Murray & Roberts Water (MRW), together with its European technology partner, Organica Water, on Wednesday launched an innovative, environment-friendly wastewater treatment plant that closely resembles a greenhouse at the eThekwini municipality’s Verulam Wastewater Treatment Works.
The first of its kind in South Africa, the new demonstration plant not only eliminates the unpleasant odours usually associated with wastewater treatment facilities but also produces 30% less sludge, uses 30% less energy and has a 50% to 75% smaller geographic footprint.
It uses fixed-bed activated sludge technology and comprises biomodules that are designed to fit into customised biological reactors which are aesthetically designed to complement the often highly urbanised environments in which they are situated.
With no odour or splash, the wastewater treatment plant can be located virtually anywhere, thus substantially lowering infrastructure costs to connect to customers and enhancing land value around the facility. No buffer zones are required and the value of land close to water treatment facilities is no longer compromised, Organica Water senior manager Oscar Palomino told guests at the launch.
An example of one of the facilities that Organica has constructed in ten countries over the past 17 years is a facility located beneath a landscaped traffic circle in an upmarket part of Hainan, China.
Palomino said these facilities combined engineering, chemistry and sophisticated information technology with architecture for the first time. “This is a water reclamation garden, educational facility and symbol of sustainability in the community that enables cost-efficient water reuse and allows for maximised development opportunities, particularly in populated areas where footprint and odour are significant concerns.”
Solids, soil and other contaminates are removed from the wastewater, which then flows through a series of reactors that are configured to create ecosystems that are arranged to form a complex network.
Each biomodule includes a selection of plants and plant racks, biofibre media and fastening mechanisms. The roots of the plants, which grow down to 1.5 m into the wastewater, support and promote the growth of bacteria and other organisms which metabolise the contaminants in the wastewater.
These link up with a polymer-based microfibre which provides an additional artificial root structure and becomes the ideal fixed habitat for these organisms.
The Verulam-based prototype cost R20-million to build and is located alongside the existing wastewater treatment plant. It will process a sample of the wastewater conventionally treated there, mirroring volume and quality fluctuations and allowing for comparative studies of its performance over the next year.
Performance testing will begin in May.
According to Organica, ongoing research shows that the broader and more complex ecology that is used not only delivers high water quality, in keeping with stringent international specifications, but breaks down a wider range of pollutants, including medicines, with higher efficiency.
MRW secured the exclusive licence for Organica Technology in South Africa – and non-exclusively in the rest of the Southern African Development Community region, early in 2016.
Construction of the Verulam plant began in September 2017 and was completed in February. It has been operational since March.
Palomino said that cost savings on much smaller concrete structures, land, pipework and the absence of clarifiers needed by conventional systems meant the technology was price competitive. However, over the 25-year lifecycle of the plant, the differences were more considerable with big plants providing impressive economies of scale.
However, at the same time, smaller plants could also enable wastewater treatment far closer to source. He said this solution was suitable for any place that people gathered, including airports, rest tops, schools, shopping malls and parks, and provided on site recycling of water for irrigation, cooling towers, toilets or any other nonpotable use.
In addition, it was possible for older facilities to be upgraded and refitted with this technology.
eThekwini Water and Sanitation head Ednick Msweli said the municipality was monitoring progress closely and would consider investing in this technology for planned upgrades of water infrastructure that were required in the near future.