Background
Aberdeen Harbour Expansion project is one of the largest infrastructure projects in the UK and will make the harbour the largest berthage port in Scotland. Construction of the harbour requires a steady source of concrete to produce precast forms. The site receives numerous concrete trucks each day that require washdown of the chutes creating wastewater with solids and a high pH. A treatment system was therefore needed to treat the concrete wash water to be reused or discharged.
The Overall Objective
The overall objective was to provide continuous concrete wash water treatment to remove solids and correct the high 11+ pH to a neutral 7. The treated water could then be reused to continue the process of washdown of equipment and concrete lorry chutes. The site can both reduce the overall water usage and meet the environmental site criteria for any discharges water.
Solution
Although the volume and frequency of the concrete wash water needed to be continuous treated, it was a low flow rate and could be easily treated using our PM20 pH correction unit. The Siltbuster system consisted of a PM20 which has an integrated lamella clarifier and a reaction tank for dosing CO2. Siltbuster only uses CO2 as a safe, effective way to correct highly alkaline water. After the reaction tank, the water passes through the lamella plates and precipitates out the solids.
Leaving the PM20 unit, the suspended solids in the water are significantly reduced and the pH is corrected to neutral – ready for reuse and safe to discharge.
