scholarly journals Absorbed Pb2+ and Cd2+ Ions in Water by Cross-Linked Starch Xanthate

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Kai Feng ◽  
Guohua Wen

A cross-linked starch xanthate was prepared by graft copolymerization of acrylamide and sodium acrylate onto starch xanthate using potassium persulfate and sodium hydrogen sulfite initiating system and N,N′-methylenebisacrylamide as a cross-linker. As this kind of cross-linked potato starch xanthate can effectively absorb heavy metal ions, it was dispersed in aqueous solutions of divalent heavy metal ions (Pb2+ and Cd2+) to investigate their absorbency by the polymer. Factors that can influence absorbency were investigated, such as the ratio of matrix to monomers, the amount of initiator and cross-linker, pH, and the concentration of metal ions. Results were reached and conclusion was drawn that the best synthetic conditions for the polymer adsorbing Pb2+ and Cd2+ were as follows: the quality ratio of matrix to monomers was 1 : 12 and 1 : 11, the amount of initiator was 2.4% and 3.2% of matrix, and the amount of cross-linker was 12 mg and 13 mg. When the initial concentration of ions was 10 mg/L, the highest quantities of adsorption of Pb2+ and Cd2+ were 47.11 mg/g and 36.55 mg/g. Adsorption mechanism was discussed by using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) test, and adsorption kinetic simulation.

2011 ◽  
Vol 64 (8) ◽  
pp. 1620-1628 ◽  
Author(s):  
Dengliang He ◽  
Guangfu Yin ◽  
Faqin Dong ◽  
Laibao Liu ◽  
Xiaoli Tan ◽  
...  

Foitite from Linshou mine in China's Hebei province was investigated as an adsorbent to remove Pb(II) and Cu(II) from aqueous solution. The results showed that foitite can readily remove heavy metal ions from aqueous solution. The data shows that the metal uptake for Pb(II) increases rapidly, accounting for 74.47% when contact time was 2 min. In contrast to Pb(II), there was a worse capability for adsorption of Cu(II). In the first 4 min, the metal uptake accounted for 34.7%. According to the analytical results obtained from X-ray diffraction, laser Raman spectrum, X-ray energy dispersive spectrometer, and Zeta potential, the removal mechanism of Pb(II) and Cu(II) by using foitite can be explained as following: firstly, the existence of an electrostatic field around foitite particles can attract heavy metal ions and consequently combine heavy metal ions with OH−; secondly, heavy metal ions in the solution are exchanged with the Fe3+ and Al3+ in the foitite.


2020 ◽  
Vol 9 (3) ◽  
pp. 1420-1426

Bimetallic metal oxide nanomaterials are synthesized by microwave combustion route encourage to the synthetic chemists because of its simplicity. Microwave burning of single-phase oxide materials with polymer as fuel to form its multiphase nanomaterials. Nanosized Zirconium vanadate (ZrV2O7) material is prepared by self-propagating combustion methods using a polymer as a fuel. Zirconium oxide (ZrO2) and vanadium pentoxide (V2O5) with polyvinyl alcohol were ignited in an open atmosphere and complete burning in a microwave oven for about 15 minutes to form a zirconium vanadate sample. Adsorption study of heavy metal ions like lead and mercury ions on the prepared sample is well studied. The structure of as-prepared ZrV2O7 and its adsorbed sample was well studied by employing a powder X-ray diffraction (XRD) tool. The morphology of as-prepared ZrV2O7 and adsorbed sample material was studied by Scanning Electron Micrograph (SEM) tool. Fourier Transform Infrared (FTIR) spectral study was undertaken to know the bonding in the prepared zirconium vanadate nanomaterials. Further, the adsorption study of heavy metal ions on the ZrV2O7 sample is also undertaken at room temperature.


