The objective of this study was to utilize agro-lignocellulosic wastes for growing oyster mushroom which become problematic for disposal. Pleurotus ostreatus was cultivated on five agro-industrial wastes: rice straw (RS), wheat straw (WS), corncobs (CC), saw dust and rice husk @ 3:1 (SR) and sugarcane bagasse (SB). Approximately 500 g sized polypropylene bags (20.32 × 30.48 cm) were used for each substrate. The SR significantly improved the number of fruiting body (27.80), size of the fruiting body (5.39 g), yield (115.13 g/packet), ash and shortened the days for stimulation to primordial initiation and harvest (9.2 days). The maximum percentage of visual mycelium growth with the least time (15.0 days) to complete the mycelium running was found in SB, whereas the highest biological efficiency value (56.5) was calculated in SR. The topmost value of total sugar (33.20%) and ash (10.87 g/100 g) were recorded in WS, whereas the utmost amount of protein (6.87 mg/100 g) and total polyphenolics (196.88 mg GAE/100 g) were detected from SB and SR, respectively. Overall SR gave the highest amount of the fruiting body with the topmost polyphenols and ash, moderate protein and total sugar, and secured maximum biological efficiency too. The results demonstrate that saw dust with rice husk could be used as an easy alternative substrate for oyster mushroom cultivation.

Red Sea coastal development has rapidly accelerated in recent decades that has led to a rise in the anthropogenic heavy metal levels in sediments. A total of 80 surficial sediment samples were collected from the shallow waters along the eastern Red Sea coast near Jeddah, Saudi Arabia. These samples were collected from three locations, designated as North, Middle and South of Jeddah, to assess the concentrations of six heavy metals: chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb). The results showed that the concentrations (mg/kg) of these metals in the studied sediments follow this order: Pb (77.34 ± 150.59) > Mn (36.52 ± 37.72) > Zn (18.02 ± 23.94) > Cr (9.56 ± 5.81) > Cu (9.18 ± 13.67) > Ni (3.68 ± 4.54). The majority of the polluted sediments were recorded in the Middle and South locations. Pollution and enrichment indices such as Geo-accumulation indices (Igeo), Enrichment Factors (E_f), Contamination Factors (C_f), Pollution Load Indices (PLI), Potential Ecological Risk Indices (PERI) and Potential Toxicity Response Indices (RI) were calculated from the measured metals to establish baselines for the region and assess specific metal enrichments by location along the Jeddah coastline. The Igeo values showed that 30% of the Southern location stations are considered moderately to highly polluted. The Ef for all the studied sediments followed this order: Pb (extremely severe enrichment) > Zn > Cu > Cd > Cr (severe enrichment) > Ni (moderate enrichment).

Integrated wastewater treatment processes are needed due to the inefficient removal of emerging pharmaceuticals by single methods. Herein, an adsorbent-photocatalyst integrated material was fabricated by coupling calcium alginate with sulfur-doped TiO₂/tungsten disulfide (S-TiO₂/WS₂/alginate beads) for the removal of oxytetracycline (OTC) from aqueous solution by an integrated adsorption-photocatalysis process. The semiconductor S-TiO₂/WS₂ hybrid photocatalyst was synthesized with a hydrothermal method, while the integrated adsorbent-photocatalyst S-TiO₂/WS₂/alginate beads were synthesized by blending S-TiO₂/WS₂ with sodium alginate using calcium chloride as a precipitating agent. The physicochemical characteristics of S-TiO₂/WS₂/alginate beads were analyzed using X-ray diffraction , scanning electron microscopy, elemental mapping, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The integrated adsorption-photocatalysis process showed enhanced removal from 92.5 to 72%, with a rise in the OTC concentration from 10 to 75 mg/L respectively. The results demonstrated that the adsorption of OTC onto S-TiO₂/WS₂/alginate beads followed the Elovich kinetic model and Redlich–Peterson isotherm models. The formations of H-bonds, cation bridge bonding, and n-π electron donor-acceptor forces were involved in the adsorption of OCT onto S-TiO₂/WS₂/alginate beads. In the integrated adsorption-photocatalysis, surface-adsorbed OTC molecules were readily decomposed by the photogenerated active radical species (h⁺, O₂^•−, and HO^•). The persulfate addition to the OTC solution further increased the photocatalysis efficacy due to the formation of additional oxidizing species (SO₄^•⁻, SO₄⁻). Moreover, S-TiO₂/WS₂/alginate beads showed favorable efficiency and sustainability in OTC removal, approaching 78.6% after five cycles. This integrated adsorption-photocatalysis process offered significant insight into improving efficiency and reusability in water treatment.

