Results for the effect of RHA loading on pH and TDS controls are
presented in Fig. 3. As indicated earlier, different doses of RHA
were used while the pH and TDS were measured before and after
dosing. From Fig. 3, it is shown that pH of the treated water
increased compared to the initial pH of the raw water using both
URHA and PRHA for all the doses. However, pH values of clarified
treated water from PRHA were lower than those obtained using
URHA. Fig. 3 shows an initial decrease in the pH of treated water
using URHA with increase in URHA doses up to 12 g, an increase
was observed when 16 g of URHA was used and thereafter
decreased and increased at 24 g dosage. A different observation