Performance evaluation and antifouling analyses of cellulose acetate/nanodiamond nanocomposite membranes in water treatment

Abstract

In this study, nanocomposite membranes based on cellulose acetate (CA) and nanodiamond (ND) were prepared by applying phase inversion methods. In order to achieve efficient dispersion and more hydrophilic NDs, they were functionalized via heat treatment (ND-COOH). The prepared nanocomposite membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), contact angle, porosity measurement, tensile strength, and abrasion resistance techniques. Furthermore, the governing fouling mechanisms were determined by using classic models as well as combined fouling models. Moreover, the effect of precoagulation with polyaluminum chloride (PAC) on the humic acid (HA) filtration was investigated. The obtained results showed that in the presence of ND-COOH, the abrasion resistance of nanocomposite CA membrane was three times higher than that of pristine CA membrane. Besides, the nanocomposite membranes with 0.5 wt % of raw and functionalized ND exhibited excellent hydrophilicity and PWF. The analysis of fouling mechanism based on Hermia's model revealed that the cake formation is prevailing mechanism for CA and CA/ND (0.5 wt %) membranes while for CA/ND-COOH (0.5 wt %) membrane, experimental results are fitted by combined cake filtration-complete blocking (CFCB) model. It confirms that pretreatment with PAC can significantly mitigate fouling and improve HA removal.

High‐density polyethylene membranes embedded with carboxylated and polyethylene glycol‐grafted nanodiamond to be used in membrane bioreactors

“…Etemadi et al prepared pristine and carboxylated ND‐embedded cellulose acetate (CA) membranes. Obtained results revealed that the presence of both pristine and carboxylated NDs improved thermal, mechanical, and antibacterial characteristics of the membrane, and also, CA/ND‐COOH membrane showed even better properties than CA/ND membrane owing to the better dispersion of carboxylated NDs.…”

“…It can be seen that the hydrophilicity of the membranes improved with increasing the content of ND‐COOH and ND‐PEG nanoparticles. This improvement in the membrane hydrophilicity can be ascribed to the presence of hydrophilic functional groups on the surface of modified ND nanoparticles . Moreover, PE/ND‐PEG nanocomposite membranes have minimum contact angle values as a result of hydrophilic hydroxyl groups of PEG chains.…”

“…It has been accepted that the presence of hydrophilic nanoparticles within the polymer membranes can improve membrane properties by affecting hydrophilicity, mechanical strength, porosity, morphology, permeability, and so on . PVDF/graphene oxide (GO) membranes were prepared by Zhao et al, and the result demonstrated that the presence of GO increased water flux and antifouling behavior of PVDF/GO membranes and decreased cleaning frequency.…”

“…In recent years, diamond nanoparticles have attracted lots of attention considering their superior properties like hydrophilicity, antibacterial behavior, biocompatibility, non‐toxicity, chemical stability,, thermal stability, and excellent hardness . Nanodiamond (ND) can be functionalized due to the presence of various functional groups on its surface . Beside the superior properties, ND suffers from agglomeration because of its higher surface energy which causes high tendency to nanoparticles aggregation.…”

Synthesis, characterization, and anti-fouling properties of cellulose acetate/polyethylene glycol-grafted nanodiamond nanocomposite membranes for humic acid removal from contaminated water

“…As reported in the literature, nanocomposite membranes such as HDPE/SiO 2 [11], polyethersulfone (PES)/ Stöber silica [30], CA/organically modified montmorillonite [7], polyamide (PA)/multi-wall carbon nanotube (MWCNT) [31], polysulfone/GO-TiO 2 [9], and PVDF/TiO 2 [32] enhanced the performance of polymeric membranes in HA removal from contaminated water. In our previous work, pristine and carboxylated ND particles, i.e., ND and ND-COOH were added to the CA polymer to investigate the anti-fouling properties of the prepared nanocomposite CA membranes in HA removal from contaminated water [33]. Obtained results were promising; however, anti-fouling properties were far from our preliminary goal.…”