Membrane fouling, a major challenge in desalination, is addressed in this study by investigating three different chemical cleaning protocols (A, B, and C) targeting fouled reverse osmosis (RO) membranes and microbial community composition. Cleaning protocols A and B involve different chemical treatments selected based on preliminary tests and literature review, while protocol C follows the manufacturer’s standard recommendation. Membrane morphology, foulant composition, and microbial community variability in fouled, virgin, and cleaned membranes are studied. Effective biofilm removal is observed across all protocols using scanning electron microscopy (SEM), while spectroscopic techniques highlight interactions between foulants and membranes. Importantly, a critical gap in understanding how cleaning strategies influence microbial communities on membranes is addressed. Shifts in dominant bacterial phyla (Proteobacteria, Firmicutes, and Actinobacteria) after cleaning are identified through 16S rRNA amplicon sequencing. Cleaning A showed the best results in reducing microbial counts and restoring composition similar to virgin membranes. Additionally, chemical treatment increased dominance of resistant genera such as Staphylococcus, Bacillus, Citrobacter, and Burkholderia. This study emphasizes the necessity for tailored fouling cleaning strategies for RO membranes, with Cleaning A is a promising solution, paving the way for enhanced water purification technologies.

Microbial composition across substrates in mangroves, particularly in the Middle East, remains unclear. This study characterized bacterial communities in sediment, water, Terebralia palustris snail guts, and plastic associated with Avicennia marina mangrove forests in two coastal lagoons in the Sea of Oman using 16S rDNA gene MiSeq sequencing. The genus Vibrio dominated all substrates except water. In the gut of snails, Vibrio is composed of 80–99% of all bacterial genera. The water samples showed a different pattern, with the genus Sunxiuqinia being dominant in both Sawadi (50.80%) and Qurum (49.29%) lagoons. There were significant differences in bacterial communities on different substrata, in particular plastic. Snail guts harbored the highest number of unique Operational Taxonomic Units (OTUs) in both lagoons, accounting for 30.97% OTUs in Sawadi and 28.91% OTUs in Qurum, compared to other substrates. Plastic in the polluted Sawadi lagoon with low salinity harbored distinct genera such as Vibrio, Aestuariibacter, Zunongwangia, and Jeotgalibacillus, which were absent in the Qurum lagoon with higher salinity and lower pollution. Sawadi lagoon exhibited higher species diversity in sediment and plastic substrates, while Qurum lagoon demonstrated lower species diversity. The principal component analysis (PCA) indicates that environmental factors such as salinity, pH, and nutrient levels significantly influence bacterial community composition across substrates. Variations in organic matter and potential anthropogenic influences, particularly from plastics, further shape bacterial communities. This study highlights the complex microbial communities in mangrove ecosystems, emphasizing the importance of considering multiple substrates in mangrove microbial ecology studies. The understanding of microbial dynamics and anthropogenic impacts is crucial for shaping effective conservation and management strategies in mangrove ecosystems, particularly in the face of environmental changes.

The development of durable photocatalytic supports resistant in harsh environment has become challenging in advanced oxidation processes (AOPs) focusing on water and wastewater remediation. In this study, stainless steel (SS), SS/Ti (N,O) and SS/Cr-N/Cr (N,O) anticorrosion layers on SS meshes were dip-coated with sol gel synthesised C-N-TiO₂ photo catalysts pyrolysed at 350 °C for 105 min, using a heating rate of 50 °C/min under N₂ gas. The supported C-N-TiO₂ films were characterised by scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy. The results showed that C-N-TiO₂ was successfully deposited on anticorrosion coated SS supports and had different morphologies. The amorphous C and TiO₂ were predominant in C-N-TiO₂ over anatase and rutile phases on the surface of SS and anticorrosion supports. The C-N-TiO₂ coated films showed enhanced photocatalytic activity for the decolouration of O.II dye under both solar and UV radiations. The fabricated C-N-TiO₂ films showed significant antibacterial activities in the dark as well as in visible light. Herein, we demonstrate that SS/Ti(N,O) and SS/Cr-N/Cr(N,O) anticorrosion coatings are adequate photocatalytic and corrosion resistant supports. The C-N-TiO₂ photo catalytic coatings can be used for water and wastewater decontamination of pollutants and microbes.

Microbial composition across substrates in mangroves, particularly in the Middle East, remains unclear. This study characterized bacterial communities in sediment, water, Terebralia palustris snail guts, and plastic associated with Avicennia marina mangrove forests in two coastal lagoons in the Sea of Oman using 16S rDNA gene MiSeq sequencing. The genus Vibrio dominated all substrates except water, which featured unique genera Sunxiuqinia and Pseudomonas. There were significant differences in bacterial communities on different substrata, in particular plastic. Snail guts harbored the highest number of unique Operational Taxonomic Units (OTUs) in both lagoons. Plastic in the polluted Sawadi lagoon with low salinity harbored distinct genera like Vibrio, Aestuariibacter, Zunongwangia, and Jeotgalibacillus absent in Qurum lagoon with higher salinity and low pollution. Sawadi lagoon exhibited higher species diversity in sediment and plastic substrates, Qurum lagoon demonstrated lower overall species diversity. The PCA indicates that environmental factors like salinity, pH, and nutrient levels significantly influence bacterial community composition across substrates. Variations in organic matter and potential anthropogenic influences, particularly from plastics, further shape bacterial communities. This study highlights the complex microbial communities in mangrove ecosystems, emphasizing the importance of considering multiple substrates in mangrove microbial ecology studies.

Bio-based materials facilitate greener approach to engineering novel materials with multifunctional properties for various applications including water treatment. In this study, we extracted gliadin from wheat gluten using alcoholic solvent. The aggregation limitations of gliadin protein were overcome by functionalisation with metal oxides (MOs) TiO₂, AgFe₂O₃ and AgFe-TiO₂ prepared by chemical precipitations. The novel composites were characterised by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), thermogravimetry analysis (TGA), Brunauer Emmet-Teller (BET), and zeta potential. The multifunctionality of MOs-gliadin composites was tested through toxic Escherichia coli (E. coli) inactivation and Co²⁺ adsorption from water. The antibacterial results showed excellent inhibition under both dark and light conditions. The maximum Co²⁺ uptake, 101 mg/g was reached with TiO₂@gliadin after 24 h and best fitted the Langmuir isotherm model. The adsorption process followed pseudo-second order model with an equilibrium adsorption capacity, q_e2= 89.86 mg/g closer to the experimental data. Thermodynamic investigations indicated that ΔG^°=-9.677kJ/mol,ΔH°=-123kJ/mol,and ΔS°=0.490J.K/mol, respectively, suggesting that adsorption was spontaneous and endothermic. The regenerated TiO₂@gliadin composite was still efficient after five consecutive cycles. This study demonstrates that MOs-gliadin blended composites are sustainable for water purification.