Dr Tony Brooke of CBIO gives an honest opinion of the current state of the Environmental Biotechnology industry and how it is perceived by potential customers
What is the role targeted bioaugmentation has in optimising treatment plant operation?
Risking an unfair generalisation the water industry could be labelled as broadly sceptical regarding the benefits of bioaugmentation. This scepticism can be justified where bioaugmentation has in the past been sold as the ‘silver-bullet’ to cure any ailment afflicting a treatment plant. Bioaugmentation and affiliated technologies have therefore suffered from being poorly understood and miss-sold.
However, the evidence gathered from around the world shows that bioaugmentation does work; but when the conditions are right. The key to its effective implementation is to not only understand the wastewater treatment process and the role of bacteria within it but also to understand in detail the particular waste stream to be treated.
There could be several reasons for a treatment plant to fail to meet its discharge consents – only a few of which could be remedied using bioaugmentation.
In practice bioaugmentation is quite often the last resort prior to pouring concrete. There could be issues of temperature, dissolved oxygen, pH, mechanical failure – all of which should be considered before calling in the microbiologists.
If all other avenues have been explored there are still several questions that require answering before a biological solution can be recommended. Even if the nature of the problem is understood it can take detailed investigation to uncover the cause e.g. a rogue hydrocarbon from a cottage industry knocking out the nitrification in a village’s treatment works. Once the cause and scale of the problem has been identified all other factors within the treatment works must be assessed to ensure there are no other inhibitors present to negate a biological recovery program.
An example of such an exercise that we have worked on was a small treatment works that had rarely met its ammonia discharge consent. The installation team had added, at great expense, nitrifying bacteria in an attempt to re-start nitrification. This had no impact. Following this a bioaugmentation regime was implemented. The cause of the problem was found to be that intermittent oil discharges from a nearby haulage company had reached the plant killing the nitrifying population.
The recovery strategy involved the installation of a continuous bioaugmentation unit, generating 6m3/day of actively growing, pre-acclimatised hydrocarbon degrading bacteria, allowing the nitrifying population to recover. Following this installation, the plant remained in consent for ammonia. This medium-term solution proved cost-effective until capital funds became available to increase the capacity of the plant by 50pc.
I feel that bioaugmentation has been given a bad name due to the failure by some to understand not only the basic bacterial processes, but also the waste streams they have attempted to treat.
Bioaugmentation will not solve all your problems, however when the conditions are right and the understanding is there, it has proved to be the most cost-effective solution available.