Patent ID: 9682876
Date: 2017-06-20
CPC Classifications: B01D,B03D,C02F

Claim:
1. A method of treating wastewater comprising: a) introducing wastewater having a first turbidity level into a treatment line of a wastewater treatment system, the wastewater treatment system comprising a mixing tank receiving the wastewater introduced into the treatment line, a transfer pump operably coupled to the treatment line downstream of the mixing tank, a first injector operatively coupled to the treatment line, a second injector operatively coupled to the treatment line, a third injector operatively coupled to the treatment line, a mixing apparatus operably coupled inline with the treatment line downstream of the transfer pump, a separator operably coupled to the treatment line downstream of the mixing apparatus, and a recirculation line operably coupled to the treatment line downstream of the separator; b) injecting a first aqueous polymer mixture through the first injector into the wastewater flowing into the mixing tank to flocculate suspended solids within the wastewater, wherein the wastewater and flocculated suspended solids flowing into the mixing tank flow to the transfer pump; c) selectively injecting a second aqueous polymer mixture through one of the second injector or the third injector into the wastewater and flocculated suspended solids pumped by the transfer pump from the mixing tank to the mixing apparatus to further flocculate suspended solids within the wastewater, the second injector being downstream of the mixing tank and upstream of the transfer pump and the third injector being downstream of the transfer pump and upstream of the mixing apparatus; d) removing the flocculated suspended solids from the wastewater with the separator to form a treated water having a second turbidity level, the second turbidity level being lower than the first turbidity level; e) recirculating a portion of the treated water through the recirculation line to form a re-circulated portion of the treated water and discharging a remainder of the treated water to a desired location; f) introducing a first raw polymer into a first portion of the re-circulated portion of the treated water to form the first aqueous polymer mixture injected in step b); and g) introducing a second raw polymer into a second portion of the re-circulated portion of the treated water to form the second aqueous polymer mixture injected in step c).