MechChem Africa January-February 2022

⎪ Cover story ⎪

bills and valorised biogas and the recovery of other resources. “Financiers are often willing to fund the capex, while Veolia can put a deal together based on a monthly service fee to operate and maintain the plant for the duration of the contract. This ensures that clients benefit from the financial and environmental values while demonstrating responsible resource management,” Murray points out. “This is pretty much what we have been piloting inKZN for the past 20 years.Without having to go to high-end technologies, we are now in a far better position to implement efficiency optimisation improvements and monitoring systems to give early warnings of changes to the inflow, TDS loads or system filtration efficiencies. When wastewater of an unexpected quality enters a treatment system, the fouling on downstream mem- branes and such can quickly become hugely problematic and expensive. Careful monitor- ing and management can help to avert such problems,” he explains. Making sure that water is fit-for-purpose can reduce scaling, fouling of pipes and cor- rosion. Citing a success in the gold mining industry he says a refinery was able to save around tens of millions per year by reducing the corrosion damage on its pumps. “Each pump was costing in the region of R8-million and the mine was having to replace up to six pumps a year. By getting the water quality right, only two pumps had to be refurbished in the following year, which saved on both the pump replacement costs and on associated downtime,” he says. “Veolia Services is an environmental com- pany that, as well as water, looks at energy and solid waste management. Underpinning all of these services, we strive to deliver the SDGs by embracing a shared and respon - sible approach for the mutual benefit of the planet, society, our clients, employees and shareholders. “We believe this makes Veolia a model company fordeliveringecological transforma- tion,” Murray concludes. q

Veolia’s Memthane ® technology uses anaerobic biological treatment and membrane separation to provide potable water, biogas and a sludge suitable for fertiliser.

ally strive tofind improvementson traditional, well-known treatment technologies.”

thewastewater treatment requirements from end toend. Clients come touswithaneffluent andaskuswhatwe candowith it.Wewill then analyse the treatment needs and identify the offtakes, their potential value and the residue disposal costs. From a water perspective, we canmake thewater environmentally friendly and safe at many levels: for direct use as grey water in the factory, for discharging back into the environment as surface water, or we can treat it for use at any quality level required,” Murray informs MechChem Africa . In addition, issues such as pipe bursts can causewater dependent businesses tocome to a grinding halt for two to three days. Properly managed reuse systems can significantly reduce these risks. While water reuse is gaining traction in South Africa, Murray says that water costs are still reasonably cheap compared to inter- national standards, whichmakes investments harder to justify. “We are responding to this challenge by putting funding mechanisms in place to make it easier for users to invest in reuse systems such as these,” he notes. Options include securing finance for an eight to ten year repayment period on capex, which can make a business case quite strong with respect to returns. “We are happy to consider co-funding of such systems or success-based models that are funded via shared savings accrued from reduced water

Water reuse in the food and beverage industry

Another area of increasing demand forwater reuse technologies in South Africa is inwater challenged areas such as the Eastern Cape, where businesses are coming under pres- sure to reduce their offtake from the local municipalities. “We are currently running a resource recovery project inMossel Baywith a dairy producer, for example, withwastewa- ter volumes that contain organicmatter from milk, yoghurt and cheese residues,” Murray continues. Using Veolia’s Memthane ® technology, which combines anaerobic biological treat- ment andmembrane separation, the company can provide an innovative and environmen- tally friendly waste water processing system that produces a methane rich fuel gas from organic solids, while alsodelivering highqual- ity potable water for reuse in the process. In Mossel Bay, themethane gas is stored inpres- surised tanks for use in the factory’s boilers and even the sludge that remains is reused by the local farming community as a fertiliser. This project is currently converting a minimumof 60%of thewastewater topotable standards. This is combinedwith the incoming municipal stream on the factory side of the water meter, reducing demand and associ- ated costs. “If a producer is paying R34/m 3 for water and the water recycling costs are between R18 and R22/m 3 , then installing a wastewater treatment plant can be very cost effective as well as environmentally friendly. “While the company gets kudos for reduc - ing its offtake and for reducing municipal ef - fluent treatment requirements, we estimate thepaybackperiodbasedonthecurrent reuse rate to be in the region of eight years – and this doesn’t include the cost reductions due to expenses and fines associated with having to safely dispose of these effluents, which can ratchet up very quickly. “Going forward, we seek to take care of

One of Veolia’s flagship projects has been treating wastewater and supplying it for reuse to local industries in KwaZulu-Natal for the past 20 years.

January-February 2022 • MechChem Africa ¦ 5