scholarly journals Fabrication of Lignin-based Magnetic Adsorbent via Thiol-ene Click Reaction for the Effective Removal of Pb(II)

Author(s):  
Xuan Zhou ◽  
Yunlong Liu ◽  
can Jin ◽  
Guomin Wu ◽  
Guifeng Liu ◽  
...  

Abstract The effective and selective removal of heavy metal ions from sewage is a major challenge, and of great significance to the treatment and recovery of metal waste. Herein, a novel magnetic lignin-based adsorbent L@MNP was synthesized by thiol-ene click reaction under UV light irradiation. Multiple characterization techniques containing FT-IR, XRD, elemental analysis, VSM, SEM and TEM confirmed the formed nano-morphology and structure of L@MNP. Effects of pH, contact time, initial metal concentration and temperature on the batch adsorption of Pb(II) by L@MNP were investigated. Due to the existence of sulfur and oxygen containing sites, the maximum adsorption capacity of L@MNP for Pb(II) could reach 97.38 mg/g, while the adsorption equilibrium was achieved within 30 min. Adsorption kinetics and isotherms were well described by the pseudo-second-order model and Langmuir model, respectively, suggesting a chemical and monolayer adsorption process. In addition, L@MNP showed a high adsorption selectivity (kPb = 0.903) toward Pb(II) in the presence of other co-existing metal ions. Experimental results also revealed that L@MNP displayed structural stability, easy recovery under external magnetic field, and acceptable recyclability after the fifth cycle. Considering its facile preparation, low cost and high adsorption efficiency, the developed L@MNP adsorbent demonstrated great potential in removing heavy metal ions from wastewater.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1891
Author(s):  
Zongkun Lin ◽  
Yuru Yang ◽  
Zizhan Liang ◽  
Lei Zeng ◽  
Aiping Zhang

In order to avoid the secondary pollution of the toxic residue of chemical crosslinking agent accompanied by chemical hydrogel adsorbent and enhance the adsorption performance of physical hydrogel, chitosan/calcium alginate/bentonite (CTS/CA/BT) composite physical hydrogel was constructed. The formation mechanism and structure of the composite hydrogel were determined by FTIR, XRD and SEM. Adsorption performances of the hydrogel toward Pb2+, Cu2+ and Cd2+ in water under different condition as well as multi-ion competitive sorption were investigated. The adsorption processes were described with the canonical adsorption kinetics and isotherms models. With the utilization of XPS analysis and adsorption thermodynamics analysis, it was found that the adsorptions were spontaneous physico-chemical adsorptions. The results showed that the maximum adsorption capacity of the hydrogel for Pb2+, Cu2+ and Cd2+ reached up to 434.89, 115.30 and 102.38 mg·g−1, respectively, better than those of other physical hydrogels or chitosan/bentonite composite. Moreover, the composite hydrogel improved the collectability of bentonite and showed a good reusability. The modification of bentonite and the formation of hydrogel were completed simultaneously, which greatly simplifies the operation process compared with the prior similar works. These suggest that the CTS/CA/BT composite hydrogel has promising application prospects for removal of heavy metal ions from water.


2007 ◽  
Vol 56 (9) ◽  
pp. 51-57 ◽  
Author(s):  
J.K. Yang ◽  
M.R. Yu ◽  
S.M. Lee

In this study, the applicability of calcined starfish (SF) and iron-coated SF (ICSF) as potential adsorbents for the treatment of wastewater containing heavy metal ions was evaluated. ICSF was prepared by mixing FeCl3 solution previously adjusted to pH 7 ∼ 9 with SF at 105 °C. From the dissolution test at pH 2, ICSF showed strong acid-proof properties. In the batch adsorption, Cu(II) adsorption onto ICSF was completed within 150 minutes, while 47% Cu(II) was removed with SF alone. This result clearly suggests that the coated Fe(III) serves additional adsorption sites, resulting in the enhanced removal of heavy metal ions. The removed fraction of both Cu(II) and Pb(II) increased with increasing solution pH and nearly complete removals of Pb(II) and Cu(II) were observed at around pH 6 and 8, respectively. From the adsorption isotherm of Cu(II) onto SF and ICSF at pH 3.0, the removed amount of Cu(II) by ICSF was greater than that by SF over the entire concentration range studied. In the column test, the breakthrough of Cu(II) in the ICSF column was greatly retarded compared to that in the SF column. Based on the drinking water regulations for Cu(II), SF and ICSF were able to remove 3400 and 8600 mg/kg of Cu(II) from the wastewater, respectively.


2019 ◽  
Vol 9 (3) ◽  
pp. 547 ◽  
Author(s):  
Min Wang ◽  
Zhuqing Wang ◽  
Xiaohong Zhou ◽  
Shikun Li

In this study, we prepared a novel calcium alginate-disodium ethylenediaminetetraacetate dihydrate hybrid aerogel (Alg-EDTA) by chemical grafting and vacuum-freeze-drying to remove heavy metal ions from wastewater. Experimental results show that the as-prepared Alg-EDTA adsorbent has a high affinity for heavy metal ions, such as Cd2+, Pb2+, Cu2+, Cr3+, and Co2+, and can adsorb >85% of metal ions from the corresponding solution. Alg-EDTA also exhibits high selectivity toward Cd2+, and the maximum adsorption capacity for Cd2+ reached 177.3 mg/g, which exceeds the adsorption capacity of most reported Cd2+-adsorbents. Adsorbent regeneration can be achieved by a simple acid-washing process, and adsorption performance of Alg-EDTA remains stable after repeated use. All these findings indicate that Alg-EDTA has a promising prospect in the treatment of heavy metal ions wastewater.


