ANC CONTROL

ACID NEUTRALIZING CAPACITY

OBJECTIVE

Measure the ability of the effluenct to neutralize acids in order to determine how much solid lime is being carried out of the reactor. ANC and pH measures do not give the same information; it is possible that having high ANC water can have low PH.

STANDARD PROCEDURE

Tests are done following the procedure outlined in "Laboratory research in environmental engineering - Laboratory manual" fall 2006 by Weber M., Lion L. and Bisogni J., as shown below.
1. Calibrate the pH probe using standard buffer solutions for pH 4, 7 and 10.
2. Weigh a 100ml plastic beaker; add 50ml of a 2.5mM solution of Na2CO3 and weigh again.
3. Place the beaker on the magnetic stirrer, add a stir bar and stir slowly with the pH probe inside the beaker.
4. Use grand plot analysis http://ceeserver.cee.cornell.edu/mw24/Software/ph_meter.htm. Add 0.05 N HCl solution using a digital pipette in increments of 0.25ml.
5. Repeat the process until you have three non-zero y-values on the gran plot.
6. Save the gran data.