Highly effective and reusable Ni-Al oxide/Zn0.4Co0.6Fe2O4 superparamagnetic aerogel for oil-water separation.

Oily wastewater from the oil industry and oil spill accidents has become a serious environmental problem and has attracted worldwide attention. The present study reports on the successful preparation of a novel magnetic Ni-Al oxide/Zn0.4Co0.6F2O4 mesoporous aerogel (MNA) as a highly selective adsorbent for oil removal from water. Oleic acid (OA) and Triton X-100 (TX) were used as hydrophobic agents for MNA surface modification. It was found that the attached amount of OA on the mesoporous MNA aerogel is 3.5 times larger than that of TX, giving an advantage to MNA-OA in oil separation. The MNA-OA displayed superhydrophobicity (contact angle ∼150°) and superparamagnetism properties that allowed the adsorbent to be used selectively for oil removal. The MNA-OA was found to have a high oil removal efficiency of ∼97% with an adsorption capacity of ∼2 g/g. Furthermore, the produced magnetic adsorbent has high stability due to the strong chemical binding of OA, which is demonstrated by its good reusability performance. Throughout five separate runs, the MNA-OA was shown to be a very efficient and reusable adsorbent for oily wastewater.

Cold atmospheric plasma: a sustainable approach to inactivating viruses, bacteria, and protozoa with remediation of organic pollutants in river water and wastewater.

Innovative technologies are needed to enhance access to clean water and avoid waterborne diseases. We investigated the performance of cold atmospheric plasma (CAP), a clean and sustainable approach for microbial inactivation and total organic carbon (TOC) degradation in environmental water. Water matrices played a crucial role in the performance of CAP efficacy; for example, complete removal of ɸX174 from dH2O required 1 min of treatment, while ɸX174 reductions of ~ 2log10 and 4log10 were obtained after 10 min of CAP exposure in river water and wastewater samples, respectively. Similarly, after 10 min of CAP treatment, bacterial concentrations decreased by 3 log10 and 4 log10, in river and wastewater samples, respectively. In contrast, after 30 s of contact time, a 4 log10 reduction of bacteria was accomplished in dH2O. Complete removal of Acanthamoeba from dH2O was found after 30 min of CAP treatment, whereas it was not removed from surface water or wastewater at the same exposure time. Additionally, the approach successfully reduced TOC, and the degradation kinetics of TOC were represented by pseudo-first-order. CAP showed higher rates of TOC degradation in the final effluent of the wastewater treatment plant compared to surface water. The difference in CAP performance between river water and wastewater could be attributed to the bulk structure of humic acids in river water compared to small organic byproducts in the final effluent of WWTP. Overall, the findings reported here support the idea that CAP holds promise as a sustainable solution for controlling pathogens, removing organic water pollution, and integrating with traditional purification processes. Low-cost systems may advance CAP technology and increase its widespread use.

SiO2/Zn0.4Co0.6Fe2O4 aerogel: an efficient and reusable superparamagnetic adsorbent for oily water remediation.

Magnetic SiO2/Zn0.4Co0.6Fe2O4 aerogels were successfully prepared by sol-gel method with two different drying steps: ambient pressure drying (APD) and freeze-drying (FD). The surface chemistry of silica was modified to be hydrophobic by oleic acid. The prepared materials were fully characterized, displaying superparamagnetic behavior with saturation magnetizations of 10.2 and 15.1 emu g-1, and contact angles of ∼130° and ∼140° for the materials prepared by the APD and FD methods, respectively, indicating the hydrophobic surfaces of the prepared materials. This hydrophobicity allows the efficient separation of oil. Specifically, as high as 1.7 and 2 g g-1 adsorption capacities were obtained when using APD-dried and FD-dried silica aerogels, respectively, suggesting the preference for the FD method. Additionally, magnetic recovery and reuse of the adsorbents were successfully implemented in an attempt to reduce the overall practical application costs. To sum up, the prepared materials are good candidates for oil removal from wastewater and the protection of the environment.

Nanomaterials: a review of emerging contaminants with potential health or environmental impact.

Nanotechnologies have been advantageous in many sectors and gaining much concern due to the unique physical, chemical and biological properties of nanomaterials (NMs). We have surveyed peer-reviewed publications related to "nanotechnology", "NMs", "NMs water treatment", "NMs air treatment", and "NMs environmental risk" in the last 23 years. We found that most of the research work is focused on developing novel applications for NMs and new products with peculiar features. In contrast, there are relatively few of publications concerning NMs as environmental contaminants relative to that for NMs applications. Thus, we devoted this review for NMs as emerging environmental contaminants. The definition and classification of NMs will be presented first to demonstrate the importance of unifying the NMs definition. The information provided here should facilitate the detection, control, and regulation of NMs contaminants in the environment. The high surface-area-to-volume ratio and the reactivity of NMs contaminants cause the prediction of the chemical properties and potential toxicities of NPs to be extremely difficult; therefore, we found that there are marked knowledge gaps in the fate, impact, toxicity, and risk of NMs. Consequently, developing and modifying extraction methods, detection tools, and characterization technologies are essential for complete risk assessment of NMs contaminants in the environment. This will help also in setting regulations and standards for releasing and handling NMs as there are no specific regulations. Finally, the integrated treatment technologies are necessary for the removal of NMs contaminants in water. Also, membrane technology is recommended for NMs remediation in air.

