Novel pectin based composite hydrogel derived from grapefruit peel for enhanced Cu(II) removal

Zhang, Wei; Song, Jianyang; He, Qiulai; Wang, Hongyu; Lyu, Wanlin; Feng, Hui-Juan; Xiong, Wenqi; Guo, Wenbin; Wu, Jing; Ling, Chen

doi:10.1016/j.jhazmat.2019.121445

Cited by 178 publications

(24 citation statements)

References 51 publications

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“…of Cu(II) and the contact time were close, the Cu(II) C r for nanotubes were almost 20 to 30 times higher than those for AL-PEI-CS 2 and far beyond the discharged standard of 2 mg/L. Similar phenomenon was also observed for hydrogel prepared by Zhang et al [41] (Fig. 3(b)).…”

Section: Residual Concentration Of Cu(ii) At the Presence Of Cationssupporting

confidence: 79%

Performance of a modified alkaline lignin towards copper adsorption under different conditions

Zheng

Wang

Dai³

et al. 2021

Environmental Engineering Research

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Polyethyleneimine and carbon disulfide were employed to modify alkaline lignin (AL) in order to introduce -NH, -NH2 and -CSS- groups. Its adsorption performance towards Cu(II) was evaluated based on the residual concentration (Cr) against the discharge permissible concentration for Cu(II) (2.0 mg/L) established by the World Health Organization. The evaluation was operated under different conditions such as adjusting the solution pH, Cu(II) coexisting with K(I), Na(I), Ca(II) or Mg(II), changing the contact time (t) and initial concentration of Cu(II) (C0), as well as regeneration. When t and C0 equaled to 180 min and 50 mg/L, Cr was less than 2.0 mg/L at pH of 5.03 to 5.65. Under the situation of Cu (II) coexisting with 50 mg/L of K(I), Na(I), Ca(II) or Mg(II), Cr was as low as 1.96, 1.53, 1.97 or 1.55 mg/L (t = 180 min, C0 = 50 mg/L), respectively. Even the modified AL was regenerated and reused four times, Cr was closed to 2 mg/L for each time (t = 180 min, C0 = 51 mg/L). By comparing with other lignin-based materials according to the adsorption equilibrium time, the maximum adsorption capacity, and Cr, the modified AL exhibited higher application potential in copper-loaded water treatment.

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Section: Residual Concentration Of Cu(ii) At the Presence Of Cationssupporting

confidence: 79%

Performance of a modified alkaline lignin towards copper adsorption under different conditions

Zheng

Wang

Dai³

et al. 2021

Environmental Engineering Research

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“…The experimental data fitted by the pseudo-second-order kinetics model (R 2 = 0.992) was better than the pseudo-first-order kinetics model (R 2 = 0.921) ( Figure S2 and Table S1), suggesting that chemisorption was the leading factor in the uptake of Cu(II) by ASHMA. Meanwhile, the Q e value calculated by pseudo-second-order kinetics is closer to those obtained by the experiment [36].…”

Section: Adsorption Propertiessupporting

confidence: 78%

“…Thermodynamic parameters such as standard enthalpy change (∆H • ), entropy change (∆S • ) and Gibbs free energy change (∆G • ) were estimated (Table S2). ∆H • values for ASHMA was 10.991 kJ/mol, the adsorption of Cu(II) was endothermic, which indicated that various binding mechanisms (such as ion exchange and chemical reactions) may be involved in the adsorption process [36,37]. Also, the ∆S • value calculated from the intercept was 89.143 J/(mol·K) for ASHMA.…”

