Kinetics and mechanisms of precipitations

Study of struvite precipitation in anaerobic digesters

“…Phosphate is also present from the start because it is added in the feeding. Thus with added NH4Cl, struvite appears from the start, as all the ions are in solution, and precipitation is very rapid, in agreement with the kinetic studies of Gunn and Murthy (1972). For this reason, crystal growth soon stops, and the size is the same at 60 and 90 days.…”

“…The kinetics and mechanism of struvite precipitation have been studied by adding a solution of ammonium hydrogen phosphate to a solution of magnesium sulphate and ammonium hydroxide (Gunn and Murthy, 1972). Gunn (1976) also studied the dependence of the induction period upon the mean ionic concentration of Mg 2+, NH4+and PO]-.…”

Radium uptake during barite recrystallization at 23±2°C as a function of solution composition: An experimental 133Ba and 226Ra tracer study

“…A vast number of kinetic studies have been published in the last decades, mainly involving measurements of barite precipitation or dissolution rates under a variety of conditions, mostly far removed from saturation equilibrium (Bovington and Jones, 1970;Gunn and Murthy, 1972;Hostomsky et al, 1981;Rizkalla, 1983;Prieto et al, 1990;Fernandez-Diaz et al, 1990;Christy and Putnis, 1993;Dove and Czank, 1995). Such studies focused on the effects of temperature, saturation state, solution composition and additives (inhibitors or catalysts) on the barite precipitation or dissolution kinetics.…”

Precipitation of barium sulphate in a hollow fiber membrane contactor: Part II The influence of process parameters

“…The intensity I (Cd) of light transmitted by the suspension was related by Beer-Lambert's law to the projected surface area, A p , of particles in unit volume of suspension, to the length l (m) of light path in the suspension, and to the intensity I 0 (Cd) of light transmitted by the clear liquid (Gunn and Murthy, 1972):…”