scholarly journals Augmenting granular activated carbon with natural clay for multicomponent sorption of heavy metals from aqueous solutions

2017 ◽  
Vol 76 (8) ◽  
pp. 2213-2221 ◽  
Author(s):  
Nuhu Dalhat Mu'azu ◽  
Mohammed Hussain Essa ◽  
Salihu Lukman

Multicomponent adsorption of Cd, Cr, Cu, Pb and Zn onto date palm pits based granular activated carbon (GAC) augmented with highly active natural clay at different proportion was investigated. The effects of the initial pH and the adsorbents mixed ratio on the removal selectivity sequence of the metals evaluated. Batch adsorption experiments were undertaken at initial pH 2, 6 and 12. At initial pH 2, both the percent removal and the metals adsorptive capacity decreased with increasing GAC to clay ratio (from 0 to 1) with the percentage removal of Cd, Zn and Cr ions dropping from 68, 81, 100% to 43, 57 and 70%, respectively. At both pH 6 and 12, the percentage removals and adsorption capacities of all the heavy metal ions are higher than at pH 2. Selectivity sequences for pH 2, 6 and 12 followed the order Pb > Cr > Cu > Zn > Cd; Pb > Cr > Cu > Cd > Zn and Cd > Cr > Cu > Pb > Zn, respectively. The adsorption trends were analyzed in relation to point of zero charge and ξ-potential and the metals ions speciation at different pH. These results will help better understand the feasibility of augmenting GAC with natural clay minerals during fixed bed column test which is more beneficial for practical industrial applications.

2003 ◽  
Vol 47 (1) ◽  
pp. 113-120 ◽  
Author(s):  
D.S. Chaudhary ◽  
S. Vigneswaran ◽  
V. Jegatheesan ◽  
H.H. Ngo ◽  
H. Moon ◽  
...  

Wastewater treatment has always been a major concern in the developed countries. Over the last few decades, activated carbon adsorption has gained importance as an alternative tertiary wastewater treatment and purification process. In this study, granular activated carbon (GAC) adsorption was evaluated in terms of total organic carbon (TOC) removal from low strength synthetic wastewater. This paper provides details on adsorption experiments conducted on synthetic wastewater to develop suitable adsorption isotherms. Although the inorganics used in the synthetic wastewater solution had an overall unfavourable effect on adsorption of organics, the GAC adsorption system was found to be effective in removing TOC from the wastewater. This study showed that equation of state (EOS) theory was able to fit the adsorption isotherm results more precisely than the most commonly used Freundlich isotherm. Biodegradation of the organics with time was the most crucial and important aspect of the system and it was taken into account in determining the isotherm parameters. Initial organic concentration of the wastewater was the determining factor of the model parameters, and hence the isotherm parameters were determined covering a wide range of initial organic concentrations of the wastewater. As such, the isotherm parameters derived using the EOS theory could predict the batch adsorption and fixed bed adsorption results of the multi-component system successfully. The isotherm parameters showed a significant effect on the determination of the mass transfer coefficients in batch and fixed bed systems.


2018 ◽  
Vol 108 ◽  
pp. 171-182 ◽  
Author(s):  
Alcione Aparecida de Almeida Alves ◽  
Adriana Dervanoski da Luz ◽  
Aline Raquel Müller Tones ◽  
Thyara Campos Martins Nonato ◽  
Giselle Louise de Oliveira Ruiz ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Lingjie Liu ◽  
Min Ji ◽  
Fen Wang

