Biofiltration can be an effective drinking water treatment process when ozo
nation is practiced beforehand. The objectives and therefore the designs of
these two processes are usually not related to biological treatment goats,
and no effort has been made to determine the compatibility of the goals of
these integrated treatment processes. The optimal application of ozone (O-
3) for disinfection is the minimum dose that provides a target level of mic
roorganism inactivation. This dose was equivalent to the optimal O-3 dose f
or biological treatment, defined as the minimum dose that would achieve the
maximum relative BDOCrapid removal. Additionally, the O-3 process is limit
ed with respect to controlling the formation of BDOCrapid. Increasing the O
-3 dose beyond the optimal dose will result in little additional BDOCrapid
formation, little additional release of biodegradable dissolved organic car
bon to the distribution system, and an increase in the cost of operation. A
conceptual approach for optimizing the O-3 and biofiltration processes for
biological treatment objectives is described for three case studies. The r
esults indicate that biological treatment goals can be satisfied to a large
degree while simultaneously meeting other drinking water treatment objecti
ves such as disinfection and particle removal.