Granular activated carbon: Importance of surface properties in the adsorption of naturally occurring organics

Fluorescence spectroscopic characterization of DOM fractions isolated from a filtered river water after ozonation and catalytic ozonation

“…The density of surface hydroxyl groups on the catalysts in water was measured according to a saturated deprotonation method (Laiti et al, 1995). The pH zpc (pH of zero point of surface charge) was measured with a powder addition method (Newcombe et al, 1993). Another method proposed by Stumm (1992) was also employed to measure the pH zpc for the purpose of comparison.…”

Adsorption of Pb(II) from Aqueous Solution on Oxidized Activated Carbon Fibers

“…The pH of the point of zero charge (pHpzc) for ACFs was determined by pH drift method [7]. The mixture of 25 mL of NaCl solution (0.1 mol/L) and 0.1 g ACF at different initial solution pH was agitated at 100 rpm for 24 hours at 298 K. The initial pH of NaCl solution was adjusted between pH 2 and 12 by adding 0.1 mol/L HCl or NaOH.…”

“…In general, heavy metals such as lead, cadmium and nickel in aqueous solution are positively charged, hence it becomes difficult for ACFs to adsorb heavy metals owing to the repulsion between the positivelycharged surface and heavy metals when solution pH is below pHpzc. In contrast, heavy metals tend to be adsorbed due to the electrostatic attraction by the surface negatively charged [3,7,15].…”

An Efficient Removal of Toxic Cr(VI) from Aqueous Solution by MnO2 Coated Polyaniline Nanofibers: Kinetic and Thermodynamic Study

“…The procedure of pH PZC drift method [20] could be described as follows: To a series of 250 mL conical flasks, 50 mL of 0.01N NaCl was added. Then, the initial solution pH values (say pH initial) were adjusted in the range between 1-9 with pH intervals of one, using 0.01N HCl solutions and 0.01N NaOH.…”