Enhancing membrane performance for oily wastewater treatment: comparison of PVDF composite membranes prepared by coating, blending, and grafting methods using TiO, BiVO, CNT, and PVP.

This comparative study investigates the modification of polyvinylidene fluoride (PVDF) membranes with different nanoparticles (TiO or TiO-based composites containing BiVO and/or CNT), using three distinct methods (blending, coating, and grafting) and polyvinylpyrrolidone (PVP). The objective was to enhance the photocatalytic and filtration performance for the separation of oil-in-water emulsions. Regarding the UV activity, the PVDF-TiO/CNT/PVP-coated membrane presented the best performance.

Effects of Different TiO/CNT Coatings of PVDF Membranes on the Filtration of Oil-Contaminated Wastewaters.

Six different TiO/CNT nanocomposite-coated polyvinylidene-fluoride (PVDF) microfilter membranes (including -OH or/and -COOH functionalized CNTs) were evaluated in terms of their performance in filtering oil-in-water emulsions. In the early stages of filtration, until reaching a volume reduction ratio (VRR) of ~1.5, the membranes coated with functionalized CNT-containing composites provided significantly higher fluxes than the non-functionalized ones, proving the beneficial effect of the surface modifications of the CNTs.

Investigation of Photocatalytic PVDF Membranes Containing Inorganic Nanoparticles for Model Dairy Wastewater Treatment.

Membrane separation processes are promising methods for wastewater treatment. Membrane fouling limits their wider use; however, this may be mitigated using photocatalytic composite materials for membrane preparation. This study aimed to investigate photocatalytic polyvinylidene fluoride (PVDF)-based nanocomposite membranes for treating model dairy wastewater containing bovine serum albumin (BSA).

Outstanding Separation Performance of Oil-in-Water Emulsions with TiO/CNT Nanocomposite-Modified PVDF Membranes.

Membrane filtration is an effective technique for separating micro- and nano-sized oil droplets from harmful oil-contaminated waters produced by numerous industrial activities. However, significant flux reduction discourages the extensive application of this technology; therefore, developing antifouling membranes is necessary. For this purpose, various titanium dioxide/carbon nanotube (TiO/CNT) nanocomposites (containing 1, 2, and 5 wt.

Visible-light-driven photocatalytic PVDF-TiO/CNT/BiVO hybrid nanocomposite ultrafiltration membrane for dairy wastewater treatment.

Enhancing the performance of polymeric membranes by nanomaterials has become of great interest in the field of membrane technology. The present work aimed to fabricate polyvinylidene fluoride (PVDF)-hybrid nanocomposite membranes and modify them with TiO and/or BiVO nanoparticles and/or carbon nanotubes (CNTs) in various ratios. Their photocatalytic performance under visible light was also investigated.

Surface-initiated polymerization of PVDF membrane using amine and bismuth tungstate (BWO) modified MIL-100(Fe) nanofillers for pesticide photodegradation.

Pirimicarb as a pesticide is used to control the aphids in the agriculture field; however, it affects the groundwater ecosystem by leaching through the soil profile. The post-synthetic amine and BWO modified MIL-100 (Fe) nanofillers were synthesized. The photocatalytic property of amine-functionalized and BWO@MIL-100(Fe) nanofillers was confirmed by the lesser bandgap energy than the unmodified MIL-100 (Fe) nanofiller.

Statistical Analysis of Synthesis Parameters to Fabricate PVDF/PVP/TiO Membranes via Phase-Inversion with Enhanced Filtration Performance and Photocatalytic Properties.

Non-solvent induced phase-inversion is one of the most used methods to fabricate membranes. However, there are only a few studies supported by statistical analysis on how the different fabrication conditions affect the formation and performance of membranes. In this paper, a central composite design was employed to analyze how different fabrication conditions affect the pure water flux, pore size, and photocatalytic activity of polyvinylidene fluoride (PVDF) membranes.

Comparison of filtering models for milk substitutes.

Membrane-based methods of filtering are becoming increasingly popular in the food industry, but membrane fouling significantly affects filtration performance, making the characterisation of fouling mechanisms critical. This study examined the applicability of three mathematical models. The resistance-in-series model divides the total resistance into membrane resistance, reversible resistance and irreversible resistance.