2017 ◽  
Vol 4 (9) ◽  
pp. 1851-1858 ◽  
Author(s):  
Zhe Chen ◽  
Yu Liang ◽  
Dashuang Jia ◽  
Wanying Chen ◽  
Zhimin Cui ◽  
...  

Layered silicate RUB-15 exhibited high adsorption abilities for not only UO22+ but also heavy metal ions through ion-exchange.


Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
Muhammad Tahir Amin ◽  
Abdulrahman Ali Alazba ◽  
Muhammad Shafiq

We investigated the adsorption of lead (Pb2+) and nickel (Ni2+) ions by electrospun membranes of polyacrylonitrile (PAN) nanofiber activated with NaHCO3 (PANmod). Analysis by Fourier-transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDX) validated the functionalization of PAN nanofibers with NaHCO3, and the successful agglomeration of Pb2+ and Ni2+ onto PANmod. After a rapid uptake of the heavy metal ions (15 min), the equilibrium contact time was attained (60 min) following a linear increase of both adsorption capacity and removal efficiency. PANmod showed a better affinity for Ni2+ than Pb2+. The adsorption on PANmod was best described by the pseudo-second-order kinetic model for both studied models, supporting chemisorption. By varying the solution pH from 2.0 to 9.0, we found that the adsorption capacity followed an increasing trend, reaching a maximum at the pH of 7.0. Despite increasing adsorption capacities, the removal efficiency of both heavy metal ions exhibited a decreasing trend with increase in initial concentrations. The amount of PANmod directly affects the removal efficiency, with 0.7 and 0.2 g being the optimum dose for maximum uptake of Pb2+ and Ni2+, respectively. The Langmuir model fitted well the Pb2+ adsorption data suggesting monolayer adsorption, and the Freundlich model perfectly fitted the Ni2+ adsorption data, indicating heterogeneous adsorption. The estimated values of the mean free energy of adsorption in the D–R isotherm indicated a physical adsorption of both heavy metal ions into the surface of the PANmod.


2019 ◽  
Vol 97 (8) ◽  
pp. 621-628 ◽  
Author(s):  
T.E. Nikiforova ◽  
V.A. Kozlov ◽  
M.K. Islyaikin

The sorption process of heavy metal ions from aqueous solutions using chitosan flakes and chitosan beads was studied. Chitosan gel beads were prepared using covalent crosslinking of chitosan chains by epichlorohydrin with ionic gelation by sodium tripolyphosphate. The capability of chitosan beads to absorb the heavy metal ions from aqueous solutions was studied, and the physicochemical characteristics of the sorbent were evaluated using SEM and FTIR on the model solution treatment. It was found that competitive proton sorption takes place in acidic media, which results in a transformation of amino groups into inactive ammonium-salt form and decreases in heavy metal sorption onto chitosan from aqueous acidic media. Batch adsorption experiments were performed to examine the influence of various factors such as the initial concentration of metal salts, pH, and agitation duration on the process. It was established that metal ion sorption is pH dependent and has an optimum effect at a pH of 6.0. Following the Langmuir equation, the maximum sorption of Cu2+ions is estimated to be 1,6 mol/kg of modified chitosan. The kinetic study revealed that the adsorption kinetics are well-fitted to the kinetic equation of pseudo second order. Thus, sorption of heavy metal ions by chitosan is considered to be a competitive process that occurs on amino groups of the sorbent with equivalent coordinated participation of metal cations, protons, and anions.


2019 ◽  
Vol 43 (15) ◽  
pp. 5879-5889 ◽  
Author(s):  
Chengzhao Jin ◽  
Guixiang Teng ◽  
Yinan Gu ◽  
Hao Cheng ◽  
ShaoPeng Fu ◽  
...  

A l-cysteine functionalized magnetic hollow MnFe2O4 nanosphere material has been synthesised, with high magnetism, large interior cavities, and high porosity and surface activity. It has high adsorption efficiency and regenerated adsorption capacity for the removal of Cr6+ and Pb2+ in contaminated water.


Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 156 ◽  
Author(s):  
Xiaoye Zhang ◽  
Yingxi Qin ◽  
Guifang Zhang ◽  
Yiping Zhao ◽  
Chao Lv ◽  
...  

In this work, three kinds of hyperbranched polyamidoamine-palygorskite (PAMAM-Pal) were designed and synthesized by grafting the first generation polyamidoamine (G1.0 PAMAM), G2.0 PAMAM and G3.0 PAMAM onto Pal surfaces, respectively. Then, these PAMAM-Pals were used as additives to prepare polyvinylidene fluoride (PVDF)/hyperbranched polyamidoamine-palygorskite bicomponent composite membranes. The structures of the composite membranes were characterized by Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TEM), X-ray photoelectron spectroscopy (XPS), field-emission scanning electronmicroscopy (SEM), atomic force microscope (AFM) and Thermogravimetric analysis (TGA). The adsorption properties of composite membranes to heavy metal ions was studied, and the results found that the maximum adsorption capacities for Cu(II), Ni(II) and Cd(II) could reach 155.19 mg/g, 124.28 mg/g and 125.55 mg/g, respectively, for the PVDF/G3.0 PAMAM-Pal membrane, while only 23.70 mg/g, 17.74 mg/g and 14.87 mg/g could be obtained for unmodified membranes in the same conditions. The high adsorption capacity can be ascribed to the large number of amine-terminated groups, amide groups and carbonyl groups of the composite membrane. The above results indicated that the prepared composite membrane has a high adsorption capacity for heavy metal ions removal in water treatment.


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