What exactly is anaerobic digestion?

For those that work in the wastewater treatment facilities across the country, anaerobic digestion is a term that is commonly used and understood, but for those that are less aware of what it means, hopefully this article can help.

Aside from being a complex word, it is also a complex process which effectively means that anaerobic digestion is a “biological wastewater treatment process that is used for treatment and reduction of organic wastes such as organic sludge or concentrated organic industrial waste which contain solids.”

When the amount of waste is reduced, the treated sludge that is left over is easier to dispose due to less volume it becomes easier to dispose. There is also an upside to this kind of waste treatment, the microbial action during the whole process also helps in biogas generation which can then be used as a clean energy source.

However, it’s most common use is now found in the agricultural industry. The residual sludge is used in farming products specifically to help with crop growth and even powering machinery with the residual methane production.

One of the big advantages for farmers is that, anaerobic digestion helps in providing diversified farm revenue which is critical to the long term financial viability of many farms. Whilst farms have created income from fertilisers in the past, anaerobic digestion helps to also create other products which the agricultural industry can not only benefit from but also use as a gateway to create other opportunities for their industry.

There are advantages to anaerobic digestion which can help wastewater businesses as well as the agricultural system as mentioned above. These include;

Economic advantages:

  • Additional income – Especially for those in the agricultural communities that have to deal with animal wastage. The re-use can not only save on waste but also provide an income for the redistribution of waste material.
  • Reduction in the cost of fossil energies – using the methane that is produced from the anaerobic digestion can be a fuel and heating source for commercial use.
  • Diversification of crops – in farming this can be a massive source of potential for income as well as growing new crops on land.
  • Reduction of manure purchase – this can account for up to 30% of a farmers costs for the year, so any reduction is worthwhile.

Agronomic advantages

  • You can turn the liquid manure (organic waste) into a fertilizer, more easily assimilated then by the plants and it even reduces waste and smells caused.
  • You can competitively cost out organic waste processing.
  • Suppressing the smells caused by organic waste.

Environmental advantages

  • Biogas that is created by anaerobic digestion is replaces fossil energy usage on sites that go through increased use in colder periods, helping the environment and creating new opportunities for those business to be more self-sufficient.
  • Creates sustainable way to manage organic waste in the local environment as well as having a national impact when rolled out across multiple sites.