Gold Coast Desalination Plant - Pretreatment

From Desal Wiki
Pretreatment Configuration
Acidification
Type: Sulphuric Acid

General Description

The pretreatment consists of chemical conditioning, pH reduction by sulphuric acid injection, coagulant (ferric sulphate) & polymer (polyDADMAC) injection. Four flocculation trains allow for time for floc formation.

From the flocculation tanks the water flows through the 18 open gravity dual media filters (sand/anthracite) which removes the suspended solids and decreases the turbidity and SDI.

The filters backwash automatically with air & water typically every 48 hours. The backwash water is then pumped to the residuals treatment area.

After going through the dual media filters the water enters the filtered sea water storage tank and from there the filtered sea water is pumped through the cartridge filters.

  • Ferric sulfate dose-rate 3.1 to 3.6 mg/L as Fe
  • No pH correction (improved boron removal 1st pass with higher pH)
  • SDI15 maturation time to < 3.5 ~ 2 -3 hrs
  • SDI15 range 2.2 to 3.3
  • Filter run times 50 to 70 hrs