N-doping effectively enhances the adsorption capacity of biochar for heavy metal ions from aqueous solution

Hydroxyapatite (HAP) is an effective adsorbent for removing heavy metal ions. In this study, HAP was prepared by sol-gel method and used for removing Cu2+ from aqueous solution. Initial concentration of Cu2+ in the aqueous solution was evaluated as an important parameter determining uptake. The removal efficiency and the adsorption capacity of HAP for Cu2+ were investigated. EDS analysis indicated the presence of Cu2+ on the HAP surface.

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N-doped carbon xerogels as adsorbents for the removal of heavy metal ions from aqueous solution

RSC Advances ◽

10.1039/c4ra12441c ◽

2015 ◽

Vol 5 (10) ◽

pp. 7182-7191 ◽

Cited By ~ 25

Author(s):

Bin Yang ◽

Chengxiang Yu ◽

Qingni Yu ◽

Xingwang Zhang ◽

Zhongjian Li ◽

...

Keyword(s):

Aqueous Solution ◽

Heavy Metal ◽

Metal Ions ◽

Adsorption Capacity ◽

Heavy Metal Ions ◽

Textural Property ◽

Carbon Xerogel ◽

Carbon Xerogels ◽

Cu Ions

The adsorption capacity for Pb, Zn and Cu ions in aqueous solution can be significantly improved by the introduction of N into the carbon xerogel (CX) matrix in the basis of the extraordinary textural property.

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Comparative Bio-sorption of Cadmium and Nickel Ions from Aqueous Solution onto Fibers of Date Palm using Fluidized Bed Column

Revista de Chimie ◽

10.37358/rc.19.5.7160 ◽

2019 ◽

Vol 70 (5) ◽

pp. 1507-1512

Author(s):

Baker M. Abod ◽

Ramy Mohamed Jebir Al-Alawy ◽

Firas Hashim Kamar ◽

Gheorghe Nechifor

Keyword(s):

Aqueous Solution ◽

Heavy Metal ◽

Metal Ions ◽

Fluidized Bed ◽

Removal Efficiency ◽

Heavy Metal Ions ◽

Date Palm ◽

Operating Conditions ◽

Initial Concentration ◽

Bed Height

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).

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Biodegradable composite adsorbents of modified cellulose and chitosan to remove heavy metal ions from aqueous solution

Current Research in Green and Sustainable Chemistry ◽

10.1016/j.crgsc.2021.100119 ◽

2021 ◽

pp. 100119

Author(s):

Md Hafezur Rahaman ◽

Md Ataul Islam ◽

Md Monjurul Islam ◽

Md Aminur Rahman ◽

Nur SM. Alam

Keyword(s):

Aqueous Solution ◽

Heavy Metal ◽

Metal Ions ◽

Heavy Metal Ions ◽

Biodegradable Composite ◽

Composite Adsorbents ◽

Modified Cellulose

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Effects of Electronegativity and Hydration Energy on the Selective Adsorption of Heavy Metal Ions by Synthetic NaX Zeolite

Materials ◽

10.3390/ma14154066 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4066

Author(s):

Xianyuan Fan ◽

Hong Liu ◽

Emmanuella Anang ◽

Dajun Ren

Keyword(s):

Heavy Metal ◽

Metal Ions ◽

Adsorption Capacity ◽

Heavy Metal Ions ◽

Binary Systems ◽

Adsorption Mechanism ◽

Selective Adsorption ◽

Hydration Energy ◽

Nax Zeolite ◽

High Electronegativity

The adsorption capacity of synthetic NaX zeolite for Pb2+, Cd2+, Cu2+ and Zn2+ in single and multi-component systems were investigated. The effects of electronegativity and hydration energy on the selective adsorption, as well as potential selective adsorption mechanism of the NaX zeolite for Pb2+, Cd2+, Cu2+ and Zn2+ were also discussed. The maximum adsorption capacity order of the heavy metals in the single system was Pb2+ > Cd2+ > Cu2+ > Zn2+, and this could be related to their hydration energy and electronegativity. The values of the separation factors (α) and affinity constant (KEL) in different binary systems indicated that Pb2+ was preferentially adsorbed, and Zn2+ presented the lowest affinity for NaX zeolite. The selective adsorption capacities of the metals were in the order, Pb2+ > Cd2+ ≈ Cu2+ > Zn2+. The trend for the selective adsorption of NaX zeolite in ternary and quaternary systems was consistent with that in the binary systems. Pb2+ and Cu2+ reduced the stability of the Si-O-Al bonds and the double six-membered rings in the NaX framework, due to the high electronegativity of Pb2+ and Cu2+ than that of Al3+. The selective adsorption mechanism of NaX zeolite for the high electronegative metal ions could mainly result from the negatively charged O in the Si-O-Al structure of the NaX zeolite, hence heavy metal ions with high electronegativity display a strong affinity for the electron cloud of the oxygen atoms in the Si-O-Al. This study could evaluate the application and efficiency of zeolite in separating and recovering certain metal ions from industrial wastewater.

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