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This study aims to investigate the morphology and physicochemical properties of BiOBr/Polyvinylidene fluoride (PVDF) composite membranes and the differences in the properties of BiOBr/PVDF composite membranes made by adding different precursor ratios during the casting process.

In this paper, sodium bromide and Bi(NO3)3 were used as precursors for the preparation of BiOBr photocatalysts, and PVDF membranes were modified by using the phase conversion method in conjunction with the in situ deposition method to produce BiOBr/PVDF hydrophilic composite membranes with both membrane separation and photocatalytic capabilities.

The characterization results confirmed that the composites were successfully and homogeneously co-mingled in the PVDF membranes. The related performance of the composite membrane was tested, and it was found that the composite membrane with the optimal precursor incorporation ratio had good photocatalytic efficiency and antipollution ability; the removal efficiencies of methyl orange, rhodamine B and methylene blue were 80.43%, 85.02% and 86.94%, respectively, in 2.5 h. The photocatalytic efficiency of composite membranes with different precursor ratios increased and then decreased with the increase of the precursor addition ratio.

The composite membrane is prepared by phase conversion method with in situ deposition method, and the BiOBr material has unique advantages for the degradation of organic dyes. The comprehensive experimental data can be known that the composite membrane prepared in this paper has high degradation efficiency and good durability for organic dyes.

Micropollutants in the aquatic environment pose threats to both ecosystems and human health. Traditional wastewater treatment plants (WWTP) reduce some micropollutants, especially those who adhere to sludge or suspended matter. The hydrophilic micropollutants, on the other side, which may be non-biodegradable and resistant to UV-treatment etc. are typically transported untreated into the water recipients. This paper contains a literature study on the state of the art of advanced wastewater treatment technologies for reducing micropollutants such as pharmaceutical degradation products, personal care products, surfactants and industrial chemicals including heavy metals.

This literature study is completed using the most extensive and expansive literature database in the World to date, Google Scholar (GS). Published papers in recognized scientific journals are sought out in GS, and for relevance for this literature study, papers published here from 2016 and onwards (the last 5 years) have been chosen to eliminate irrelevant studies.

The result of the study is that there are many promising technologies on the market or emerging; however, no one solution treats every micropollutant equally well. Since advanced technologies often require expensive investments for municipalities and companies, it is important to identify which micropollutants pose the highest risk towards human health and the environment, because choosing systems to eliminate them all is not economically wise, and even choosing a system combining the existing technologies can be more expensive than states, municipalities and private companies are capable of investing in.

The research is limited to published papers on GS, which may omit certain papers published in closed databases not sharing their work on GS.

The practical implications are that practitioners cannot find go-to solutions based on the conclusions of the research and thus need to use the results to investigate their own needs further in order to make the wisest decision accordingly. However, the paper outlines the state of the art in advanced wastewater treatment and explains the benefits and downsides of the technologies mentioned; however, more research in the field is required before practitioners may find a proper solution to their specific issues.

The social implications are that the consequences of introducing a removal of micropollutants from the water environment can ultimately effect the citizens/consumers/end-users through added costs to the tariffs or taxes on advanced wastewater treatment, added costs on everyday goods, wares and products and added costs on services that uses goods, wares and products that ultimately produces micropollutants affecting the water environment.

This paper presents a much needed state of the art regarding the current advanced technologies to mitigate micropollutants in wastewater. The overview the paper provides supports politics on national as well as international levels, where larger unions such as the EU has stated that advanced wastewater treatment will be the next step in regulating pollutants for aquatic outlet.

This work describes the fabrication of composite nanogrease based on carbon nanotubes (CNTs) as an additive at different volume concentrations 0, 0.5, 1, 2 and 3 Wt.% and investigates the correlation between CNTs and grease rheological behaviour. In addition, study the influence of shear thinning rate at various temperatures and investigates the thermal conductivity of nanogrease. The results demonstrated that grease behaves like a Newtonian viscoelastic material with a narrow linear domain. The thermal conductivity of nanogrease was enhanced by about 31.58 per cent, and the thermal and mechanical stabilities improved. Moreover, the apparent viscosity and dropping point increased by about 93 and 27 per cent, respectively.

Grease was dissolved in chloroform (10 Wt.%), at 25°C for 1 h. In parallel, functionalized CNTs with different volume concentrations (0.5, 1, 2 and 3 Wt.%) were dispersed in N,N-dimethylformamide; the dispersion was stirred for 15 min, and then sonicated (40 kHz, 150 W) for 30 min. Grease solution was then added to the CNTs. The nanofluid was magnetically stirred for 15 min and then sonicated for 2 h. This ensured uniform dispersion of nanoparticles in the base fluid.

Inexpensive and simple fabrication of nanogrease. Thermal conductivity of nanogrease was typically enhanced compared to other reported studies. Apparent viscosity and dropping point increases with the increase the volume concentration.

This work describes the inexpensive and simple fabrication of nanogrease for improving properties of lubricants, which improve power efficiency and extend lifetimes of mechanical equipment.

This paper aims to investigate the reusability of metal/metal oxide-coupled ZnO nanorods (ZnO NRs) to degrade rhodamine B (RhB).

