Have your cake and eat it too? Make electricity while cleaning your water supply

Sustainability problem– Clean water and reliable electricity

Sustainability technology– Anaerobic digestion to treat waste water streams

Typically, cities require that water meet a certain set of specifications regarding its pH level, BOD (biochemical oxygen demand), COD (Chemical oxygen demand) etc. In order to clean the water, large industrial users have to use large amounts of electricity as a part of the aerobic process of water treatment. This process is both costly as well as energy intensive.

Anaerobic respiration to treat water is an innovative way to hit two birds with one stone; the process breaks down the organic matter in water and converts it into biogas, which can further be used to generate electricity or channelled to a CHP plant. PurposeEnergy has developed a bio-reactor that is applicable to the food and beverage industry and permits the production of upto 220 kWH of energy daily, in addition to treating waste water.

Such a technology can transcend beyond the food and beverage industry and find widespread application in developing cities in emerging economies. The bio-reactor can in theory eliminate the need for complex and expensive filtration systems and at the same time, facilitate both clean cooking fuels as well as biogas micro-grid development, thereby reducing dependency on fossil fuels and grid powered energy.



Key stakeholders and their role in implementation

  • Developers such as PurposeEnergy to innovate around their existing technology to be able to cater to waste water beyond the kind generated by food/beverage industries (i.e. treat other kinds of contaminants and organic matter)
  • City governments to create a program or partnership with developers and help channel funds necessary for research and development (enter into a long term contract to deploy the products across the city)
  • Planners and designers to innovate around how these reactors can be set up across neighbourhoods and municipalities





Comment on other post: Dynamic Buildings for a Sustainable Future

This is certainly one of the more futuristic technologies i’ve seen, thanks for sharing! It would be great to learn more about the engineering behind this, because (and I have very limited civil engineering knowledge), the first thing that comes to mind is wind/earthquake loads and factor of safety in building design. How high can this go? We seem to be in an age where everything is being built vertically, and we need to be smart about the way we use land.


A second thought that comes to mind is how customizable the design is. I’m imagining a city full of structures like this: would it end up looking monotonous if every building resembled such a dynamic structure in its general shape, size, colour and design? A big part of having a healthy life is to be able to experience the variety in the natural and built environment. I am curious to know how this design can evolve to portray different shapes and sizes so as to avoid cities looking like templates.

By Aksheya Chandar (ac4154)

It is a fascinating technology though.


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