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Solar-driven photocatalytic approach is an attractive, clean, and effective way for decontamination of water. In this work, visible-light-activated TiO 2 nanoflakes (TNFs) and carbondoped TiO 2 nanoflakes (C-TNFs) were synthesized via a facile hydrothermal route using different carbon sources. The assynthesized nanostructures were successfully characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM), critically disclosing the anatase nature containing titanium−oxygen having flake/plateletlike morphology with ∼32 nm in size, respectively. The photocatalytic activity was characterized via the degradation of methylene blue (MB) and bacterial inactivation of Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The experimental results showed that C-TNFs significantly enhanced photocatalytic activity compared to bare TNFs. It was found that TNF nanocatalysts exhibited superior photocatalytic activity against photodegradation of MB (92.7%) and antibacterial activity (85.6%) under sunlight irradiation. In addition, reduced graphene oxide (RGO)-TNFs have a good recycling ability and are expected to be a promising candidate for photocatalytic applications under sunlight. Consequentially, the higher activity of RGO-TNF nanocatalysts under sunlight irradiation for organic degradation and bacterial inactivation implies that hydrothermal synthesis allows for the preparation of efficient and low-cost carbon-doped photocatalysts for the photodegradation of a wide range of environmental pollutants.

This study is based on an environmental assessment of acetylsalicylic acid and naproxen in waste and tap water samples of twenty different locations of municipal area of Sukkur city, Sindh, Pakistan. Both drugs belong to the most frequently used Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) group. The specified pharmaceuticals were extracted from the wastewater and tap water samples by Solid Phase Extraction (SPE) method using Waters Oasis hydrophilic lipophilic balance (HLB) cartridges. Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) technique was applied for the detection and quantification of selected drugs. Negative Electron Spray Ionization (ESI) was used along with Multi Reaction Monitoring (MRM) mode. Pharmaceuticals concentration were found 7.38-827 µg/L and 5.47-328.95 µg/L in waste and tap water samples, respectively. The results obtained are comparable with the data reported in literature. Human health risk assessment caused by acetylsalicylic acid and naproxen in aquatic media was observed by applying Risk Quotient (RQ) approach. The calculated RQ values are low enough (order of 10-3 to 10-5) to cause a direct risk for consumers, but their presence in water may pose a danger synergistically.

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In the present study, jamun seed waste has been explored for the removal of Pb(II) ions from aqueous solution. The multi-variant sorption optimization was achieved by the factorial design approach. 99.91% of Pb(II) ions was removed from aqueous solution. The results predicted by the model were in good agreement with the experimental results (the values of R 2 and R 2 adj . were found to be 99.89% and 99.95%, respectively). Langmuir and D-R isotherm studies were carried out to fi nd adsorbent's capacities (183.9 ± 0.31 mg/g and 184.5 ± 0.16 mg/g respectively), sorption free energy 13.17 ± 0.16 and RL values in the range of 0.05-0.77, suggested the favorable chemical and/or ion exchange nature of the sorption process. The FT-IR study was carried out for unloaded and Pb(II) ions loaded jamun seed, indicated, Pb(II) ions associated with nitrogen and oxygen of jamun seed containing moieties during the adsorption process. The proposed method was successfully validated and applied for the treatment of Pb(II) ions contaminating drinking water.