If people took a short trip forward in time to 2040, and then looked back at how some organisations in the water industry successfully achieved carbon net-zero, it’s likely one will see a large four-letter word – Nigg.
This Scottish Water treatment centre in Aberdeen is currently leading the way as a centre of excellence for biogas production (from sludge), with its dedicated team tirelessly focused on improving efficiencies.
It is one of the first wastewater treatment plants in the United Kingdom to successfully co-digest. The Nigg Wastewater Treatment Works, which was built in 2002, has made some significant steps forward since Scottish Water took over ownership and operations in December 2018.
It worked with Cambi to upgrade the existing thermal hydrolysis process (THP) and helped install a new digester mixing system from Landia.
From initially producing 250 cubic metres of gas per tonne of dry solids, levels have increased; first to 350, and this has now climbed to an impressive 400 to 420.
The 400-plus figure is also being achieved without unlimited, costly power.
Typically, if standard propellers were in use, around 17...
Improving efficiencies
