Have you heard of the term 'high rate algal ponds'? You'd be excused if you hadn't but, since you are here and reading this post, you'd obviously like to know more.
High-rate algal ponds, also called HRAPs, are shallow raceway ponds that move wastewater via a low-power paddle wheel. They are typically used in two scenarios:
HRAPs are designed to boost the breakdown of organic waste via algal and bacterial growth and inactivate pathogens via exposure to sunlight. The organic breakdown and pathogen reduction are sped up, which results in smaller retention times in comparison to standard lagoon systems. The residence time is generally between 4-10 days and the depth of ponds is typically between 30cm and 50cm.
High-rate algal ponds are sustainable, low-energy and low-cost alternative wastewater treatment options. They also take only 4-10 days to treat wastewater, compared to a conventional system that requires 66 days to treat wastewater to a similar level of treatment. It is also worth noting that:
HRAPs are being found to benefit more and more people, including rural communities and areas that create high-strength wastewater. In South Australia they are having great success with HRAPs in rural communities - the below table shows a few places where HRAPs can be used for comparisons:
If you would like some further information regarding wastewater solutions, give Express Wastewater a call at 1300 722 517 and we can discuss your needs today.
Local Government Association of South Australia (High Rate Algal Ponds): https://www.lga.sa.gov.au/about-lga/what-we-do/community-wastewater-management-systems/high-rate-algal-ponds-hrap
In Daily (A better model for sewage systems – and the Murray): https://indaily.com.au/news/sponsored-content/2019/03/07/a-better-model-for-sewage-systems-and-the-murray/