Water, Sewage & Effluent May-June 2018 | Page 40

The root system in the first-generation prototype VUF-MEWS. Bacterial colonies living on the roots provide the processing needed to remove nutrients and metabolise metals and other harmful substances. Specific bacterial and archaea species can be inoculated to metabolise specific compounds, but this research is ongoing globally. waste is entirely possible. From an economic perspective, the technologies are becoming more affordable, with reverse osmosis (RO), ultra-filtration (UF), membrane bio-reactor (MBR), and engineered wetlands each having a rightful place in any optimal solution. What is needed in South Africa is political leadership to articulate a clear vision about the future economic growth of the country being based on a dual-stream economy where water of different qualities and price is used for different purposes. This vision should be supported by robust scientific studies, carefully designed to allay public fears. In a dual-stream reticulation economy, water recovered from waste need not necessarily be used for potable purposes, as it can easily be directed to industrial applications. In Durban South, a pulp mill and a petrochemical plant are the end users. Given the strategic importance of ‘New Water’ as a critical element in driving inclusive economic growth, consideration could be given by the government to create a water board at national level, responsible only for New Water. This would give government control, while enabling existing water boards to continue their normal task of providing bulk potable water. In effect, the existing water boards would become the customer for the product created by the New Water Board — either desalinated seawater or mine water, or water recovered from waste. International experience has shown that the key element is the management of perceptions, so branding must be credible and scientific research on human health risks must be transparent and accessible. The use of engineered wetlands as final polishers of water recovery processes is likely to grow in acceptability. u