Halloysite nanotubes (HNTs) were functionalized using 3-aminopropyltriethoxysilane (APTES) and incorporated into polyethersulfone (PES) membranes to improve the hydrophilicity of the membranes as well as the interfacial interaction between HNTs and the polymer matrix. The intrinsic properties, permeability, and selectivity of the prepared membranes were analyzed to evaluate the membrane performance. In addition, humic acid (HA) fouling experiments were conducted to measure the antifouling properties of the fabricated membranes. As HNTs and functionalized HNTs (f-HNTs) contents are increased, hydrophilicity and mechanical strength were enhanced, and membranes with f-HNTs showed further improved performance. The pure water flux of membranes with 2% HNTs and f-HNT was 7.5 times higher than that of a pristine PES membrane without a trade-off relation between the water flux and HA rejection. The membranes with f-HNTs showed the highest antifouling properties compared to membranes with HNTs because enhanced hydrophilicity played a key role in preventing accumulation of HA.
In this study, we fabricated a nanocomposite polyethersulfone (PES) HF membrane by blending acid functionalized carbon nanotubes (FCNT) to address the issue of reduced membrane life, increased energy consumption, and operating costs due to low permeability and membrane fouling in the ultrafiltration process. Additionally, we investigated the effect of FCNT blending on the membrane in terms of the physicochemical properties of the membrane and the filtration and antifouling performance. The FCNT/PES nanocomposite HF membrane exhibited increased water permeance from 110.1 to 194.3 LMH/bar without sacrificing rejection performance and increased the flux recovery ratio from 89.0 to 95.4%, compared to a pristine PES HF membrane. This study successfully developed a high filtration and antifouling polymer-based HF membrane by blending FCNT. Furthermore, it was validated that blending FCNT into the membrane enhances the filtration and antifouling performance in the ultrafiltration process.
Treatment and reuse of unconventional oil and gas (UOG)
produced
water are important strategies that address the dual challenges of
water scarcity and pollution posed by UOG production. Considering
the high salinity and complex chemistry of UOG produced water, it
is important to comprehensively analyze the water quality and potential
ecological risk of treated produced water for reuse applications.
In this study, we evaluated and compared the efficacy of pretreatment
followed by nanofiltration (NF) and reverse osmosis (RO) using membranes
of varied permselectivity in treating produced water from the Niobrara
Shale play in Colorado. We determined the efficacy of each technology
in removing inorganic and organic constituents as well as reducing
toxicity on Daphnia magna. Our results show that
the pretreatment step resulted in a minor reduction of chemical constituents
and toxicity and that the NF permeates did not meet the water quality
criteria for irrigation and livestock drinking water. Despite high
removal rates for most contaminants in the produced water by RO, the
concentrations of chloride and boron as well as the sodium adsorption
rate (SAR) in the RO permeates exceeded irrigation guidelines. We
observed the passage of surfactants with molecular weights much higher
than the molecular weight cutoff of NF and RO membranes, suggesting
that membranes are not an absolute barrier to organic contaminants.
Our results demonstrate that thorough chemical and toxicological analyses
are needed to understand the feasibility and potential risk of treating
UOG produced water for beneficial reuse.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.