Calcium carbonate

Calcium carbonate scale inhibition by three inhibitors, polyacrylic acid (PAA), aminotrimethylenephosphonic acid (ATMP) and polyamino polyether methylenephosphonate (PAPEMP), has been investigated by the bubbling method, and the calcium carbonate scales formed in the absence and presence of inhibito

Scaling, often due to the precipitation of calcium carbonate, is a current problem in economical and technical life. To study this phenomenon, some experimental procedures have been developed. They are based for example on electrochemical precipitation, use of nanofiltration and rapid controlled pre

The paper presents results of a study investigating softening by nanofiltration of the Hamma underground water resource. The Hamma wells supply the City of Constantine with hard drinking water containing calcium bicarbonate. The main parameters investigated were pressure, cross-flow velocity and wat

We studied the effect of water hardness, temperature and the nature of walls on CaCO3 heterogeneous nucleation, which is the main condition of scale. The probability of CaCO3 heterogeneous precipitation increased for weak water hardness and weak temperatures. The wall nature did not influence the pr

All MSF desalination plants have been operated at a top brine temperature below 120°C. That is because of sulfate scaling phenomena, which usually occurs when the temperature is higher than 120°C. This type of scaling is hard scale that cannot be removed easily by chemical or mechanical cleaning. In

2 2 Nanofiltration of saturated calcium sulfate solution of 0.02 mol/L calcium content, with CO3 !/SO4 ! molar ratio !3 !4 2 ranging from 0.0500 to 2.8×10 was carried out in 6.5×10 m active membrane area laboratory module at 1.2×106 Pa transmembrane pressure using the total retentate recycle mode. P

The influence of process conditions such as feed rate, calcium/carbonate ratio, pH, complexing agents [ethylenediaminetetraacetic acid (EDTA), citrate (CIT)] and their concentration on the average particle size and shape of precipitated calcium carbonate was studied. The precipitation was performed

New products based on enhanced maleate chemistry have been developed to control the broad range of deposits found in thermal desalination plants. To investigate the performance characteristics of enhanced maleate products, laboratory tests were developed to measure the control of fouling species. Th