How are Chemical Dosages Controlled?
Chemical dosages are based primarily on the amount of impu-rities in the feed-water. For example, the amount of softening chemicals needed depends on fee-water hardness;the amount of sodium sulphate needed depends on the amount of dissolved oxygen in the feed-water. In addition, however, a set amount of extra chemical treatment is added to provide a residual is akind of insurance and serves as the basis for treatment control.
