A method of treating liquid including mixing coagulant with the liquid, introducing
mixed coagulant and liquid into a primary reaction zone, containing an agitator,
of a reactor which is substantially concentrically positioned with respect to a
secondary reaction zone of the reactor, introducing flocculant into the primary
reaction zone at a location between the agitator and where the mixed coagulant
and liquid are introduced into the primary reaction zone, mixing the mixed coagulant
and liquid with the flocculant and causing the resulting mixture to flow into the
secondary reaction zone, introducing an encapsulating agent into the secondary
reaction zone, recirculating the liquid and encapsulated flocs through the primary
and secondary reaction zone, and passing the liquid and encapsulated flocs outwardly
of the reactor, and an apparatus for treating liquids including a reactor, a draft
tube substantially concentrically positioned within the reactor and being positioned
such that the liquids may flow inwardly and outwardly of the draft tube from opposed
end portions of the draft tube, wherein space inwardly of the draft tube forms
a primary mixing zone and space in the reactor, but outwardly of the draft tube
forms a secondary mixing zone, an agitator positioned within the draft tube, an
inlet positioned approximate one end portion of the draft tube which introduces
liquid and coagulant into the primary mixing zone, an inlet connected to the draft
tube and positioned between the agitator and the end portion of the draft tube
through which coagulant and liquid are introduced into the primary mixing zone,
an encapsulating agent inlet positioned in the secondary reaction zone between
the opposed end portions of the draft tube, and an outlet downstream of the encapsulating
agent inlet.