Photoperoxidation of ciprofloxacin antibiotic in aqueous medium using Fe3-XO4-Y-TiO2 particles as catalyst

Conventional treatment processes are not effective in removing micropollutants such as antibiotics and other drugs present in wastewater, and degradation methods based on advanced oxidative processes become attractive. Herein, it was synthesized Fe3-xO4-y-TiO2 particles by coprecipitation method and they were heat-treated at 100, 400, and 800 �C. The obtained solids were characterized by X-ray diffraction and thermogravimetric analysis and analytical determinations were performed using ultraviolet-visible (UV-Vis) spectrophotometry. The particles were evaluated in photoperoxidation processes on the degradation of the ciprofloxacin antimicrobial in an aqueous solution. The studies took place at pH 9; with an H2O2 concentration of 31 mg L�1 and particle mass 0.22 g L�1 previously defined and, in these conditions, degradation percentages between 40 and 85% were observed, with the removal in the Photo/H2O2/Fe3-xO4-y-TiO2 800 �C. The kinetic study performed for this process revealed the process adjusts to the first-order kinetics during the 120 min of reaction. The use of the catalyst can be attractive with the potential for degradation of the studied antimicrobial.

Studies on Wear Behaviour of Coated RHA-TIO2-LM24 Aluminium Alloy Composite

Liquid metallurgy method based aluminium matrix composites (AMCs) are extensively utilized in diverse engineering applications including shipbuilding, structural, non-structural, automotive, and aerospace owing to their superior strength, weightless, low density, excellent corrosion, and wear resistance. In the present research work, liquid state technique is employed to prepare the LM4/RHA/TiO2 composites containing four different mass proportion of RHA and TiO2. The weight proportion of reinforcements ie RHA-1,3&5 and TiO2 2,5&6 respectively.From the dry sliding wear studies, it is evident that the incorporation of RHA and TiO2 particles into the LM24 aluminium matrix alloy increases the wear resistance properties up to 45% as compared with the dry sliding behaviour of pure aluminium LM4 alloy. Dry sliding wear results revealed that the parameters like varying weight percentage, sliding speed, and applied load are the direct impact on the wear behaviour of the hybrid composites. A reduction of up to 34 % wear rate was observed by incorporation of 5% of RHA and 1% & 6 %of TiO2 particles as compared with the remaining percentage of reinforcements. The developed Coated RHA-TIO2 -LM24 aluminum alloy composite exhibits excellent mechanical properties, can be used in long-term applications in which saving weight is an important feature, such applications include and automotive engine parts and aerospace industry. In automotive industry, it can be used for making Brake disc, Turbo-compressors, Pump supporting parts, rear axle, differential housing.

Behaviour of Titanium Dioxide Particles in Artificial Body Fluids and Human Blood Plasma

The growing application of materials containing TiO2 particles has led to an increased risk of human exposure, while a gap in knowledge about the possible adverse effects of TiO2 still exists. In this work, TiO2 particles of rutile, anatase, and their commercial mixture were exposed to various environments, including simulated gastric fluids and human blood plasma (both representing in vivo conditions), and media used in in vitro experiments. Simulated body fluids of different compositions, ionic strengths, and pH were used, and the impact of the absence or presence of chosen enzymes was investigated. The physicochemical properties and agglomeration of TiO2 in these media were determined. The time dependent agglomeration of TiO2 related to the type of TiO2, and mainly to the type and composition of the environment that was observed. The presence of enzymes either prevented or promoted TiO2 agglomeration. TiO2 was also observed to exhibit concentration-dependent cytotoxicity. This knowledge about TiO2 behavior in all the abovementioned environments is critical when TiO2 safety is considered, especially with respect to the significant impact of the presence of proteins and size-related cytotoxicity.

Isolation, Characterization and Quantitation of Photoactive phases of Titanium (IV) oxide in skin-lightening products

Titanium (IV) oxide (TiO2) is used as a physical blocker of ultraviolet (UV) radiation in many skin-care products. Absorption of TiO2 through the skin is likely to interact with viable tissues because UV radiation absorption generates toxic reactive oxygen species such as hydroxyl radicals. Studies on the acute toxicity of TiO2 nanoparticles in mammals indicate that intra-tracheal instillation, intraperitoneal injection or oral instillation of TiO2 particles to the animals evoke an inflammatory response as well as certain histopathological changes. Ultrafine particles of the anatase form of titanium (IV) oxide, which are smaller than 0.1 microns, are pathogenic. In this work eight skin-lighteners containing TiO2 from South African market were studied. The TiO2 was extracted by a fusion technique and quantified by inductively coupled plasma-optical emission spectrometry (ICP-OES). Sequential solvent extraction was employed to isolate TiO2 particles for characterization employing high-resolution transmission electron microscopy (HR-TEM) and powder X-ray diffraction (PXRD). All samples considered in this study meet agreeable TiO2 % (m/m) levels as specified by all health regulatory bodies. Both forms of TiO2: anatase and rutile, were found to be present. Most samples contained nano-TiO2 in the particle size range of 16.23 nm to 51.47 nm that could lead to detrimental effects. The fact that the anatase form, known for its photocatalytic activity, was present, is a cause for concern.