HYDERABAD: Researchers at the Indian Institute of Technology-Hyderabad (IIT-H) are developing an algae-and-bacteria-based hybrid sewage treatment plant (STP) that will be cost-effective and also help produce biofuel.
The system will benefit the gated residential communities, apartments and commercial complexes like malls, that, according to environmental laws, must have a facility to treat the sewage they generate.
According to a media release by the IIT-H, the hybrid STP will be more energy-efficient than present-day STPs, which only use aerobic bacteria. Moreover, present-day STPs generate a lot of sludge, while the algae-bacterial system will produce comparatively lesser amount of sludge.
The algae-bacteria combination will work in an interesting synergy.
The microalgae to be used in this system survives through photosynthesis and releases oxygen, which will be used by the aerobic bacteria to break down organic waste in the sewage. As the bacteria breaks down the organic waste in the sewage, CO2 is released, which in turn will be assimilated by the microalgae for photosynthesis. The microalgae will also consume nitrogen and phosphorus, resulting in improved water quality.
Further, the microalgae can also be used to generate biodiesel and other value-added products, said Dr Debraj Bhattacharyya, Associate Professor at the Department of Civil Engineering at IIT-H, who heads the team of researchers working on the hybrid system.
The findings of the study have been published in journals like Journal of Industrial and Engineering Chemistry, Water Environment Research and Environmental Science and Pollution Research.