Water is touted by many as the new oil.
Well, you know what, we might be able to just about live without oil, but we cannot without water.
Makes it all the more important that we focus on ensuring sustainability of water. And it is not just the supply of water we are concerned about, it is also the quality of water.
Which is where the important domain of waste water treatment comes in.
The world gives out hundreds of billions of liters of waste water everyday. Most all this water has the potential to be recycled and reused in some form.
In the context of waste water treatment, there are two main segments – Sewage Water (domestic waster water) and Industrial Waste Water.
Sewage waste, which refers to all the water that comes out of our wash rooms and kitchens, is treated at sewage treatment plants (STP).
Industrial waste water refers to waste water that comes out industrial processes – machine washing, waste water from chemical processing and the like. This is usually treated at the industrial premises itself before being discharged into sewage or into other water bodies.
Conventional Waste Water Treatment
Most waste water treatment facilities (industrial or sewage), do the treatment in 2-3 stages. The primary stage is where large, physical things such as stones etc are removed. The second stage is where dissolved organic solids are turned into a sludge through the use of microbes. The third stage consists of chemical or other treatments to remove toxic compounds.
For all three stages, until now, most waste water treatment (either domestic or industrial) used significant energy and/or synthetic and chemical methods of treatment (except during the second stage when microbial action is relied upon to a certain extent).
However, given that the costs of energy are even increasing and with the use of chemicals raising significant concerns owing to its own pollution problems downstream, more sustainable components are being sought at all stages of waste water treatment.
This search for sustainable waste water treatment has resulted in a significant emphasis on bio-remediation. Put simply, bio-remediation is the use of biological organisms (micro-organisms, algae etc) to treat and clean pollution.
Among all bio-remediation methods, the use of algae, especially micro-algae, is gaining traction.
The reason is not difficult to comprehend – there are over 100,000 strains of microalgae, and this implies a vast diversity of algae, one or more of which could be ideal for the treatment of any type of waste water.
Use of algae as a waste water treatment agent is not exactly new. It has been used for decades in secondary treatment stage as an aeration/oxidation agent (algae breathe out oxygen which the other micro-organisms consume to grow and do their job). What is new however is that algae are being explored to do much more than aeration – removing toxic compounds, reducing acidity of waste water, coagulating organic waste into a sludge and more.
Using algae as a bioremediation agent provides one more incentive – the algal biomass thus produced could be a feedstock for a variety of products, including biofuel (both biodiesel/bioethanol as well as for biomethane), bioplastics and fertilizers.
As a result of all the above aspects, there is an increasing amount of interest in researching and piloting the use of various strains of algae for treating waste water.
A Comprehensive Report on Algae-based Waste Water Treatment
The bio team at EAI had been doing research on the use of algae for waste water treatment. Those interested might want to check out our unique report on this exciting topic.