Coconut granular activated carbon (CGAC) was modified by impregnating with ZnCl2solution to remove nitrate from aqueous solutions. Sorption isotherm and kinetic studies were carried out in a series of batch experiments. Nitrate adsorption of both ZnCl2-modified CGAC and CGAC fitted the Langmuir and Freundlich models. Batch adsorption isotherms indicated that the maximum adsorption capacities of ZnCl2-modified CGAC and CGAC were calculated as 14.01 mgN·g−1and 0.28 mgN·g−1, respectively. The kinetic data obtained from batch experiments were well described by pseudo-second-order model. The column study was used to analyze the dynamic adsorption process. The highest bed adsorption capacity of 1.76 mgN·g−1was obtained by 50 mgN·L−1inlet nitrate concentration, 20 g adsorbents, and 10 ml·min−1flow rate. The dynamic adsorption data were fitted well to the Thomas and Yoon–Nelson models with coefficients of correlationR2 > 0.834 at different conditions. Surface characteristics and pore structures of CGAC and ZnCl2-modified CGAC were performed by SEM and EDAX and BET and indicated that ZnCl2had adhered to the surface of GAC after modified. Zeta potential, Raman spectra, and FTIR suggested the electrostatic attraction between the nitrate ions and positive charge. The results revealed that the mechanism of adsorption nitrate mainly depended on electrostatic attraction almost without any chemical interactions.


1986 ◽  
Vol 18 (1) ◽  
pp. 31-42 ◽  
Author(s):  
E. A. Shpirt ◽  
K. T. Alben

The particle size distribution at different bed depths of a fixed bed of granular activated carbon (GAC) has been monitored during 50 weeks of a pilot column run at the Waterford, New York potable water treatment plant. Initial backwashing resulted in significant stratification of GAC in the column: larger particles (average diameter 1.18 mm) settled in the bottom of the column (105 cm), and smaller particles (average diameter 0.97 mm) were concentrated near the top (24 cm), compared to samples of unstratified virgin Calgon F400 (average diameter 1.09 mm). During column loading and initial backwashing, more fines were created than were present in the virgin GAC (average 6.5% of GAC fines in the > 40 mesh fraction, compared to only 0.3% in the > 40 mesh fraction for virgin Calgon F400). After 50 weeks of service there was an overall trend toward a smaller average particle size (0.9 mm) with development of a more regular pattern of bed stratification (1.08 mm at the bottom and 0.75 mm at the top). These changes are attributed to breaking of large particles (12-20 mesh) and creation of intermediate size particles (20-30 and 30-40 mesh).


2019 ◽  
Vol 54 (3) ◽  
pp. 168-178 ◽  
Author(s):  
Jasmina Nikić ◽  
Jasmina Agbaba ◽  
Malcolm A. Watson ◽  
Aleksandra Tubić ◽  
Marko Šolić ◽  
...  

2019 ◽  
Vol 268 ◽  
pp. 06020
Author(s):  
Joaquin Victorino Mari Armonio ◽  
Ivan Joshua Caragdag ◽  
Jaylym Aldryne Escorpizo ◽  
Karizza Mae Miranda ◽  
April Joyce Raymundo ◽  
...  

In this study, the activated carbon produced from mango kernels and corn cobs by impregnating the hydrothermally treated raw materials with 85% H3PO4 were characterize for their physical surface morphology and types of surface functional groups using SEM and FT-ir, respectively. Six samples of activated carbon were submerged for 1 hour, the second sample for 2 hours, and the third sample for 3 hours. SEM results showed that both KAC (Kernel Activated Carbon) and CAC (Corn Activated Carbon) had increasing roughness and irregularity along with residence time of the samples. Results from FT-ir (Fourier-transform infrared spectroscopy) testing of the mango kernels samples showed that a C-O stretch, C-H, C=O stretch, and C-N stretch on the surface. While corncobs consist of C-H bend, and O-H bend for the 1-HR sample. The 2-HR and 3-HR samples consist of C-O stretch, C-H wag, C-N stretch. Analysis of the relationship between residence time and adsorptive capacity was done using AAS via batch adsorption in a tri-metal solution of Cu(Copper), Ni(Nickel), and Pb(Lead) with results that showed CAC and KAC, with soaking time of 3 hours is a good adsorbent of Copper and Nickel, while soaking time of 2 hours yields the best adsorption conditions for both CAC and KAC.


2019 ◽  
Vol 5 (3) ◽  
pp. 609-617 ◽  
Author(s):  
Yifeng Huang ◽  
Zhijie Nie ◽  
Jie Yuan ◽  
Audrey Murray ◽  
Yi Li ◽  
...  

A test was developed to measure the present-day adsorptive capacity of granular activated to help drinking water treatment professionals to determine when the GAC needs replacement.


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