The present study investigates the efficiency of adsorption and photodegradation catalyzed by TiO2, ZnO, CdS and Co3O4 on the removal of methylene blue dye, in different pH values (4, 6, 9 and 11). The photocatalytic degradation of methylene blue dye in aqueous catalysts TiO2, ZnO, CdS and Co3O4 suspension follows apparent after 0.5 h of photodegradation a first-order kinetics. The photodegradation efficiency of methylene blue was fast in the present condition (pH 11, pH 6, pH 6 and pH 4) and slower in (pH 4, pH 11, pH 11 and pH 11) of ZnO, TiO2, CdS and Co3O4, respectively. The highest adsorption capacity as follow: TiO2 > ZnO ≈ CdS ≈ Co3O4, while the photocatalytic activity: ZnO > TiO2 > CdS > Co3O4.

Polycyclic aromatic hydrocarbons (PAHs) represent a large class of persistent organic pollutants in an environment of special concern because they have carcinogenic and mutagenic activity. In this paper, we focus on and discuss the effect of different parameters, for instance, initial concentration of Anthracene, temperature, and light intensity, on the degradation rate. These parameters were adjusted at pH 6.8 in the presence of the semiconductor materials (TiO2) as photocatalysts over UV light. The main product of Anthracene photodegradation is 9,10-Anthraquinone which isidentified and compared with the standard compound by GC-MS. Our results indicate that the optimum conditions for the best rate of degradation are 25 ppm concentration of Anthracene, regulating the reaction vessel at 308.15 K and 2.5 mW/cm2of light intensity at 175 mg/100 mL of titanium dioxide (P25).

Poly(vinyl chloride) suffers from degradation through oxidation and decomposition when exposed to radiation and high temperatures. Stabilizers are added to polymeric materials to inhibit their degradation and enable their use for a longer duration in harsh environments. The design of new additives to stabilize poly(vinyl chloride) is therefore desirable. The current study includes the synthesis of new tin complexes of 4-methoxybenzoic acid and investigates their potential as photostabilizers for poly(vinyl chloride). The reaction of 4-methoxybenzoic acid and substituted tin chlorides gave the corresponding substituted tin complexes in good yields. The structures of the complexes were confirmed using analytical and spectroscopic methods. Poly(vinyl chloride) was doped with a small quantity (0.5%) of the tin complexes and homogenous thin films were made. The effects of the additives on the stability of the polymeric material on irradiation with ultraviolet light were assessed using different methods. Weight loss, production of small polymeric fragments, and drops in molecular weight were lower in the presence of the additives. The surface of poly(vinyl chloride), after irradiation, showed less damage in the films containing additives. The additives, in particular those containing aromatic (phenyl groups) substitutes, inhibited the photodegradation of polymeric films significantly. Such additives act as efficient ultraviolet absorbers, peroxide quenchers, and hydrogen chloride scavengers.

There is an urgent need for the design and development of new and safer drugs for the treatment of HIV infection, active against the currently resistant viral strains. New derivatives of the non-steroidal anti-inflammatory drug indomethacin bearing benzimidazoles, benzothiazole, purine and pyridine residues 8 -13 were synthesized with the aim of developing new non-nucleoside reverse transcriptase inhibitors (NNRTIs). Alternatively, new imine analogs 16 -20 were synthesized from condensation of indomethacinyl hydrazide 15, prepared from the ester 14, with various ketone precursors. Treatment of 15 with phenyl isothiocyanate or triethyl orthoformate afforded the phenylcarbonothioyl and the oxadiazole derivatives 21 and 22, respectively. The new compounds were assayed against HIV-1 and HIV-2 in MT-4 cells. Compounds 9 and 10 were the most active in inhibiting HIV-2 and HIV-1, respectively, with EC 50 ≥ 17.60 µg mL −1 and > 1.15 µg mL −1 (therapeutic indexes (SI) of ≥ 3 and < 1, respectively), and are leading candidates for further development.

Structural modification of these compounds might optimize their anti-HCV activity by introducing diverse and potent functional groups at the pyrimidine backbone, like nitrile residue. Because of the nature of the molecules, these new derivatives will also be evaluated for their potential anti-HIV activity.

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Polycyclic aromatic hydrocarbons (PAHs) refer to hydrocarbons containing two or more fused aromatic rings. All PAHs compounds are neutral and non-polar and they have high stability. All of them having high melting points and low vapor pressures and water solubility. Generally, the solubility and volatility of PAHs compounds are decrease and hydrophobicity increase with an increase in the number of fused aromatic rings 1. Fires and agriculture fires, fossil fuels burning, metalprocessing facilities, coke oven and internal burning engines in motor vehicles 2 can produce these compounds. The delocalization of π electron made these compounds exhibit high stability and low water solubility, leading to their accumulation in food chains 3. US Environmental Protection Agency (EPA), US Food and Drug Administration (FDA), National Oceanic Atmospheric Administration (NOAA) and the European Union Priority pollutants are listed PAHs as pollutant because of their mutagenic and carcinogenic properties 4-6. The procedures of enrichment and clean up are usually required prior determination of PAHs. There are several reports mention the application of solid phase extraction on the pre concentration of PAHs