Flocculation as an analytical pre-concentration step and regeneration of flocculent agent

The finding that resin acids could be recovered from flocs prompted the hypothesis that it might be possible to design an analytical technique based on pre-concentration by flocculation of the low levels of resin acids in highly diluted receiving water samples. 95100% of expected resin acid levels were recovered in experiments performed using undiluted, 5, 10 and 50-fold diluted Tarawera River water. The tertiary flocculation/filtration technology could be efficient as process for resin acid and turbidity removal and more effective for colour removal. It is possible this could be improved by recovery or partial recovery and reuse of the flocculating agent.