Section: Adsorption Propertiesmentioning

confidence: 95%

A Functionalized Silicate Adsorbent and Exploration of Its Adsorption Mechanism

et al. 2020

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Active silicate materials have good adsorption and passivation effects on heavy metal pollutants. The experimental conditions for the preparation of active silicate heavy metal adsorbent (ASHMA) and the adsorption of Cu(II) by ASHMA were investigated. The optimum preparation conditions of ASHMA were as follows: 200 mesh quartz sand as the raw material, NaOH as an activating agent, NaOH/quartz sand = 0.45 (mass fraction), and calcination at 600 • C for 60 min. Under these conditions, the active silicon content of the adsorbent was 22.38% and the utilization efficiency of NaOH reached 89.11%. The adsorption mechanism of Cu(II) on the ASHMA was analyzed by the Langmuir and Freundlich isotherm models, which provided fits of 0.99 and 0.98, respectively. The separation coefficient (R L ) and adsorption constant (n) showed that the adsorbent favored the adsorption of Cu(II), and the maximum adsorption capacity (Q max ) estimated by the Langmuir isotherm was higher than that of 300 mg/L. Furthermore, adsorption by ASHMA was a relatively rapid process, and adsorption equilibrium could be achieved in 1 min. The adsorbents were characterized by FT-IR and Raman spectroscopy. The results showed that the activating agent destroyed the crystal structure of the quartz sand under calcination, and formed Si-O-Na and Si-OH groups to realize activation. The experimental results revealed that the adsorption process involved the removal of Cu(II) by the formation of Si-O-Cu bonds on the surface of the adsorbent. The above results indicated that the adsorbent prepared from quartz sand had a good removal effect on Cu(II).The amorphous silica structure of active silicate materials makes their reactivity much stronger than that of crystalline silica and confers these materials with excellent adsorption properties for pollutants such as heavy metals [7][8][9]. Studies have shown that the silanol groups (Si-OH) in active silicate materials are the main determinants of surface chemistry [10] and can form covalent bonds and hydrogen bonds with some ions and molecules [11]. Heavy metals such as Cu(II), Cd(II), and Pb(II) in aqueous solution were found to be removed by forming surface adsorption complexes with surface silanol [12,13]. Our team used leaching residue from lead-zinc tailings with high silicon content as a raw material to prepare an active silicate heavy metal adsorbent, which showed a very high adsorption capacity for the heavy metals Cu, Pb, Cd and Zn. The saturated adsorption capacities were 3.40, 2.83, 0.66 and 0.62 mmol/g, respectively [14].Besides, when active silicate materials are applied to the remediation of heavy metals in soil, extractable heavy metals can be transformed into forms with relatively stable valence [15,16], and the heavy metal stress and accumulation in plants can be reduced [17]. Moreover, the active silicates can be absorbed by plants as nutrient elements to form phytoliths, which play an important role in increasing grain yield and enhancing photosynthesis, pest resistance, lodging resistance, and so on...

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“…PPEA 0.05 had the earliest loss, and the loss was large in the first stage (vaporization of free water) and small in the second stage (vaporization of bound water), while PPEA 0.3 showed the opposite trend to PPEA 0.05 , which may have been because PPEA 0.3 had more fine pores (as observed in Figure 4 ) and better water-holding capacity. The third quick loss stage of 290–360 °C may have been due to the thermal decomposition of PPEAs [ 34 ]. In this degradation range, PPEA 0.3 degraded first, while PPEA 0.05 degraded most seriously.…”

Section: Resultsmentioning

confidence: 99%

Development of Pectin-Based Aerogels with Several Excellent Properties for the Adsorption of Pb2+

Wang

Shuai

et al. 2021

Foods

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Traditional aerogels lack specific functional groups for the adsorption of Pb2+, which results in a low adsorption capacity and limits the application scope. Novel porous pectin-based aerogels (PPEAs) were prepared by incorporating polyethylenimine (PEI) using ethylene glycol diglycidyl ether (EGDE) as a cross-linker for the removal of Pb2+ from water. The cross-linking mechanism, morphology, mechanical strength, thermal stability, adsorption properties, and mechanism of the aerogels were investigated. The aerogels possessed several desirable features, such as a large maximum Pb2+ adsorption capacity (373.7 mg/g, tested at pH 5.0), ultralight (as low as 63.4 mg/cm3), high mechanical strength (stress above 0.24 MPa at 50% strain), and easy recyclability. Meanwhile, the equilibrium adsorption data was well described by the Langmuir–Freundlich (Sips) model and the kinetic adsorption process was well fitted using the pseudo-second-order model. The donor groups, such as -NH2, and oxygen-containing functional groups were responsible for the Pb2+ adsorption, which was confirmed by the FTIR and XPS analysis. The excellent characteristics mean that PPEAs are highly effective adsorbents in the remediation of lead-containing wastewater.

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Novel pectin based composite hydrogel derived from grapefruit peel for enhanced Cu(II) removal

Cited by 178 publications

References 51 publications

Performance of a modified alkaline lignin towards copper adsorption under different conditions

Performance of a modified alkaline lignin towards copper adsorption under different conditions

A Functionalized Silicate Adsorbent and Exploration of Its Adsorption Mechanism

Development of Pectin-Based Aerogels with Several Excellent Properties for the Adsorption of Pb2+

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