How Parasyn Helped Greater Western Water Cut Energy Costs

Most plants aren't optimised for power or process efficiency. They're designed and manufactured to meet a standard, and operated to meet compliance, with OEM and infrastructure providers usually only making minor changes during the defects liability period. New plants, as a result, rarely come with the aeration and other process stages already optimised.

Small Changes, No Capital Spend

In conjunction with Greater Western Water, Parasyn embarked on a series of small, non-capex initiatives to optimise process control at the Altona Treatment Plant, aimed at reducing energy consumption through improved blower performance, improving plant stability through consistent and controlled ammonia management, and giving operators greater visibility into process performance to support their permit assurance.

The initiatives included:

• Improving control of the dissolved oxygen set-point using on-line effluent ammonia measurement
• Optimising secondary effluent ammonia based on downstream recycled water requirements and permit limits
• Aerator PID loop control and blower energy use optimisation following a review of existing controls

The Result

The outcome was an OPEX reduction in energy costs of approximately 13% per annum, reduced performance monitoring burden on operators for secondary treatment, greater plant stability from better loop tuning and ammonia management, and lower, more predictable chemical consumption.

The investment required was extremely small relative to the OPEX savings delivered. These were rudimentary control system changes, optimised without introducing new methodologies like Advanced Process Control or replacing any inefficient plant components or instrumentation. What was already there was simply used better.

Parasyn considers this Stage One of plant optimisation, the low hanging fruit. Stage Two would extend into further process management improvements, additional energy savings, and better automated management of process disturbances such as environmental fluctuations.