Citation:
Peter Jarvis, Emma Sharp, Marc Pidou, Roger Molinder, Simon A. Parsons, Bruce Jefferson, Comparison of coagulation performance and floc properties using a novel zirconium coagulant against traditional ferric and alum coagulants, Water Research, Volume 46, Issue 13, 1 September 2012, Pages 4179–4187
Abstract:
Coagulation in drinking water treatment has relied upon iron (Fe) and aluminium
(Al) salts throughout the last century to provide the bulk removal of
contaminants from source waters containing natural organic matter (NOM).
However, there is now a need for improved treatment of these waters as their
quality deteriorates and water quality standards become more difficult to
achieve. Alternative coagulant chemicals offer a simple and inexpensive way of
doing this. In this work a novel zirconium (Zr) coagulant was compared against
traditional Fe and Al coagulants. The Zr coagulant was able to provide between
46 and 150% lower dissolved organic carbon (DOC) residual in comparison to the
best traditional coagulant (Fe). In addition floc properties were significantly
improved with larger and stronger flocs forming when the Zr coagulant was used
with the median floc sizes being 930 υm for Zr; 710 υm for Fe and 450 υm for Al.
In pilot scale experiments, a similar improved NOM and particle removal was
observed. The results show that when optimised for combined DOC removal and low
residual turbidity, the Zr coagulant out-performed the other coagulants tested
at both bench and pilot sca
