Effects of pre-treatment with magnetic ion exchange resins on coagulation/flocculation process.
A new Magnetic Ion EXchange resin for DOC (Dissolved Organic Carbon) removal (MIEX DOC Resin) has been evaluated as water pre-treatment at the Drinking Water Treatment Plant (DWTP) of Florence in order to reduce the oxidant demand and disinfection by-products (DBPs) formation potential. This pre-treatment leads to several effects on downstream treatment processes. In this experimental study the effects of MIEX pre-treatment on clariflocculation process were evaluated with respect to coagulant demand reduction and characteristics of flocs formed. The analysis was conducted using traditional jar test procedures and a Photometric Dispersion Analyser (PDA2000) which provided continuous information about the aggregation state of particles during the jar tests. For a fixed turbidity goal in clarified water, ion exchange pre-treatment led to coagulant dosage reduction up to 60% and PDA results shown that flocs formed in pre-treated water were bigger and more resistant to shearing effects than those formed by conventional clariflocculation.
Sani
B
B
Department of Civil and Environmental Engineering, University of Florence, Via S. Marta, 350139, Florence, Italy. beatrice.sani@dicea.unifi.it
Basile
E
E
Rossi
L
L
Lubello
C
C
D005427:Flocculation; D007475:Ion Exchange Resins / Q000737:chemistry*; D008280:Magnetics; D015203:Reproducibility of Results; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods*
D007475:Ion Exchange Resins