Added equations to calculate the alkalinity concentration in the outlet based on the softening procedure.
For single-stage-lime and excess-lime: Examples in the book were used to build equations (Crittenden, J. C., & Montgomery Watson Harza (Firm). (2012). Water treatment principles and design. Hoboken, N.J: J.Wiley.)
For single-stage-lime-soda and excess-lime-soda, methods provided by NMSU were used. Need to be verified.
Added equations to calculate the alkalinity concentration in the outlet based on the softening procedure.