scholarly journals Procedure for Calculating the Calcium Carbonate Precipitation Potential (CCPP) in Drinking Water Supply: Importance of Temperature, Ionic Species and Open/Closed System

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 42
Author(s):  
Camilla Tang ◽  
Berit Godskesen ◽  
Henrik Aktor ◽  
Marlies van Rijn ◽  
John B. Kristensen ◽  
...  
Keyword(s):  
Drinking Water ◽  
Calcium Carbonate ◽  
Open Source Software ◽  
Open Systems ◽  
Ionic Species ◽  
Water Systems ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation ◽  
Closed Systems ◽  
Drinking Water Systems

The calcium carbonate (CaCO3) precipitation potential (CCPP) can predict the potential for corrosion and lime scaling in drinking water systems. CCPP can be calculated by different standards, but none of these consider all of the conditions in drinking water systems where temperatures can reach 100 °C and the water exchanges CO2 with the atmosphere. We provided and demonstrated a procedure for CCPP calculations using the open-source software PHREEQC with the phreeqc.dat database at temperatures relevant for drinking water systems (10–90 °C) and for open systems in equilibrium with atmospheric CO2. CCPP increased by 0.17–1.51 mmol/kg when the temperature was increased from 10 °C to 90 °C and increased by 0.22–2.82 mmol/kg when going from closed to open systems at 10 °C. Thus, CaCO3 precipitation may be underestimated if CCPP is only considered for the lower sample temperature and for closed systems. On the other hand, CCPP10 decreased by 0.006–0.173 mmol/kg when including the ionic species from the German DIN 38404-10 standard in addition to calcium, alkalinity and pH, indicating that all relevant ionic species should be included in CCPP calculations. CCPP values should always be reported with the calculation procedure and temperature to avoid inconsistency in literature.

Test method for evaluation of anti-scale devices for cooling condensers

2004 ◽  
Vol 49 (2) ◽  
pp. 161-168
Author(s):  
J.B. Vestergaard
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Water Systems ◽  
Test Method ◽  
Cooling Towers ◽  
Germination Time ◽  
Air System ◽  
Closed Systems ◽  
Local Water ◽  
Drinking Water Systems

Can new types of anti-scaling devices prevent scaling on condensing pipes in industrial cooling condensers and supersede conventional water treatment? To examine this question a test method has been developed, test rigs have been built and different kinds of anti-scale devices have been tested. As cooling towers are based on an open-air system with evaporation of water they will have higher demands on the effectiveness of the anti-scale devices compared to the closed systems which are typical drinking water systems in buildings. The test method is based on an open-air system. The rigs are mobile and can be used to give an indication of whether it is possible to treat the local water with an anti-scale device. The result of the test is a scaling rate and a germination time. In addition to these tests the anti-scale devices have been tested in the field at cooling condensers.

Scaling in domestic heating equipment: getting to know a complex phenomenon

2004 ◽  
Vol 49 (2) ◽  
pp. 129-136 ◽  
Author(s):  
H. Brink ◽  
P.G.G. Slaats ◽  
M.W.M. van Eekeren
Keyword(s):  
Drinking Water ◽  
Calcium Carbonate ◽  
Saturation Index ◽  
Carbonate Precipitation ◽  
Heating Equipment ◽  
Calcium Carbonate Precipitation ◽  
Domestic Heating ◽  
Scaling Properties ◽  
Langelier Saturation Index ◽  
Water Companies

Excessive scaling is one of the main nuisances in relation to the use of drinking water. Ever more water companies try to minimise scaling. Although scaling is an old problem, prediction of scaling has been proven to be very tricky. Traditionally, the (Langelier) Saturation Index is used to evaluate scaling properties of drinking water. From experience it is well known that this parameter is not suitable for proper prediction. New parameters have been developed and standardised for scaling prediction, namely the Calcium Carbonate Precipitation Potential, calculated at a temperature of 90°C (CCPP90); the Saturation Index, also calculated at a temperature of 90°C (SI90); the Nucleation Index (NI) and the Measured Calcium Carbonate Precipitation (MCCP). These parameters are currently successfully used in The Netherlands. The development of new parameters to predict scaling in domestic heating equipment has resulted in a better understanding of processes involved. Even now unexpected and at first sight contradictory results are obtained frequently. With the use of the developed measuring techniques, solutions may be found to combat excessive scaling.

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