2013 ◽  
Vol 67 (2) ◽  
pp. 306-310 ◽  
Author(s):  
Wen Ding ◽  
Shen-yong Zhai ◽  
Jun-tao liu ◽  
Rou Wang ◽  
Rong Li

Dialdehyde 8-aminoquinoline starch (DASQA) was synthesized by the reaction of dialdehyde starch (DAS) and 8-aminoquinoline and was used to adsorb various ions from aqueous solution. DASQA was characterized by Fourier transform infrared (FT-IR) spectra, thermogravimetric analysis, X-ray diffraction analysis. The adsorption properties of the polymer for Pb2+, Cu2+, Cd2+, Ni2+, and Zn2+ were investigated. The result of the experiment reveals that the adsorption for Cd2+ and Zn2+were approximately 2.51 mmol/g, 2.17 mmol/g, followed by Pb2+ 1.93 mmol/g, Ni2+ 1.66 mmol/g, Cu2+ 1.19 mmol/g. Furthermore, the kinetic experiments indicated that the adsorption of DASQA for the above metal ions achieved equilibrium within 2 h. Therefore, DASQA is an effective adsorbent for the removal of different heavy metal ions from industrial waste solutions.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4066
Author(s):  
Xianyuan Fan ◽  
Hong Liu ◽  
Emmanuella Anang ◽  
Dajun Ren

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.


1984 ◽  
Vol 13 (2) ◽  
pp. 83-86 ◽  
Author(s):  
Michihiro Murata ◽  
Masayuki Omatsu ◽  
Syuji Mushimoto

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 291 ◽  
Author(s):  
Dongxiao Ouyang ◽  
Yuting Zhuo ◽  
Liang Hu ◽  
Qiang Zeng ◽  
Yuehua Hu ◽  
...  

Tailings generated from mineral processing have attracted worldwide concerns due to creating serious environmental pollution. In this work, porous adsorbents were prepared as a porous block by using silicate tailings, which can adsorb heavy metal ions from the solution and are easy to separate. The synthesized silicate porous material (SPM) was characterized by X-ray diffraction (XRD), Brunner–Emmet–Teller (BET), and scanning electron microscope (SEM). The material presented a surface area of 3.40 m2⸱g−1, a porosity of 54%, and the compressive strength of 0.6 MPa. The maximum adsorption capacities of Pb2+, Cd2+, and Cu2+ by SPM were 44.83 mg·g−1, 35.36 mg·g−1, and 32.26 mg·g−1, respectively. The experimental data were fitted well by the Freundlich and Langmuir adsorption models. The kinetics of the adsorption process were fitted well by the pseudo-first order kinetic equation. These results show that the porous materials prepared with silicate tailings could act as an effective and low-cost adsorbent for the removal of heavy metal ions from wastewater. This study may provide a new thought on the high-value utilization of tailing for alleviating environmental pressure.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Shengtao Hei ◽  
Yan Jin ◽  
Fumin Zhang

Porousγ-Fe2O3nanoparticles were prepared via a solid-state conversion process of a mesoporous iron(III) carboxylate crystal, MIL-100(Fe). First, the MIL-100(Fe) crystal that served as the template of the metal oxide was synthesized by a low-temperature (<100°C) synthesis route. Subsequently, the porousγ-Fe2O3nanoparticles were fabricated by facile thermolysis of the MIL-100(Fe) powders via a two-step calcination treatment. The obtainedγ-Fe2O3was characterized by X-ray diffraction (XRD), N2adsorption, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) techniques, and then used as an adsorbent for heavy metal ions removal in water treatment. This study illustrates that the metal-organic frameworks may be suitable precursors for the fabrication of metal oxides nanomaterials with large specific surface area, and the prepared porousγ-Fe2O3exhibits a superior adsorption performance for As(V) and As(III) ions removal in water treatment.


2020 ◽  
Vol 81 (1) ◽  
pp. 170-177 ◽  
Author(s):  
Tao Gong ◽  
Yongbai Tang

Abstract Novel magnetic Fe3O4@SiO2-ethylenediamine tetraacetic acid (adsorbent) CMS–COOH-modified magnetic materials, CMS was prepared by surface modification of amino-functionalized Fe3O4@SiO2 (-NH2-modified magnetic materials, NMS) with EDTA using water-soluble carbodiimide as the cross-linker in deionized water solution. The phase structure, infrared spectra, thermal analysis and magnetic properties of were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis, and vibrating sample magnetometry and its properties for removal of heavy metal ions under varied experimental conditions were also investigated. The results revealed that CMS had good tolerance to low pH and exhibited good removal efficiency for the metal ions. The maximum adsorption capacities of CMS were found to be 0.11 mmol g−1 for Cu(II) at pH5.0 (30 °C) and 0.14 mmol g−1 for Pb(II) ions at pH2.0 (30 °C).


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