Removal of bromate from water using modified activated carbon

2012 ◽  
Vol 12 (3) ◽  
pp. 398-405 ◽  
Author(s):  
Tongmian Liu ◽  
Fuyi Cui ◽  
Dongmei Liu ◽  
Zhiwei Zhao ◽  
Zhiquan Liu ◽  
...  

Coal-based activated carbon (AC) was treated chemically with nitric acid, sodium hydroxide and ammonia, and its ability to adsorb bromate was investigated. Several techniques were used to characterize the physicochemical properties of these materials, including surface area, pHpzc, and Boehm titration. Results indicated that surface physical and chemical properties can influence the adsorption uptake of bromate on ACs simultaneously. Surface basicity and pHpzc were both found to influence the electrostatic interactions between the bromate ions and the surface of the carbon. A correlation was found between basic groups and the adsorption capacity for bromate. The adsorption capacity of the carbon was found to be linearly proportional to the amount of basic groups on the surface. The bromate adsorption data collected from all the samples were found to fit the Toth isotherm model, indicating that the bromate adsorption process could occur on heterogeneous surfaces.

2018 ◽  
Vol 876 ◽  
pp. 91-96 ◽  
Author(s):  
Hoa Thai Ma ◽  
Van Thi Thanh Ho ◽  
Nguyen Bao Pham ◽  
Long Giang Bach ◽  
Tuan Dinh Phan

Surface modification of activated carbon (AC) could be done through different methods in order to modify their specific physical and chemical properties to facilitate metals removal from wastewater. Three methods were used to modify the rice husk AC (RHAC) including the use of (1) HNO3, (2) dithizone and (3) the combination of HNO3 with dithizone. These modification agents were increased its affinity towards the desired pollutant. The modification methods demonstrated the effective process for the metal ions adsorption capability and the removal of them from water. For Ni2+ and Cd2+ adsorption, RHAC was modified by HNO3 giving the best adsorption capacity in comparison with using dithizone or the combination of HNO3 with dithizone. That adsorption was reached 17.23 mg/g for Ni2+ and 29.61 mg/g for Cd2+. Additionally, the surface area, which was characterized by BET (Brunauer–Emmett–Teller) of RHAC, was 710.8 m2/g and DA micropore volume was 0.447 (cm3/g). Especially, the only modified RHACs had the peak of N-H functional group by using Fourier transform infrared spectrum (FTIR). Besides, the only RHAC modification by HNO3 had peak of C=O. That significantly contributed to increase the metal ions adsorption capacity of RHAC.


2013 ◽  
Vol 726-731 ◽  
pp. 1687-1690
Author(s):  
Jing Zhang ◽  
Jian Song Liu ◽  
Chun Liu ◽  
Jing Liang Yang ◽  
Lei Zhang

The structure and surface chemical properties of activated carbon after nitric acid modification and their influences on adsorption and catalytic ozonation of acid red 3R were investigated. The results showed that both specific surface area and micropore volume of activated carbon decreased, but mesopore volume increased after nitric acid modification. The adsorption capacity and catalytic ozonation performance of modified activated carbon were influenced due to the increased surface acidic functional groups. The adsorption capacity of modified activated carbon was enhanced under acidic condition due to dispersion interaction between increased surface acidic functional groups and acid red 3R. The increase in surface acidic functional groups of activated carbon was also considered to be responsible for improvement of the catalytic ozonation of acid red 3R under alkaline condition, because of their participation in the ozone decomposition and OH generation.


Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 882 ◽  
Author(s):  
Haifeng Wen ◽  
Daofang Zhang ◽  
Lin Gu ◽  
Haixiang Yu ◽  
Minmin Pan ◽  
...  

Sludge-derived activated carbon (SAC) was prepared by Fenton activation and calcination, and used as adsorbent to eliminate Eriochrome Black T (EBT) dye from aqueous media. The characterization results indicated that the produced SAC had a porous structure, high specific surface area, and abundant functional groups on its surface. The adsorption process was affected by pH, adsorbent dosage, time, and temperature. The adsorption capacity increased with temperature, and the highest adsorption capacity reached 178.2 mg·g−1 in 48 h at 318 K and pH 6. The results of the adsorption isotherm, kinetic, and thermodynamic analyses revealed that the adsorption of EBT onto SAC was naturally endothermic and spontaneous, involved both physical and chemical processes, and belonged mostly to the multilayer type of adsorption.


Author(s):  
Long Wu ◽  
Yimeng Cai ◽  
Jiayong Tu ◽  
Shizhe Wang ◽  
Noriyuki Kobayashi ◽  
...  

AbstractActivated carbon (AC) was modified by using non-thermal plasma in O2, N2 and O2/N2 atmospheres to increase its Cu(II) adsorption capacity and quantify the influences of the modifying atmospheres. SEM, BET, FT-IR and XPS were used to characterize the surface physical and chemical properties of AC. The results show that the AC modified by using plasma had significantly better Cu(II) adsorption performance than the raw AC. Among the O2, N2 and O2/N2 atmospheres, the AC with plasma modification in N2 showed best Cu(II) adsorption performance and the Cu(II) adsorption capacity was 369.5% higher than the raw AC. The AC modified in O2 atmosphere can form C—COOH groups, while the AC modified in N2 atmosphere can form C—NH2 groups. These two groups are both beneficial for Cu(II) adsorption, where the —NH2 groups are more effective for Cu(II) adsorption compared to —COOH groups. The chemisorption dominated the Cu(II) adsorption on the plasma modified AC and the adsorption performance was dependent on the surface functional groups properties of AC.


2019 ◽  
Vol 48 (2) ◽  
pp. 385-391 ◽  
Author(s):  
Mohamad Jani Saad ◽  
Chin Hua Chia ◽  
Sarani Zakaria ◽  
Mohd Shaiful Sajab ◽  
Sufian Misran ◽  
...  

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