Waikouaiti Water Treatment Sludge

Feasibility Study for Dewatering Sludge

Project Description
Wastewater from the Waikouaiti WTP is currently discharged into a three pond settling system. Supernatent from the ponds is discharged to the Waikouaiti River (upstream of intake) and settled sludge is taken to the landfill for disposal. This project involved investigating the feasibility of the installation of dewatering bags for sludge management at the Waikouaiti Water Treatment Plant with the aim to reduce costs associated with the handling and disposal of sludge.

Services Provided
Fluent Solutions was engaged to review the applicability of a dewatering system and submit a preliminary design and cost estimates.

Specific services included:

• Investigation of options for the installation of Geobags and associated works for dewatering sludge
• Site visits to confirm the best layout for various technologies
• Preliminary design of a Geobag dewatering system
• Polymer dosing system design
• Capital and operating cost estimates
• Reporting on sludge dewatering and disposal options

Challenges
The type of polymer being used and the location of the dosing point to thicken the wastewater stream to enhance the formation of manageable sludge needed to be considered very carefully to ensure that there was no possibility of fouling the membranes.