COMPARISON OF TERTIARY FILTERS OPERATIONAL PERFORMANCE

摘要

The upgraded Maroochydore STP was commissioned in February 2007 to produce Class A recycled water. Cloth filters consisting of a woven polyester fabric with 10um pore size provide tertiary filtration at this plant. This paper reviews the results from 3 years of operation of these filters and compares it with the performances of a conventional sand filter at Noosa STP, and a continuous backwash sand filter followed by an ozone-BAC filter at Landsborough STP. The conventional sand filters and the ozone-BAC filter produced recycled water that complied with the turbidity requirements of the Queensland Water Recycling Guidelines. The cloth filters at Maroochydore were adversely affected by fouling, which required the development of a chemical cleaning regime. The most recent results from Maroochydore comply with the maximum Class A Recycled Water turbidity requirement, and the rolling annual 95%-ile turbidity has been improved to 2.2 NTU, only slightly above the Guideline value. Operation and maintenance costs are compared for the different types of filters.