The ubiquitous presence of pharmaceutical drugs and microbes in the water is leading to the development of drug resistant microbes. Therefore, efficient materials that can remove or inactivate the drug and microbe contaminants are required. In this work, nickel sulfide/calcium alginate (Ni₃S₄/CA), silver sulfide/calcium alginate (Ag₂S/CA), modified titanium dioxide/calcium alginate (TiO₂/CA), and Ni₃S₄/Ag₂S/TiO₂/calcium alginate (Ni₃S₄/Ag₂S/TiO₂/CA) aerogels have been synthesized for the removal of the oxytetracycline (OTC) drug and microbial contaminants from real beverage industry wastewater. The results revealed that Ni₃S₄/Ag₂S/TiO₂/CA aerogel is highly efficient for OTC adsorption and inactivation of microbes compared to Ni₃S₄/CA, Ag₂S/CA and TiO₂/CA aerogels. The OTC adsorption depends greatly on the solution pH, and optimum OTC removal was observed at pH 6 in its zwitterionic (OTC^±) form. The formation of H-bonding and n-π electron donor-acceptors is possible to a considerable extent due to the presence of the double bond benzene ring, oxygen and nitrogen, sulfur-containing functional groups on the OTC molecules, and the Ni₃S₄/Ag₂S/TiO₂/CA aerogel. Based on the statistical analysis, root-mean-square deviation (RMSD), chi square (χ²) values, and higher correlation coefficient (R²) values, the Redlich–Peterson isotherm model and Elovich kinetic model are most suited to modelling the OTC adsorption onto Ni₃S₄/Ag₂S/TiO₂/CA. The prepared aerogels’ excellent antimicrobial activity is observed in the dark and with solar light irradiation. The zone of inhibition analysis revealed that the antimicrobial activity of the aerogels is in the following order: Ni₃S₄/Ag₂S/TiO₂/CA > TiO₂/CA > Ag₂S/CA > Ni₃S₄/CA, respectively. Moreover, the antimicrobial results demonstrated that reactive oxygen species, electrons, and active radical species are responsible for growth inhibition and killing of the microbes. These results indicated that Ni₃S₄/Ag₂S/TiO₂/CA aerogel is highly efficient in decontaminating pollutants from wastewater.

Advanced photocatalysts that can utilize solar energy for water purification applications are always needed. The present article reports a facile fabrication of tungsten oxide (WO₃)/bismuth oxychloride (BiOCl) immobilized on polyaniline (PAn) (BiOCl/WO₃@PAn) heterojunction nanocomposite photocatalyst. The designed nanocatalyst was tested for 2-chlorophenol (2-CP) decontamination from the aquatic system. Synthesized WO₃, BiOCl, and BiOCl/WO₃@PAn nanocomposites were distinguished via UV-DSR, photoluminescence, SEM, TEM, XRD, and XPS analysis. The combination of PAn with WO₃ and BiOCl showed a synergistic impact on the photocatalytic efficiency of the BiOCl/WO₃@PAn nanocomposite. The synthesized BiOCl/WO₃@PAn nanocomposite showed higher visible light absorption behavior and bandgap energy reduction than the WO₃ and BiOCl. The obtained data shows that 2-CP photocatalysis by the BiOCl/WO₃@PAn is controlled by degradation time, pH, and pollutant amount in the solution. The highest photocatalytic degradation of 2-CP (99.7%) was recorded at pH 5 and 25 mg/L concentration within 240 min. The photocatalysis mechanism and active radical scavenging study discovered that ^•O₂⁻ and ^•OH, were responsible for the 2-CP mineralization onto the BiOCl/WO₃@PAn nanocomposite. The BiOCl/WO₃@PAn nanocomposite showed enhanced decontamination properties over pristine catalysts. The reusability of the synthesized BiOCl/WO₃@PAn nanocomposite was evaluated. It found that the photocatalyst could be recycled for up to four cycles for 2-CP degradation without significantly losing the photocatalytic properties. The fabricated BiOCl/WO₃@PAn nanocomposite catalyst presented exceptional catalytic and recycling properties, indicating an effective method for scavenging hazardous organic contaminants under solar irradiation and green technology for wastewater purification.