with an average pore size in the micropore range from the same raw material.



10.29007/ps3m ◽  
2020 ◽  
Author(s):  
Yuvarat Ngernyen ◽  
Werawit Phiewruangnont ◽  
Ratchapon Anachai ◽  
Andrew Hunt

This present work aims to reduce the color of biodiesel from crude palm oil through the application of activated carbon prepared from chili stem waste. Chilli stem was converted into activated carbon using 30 wt% KOH at a ratio of 1:2 for 1 h, followed by carbonization at 500 oC under an N2 atmosphere for a further hour. Physico-chemical characteristics of the raw material and activated carbon were analyzed including thermogravimetric analysis, proximate analysis, and porosities. The results demonstrated that the activated carbon was a porous material with a highly mesoporous structure (84.5%). The surface area of activated carbon was 10.6 m2/g and it exhibited an average pore diameter of 27.25 nm which was suitable for the removal of large highly colored molecules. Batch adsorption experiments were performed to investigate the reduction in color of the biodiesel. Ratios of activated carbon to biodiesel of 0.002 and 0.1 w/v were used in the study. For comparison, the adsorption was also tested against a commercial activated carbon with a surface area of 1,130 m2/g, but lower average pore size of 3.72 nm. The chili stem activated carbon can reduce color by approximately 15% within 24 h and the maximum color reduction was 95% after 96 h for both activated carbon to biodiesel ratios. The color of biodiesel changes from dark red to yellow and eventually resulted in a pale yellow color with longer adsorption times and was deemed more attractive for use. Moreover, commercial activated carbon with its small pore size could not reduce the color, with a maximum reduction of only 3%.



Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 257
Author(s):  
Jie Ren ◽  
Nanwei Chen ◽  
Li Wan ◽  
Guojian Li ◽  
Tao Chen ◽  
...  

In this study, a new method for economical utilization of coffee grounds was developed and tested. The resulting materials were characterized by proximate and elemental analyses, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption–desorption at 77 K. The experimental data show bio-oil yields reaching 42.3%. The optimal activated carbon was obtained under vacuum pyrolysis self-activation at an operating temperature of 450 °C, an activation temperature of 600 °C, an activation time of 30 min, and an impregnation ratio with phosphoric acid of 150 wt.%. Under these conditions, the yield of activated carbon reached 27.4% with a BET surface area of 1420 m2·g−1, an average pore size of 2.1 nm, a total pore volume of 0.747 cm3·g−1, and a t-Plot micropore volume of 0.428 cm3·g−1. In addition, the surface of activated carbon looked relatively rough, containing mesopores and micropores with large amounts of corrosion pits.



2013 ◽  
Vol 798-799 ◽  
pp. 1123-1127
Author(s):  
Hua Lei Zhou ◽  
Qiong Qiong Zhu ◽  
Dong Hua Huang

The activated carbon with high surface area was prepared by KOH activation from anthracite and used as adsorbent for removal of Cr (VI) from aqueous solution. The pore structure and surface properties were characterized by N2 adsorption at 77K, transmission electron microscope (TEM) and Fourier transform infrared spectroscopy ( FTIR). Effect of pH and isotherms at different temperature were investigated. Results show that the prepared carbon is a microporous-and mesoporous-adsorbent with developed pore structure and abundant surface oxygen-containing groups. PH value of the solution plays key function on the adsorption. The chemical adsorption dominates the adsorption process. The activated carbon exhibits much higher Cr adsorption capacity than the commercial activated carbon at initial pH of ~3. The equilibrium adsorption data are fitted by both Freundlich model and Langmuir model well.



2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Huaxing Xu ◽  
Biao Gao ◽  
Hao Cao ◽  
Xueyang Chen ◽  
Ling Yu ◽  
...  

Nanoporous activated carbon material was produced from the waste rice husks (RHs) by precarbonizing RHs and activating with KOH. The morphology, structure, and specific surface area were investigated. The nanoporous carbon has the average pore size of 2.2 nm and high specific area of 2523.4 m2 g−1. The specific capacitance of the nanoporous carbon is calculated to be 250 F g−1at the current density of 1 A g−1and remains 80% for 198 F g−1at the current density of 20 A g−1. The nanoporous carbon electrode exhibits long-term cycle life and could keep stable capacitance till 10,000 cycles. The consistently high specific capacitance, rate capacity, and long-term cycle life ability makes it a potential candidate as electrode material for supercapacitor.



2019 ◽  
Vol 6 (9) ◽  
pp. 190523 ◽  
Author(s):  
Lu Luo ◽  
Xi Wu ◽  
Zeliang Li ◽  
Yalan Zhou ◽  
Tingting Chen ◽  
...  

Activated carbon (AC) was successfully prepared from low-cost forestry fir bark (FB) waste using KOH activation method. Morphology and texture properties of ACFB were studied by scanning and high-resolution transmission electron microscopies (SEM and HRTEM), respectively. The resulting fir bark-based activated carbon (ACFB) demonstrated high surface area (1552 m 2 g −1 ) and pore volume (0.84 cm 3 g −1 ), both of which reflect excellent potential adsorption properties of ACFB towards methylene blue (MB). The effect of various factors, such as pH, initial concentration, adsorbent content as well as adsorption duration, was studied individually. Adsorption isotherms of MB were fitted using all three nonlinear models (Freundlich, Langmuir and Tempkin). The best fitting of MB adsorption results was obtained using Freundlich and Temkin. Experimental results showed that kinetics of MB adsorption by our ACFB adsorbent followed pseudo-second-order model. The maximum adsorption capacity obtained was 330 mg g −1 , which indicated that FB is an excellent raw material for low-cost production of AC suitable for cationic dye removal.



2019 ◽  
Vol 79 (8) ◽  
pp. 1561-1570
Author(s):  
Wei Chen ◽  
Fengting Chen ◽  
Bin Ji ◽  
Lin Zhu ◽  
Hongjiao Song

Abstract The adsorption behavior and the underlying mechanism of methylene blue (MB) sorption on biochars prepared from different feedstocks at 500 °C were evaluated. The biochar feedstocks included Magnolia grandiflora Linn. leaves biochar (MBC), pomelo (Citrus grandis) peel biochar (PBC) and badam shell biochar (BBC). The results of characterizing and analyzing the samples showed that different biochars had different effects on the adsorption of MB. It could be found that MBC had the best adsorption effect on MB due to its largest average pore diameter of 5.55 nm determined by Brunauer-Emmett-Teller analysis. Under the optimal conditions, the maximum adsorption capacities of BBC, PBC and MBC were 29.7, 85.15 and 99.3 mg/g, respectively. The results showed that the amount of adsorption was affected by the pH value. The maximum adsorption capacity of MBC was 46.99 mg/g when it was at pH of 3, whereas for the same experimental conditions the maximum adsorption capacity of BBC and PBC was 25.29 mg/g at pH of 11 and 36.08 mg/g at pH of 7, respectively. Therefore, MBC was found to be a most efficient low-cost adsorbentl for dye wastewater treatment compared with BBC and PBC, and it had the best removal effect under acidic conditions.



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