Removal of chemical and microbial water pollutants by cold plasma combined with Ag/TiO2-rGO nanoparticles.

This study aimed to investigate the synergistic effect of the cold atmospheric plasma (CAP) and heterogeneous photocatalytic processes in an aqueous solution to enhance water purification efficacy and reduce the energy cost required by CAP. 0.1% Ag/TiO2-reduced graphene oxide (rGO) nanoparticles (NPs) photo-composite were prepared and fully characterized. Data showed that Ag nanoparticles and the rGO play an important role in increasing the efficiency of the whole treatment process and the photo-composite (0.1% Ag/TiO2-1% rGO at 400 °C) revealed the highest phenol removal rate with excellent reusability. Also, complete inactivation (~ 5log10 reduction) of both E. coli and S. aureus by NPs was observed without CAP exposure, whereas a minimal effect (0.1-0.5 log10) on viruses (Adenovirus (AdV), rotavirus, and ɸX174) was observed after 10 min incubation. Interestingly, the photocatalytic virus inactivation test was promising, as it resulted in > 4.7log10 reduction of AdV at 2 min treatment, whereas < 1log10 could be reduced using only CAP at the same treatment time. Accordingly, we believe that this work could provide new insights into how the synergy between CAP and 0.1% Ag/TiO2-1% rGO photo-composite in aqueous media imposes a great potential for environmental applications, such as water purification and microbial inactivation.

Probing protein rejection behavior of blended PES-based flat-sheet ultrafiltration membranes: A density functional theory (DFT) study.

Membrane fouling is a common problem in membrane technology and causes detrimental effects for the applied membranes such as loss of integrity and productivity. Henceforward, we devoted this work to fabricate membranes that pose favored criteria in the direction of alleviating membrane fouling incidence. Herein, the fabricated membranes were traced via an assortment of both experimental and molecular modeling verifications to understand the mechanism of interaction. To do so, firstly, three different ultrafiltration (UF) membranes had been prepared via facile wet phase inversion method thru dipping a casting solution composed of polyethersulfone-polyvinyl pyrrolidone (PES-PVP) and polyethersulfone-Pluronic P31R1 (PES-P31R1) in a water coagulation bath. Regarding the practical-based data, the pristine PES membrane exhibited the highest rejection of bovine serum albumin (BSA) protein (model foulant) compared with the modified PES-based membranes. The membrane chemical compositions were elucidated with ATR-FTIR Spectroscopy. On the other hand, molecular modeling has been carried out via calculating thermodynamic parameters, level parametric method, and density functional theory (DFT). Thermodynamic parameters analysis indicated that the noticeable difference of BSA rejection may be ascribed to different entropy behavior for the fabricated membranes. In addition, the level parametric method (PM6) and density functional theory DFT: B3LYP with 6-31g (d,p) basis set models clarified the interaction manner of BSA molecules to membrane surfaces.

Synthesis, characterization and adsorption properties of microcrystalline cellulose based nanogel for dyes and heavy metals removal.

Recently, naturally occurring biopolymers have attracted the attention as potential adsorbents for the removal of water contaminants. In this work, we present the development of microcrystalline cellulose (MCC)-based nanogel grafted with acrylamide and acrylic acid in the presence of methylene bisacrylamide and potassium persulphate as a crosslinking agent and initiator, respectively. World-class facilities such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), surface analysis, field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM) and zeta sizer were used to characterize the synthesized MCC based nanogel. The prepared nanogel was applied to remove reactive red 195 (RR195) dye and Cd (II) from aqueous medium at different operational conditions. The adsorption experiments showed that the feed concentration of monomers has a significant effect on the removal of RR195 which peaked (93% removal) after 10min of contact time at pH2 and a dose of 1.5g/L. On contrary, the feed concentration has insignificant effect on the removal of Cd (II) which peaked (97% removal) after 30min of contact time at pH6 and a dose of 0.5g/L. The adsorption equilibrium data of RR195 and Cd (II) was best described by Freundlich and Langmuir, respectively. Conclusively, the prepared MCC based nanogels were proved as promising adsorbents for the removal of organic pollutants as well as heavy metals.