Patent ID: 6896816
Filing Date: 2005-05-24
Classification: B01D,C02F,Y02W

Abstract:
1. A method of treating waste material containing at least one contaminant in a separator to substantially separate the contaminant from the waste material using aeration in which the separator is provided with a diffuser located intermediate the ends of the separator dividing the separator into a sludge collection zone located at or towards the top of the separator and a clear zone located at or towards the lower part of the separator, and a clear waste outlet located at a level in the separator above the level of a recirculation outlet, said method comprising the steps of: introducing an incoming feed stream of the waste material containing the contaminant into the separator; at least partially separating the waste material in the separator into a substantially aerated portion containing a major amount of the contaminant into the sludge collection zone and into a partially treated portion of the waste material having a residual or minor amount of contaminant into the clear zone; passing the partially treated portion of the waste material through the recirculation outlet into a recirculation loop having a mixer for aerating the partially treated portion in the recirculation loop; aerating the partially treated portion using the mixer; and, returning the aerated partially treated portion to the separator such that introduction of the returned aerated partially treated portion to the separator maintains conditions of aeration in the separator thereby preventing the substantially aerated portion containing the major amount of contaminant in the sludge collection zone of the separator from de-aerating and fouling the separator.