Combined Adsorption Isotherms for Measuring the Adsorption Capacity of Fly Ash in Concrete

2014 ◽  
Vol 2 (4) ◽  
pp. 614-620 ◽  
Author(s):  
Zeyad T. Ahmed ◽  
David W. Hand ◽  
Melanie K. Watkins ◽  
Larry L. Sutter
Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2741
Author(s):  
Pengcheng Lv ◽  
Ruihong Meng ◽  
Zhongyang Mao ◽  
Min Deng

In this study, the hydrated sodium aluminosilicate material was synthesized by one-step hydrothermal alkaline desilication using fly ash (FA) as raw material. The synthesized materials were characterized by XRD, XRF, FT-IR and SEM. The characterization results showed that the alkali-soluble desilication successfully had synthesized the sodium aluminosilicate crystalline (N-A-S-H) phase of sodalite-type (SOD), and the modified material had good ionic affinity and adsorption capacity. In order to figure out the suitability of SOD as an adsorbent for the removal of ammonium and phosphorus from wastewater, the effects of material dosing, contact time, ambient pH and initial solute concentration on the simultaneous removal of ammonium and phosphorus are investigated by intermittent adsorption tests. Under the optimal adsorption conditions, the removal rate of ammonium was 73.3%, the removal rate of phosphate was 85.8% and the unit adsorption capacity reached 9.15 mg/L and 2.14 mg/L, respectively. Adsorption kinetic studies showed that the adsorption of ammonium and phosphorus by SOD was consistent with a quasi-secondary kinetic model. The adsorption isotherm analysis showed that the equilibrium data were in good agreement with the Langmuir and Freundlich model. According to thermodynamic calculations, the adsorption of ammonium and phosphorus was found to be a heat-absorbing and spontaneous process. Therefore, the preparation of SOD by modified FA has good adsorption properties as adsorbent and has excellent potential for application in the removal of contaminants from wastewater.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 63
Author(s):  
Maria Harja ◽  
Gabriela Buema ◽  
Nicoleta Lupu ◽  
Horia Chiriac ◽  
Dumitru Daniel Herea ◽  
...  

Fly ash/magnetite material was used for the adsorption of copper ions from synthetic wastewater. The obtained material was characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area, and vibrating sample magnetometer (VSM). Batch adsorption experiments were employed in order to investigate the effects of adsorbent dose, initial Cu (II) concentration and contact time over adsorption efficiency. The experimental isotherms were modeled using Langmuir (four types of its linearization), Freundlich, Temkin, and Harkins–Jura isotherm models. The fits of the results are estimated according to the Langmuir isotherm, with a maximum adsorption capacity of 17.39 mg/g. The pseudo-second-order model was able to describe kinetic results. The data obtained throughout the study prove that this novel material represents a potential low-cost adsorbent for copper adsorption with improved adsorption capacity and magnetic separation capability compared with raw fly ash.


2014 ◽  
Vol 53 (17) ◽  
pp. 6985-6989 ◽  
Author(s):  
Zeyad T. Ahmed ◽  
David W. Hand
Keyword(s):  
Fly Ash ◽  

2019 ◽  
Vol 19 (3) ◽  
pp. 475-483 ◽  
Author(s):  
Muvumbu Jean-Luc Mukaba ◽  
Alechine Emmanuel Ameh ◽  
Chuks Paul Eze ◽  
Leslie Felicia Petrik

2016 ◽  
Vol 18 (2) ◽  
pp. 437-443 ◽  

<div> <p>Adsorption is one of the methods that can be used for metal removal. In this study five metals were used cadmium, chromium, lead, copper and Nickel (Cd, Cr, Pb, Cu, and Ni) over a concentration range from 0.8 to about 7 mg l<sup>-1</sup> for each metal. Adsorbents were prepared with increasing chitosan to bentonite ratio from 0 to 0.67 g chitosan/g bentonite. The study showed that adsorption of metals on plain bentonite and chitosan modified bentonite can fit well with Langmuir and Freundlich adsorption isotherms. Furthermore, the bentonite adsorption capacity will decrease with the increase of chitosan/bentonite ratio. This study concluded that bentonite is a good adsorbent. However, the applicability of bentonite as potential adsorbent may be limited by its physical properties such as slow settling rate and difficulty to use it as an adsorbent in adsorption columns. Despite the decrease of maximum theoretical adsorption capacity as a result of chitosan modification, the addition of small amount of chitosan can improve the physical characteristics of bentonite clay to be used as an adsorbent.&nbsp;</p> </div> <p>&nbsp;</p>