ZnO NRs particles were synthesized by precipitation method and used to remove various types of metal ions such as Cu²⁺, Ag⁺, Mn²⁺, Ni²⁺, Pb²⁺, Cd²⁺ and Cr²⁺ ions under UV illumination. The metal/metal oxide-coupled ZnO NRs were characterized by scanning electron microscope, X-ray diffraction and UV-Vis diffuse reflectance. The photodegradation of RhB dye by these metal/metal oxide-coupled ZnO NRs under UV exposure was assessed.

The metal/metal oxide-coupled ZnO NRs were successfully reused to remove RhB dye in which more than >90% of RhB dye was degraded under UV exposure. Furthermore, the coupling of Ag, CuO, MnO₂, Cd and Ni particles onto the surface of ZnO NRs even enhanced the degradation of dye. The dominant reactive species involved in the degradation of RhB dye were ^•OH- and ^•O₂⁻-free radicals.

The coupling of metal/metal oxide onto the surface of ZnO NRs after metal ions removal could affect the photocatalytic performance of ZnO NRs in the degradation of organic pollutants in subsequent stage.

A good reusability performance of metal/metal oxide-coupled ZnO NRs make ZnO NRs become a desirable photocatalyst material for the treatment of wastewater, which consists of both heavy metal ions and organic dyes.

Metal/metal oxide coupling onto the surface of ZnO NRs particles improved subsequent UV-assisted photocatalytic degradation of RhB dye.

Over the past decades, intense efforts have been devoted to design and synthesize efficient photocatalysts which are active under sunlight for environmental and energy applications. Titanium dioxide (TiO₂) has attracted much attention over many years for organic contaminant degradation in air or water due to its strong optical absorptivity, chemical stability and low cost. However, TiO₂ has a very low photo quantum yield which prompts the easy recombination of photogeneration electron/hole pairs. In addition, bandgap of 3.2 eV restrains application of this photocatalyst mainly to the UV range.

Vertically oriented one-dimensional TiO₂ nanostructures remarkably improve electron transport by creating a direct conduction pathway, decreasing intercrystalline contacts and stretching grown structure with the specified directionality. In this research, to enhance the visible light absorbance of TiO₂, prearranged hydrogenated titanium dioxide nanorods (H-TNRs) in the presence of H₂/N₂ gas flow are hydrothermally synthesized.

The X-ray diffraction patterns illustrated the characteristic peaks of tetragonal rutile TiO₂ and confirmed that there is no phase change after hydrogenation. Trivalent titanium ions surface defects and oxygen vacancies were considered as major reasons for redshift of absorption edge toward visible region and subsequently narrowing the bandgap to 2.27 eV. The optimized photocatalysts exhibited high visible-light-driven photocatalytic activity for degradation of methylene blue in water within 210. The synthesized H-TNRs established themselves as promising photocatalysts for organic compounds degradation in the aqueous solution.

To the best of the authors’ knowledge, this work is original and has not been published elsewhere nor is it currently under consideration for publication elsewhere.

Petroleum hydrocarbons are naturally occurring flammable fossil fuels used as conventional energy sources. It has carcinogenic, mutagenic properties and is considered a hazardous pollutant. Soil contaminated with petroleum hydrocarbons adversely affects the properties of soil. This paper aim to remove pollutants from the environment is an urgent need of the hour to maintain the proper functioning of soil ecosystems.

The ability of micro-organisms to degrade petroleum hydrocarbons makes it possible to use these microorganisms to clean the environment from petroleum pollution. For preparing this review, research papers and review articles related to petroleum hydrocarbons degradation by micro-organisms were collected from journals and various search engines.

Various physical and chemical methods are used for remediation of petroleum hydrocarbons contaminants. However, these methods have several disadvantages. This paper will discuss a novel understanding of petroleum hydrocarbons degradation and how micro-organisms help in petroleum-contaminated soil restoration. Bioremediation is recognized as the most environment-friendly technique for remediation. The research studies demonstrated that bacterial consortium have high biodegradation rate of petroleum hydrocarbons ranging from 83% to 89%.

Proper management of petroleum hydrocarbons pollutants from the environment is necessary because of their toxicity effects on human and environmental health.

This paper discussed novel mechanisms adopted by bacteria for biodegradation of petroleum hydrocarbons, aerobic and anaerobic biodegradation pathways, genes and enzymes involved in petroleum hydrocarbons biodegradation.

The purpose of this study is to investigate the using of rice husk (RH) which is a green material derived from agricultural waste with the ability to absorb heavy metal. It has been used in wastewater treatment. In this research, a kaolin-based green ceramic water filter (CWF) incorporated with two different additives (RH and zeolite-based RH ash [RHA]) was successfully fabricated.

The weight ratio of kaolin:additive was varied (90:10, 80:20 and 70:30) and fabricated via the slip-casting technique. The green CWFs were dried (60°C for 1 h), followed by sintering (1,200°C).

