A call for action
Today I would start with a confession: I decided to study Environmental Engineering to try to heal some of our environmental damages, to be able to go to bed in the night feeling useful to both the Society and the Environment BUT ( and it’s a huge but) I started this journey with a kind of pessimistic perspective. I mean that my hope in a substantial change of our habits, mindsets, business and government models in order to achieve meaningful progress was poor. I felt like a kind of naive girl with unrealistic wishes.
But one day, that really started as any other day, I came to know of Ecological Engineering and the huge opportunities it opens. It’s been a catharsis, it boosts my hope to the highest levels. And it’s always here that I heard for the first time about United Nations’s Sustainable Development Goals, a “plan of action for people, planet and prosperity” to be achieved by 2030 with the pledge that no one will be left behind.
These Goals have the potential to really revolutionize the world as we intend it today and their realization rely on us, on our choices as individuals and professionals.
So today I want to talk to you about the SDG9 and how it can be achieved in the framework of the Wastewater infrastructures.
Goal 9: Industry, innovation and infrastructure
The SDG9 aim to “build resilient infrastructure, promote sustainable industrialization and foster innovation”. Increment of productivity and incomes, and improvements in health and education are in fact directly related with investments in infrastructure.
But for what concerns the topic of this blog, I want to focus on the target 4 that it’s about upgrading infrastructure and retrofitting industries to make them sustainable, with increased resource-use efficiency and greater adoption of clean and environmentally sound technologies and industrial processes, with all countries taking action in accordance with their respective capabilities.
The idea at the basis of this target is that the environment, society, economy and technology are constantly evolving under the effect of some drivers, which differ from country to country, so the role of businesses and governments is to respond to these changed infrastructure needs and expectations. Obviously most of the time these needs come with a series of associated challenges but, as we know as engineers, a challenge is nothing less than a disguised opportunity.
Water Infrastructure in Australia
The Future Trends chapter of Australian Infrastructure Audit 2019 identifies several key influences on the future of the infrastructure sector in Australia.
Talking about the water sector, for many user the access to a safe, reliable and affordable water is taken so much for granted that almost half of Western Australians don’t know where their drinking water comes from, based on a Water Corporation’s survey. This is an expression of the high quality services provided to the users over many decades.
However, the sector faces challenges from factors such as population growth, climate change and changing user expectations. The climate change represent the major risk because it directly impact on the amount of water available in waterways and groundwater and extreme weather events such as floods, cyclones and bushfires can damage assets or disrupt wastewater treatment processes. On the other hand the growing water demand due to the population growth requires increases in water supply posing issues of how manage water security efficiently.
The Australian Infrastructure Audit 2019 continue pointing out that many of the water assets are reaching the end of their life cycle, and are approaching their full capacity or were designed and built many decades ago, for a nation of a different scale and distribution than it is today.
But this represents the opportunity to move from a linear approach of “capture, use and dispose” to an integrated water-cycle management where we use, recycle and reuse water resources.
‘Circular’ WWTPs
It’s about bringing the circular economy into the urban wastewater treatment plants (WWTPs). The circular economy (CE) offer the possibility not only to integrate energy production and resource recovery during water treatment, but even to create a framework that is resilient and regenerative (Veolia).
I think that this is the major benefit of the CE application: it gives us the possibility to leave behind a more healed environment for the future generations and a basis on which to work for further progresses. Considering how essential is clean water for our lives the water community has a central role to play in moving the world from a linear resources consumption towards a circular one.
What Circular WWTP consists of?
- First of all, it involves Nutrients Recovery that has positive impact on environment by reducing the demand of fossil-based fertilizers and consequently, reduce the consumption of water and energy ( ). It’s possible recover biosolids as fertilizer, phosphorous and nitrogen through recycling of sewage sludge or wastewater, from urine separation from the main wastewater stream or through aqua-species.
- Fit-for-Purpose Water Reuse: Examples of reuse include irrigation of specific agriculture, industrial purposes, toilet flushing, and groundwater replenishing. This as the major benefit to reduce the pressure on the water supply system while improving quality of waterways used for abstraction of drinking water thanks to WWTPs effluent quality. Another solution could be to introduce potable treated wastewater into a water distribution system but big operational cost due to very high effluent quality requirements and the lack of social acceptance make this solution still not feasible.
- Energy recovery can be done through biogas production which is useful for heat and electricity generation, heat pumps in treatment plant effluents, and energy recovery from various high temperature streams by heat exchanger. The most exciting thing is that is perfectly possible to implement an energy self-sufficient WWTP through Combined Heat and Power (CHP) technologies which generate both electricity and heat from biogas at the same time.
The figure below is an exhaustive description of the circular WWTP of the future:
This is just a glimpse of the topic but I hope that you got excited as I am! Thanks for reading!
Green & Blue Engineering 