scholarly journals Nickel (Ni2+) Removal from Water Using Gellan Gum–Sand Mixture as a Filter Material

2021 ◽  
Vol 11 (17) ◽  
pp. 7884
Author(s):  
Thi Phuong An Tran ◽  
Hoon Cho ◽  
Gye-Chun Cho ◽  
Jong-In Han ◽  
Ilhan Chang

Microbial biopolymers have been introduced as materials for soil treatment and ground improvement purposes because of their ability to enhance soil strength enhancement and to reduce hydraulic conductivity. Several studies in the field of environmental engineering have reported heavy metal adsorption and removal from contaminated water using common biopolymers. In particular, gellan gum biopolymers have drawn significant attention for use in metal ion adsorption. This study aims to investigate the heavy metal adsorption capacity of a gellan gum biopolymer–sand mixture when nickel-contaminated water is pumped upward through a uniform gellan gum–sand mixture column. The main aims of this study are (1) to clarify the Ni2+ adsorption phenomenon of gellan gum-treated sand, (2) to assess the Ni2+ adsorbability of gellan gum–sand mixtures with different gellan gum content, and (3) to examine the gellan gum–sand filter thickness and flow rate effects on Ni2+ adsorption. The results of this experiment demonstrate the effectiveness of gellan gum in terms of Ni2+ adsorption and water flow rate control, which are essential criteria of a filter material for contaminated water treatment.

2012 ◽  
Vol 65 (9) ◽  
pp. 1570-1576 ◽  
Author(s):  
Guanling Song ◽  
Lijing Cao ◽  
Xiao Chen ◽  
Wenhua Hou ◽  
Qunhui Wang

A kind of electric arc furnace (EAF) steel slag was phosphated, and its isothermal and dynamic adsorptions of copper, cadmium, and lead ions were measured to determine if heavy metal adsorption changes after phosphorus adsorption. The surface area increased greatly after the slag was phosphated. Isothermal adsorption experiments showed that the theoretical Qmax of the EAF steel slag on Cu2+, Cd2+, and Pb2+ improved 59, 50, and 89% respectively after it was phosphated. Dynamic adsorption results showed that the greatest adsorption capacities of unit volume of Cu2+, Cd2+, and Pb2+ were 2.2, 1.8, and 1.8 times that of the column packed with original EAF steel slag when the column was packed with phosphate EAF steel slag at the same heavy metal ion concentration. The breakthrough time, the exhaustion time and elution efficiency of the column also increased when the column was packed with phosphated EAF steel slag compared with that packed with original EAF steel slag. Phosphorus adsorption could further improve the heavy metal ion adsorption of the EAF steel slag.


2019 ◽  
Author(s):  
Chem Int

A study of removal of heavy metal ions from heavy metal contaminated water using agro-waste was carried out with Musa paradisiaca peels as test adsorbent. The study was carried by adding known quantities of lead (II) ions and cadmium (II) ions each and respectively into specific volume of water and adding specific dose of the test adsorbent into the heavy metal ion solution, and the mixture was agitated for a specific period of time and then the concentration of the metal ion remaining in the solution was determined with Perkin Elmer Atomic absorption spectrophotometer model 2380. The effect of contact time, initial adsorbate concentration, adsorbent dose, pH and temperature were considered. From the effect of contact time results equilibrium concentration was established at 60minutes. The percentage removal of these metal ions studied, were all above 90%. Adsorption and percentage removal of Pb2+ and Cd2+ from their aqueous solutions were affected by change in initial metal ion concentration, adsorbent dose pH and temperature. Adsorption isotherm studies confirmed the adsorption of the metal ions on the test adsorbent with good mathematical fits into Langmuir and Freundlich adsorption isotherms. Regression correlation (R2) values of the isotherm plots are all positive (>0.9), which suggests too, that the adsorption fitted into the isotherms considered.


2019 ◽  
Vol 224 ◽  
pp. 373-387 ◽  
Author(s):  
Mohammadtaghi Vakili ◽  
Shubo Deng ◽  
Giovanni Cagnetta ◽  
Wei Wang ◽  
Pingping Meng ◽  
...  

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 486
Author(s):  
Alcina Johnson Sudagar ◽  
Slávka Andrejkovičová ◽  
Fernando Rocha ◽  
Carla Patinha ◽  
Maria R. Soares ◽  
...  

Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) regions of Portugal were used as the aluminosilicate source to compare their effect on the compressive strength and heavy metal adsorption of geopolymers. Natural zeolite, an inexpensive, efficient adsorbent, was used as an additive in formulations to enhance geopolymers’ adsorption capacities and reduce MK utilization’s environmental footprint. Geopolymers were synthesized with the replacement of MK by zeolite up to 75 wt.% (A25, B25—25% MK 75% zeolite; A50, B50—50% MK 50% zeolite; A75, B75—75% MK 25% zeolite; A100, B100—100% MK). The molar ratios of SiO2/Al2O3 and Na2O/Al2O3 were kept at 1 to reduce the sodium silicate and sodium hydroxide environmental impact. Geopolymers’ crystallography was identified using X-ray diffraction analysis. The surface morphology was observed by scanning electron microscopy to understand the effect of zeolite incorporation. Chemical analysis using X-ray fluorescence spectroscopy and energy dispersive X-ray spectroscopy yielded information about the geopolymers’ Si/Al ratio. Compressive strength values of geopolymers obtained after 1, 14, and 28 days of curing indicate high strengths of geopolymers with 100% MK (A100—15.4 MPa; B100—32.46 MPa). Therefore, zeolite did not aid in the improvement of the compressive strength of both MK-based geopolymers. The heavy metal (Cd2+, Cr3+, Cu2+, Pb2+, and Zn2+) adsorption tests exhibit relatively higher adsorption capacities of Barqueiros MK-based geopolymers for all the heavy metals except Cd2+. Moreover, zeolite positively influenced divalent cations’ adsorption on the geopolymers produced from Barqueiros MK as B75 exhibits the highest adsorption capacities, but such an influence is not observed for Alvarães MK-based geopolymers. The general trend of adsorption of the heavy metals of both MK-based geopolymers is Pb2+ > Cd2+ > Cu2+ > Zn2+ > Cr3+ when fitted by the Langmuir isotherm adsorption model. The MK and zeolite characteristics influence geopolymers’ structure, strength, and adsorption capacities.


Author(s):  
Wensong Zou ◽  
Xuezhen Feng ◽  
Wenfei Wei ◽  
Yuanhao Zhou ◽  
Ranhao Wang ◽  
...  

2021 ◽  
Vol 289 ◽  
pp. 112398
Author(s):  
Andrea B. Saralegui ◽  
Victoria Willson ◽  
Néstor Caracciolo ◽  
M. Natalia Piol ◽  
Susana P. Boeykens

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