Removal of metal ions and humic acids through polyetherimide membrane with grafted bentonite clay

Abstract

Functional surfaces and polymers with branched structures have a major impact on physicochemical properties and performance of membrane materials. With the aim of greener approach for enhancement of permeation, fouling resistance and detrimental heavy metal ion rejection capacity of polyetherimide membrane, novel grafting of poly (4-styrenesulfonate) brushes on low cost, natural bentonite was carried out via distillation-precipitation polymerisation method and employed as a performance modifier. It has been demonstrated that, modified bentonite clay exhibited significant improvement in the hydrophilicity, porosity, and water uptake capacity with 3 wt. % of additive dosage. SEM and AFM analysis showed the increase in macrovoides and surface roughness with increased additive concentration. Moreover, the inclusion of modified bentonite displayed an increase in permeation rate and high anti-irreversible fouling properties with reversible fouling ratio of 75.6%. The humic acid rejection study revealed that, PEM-3 membrane having rejection efficiency up to 87.6% and foulants can be easily removed by simple hydraulic cleaning. Further, nanocomposite membranes can be significantly employed for the removal of hazardous heavy metal ions with a rejection rate of 80% and its tentative mechanism was discussed. Conspicuously, bentonite clay-bearing poly (4-styrenesulfonate) brushes are having a synergistic effect on physicochemical properties of nanocomposite membrane to enhance the performance in real field applications.

Efficient photocatalytic degradation of aniline blue under solar irradiation by ternary cobalt ferrite / graphitic carbon nitride / bentonite nanocomposite.

“…The XRD 210) and ( 144) planes as reported in literature [Hebbar et al 2018] [Bunaciu et al 2015]. The increase in the value of crystallite size of the composite compare to cobalt ferrite con rms the encapsulation of the ferrite core by graphitic carbon nitride and bentonite.…”

Adsorption of Mercury Using Different Types of Activated Bentonite: A Study of Sorption, Kinetics, and Isotherm Models

“…This material has good porosity and large surface area (Didi et al, 2009;Hebbar et al, 2018;Javed et al, 2018;Sanz-pérez et al, 2019). Various bentonite applications have been developed in various fields including adsorbent (Lee, 2015), isotherm modelling (Zheng et al, 2009), and removal of paraquat from water (Sidhoum et al, 2013), with metal ion sorption as one of the essential applications.…”

Nanoclays‐Incorporated Thin‐Film Nanocomposite Membranes for Reverse Osmosis Desalination

“…[ 39 ] Hebbar et al utilized functionalized bentonite to improve nanofiltration performance in removal of heavy metals and humic acids. [ 40 ] However, most of the nanoclays reported have relatively low dispersity in solvents, which have to undergo long‐time activation or complicated surface modifications prior to be dispersed in water or organic solvents. [ 38–40 ] Laponite (Na +0.7 [Si 8 Mg 5.5 Li 0.3 O 20 (OH) 4 ] 0.7− ) nanoclays (NC‐LAP), a type of synthetic nanoclays, have been discovered and commercialized for decades, and commonly used as a film‐forming agent, emulsifier, and gelling agent.…”

“…[ 40 ] However, most of the nanoclays reported have relatively low dispersity in solvents, which have to undergo long‐time activation or complicated surface modifications prior to be dispersed in water or organic solvents. [ 38–40 ] Laponite (Na +0.7 [Si 8 Mg 5.5 Li 0.3 O 20 (OH) 4 ] 0.7− ) nanoclays (NC‐LAP), a type of synthetic nanoclays, have been discovered and commercialized for decades, and commonly used as a film‐forming agent, emulsifier, and gelling agent. [ 41,42 ] Owing to its excellent aqueous dispersity, small size and nontoxicity, Laponite can be a good candidate as nanofillers in TFN membranes, which requires no complicated pretreatment when being blended with the aqueous monomer solution for interfacial polymerization.…”