Internship finished!

During the last couple of weeks spent in India, my internet was cut off, so now I can sum up my placement for you all, detailing some of the work I carried out while also letting you know that I made it back to England safe and sound!

The last few weeks of my placement revolved around harvesting microalgae by homogenising huge water samples with a centrifuge, which was dull but we were able to harvest a lot of microalgae dry weight.

At the same time, we added 90ml samples of wastewater to sterile Petri dishes containing a single cover slip in each. We then added 10ml of Chlorella vulgaris or Scenedesmus obliquus to one Petri dish and, to one Petri dish where there was 80ml of wastewater, we added 10ml of both species. This was done in duplicate and with a control (with just wastewater). The idea being that after a couple of weeks, a biofilm layer would form on the cover slips. We found more biofilm produced when the two microalgae grew together showing that at least these two species grow better together rather than in isolation.

I also did tests on their ability to reduce nutrient concentrations in water. By using a spectrophotometer to emit light of certain wavelengths into water samples you can determine Nitrogen and Phosphorus concentrations in water. If you do this for untreated wastewater and then to samples treated with C. vulgaris, S. obliquus or both strains of the microalgae, then you can ascertain how much concentrations of Nitrogen and Phosphorus were reduced in the water. We also found that when the two species lived in consortium, a more efficient removal of inorganic Nitrogen and Phosphorus occurred. When on their own, C. vulgaris removed over 90% of Nitrogen from the water and S. obliquus removed 85% of Phosphorus. However, both didn’t fare so well in remediating the water of the other pollutant.

The work I did illustrates the importance of growing microalgae together as they more effectively remediate wastewater together. They also complement each other when it comes to growth in general (shown by biofilm formation). This is important in growing microalgae in a cheaper, efficient and faster way.

Microalgae first became interesting to scientists when it was found that they could be used as a biofuel source – one that doesn’t require the same space and chemical requirements other biofuels do (such as rapeseed) with less CO2 production. Yields of biofuel could be great considering the size of the organisms. However, optimising the growth conditions for microalgae have required a lot of research since.

With an increading global population though, the clean water demand is also getting ever greater. And since the costs of chemically and mechanically purifying water is too great, using microalgae have the potential to solve two problems for humanity – bioremediation of wastewater as a way of recycling water, while being grown on the wastewater to produce a green fuel to cope with the ever growing electricity demands of the world!

It’s been a great experience, working on this project (even if not everything ran smoothly!) An idea of working in the laboratory has been interesting and though it might not be for me in the future, I am still keeping my options open (especially if it means I can visit other countries) 😉 xxxxxxxxxx