Onsite Testing
If you don’t measure it, you can’t manage it!
Overview
Actively measuring diffuser performance provides invaluable data about the state of the diffusers. Knowledge is power!
Simple Tests
Backpressure tests
The simplest tests involve taking diffuser backpressure and air flow measurements over the full range of diffusers air flow, generating a backpressure curve. This illustrates the impact of membrane deterioration and fouling of the diffuser slits, affecting bubble formation and increasing pressure loss across the diffuser. Regular backpressure tests can track increasing backpressure over time and measure the benefits of acid cleaning.
There are a variety of diffuser failures that can result in a dramatic drop in performance and jeopardise the effective treatment of influent.
Advanced Tests
Off-gas tests
Standard Off-gas tests measure the amount of oxygen transferred into the mixed-liquor for a given volume of air and water depth. The transfer of oxygen is affected by fouling on the surface of the diffuser. The tests involve the deployment of a floating gas hood over selected grids in each tank to capture spent ‘off-gases’ from the tank.
Using this method is an excellent way of benchmarking and tracking performance as diffusers age. The results are reported as Alpha factors.
A basic ‘off-gas test’ derived Alpha of 0.8 means, for example, that oxygen transfer efficiency into sewage mixed liquor at zero DO and 20C was 80% of the oxygen transfer into clean water.
Alphas measured in ‘real world’ tests range from about 0.75 down to 0.4 – with the highest values obtained when the diffusers are new and are also affected by influent characteristics.
There is always a fall-off in diffuser efficiency with time as the diffuser membranes age and foul. It is generally progressive and can range from 3-6% per annum, depending on whether or not the diffusers have been regularly cleaned and the characteristics of the wastewater.
Enhanced Off-Gas Testing
Simple off-gas tests provide an excellent guide to overall oxygen transfer efficiencies, but interpretation of their results can be affected by simultaneous variations in wastewater strength and surfactant concentrations.
Use of the gas hood, on its own, allows us to determine current total Alpha values (Alpha-T), which are a product of both the diffuser deterioration (Performance Factor) and of the inhibiting effects of transient surfactants in the wastewater mixed liquor (Alpha-W).
We now strongly advocate use of a portable test column to be used in conjunction with our gas hood to allow us to assess Alpha-W values, and hence determine Performance Factors – the most accurate and relevant indicator diffuser condition.
Who is this important to?
Operators, Process Engineers, Asset Managers
Benefits:
- Uncover the true state of your diffusers
- Benchmark performance against other plants
- Gather key data to make informed, cost-effective decisions
Evidence / Data Proof
Without actual data, outdated assumptions prevail… The oldest diffusers should be the worst, correct?? Not necessarily…
Why use Aqua Audit?
- Most experienced and independent test company in Australia
- Agile test methodology and equipment deployment allows testing of multiple sample points
- Advanced techniques for increased accuracy and comparability
Remote Optimisation Audit
Get a quick desktop assessment to help plan the best course of action…
Overview
We can help you get the most out of your aeration system by analysing the data to see where there may be issues or identify where efficiencies could be realised. Working with your team, our Remote Optimisation Audit allows you to quickly get a handle on possible issues and make an effective plan to address the root causes…
Who is this important to?
Operators and Process Engineers
Benefits
At a fraction of the cost, a remote audit is a cost-effective way to see if your aeration system is functioning as it should.
Why use Aqua Audit?
- Hands-on knowledge of ‘tell-tale’ SCADA signs of wider system issues
- Experience of assessing and maintaining a wide variety of activated sludge processes and aeration systems
‘Automated System’ Optimisation
‘Live’ data is very valuable, but is it accurate and representative?
Overview
With so many variables at play, even modern systems need observation and human input. Data floods in, but what does it mean? How do you know it is accurate? Most online systems only take a small sample of the whole.
Using our reliable and portable equipment, experienced Aqua Audit staff can verify SCADA outputs and help you to understand how to uncover data and equipment issues and how to monitor your automated systems to realise the benefits of automation and to truly maximise your investment.
Who is this important to?
Operators and Process Engineers
Benefits
Maximise equipment investment
Verify automated outputs
Evidence / Data Proof
Side-by-side measurements will verify the accuracy of your online system. This will give you confidence you are getting the full picture.
Why use Aqua Audit?
- Reliable, bespoke equipment generating high data quality
- Hands-on knowledge of over 120 operational aeration systems
- Expensive in-house data for comparisons