The pH of zero net surface charge (pHpzc) of the a-TiO2 (1 1 0) surface was characterized using second-harmonic generation (SHG) spectroscopy. The SHG response was monitored during a series of pH titrations conducted at three NaNO3 concentrations. The measured pHpzc is compared with a pHpzc value calculated using the revised MUltiSIte Complexation (MUSIC) model of surface oxygen protonation. MU...

The specific adsorption of citric acid ions at hydroxyapatite interface was investigated by the means of radioisotope method (14C) as a function of citric acid ions concentration, NaCl concentration and pH. Application of the hydroxyapatite has become wide in the biomaterial field as the Ca10(OH)2(PO4)6 possess biocompatibility with human hard tissue. Hydroxyapatite was synthesized using three ...

The aim of the work was to investigate the changes in the double electrical layer at the hydroxyapatite containing different amount of carbonate ions/electrolyte solution. Besides, the main properties of the edl (electrical double layer), i.e. surface charge density and zeta potential were determined by electrophoresis measurements and potentiometer titration, respectively. The synthesized adso...

−− Benzothiazoles are organic compounds that may produce negative environmental impact when released into watercourses. In particular, 2mercaptobenzothiazole (MBT) are known to be toxic and hard to biodegrade. Activated carbon adsorption and ozonation have been identified as suitable treatment for those contaminants. However, there is some controversy about the effect of carbon surface chemical...

This study examines zinc(II)–chitosan complexes as a bio-sorbent for phosphate removal from aqueous solutions. The bio-sorbent is prepared and is characterized via Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and Point of Zero Charge (pHPZC)–drift method. The adsorption capacity of zinc(II)–chitosan bio-sorbent is compared with those of chitosan and ZnO–c...

Removal of the widespread used drug paracetamol from water was investigated using activated carbon originated from dende coconut mesocarp and babassu coconut mesocarp. Kinetic and equilibrium data were obtained at different values of pH. Both activated carbons showed high efficiency when pH ≤ pHPZC as the carbonil group of paracetamol molecule are adsorbed due to positively charged carbon surfa...

soil colloid particles influence soil chemical and physical properties by their surface electrical charge. with respect to the importance of this issue from both agricultural and environmental points of view, charging behavior of a kaolinite sample was studied in the ph range of 4 to 10 and at three background electrolyte concentrations, including 0.005, 0.05, 0.5 m nacl, by potentiometric titr...

The chemical surface of Santa Barbara Amorphous-15 (SBA-15) was functionalized with polyaniline (SBA-15/PA) and prepared using aniline ammonium persulfate as the modifying agent oxidant. samples were characterized by N2 physical adsorption at 77 K. SBA-15′s area 654.5 m2 g−1, changing to 254.6 g−1. total acidity basicity determined a modified Boehm’s method, point zero charge pH (pHpzc) determi...

The properties of hydroxyapatite (HAp) obtained from tilapia (Oreochromis niloticus) bones and its potential use as a dye adsorbent using methyl orange (MO) model were evaluated. HAp was produced by the calcination dried at 900 °C for 4 h. Then, characterized thermogravimetric (TGA) differential (dTG) analyses, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron mic...

This work shows the influence of specific surface area (BET) and surface pH of different activated carbons on the photocatalytic activity of UV-irradiated TiO2 in the 4-chlorophenol (4CP) photodegradation. Carbons were prepared from sawdust of Tabebuia Pentaphyla wood by physical activation with CO2 and by pyrolysis under N2 flow at temperatures from 450 up to 1000oC during 1h Chemical activati...