Recent development of photocatalytic nanomaterials in mixed matrix membrane for emerging pollutants and fouling control, membrane cleaning process.

Membrane-based separation is an area of extensive research in wastewater treatment, which includes the control of pollution and reuse of water. The fabrication and modification membranes for prevention and reduction of pollution to provide quality water with fouling-free membranes through the wastewater treatment are the progressive approaches in the industries. Several research works have been extensively working on modification and fabrication polymer membranes with integration of advanced oxidation process (AOP) to overcome the membrane fouling.

New Insights into The Photoactivity of Shape-Tailored BiVO Semiconductors via Photocatalytic Degradation Reactions and Classical Reduction Processes.

In the present study, additive-free, pH-driven, hydrothermal crystallization was used to obtain shape-tailored monoclinic BiVO photocatalysts. The as-prepared BiVO products were systematically characterized, uncovering their crystallographic, morphologic and optical properties, while their applicability was verified in the visible light-driven photodegradation of oxalic acid and rhodamine B. Monoclinic clinobisvanite was obtained in most cases, with their band gap values located between 2.

Intensification of the ultrafiltration of real oil-contaminated (produced) water with pre-ozonation and/or with TiO, TiO/CNT nanomaterial-coated membrane surfaces.

In the present study, commercial PES, PVDF, PTFE ultrafilter membranes, and two different nanomaterial (TiO and TiO/CNT composite)-covered PVDF ultrafilter membranes (MWCO = 100 kDa) were used for the purification of an industrial oil-contaminated (produced) wastewater, with and without ozone pretreatment to compare the achievable fouling mitigations by the mentioned surface modifications and/or pre-ozonation. Fluxes, filtration resistances, foulings, and purification efficiencies were compared in detail. Pre-ozonation was able to reduce the total filtration resistance in all cases (up to 50%), independently from the membrane material.

Utilization of Carbon Nanospheres in Photocatalyst Production: From Composites to Highly Active Hollow Structures.

Titanium dioxide-carbon sphere (TiO-CS) composites were constructed via using prefabricated carbon spheres as templates. By the removal of template from the TiO-CS, TiO hollow structures (HS) were synthesized. The CS templates were prepared by the hydrothermal treatment of ordinary table sugar (sucrose).

Matrix effect in case of purification of oily waters by membrane separation combined with pre-ozonation.

In the present study, oil in water emulsions (c = 100 ppm; d < 2 μm) was purified with ozonation followed by microfiltration using polyethersulfone (PES) membrane (d = 0.2 μm). The effects of pre-ozonation on membrane microfiltration were investigated in detail both in case of ultrapure and model groundwater matrices, applying different durations (0, 5, 10, and 20 min) of pre-ozonation.

Fouling mitigation and cleanability of TiO photocatalyst-modified PVDF membranes during ultrafiltration of model oily wastewater with different salt contents.

In the present study, TiO-coated ultrafiltration membranes were prepared and used for oily water filtration (droplet size < 2 μm). The aim of this work was to investigate the effect of different salt contents on fouling and filtration properties of neat and TiO-coated membranes during oil-in-water emulsion filtration. The effect of the TiO coating on the flux, surface free energy, and retention values was measured and compared with the neat membrane values.

Comparison of various advanced oxidation processes for the degradation of phenylurea herbicides.

Various types of advanced oxidation processes (AOPs), such as UV photolysis, ozonation, heterogeneous photocatalysis and their combinations were comparatively examined at the same energy input in a home-made reactor. The oxidative transformations of the phenylurea herbicides fenuron, monuron and diuron were investigated. The initial rates of transformation demonstrated that UV photolysis was highly efficient in the cases of diuron and monuron.

Removal of organic pollutants in model water and thermal wastewater using clay minerals.

Water treatment method was developed for the removal of different anionic dyes such as methyl orange and indigo carmine, and also for thymol applying sodium bentonite and cationic surfactant - hexadecyltrimethylammonium bromide (HTAB) - or polyelectrolytes (polydiallyldimethylammonium chloride, poly-DADMAC and poly-amines). The removal efficiency of these model substrates was examined in model water using UV-Vis spectrophotometry, HPLC and TOC analysis. The clay mineral and HTAB were added in one step to the polluted model water in Jar-test experiments.