A continuous two-phase partitioning bioreactor (C-TPPB), operated with coiled tubing made of the DuPont polymer Hytrel 8206, was tested for the bioremediation of 4-chlorophenol, as a model toxic compound. The tubing was immersed in the aqueous phase, with the contaminated water flowing tube-side, and an adapted microbial culture suspended in the bioreactor itself, with the metabolic demand of t...

This study compared the antimicrobial effectiveness of nine dental materials and a negative control agent against 21 strains or species of bacteria using an agar diffusion assay. The materials were: 1. Camphorated parachlorophenol mixed with calcium hydroxide (CPC + Ca(OH)2). 2. CPC mixed with zinc oxide (CPC + ZnO). 3. Formocresol mixed with zinc oxide and eugenol (FC + ZOE). 4. Chlorhexidine ...

The primary tooth pulpectomy is a common clinical procedure. The choice of filling material is important to the success rate, but antibacterial properties of such materials against organisms known to inhabit infected primary root canals have not been well documented. This study compared the antibacterial effectiveness of 10 materials: 1. Calcium hydroxide mixed with camphorated parachlorophenol...

Wet oxidation of phenol, 2-chlorophenol, 4-chlorophenol and 2-nitrophenol over iron oxide and manganese dioxide catalysts was tested in this work with or without hydrogen peroxide in the reaction mixture. Influence of factors such as catalyst load, reactant-hydrogen peroxide mole ratio, and reaction time was monitored for all the phenols. Increase in the amount of hydrogen peroxide in the feed ...

A new heterogeneous photocatalyst was prepared by incorporation of methylene blue into ZSM-5 zeolite. This photocatalyst effectively absorbs light in visible range of the spectrum and when irradiated with visible light, it generates reactive oxygen species (ROS) in aqueous environment. Efficiency of the photocatalyst was tested on dechlorination of a model compound 4-chlorophenol and on growth ...

Electrochemical oxidation has been proposed as a remediation method for chlorinated phenols but is hampered by anode fouling. In this work we explore the mechanism of anode fouling by chlorinated phenols, compare structure vs reactivity for phenols differing in the extent of chlorination, and relate the efficiency of oxidation to the mechanism of oxidation at different electrode types. Linear s...

Five different activated carbons (ACs) have been prepared from dried date pits using air and phosphoric acid as activating agents. The used phosphoric acid:date pit ratio dictated the characteristics of the prepared ACs; the equivalent BET-nitrogen surface area varied from 794 m²/g for a ratio of 5:1, to 1707 m²/g for a ratio of 2:1, whereas the micropore volume changed in value from 0.24 cm³/g...

An experimental study on 4-chlorophenol (4-CP) degradation in aqueous solutions by advanced oxidation process photo-Fenton type is presented. The efficiency of the oxidation process is determined by the very high oxidative potential of the OH. radicals generated by catalytic and photo-catalytic processes. The presence of the inorganic species inside the reaction medium influences the rate of th...

The effectiveness of a novel nickel-antimony doped tin oxide electrode for electrochemical degradation of organic pollutants was investigated using 4-chlorophenol (4-CP) as a model toxic organic. The experimental results demonstrate that the optimal Ni content was at Ni:Sn=1:500 in atomic ratio in the precursor coating solution, whereas the Sb:Sn ratio was set at 8:500. Using the electrode prep...

Screen printed carbon electrode (SPCE) has been modified with single wall carbon nanotube/poly(3,4-ethylenedioxythiophene) (SWCNT/PEDOT) composites for the determination of phenol and chlorophenols (phenol, 4-chlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol). The effect of the modifiers on the electrode characteristics was evaluated and the responses were optimized for the voltammetr...