Abstract:
Increasing freshwater scarcity is making reclamation of wastewater effluent
more economically attractive as a means of preserving freshwater resources.
The use of an integrated membrane system (IMS), the combination of
micro/ultra-filtration (MF/UF) followed by reverse osmosis (RO) membranes,
represents a key process for municipal wastewater reuse.
A major drawback of such systems is the fouling of both the MF/UF and RO
membranes. The water to be treated by the IMS system varies from one
wastewater treatment plant (WWTP) to another, and its fouling propensity
changes correspondingly. It is thus preferable to conduct pilot trials before
implementing a full-scale plant. This thesis aims to look at the sustainability of
IMS technology dedicated to indirect potable reuse (IPR) in terms of fouling
minimisation and cost via a 600 m3 .d-
1
pilot plant.
Wastewater reuse plants, using IMS, as well as statistical methods for
membrane optimisation were reviewed. Box-Behnken design was used to
define optimum operating envelopes of the pilot plant for both the microfiltration
and the reverse osmosis in terms of fouling minimisation. Same statistical
method was used to enhance the efficiency of the MF cleaning-in place through
bench-scale test.
Data from the pilot plant MF process allow to determine relationship between
reversible and irreversible fouling, and operating parameters and feed water
quality.
Life cycle cost analysis (LCCA) of the both trains (MF/RO/AOP and MF/AOP) of
the pilot plant was performed and compared with the LCCA of two full-scale
plant.
