Every production day in Nigeria, and in other oil producing countries, millions of barrels of produced water is generated. Being very toxic, remediation of the produced water before discharge into environment or re-use is very essential. An eco-friendly and cost effective approach is hereby reported for remediative pre-treatment of produced water (PW) obtained from Nigerian oilfield. In this approach, Telfairia occidentalis stem extract-silver nanoparticles (TOSE-AgNPs) were synthesized, characterized and applied as bio-based adsorbent for treating the PW in situ. The nanoparticles were of average size 42.8 nm ± 5.3 nm, spherical to round shaped and mainly composed of nitrogen and oxygen as major atoms on the surface. Owing to the effect of addition of TOSE-AgNPs, the initially high levels (mg/L) of Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD) and TSS of 607, 3.78 and 48.4 in the PW were reduced to 381, 1.22 and 19.6, respectively, whereas DO and COD improved from 161 and 48.4 to 276 and 19.6 respectively, most of which fell within WHO and US-EPA safe limits. Particularly, the added TOSE-AgNPs efficiently removed Pb (II) ions from the PW at temperatures between 25 ℃ to 50 ℃. Removal of TOSE-AgNPs occurred through the adsorption mechanism and was dependent contact time, temperature and dose of TOSE-AgNPs added. Optimal remediation was achieved with 0.5 g/L TOSE-AgNPs at 30 ℃ after 5 h contact time. Adsorption of Pb (Ⅱ) ions on TOSE-AgNPs was spontaneous and physical in nature with remediation efficiency of over 82% of the Pb (Ⅱ) ions in solution. Instead of discarding the stem of Telfairia occidentalis, it can be extracted and prepared into a new material and applied in the oilfield as reported here for the first time.

In order to explore the influence of the ferroelectric surface on the structure and properties of semiconductor oxides, the growth of CdS nanocrystals was regulated and controlled by taking single-crystal perovskite PbTiO₃ nanosheets as the substrate through a simple hydrothermal method. Through composition design, a series of PbTiO₃-CdS nanocomposite materials with different loading concentrations were prepared, and their microstructure and photocatalytic properties were systematically analyzed. Studies show that in the prepared product, CdS nanoparticles selectively grow on the surfaces of PbTiO₃ nanosheets, and their morphology is affected by the exposed surfaces of PbTiO₃ nanosheets. There is a clear interface between the PbTiO₃ substrate and CdS nanoparticles. The concentration of the initial reactant and the time of hydrothermal reaction also significantly affect the crystal morphology of CdS. Photocatalysis studies have shown that the prepared PbTiO₃-CdS nanocomposite material has a significant degradation effect on 10 mg/L of Rhodamine B aqueous solution. The degradation efficiency rises with the increase of CdS loading concentration. When degrading 10 mg/L Rhodamine B aqueous solution, the PbTiO₃-CdS sample with a mass fraction of 3% can reach a degradation rate of 72% within 120 min.

Solid waste has become a major environmental concern globally in recent years due to the tremendous increase in waste generation. However, these wastes (e.g., plastics and agro-residues) can serve as potential raw materials for the production of value-added products such as composites at low cost. The utilization of these waste materials in the composite industry is a good strategy for maintaining the sustainability of resources with economic and environmental benefits. In this report, the environmental impacts and management strategies of solid waste materials are discussed in detail. The study described the benefits of recycling and reusing solid wastes (i.e., plastic and agro-waste). The report also reviewed the emerging fabrication approaches for natural particulate hybrid nanocomposite materials. The results of this survey reveal that the fabrication techniques employed in manufacturing composite materials could significantly influence the performance of the resulting composite products. Furthermore, some key areas have been identified for further investigation. Therefore, this report is a state-of-the-art review and stands out as a guide for academics and industrialists.

Nowadays, copper and zinc nanoparticles are widely employed in a variety of applications. With nanoscale particle sizes, copper oxide/zinc oxide composite is easily synthesized using a variety of techniques, including hydrothermal, microwave, precipitation, etc. In the current work, chemical precipitation is used to create a copper oxide/zinc oxide nanocomposite. XRD analysis was used to determine the nanocomposite’s structural characteristics. Through SEM analysis, the surface morphological properties are investigated. EDAX is used to study the chemical composition of produced materials, while UV/Visible spectroscopy is used to determine their optical properties. The assessment of the copper oxide/zinc oxide nanocomposite’s degrading property on dyes like methyl red and methyl orange under UV and visible light are the main objectives of the current work.

Alginate-silver nanocomposites in the form of spherical beads and films were prepared using a green approach by using the aqueous extract of Ajwa date seeds. The nanocomposites were fabricated by in situ reduction and gelation by ionotropic crosslinking using calcium ions in solution. The rich phytochemicals of the date seed extract played a dual role as a reducing and stabilizing agent in the synthesis of silver nanoparticles. The formation of silver nanoparticles was studied using UV-Vis absorption spectroscopy, and a distinct surface plasmon resonance peak at 421 nm characteristic of silver nanoparticles confirmed the green synthesis of silver nanoparticles. The morphology of the nanocomposite beads and film was compact, with an even distribution of silver nanoclusters. The catalytic property of the nanocomposite beads was evaluated for the degradation of 2-nitrophenol in the presence of sodium borohydride. The degradation followed pseudo-first-order kinetics with a rate constant of 1.40 × 10⁻³ s⁻¹ at 23 ℃ and an activation energy of 18.45 kJ mol⁻¹. The thermodynamic parameters, such as changes in enthalpy and entropy, were evaluated to be 15.22 kJ mol⁻¹ and −197.50 J mol⁻¹ K⁻¹, respectively. The nanocomposite exhibited properties against three clinically important pathogens (gram-positive and gram-negative bacteria).

Xylene isomers are notorious chemical hazards, and their efficient removal from water solutions is still challenging. The current study reports a polymer nanocomposite as a potential adsorbent for successfully removing dissolved xylene isomers from contaminated water. Polystyrene-1D multiwall carbon nanotube nanocomposite (PS-MWCNT) adsorbent was prepared using the one-step bulk polymerization method. Mesoporous PS-MWCNT was prepared using the nano-crystallization phase separation method. The sulfonation of the mesoporous PS-MWCNT nanocomposites was carried out by treating the samples with concentrated sulfuric acid at elevated temperatures. The sulfonated PS-MWCNT (HO₃S-PS-MWCNT) was found to be a potential adsorbent for dissolved xylene isomers from water solution. In addition, the HO₃S-PS-MWCNT can be efficiently recycled for up to 10 consecutive cycles with negligible decline in adsorption values. The exhibited equilibrium adsorption, rate of adsorption, and rapid regeneration of the HO₃S-PS-MWCNT are clear indications for the possibility of practical utilization of these adsorbents in large-scale water treatment plants.