One project looking at the treatment of wastewater involves algal-based tertiary treatment in maturation ponds of at wastewater treatment works.  The project established a self-sustaining system, independent of electricity or expensive chemicals, to allow for the effective removal of nutrients and pathogens in effluent.

 

The project was aimed at solving problems in areas with limited resources, and infrastructure that had not been maintained. 

 

The project was implemented between April 2014 and December 2016 at the Motetema wastewater treatment works, in the Sekhukhune District Municipality.  The municipality has significant challenges with its water quality and sanitation services.  Three plants are at high risk and 13 at critical risk. 

 

The project used a selected cultured microalgae consortium to remove nutrients (e.g. nitrogen and phosphorus from human waste) from saturated ponds to levels below the minimums set in Department of Water and Sanitation guidelines.  In the three ponds tested, the percentage reduction of total phosphorus in unfiltered water (containing algae) was 94%, 85% and 84% after treatment, with total nitrogen removal in these ponds 43%, 35% and 31%, respectively.

 

There were capacity-building events to deal with matters such as regulatory processes and sludge treatment.  An intensive capacity-building exercise took place at the treatment works, with the site controller learning how to operate the new technology.

 

It is hoped that the project can be replicated in other areas. In order to scale up the project, it was recommended that a licensing model be applied, allowing companies to engage with the technology, creating job opportunities and awareness.

 

Possibilities such as aquaculture will be investigated once the algae-based process is operating optimally.

 

This project had a significant impact on reducing nutrients in wastewater effluent.  In addition, the environmentally friendly treatment method supported a reduction in human health risk downstream of the wastewater treatment works.

 

Wastewater Treatment Works video

 

Implementing agencies

 

Water Research Commission

012 761 9300

 

Council for Scientific and Industrial Research

012 841 2911