Charge Neutralization Study of Mixtures of Al13 with Alum
Chemistry and Biochemistry
Partially neutralized aluminum solns. with a basicity ([OH-]/[Al3+]) of 2.5 contain the polymeric aluminum moiety, [AlO4Al12(OH)24(H2O)127+], represented as Al13 at more than 90% of the total Al. Coagulants can be titrated into raw water until a zero zeta potential is achieved. Water types (pH range of 7.1 to 7.9) of varying alky. (50 and 100 ppm CaCO3) and varying turbidity (∼9.0, ∼62, ∼160 NTU) achieved a zero zeta potential with mixts. of Al13 and aluminum sulfate using the least amt. of total aluminum compared to aluminum sulfate (monomeric aluminum) alone.