Photocatalytic degradation of hydrocarbons and methylene blue using floatable titanium dioxide catalysts in contaminated water

Photocatalytic disintegration is a novel approach to eliminate pollution. The method utilizes the semiconductor titanium dioxide to degrade organic molecules in the presence of ultraviolet (UV) light. In this study, it is shown how the capabilities of several types of catalyst designs degrade the non-polar substance diesel fuel and the polar substance methylene blue. The floating design of foam glass coated with titanium dioxide could reduce the concentration of diesel fuel by 329 mg/L in 16 h; the submerged designs for coated glass fiber and coated steel grit could reduce methylene blue concentration by 96.6% after 4 h and 99.1% after 6 h, respectively. It could be shown that photocatalysis is a promising cost- and energy-efficient method for managing air and water pollution. It can be established as a low-technology method without requiring the use of a conventional source of energy, given an adequate amount of sun hours, or as an additional cleaning stage in water treatment plants using UV-LEDs.

Modeling Wettability Variation during Long-Term Water Flooding

Surface property of rock affects oil recovery during water flooding. Oil-wet polar substances adsorbed on the surface of the rock will gradually be desorbed during water flooding, and original reservoir wettability will change towards water-wet, and the change will reduce the residual oil saturation and improve the oil displacement efficiency. However there is a lack of an accurate description of wettability alternation model during long-term water flooding and it will lead to difficulties in history match and unreliable forecasts using reservoir simulators. This paper summarizes the mechanism of wettability variation and characterizes the adsorption of polar substance during long-term water flooding from injecting water or aquifer and relates the residual oil saturation and relative permeability to the polar substance adsorbed on clay and pore volumes of flooding water. A mathematical model is presented to simulate the long-term water flooding and the model is validated with experimental results. The simulation results of long-term water flooding are also discussed.

Homogeneous Nucleation of Supersaturated Vapors. A Comparison of Experimental Results with Theory

Some theories of homogeneous nucleation based on liquid droplet model were tested by comparing with experimental supersaturations of naphthalene, phthalic anhydride, stearic acid, bis(2-ethylhexyl) phthalate, and bis(2-ethylhexyl) sebacate required to bring about the rate of homogeneous nucleation of about 5 drops/cm3 s-1. It was found that except for highly polar substance phthalic anhydride, the classical (Becker-Doring) theory of homogeneous nucleation, if suitably scaled, yielded fairly good predictions of the nucleation behaviour.

Butadiene and Its Polymers. V. Formation of Spongy Butadiene Polymer

1. It is shown that the formation of spongy butadiene polymer is accelerated by the addition to the butadiene of most metals and certain crystalline substances. This spongy polymer is not formed on lead or copper. 2. It is shown that the formation of spongy polymer on iron takes place at practically any polymerization temperature. 3. It is proved that in the absence, both in the butadiene and in the apparatus, of oxygen and peroxides, no spongy polymer is formed, and also that peroxides accelerate the formation of spongy polymer. 4. It is proved that the activation of the formation of spongy polymer by iron is of an adsorptive nature, and the formation of spongy polymer on iron can prevent the formation of a unimolecular layer of a polar substance on the surface of the iron. 5. An outline scheme of the process of thermopolymerization of butadiene is given, with experimental data on the formation of its cyclic dimer, of a rubber-like polymer, and of the spongy polymer.