Biological treatment: Bypass of Oxic Zone

Challenge:
The membrane diffusers of the Oxic Zone within our customers biological WWTP required replacement. In the past the customer halted their production for this maintenance activity but, in this instance a loss of production had to be avoided. The customer requested a solution to enable a full maintenance event to occur in the Oxic Zone, including the removal of sand and other settled pollutants, whilst minimising any downtime in production.

Solution:
After an extensive engineering review phase, United Rentals provided a solution consisting of:

• Hoses & manifolds to provide a temporary re-routing of the incoming pre-treated wastewater & Return Activated Sludge flow.
• A series of Filtration “Open Top” (FOA) Tanks, installed in parallel, each equipped with 8 aeration panels.
• The required airflow of 400 Nm³/h per FOA in order to provide 18 kgO2/h was provided by blowers

Benefits:
As a result of the comprehensive United Rentals solution, the customer avoided problems with discharge limitations due to any lack of biological treatment. Revenues were protected as the production process could be continued without restrictions.