2011 ◽  
Vol 80-81 ◽  
pp. 298-301
Author(s):  
Shi Wei Cao ◽  
Wei Chen ◽  
Zhao Qian Jing

Fly ash Ceramsite, Artificial Biofilter Bed, Dry Umbrella Bamboo, Phosphorus Removal Abstract: High calcium fly ash ceramsite had tremendous surface area and porosity, the unit weight of fly ash adsorption column adsorption capacity of ceramsite was 0.032mg•g-1, which was higher than normal calcium fly ash ceramsite adsorption capacity. The fix adsorption column tests showed that the adsorption capacity got stable when the contact time was 3 hours and the saturation adsorption was got at the ninth hour. The result of subsequent tests showed that the phosphorus resolve would not occur if the adsorption condition doesn’t change. The pilot test with actual wastewater was done and the results showed that the PO43- concentrations of effluent were less than 0.2mg•L-1 and the removal rate reached 90%, dry umbrella bamboo was the most suitable aquatic plant. The artificial biological filter process monitoring showed that the phosphorus of the sewage was mainly removed in the front of artificial biological filter bed.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Hassan H. Hammud ◽  
Ali El-Shaar ◽  
Essam Khamis ◽  
El-Sayed Mansour

Lead adsorption by green Enteromorpha algae was studied. Adsorption capacity was 83.8 mg/g at pH 3.0 with algae (E) and 1433.5 mg/g for silicates modified algae (EM). FTIR and thermal analysis of algae materials were studied. Thomas and Yoon-Nelson column model were best for adsorbent (E) and algae after reflux (ER) and Yan model for (EM) with capacity 76.2, 71.1, and 982.5 mg/g, respectively. (ER) and (EM) show less swelling and better flow rate control than (E). Nonlinear methods are more appropriate technique. Error function calculations proved valuable for predicting the best adsorption isotherms, kinetics, and column models.


2020 ◽  
Vol 20 (8) ◽  
pp. 5089-5095
Author(s):  
Xiaomin Zhang ◽  
Jin Li ◽  
Bo He ◽  
Heng Li ◽  
Chao Qi ◽  
...  

The structural defects of bamboo-shaped carbon nanotubes (B-CNTs) provide abundant active sites for ion adsorption during wastewater treatment. However, a suitable supporting material for the growth of B-CNTs growth is less reported. In this paper, the catalytic growth of B-CNTs on the cenospheres (CSs) of coal fly ash was studied. The results showed that all CSs were covered by a layer of B-CNTs during the chemical vapor deposition (CVD) process, regardless of the fluctuation of the iron distribution from 0.52 to 2.09 wt%. B-CNTs with a diameter of 30–40 nm shared a similar morphology of compartment structures, which were uniformly scattered on the surfaces of the CSs and formed a 3D network structure. A high level of structural defects was present on the B-CNTs, which was denoted by an ID/IG value of 1.77 via Raman spectrum analysis. Adsorption experiments of the as-prepared CSs@B-CNTs revealed an excellent adsorption capacity for lead ions of 37.32 mg/g (pH 7, initial concentration of 70 mg/L). By excluding the function of CSs, the adsorption capacity of the pure B-CNTs was estimated to be as high as 275.19 mg/g, which has not been previously reported.


2011 ◽  
Vol 347-353 ◽  
pp. 1852-1855 ◽  
Author(s):  
Zheng Jun Gong ◽  
Cong Cong Tang ◽  
Cai Yun Sun ◽  
Lu Tang ◽  
Jun Chen

A natural peanut shell was used as adsorbent for removal of Cu(Ⅱ) from aqueous solution. Optimum conditions for the elimination of Cu(Ⅱ) from aqueous solution were established by means of a batch adsorption technique. The applicability of the Langmuir and Freundlich adsorption isotherms for the present system was tested. The Langmuir adsorption capacity Qmax (mg/g) is 39.68 and the equilibrium constant b is 0.00776. The Freundlich adsorption capacity k is 0.978 and adsorption intensity n is 1.65. The goodness of fitness was obtained with the Langmuir and Freundlich adsorption isotherms from the equilibrium adsorption data.


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