The green CWF of kaolin:RH with a weight ratio of 70:30 showed the best properties and satisfactory performance with a porous cross-section microstructure, highest porous area (4.58 µm²), good structure, lowest shrinkage (8.00%), highest porosity (45.10%), lowest density (1.79 g cm⁻³), highest water absorption (55.50%) and hardness (241.40 Hv). This green CWF has also achieved good permeability (42.00 L m⁻²h⁻¹) and removal of the textile dye (27.88%). The satisfactory characterization and good textile dye removal performance (75.47%) were also achieved from green CWF with kaolin:zeolite at a weight ratio of 80:20.

This research is focused on green CWF and zeolite at a certain amount with the specific characterization analysis methods.

The use of low-cost waste materials to treat dye wastewater from agricultural by-products/wastes sources in treating the dye will enhance the using of green material.

Avoiding the waste sludge that can pollute the environment can create a health issue. The use of low-cost waste materials to treat dye wastewater from agricultural by-products/wastes sources in treating the dye can avoid the waste sludge that can pollute the environment and create serious health issue.

All the kaolin-based green CWFs incorporated with two different additives (RH and zeolite-based RHA) fabricated using a simple slip-casting technique have shown the potential to be used as a filter in wastewater treatment applications.

This paper aims to study the combination of photochromic microcapsules, which use the ultraviolet (UV) rays for colour changing phenomena, and titanium oxide (TiO₂) nanoparticles (NPs), which block the UV rays by their photocatalytic activity in the sunlight on the cotton fabric.

The TiO₂ NPs mixed with photochromic printing paste are used for coating on cotton fabric and further curing is performed in a one-step process. The photochromic pigment printed fabric impregnated in a liquid solution is processed in a two-step process with two variables such as 1% TiO₂ and 2% TiO₂. The characterization of samples was done with a UV transmittance analyser, surface contact angle, antimicrobial test and fabric physical properties.

The UV protection of TiO₂-treated photochromic printed fabric was high and gives the ultraviolet protection factor rating of 2,000 which denotes almost maximum blocking of UV rays. The antibacterial activity of the one-step samples shows the highest 36 mm zone of inhibition (ZOI) against S. aureus (gram-positive) and 32 mm ZOI against E. coli (gram-negative) bacteria. The one-step sample shows the highest static water contact angle of 118.6° representing more hydrophobicity, whereas the untreated fabric is fully wetted (0.4°). In two-step processes, as the concentration of TiO₂ increased, the antibacterial activity, UV blocking and hydrophobicity became better.

This work achieves the multifunctional finishes by using photochromic microcapsules and NPs in a single process as a first attempt. The results inferred that one-step sample has achieved higher values in most of the tests conducted when compared to all other sample.

This paper introduced the simple synthesis process of self-cleaning coating with fog-resistance property using hydrophobic polydimethylsiloxane (PDMS) polymer and nano-calcium carbonate (nano-CaCO₃) and titanium dioxide (TiO₂).

The synthesis method of PDMS/nano-CaCO₃-TiO₂ is based on sol-gel process. The crosslinking between PDMS and nanoparticles is driven by the covalent bond at temperature of 50°C. The 3-Aminopropyltriethoxysilane is used as binder for nanoparticles attachment in polymer matrix. Two fabrication methods are used, which are dip- and spray-coating methods.

The prepared coated glass fulfilled the requirement of standard self-cleaning and fog-resistance performance. For the self-cleaning test BS EN 1096-5:2016, the coated glasses exhibited the dust haze value around 20%–25% at tilt angle of 10°. For the antifog test, the coated glasses showed the fog haze value were below 2% and the gloss value were above 85%. The obtained results completely achieved the standard antifog value ASTM F659-06 protocol.

Findings will provide an infrastructure support for the building glass to enhance building’s energy efficiency, cleaning performance and friendly environment.

This study proposed the simple synthesis method using hydrophobic polymer and nano-CaCO₃ and nano-TiO₂, which can achieve optimum self-cleaning property at low tilt angle and fog-resistance performance for building glass.

The research findings have high potential for building company, cleaning building company and government sector. The proposed project capable to reduces the energy consumption about 20% per annum due to labor cost, time-consuming and safety during manual cleaning.

The novel method to develop self-cleaning coating with fog-resistance using simple synthesis process and fabrication method for building glass application.

The textile industry is evolving toward nanotechnology, which provides materials with self-cleaning properties. This paper aims to provide a thorough explanation of the green synthesis and mechanism of ZnO nanoparticles, with prospective applications of zinc oxide nanoparticles (ZnO NPs) in self-cleaning textiles.

This review introduces a green mechanism for the synthesis of ZnO NPs using plant extracts, their self-cleaning properties and the mechanisms of physical, chemical and biological self-cleaning actions for textile applications.

ZnO NPs are among the several nanoparticles that are beneficial for self-cleaning textiles because of their exceptional physical and chemical properties, although review publications addressing the use of ZnO NPs in textiles for self-cleaning are uncommon. These results indicate that the plant-synthesized ZnO NPs display excellent biological, physical and chemical self-cleaning properties, the mechanism of which involves photocatalysis, surface roughness and interactions between ZnO NPs and bacterial surfaces.

Nanoformulations of plant-synthesized ZnO have been reviewed to achieve promising self-cleaning textile properties and have not been reviewed earlier.