What is the status quo with regard to mine water in South Africa?
BP There are a number of old, dilapidated gold mines in the Witwatersrand area where there are rising water levels in the mines and acid water has accumulated. This has started to decant into the Springs, Krugersdorp and central Germiston areas. The Witwatersrand holds the second largest amount of acid mine drainage (AMD) in the world.
The responsibility to deal with the AMD of these mines has fallen on the Department of Water and Sanitation.
Neutralisation is used when treating a large volume of AMD and around 200 Mℓ of water is treated a day. If that water could be recovered, it would assist Rand Water with water supply.
In Mpumalanga, there is ash water with a high pH value. In the coal mine areas, there are evaporation dams with crystal clear blue water that is toxic. Companies like Sasol and Eskom are extremely progressive in that they are recovering this water and reusing it. Desalination and evaporation technologies are used.
In Limpopo and the North West (the platinum belt), the treatment of their water is similar to the treatment of ash water in Mpumalanga.
Are mine water and industrial effluent being treated or dumped?
BP There is legislation to prevent the dumping of untreated water. Some municipalities have by-laws aimed at the discharge of industrial effluent. The legislation and by-laws should be enforced by the Green Scorpions – a network of environmental compliance and enforcement officials from national, provincial and municipal government.
Watericon does get calls from companies that have had to pay fines and are asking for assistance in complying with legislation. But I do not believe that the implementation, monitoring and enforcement of the legislation and by-laws are as effective as they could be.
However, I do believe that large corporates are trying to be responsible and are treating their water to disposable limits.
Is there a cost benefit to outsourcing wastewater treatment operations and maintenance?
BP There is definitely a long-term benefit in using reputable companies that have a track record of water treatment. Watericon has been called to a few sites to fix water issues where a significant amount of money has already been wasted on the wrong type of treatment or on a contractor that could not deliver results.
What advice would you give to companies that want to reduce the cost of water treatment?
BP With any industrial process, waste needs to be minimised from the source. Companies should try to reuse water in their industrial processes. I would also advise on scaling down large, complex systems.
CA It is important to generate value-adds from the process – e.g. the recovery of sludge products that could be sold as animal feed and generating biogas to run boilers that can reduce the cost of water treatment. Producing something that can be reused greatly reduces the cost of treatment. There is definitely a trend where a lot of our customers are focusing
on reuse plants. We were part of an interesting project with AEL Explosives. When manufacturing detonators, the company extrudes aluminium rods that go through the likes of a huge washing machine. Watericon installed a small plant to assist with recovering wastewater and washwater back into the manufacturing process. This reduced the volume of wastewater, which was difficult to treat, being directed into the main effluent plant.
BP A similar project was Willowton Oil. This was for a solar plant where the panels needed to be cleaned and cooled with water. A Watericon treatment unit was installed to reduce the hardness of the water so that it could be reused.
What about water testing?
BP Ideally, a plant would have an on-site verification laboratory. The feed composition should not alter but, when designing a plant, we do add a safety factor. There may be some variances in the composition of raw materials. With larger plants, especially when processing potable water, there would be split sampling between an on-site laboratory and an independent third-party laboratory in order to verify the accuracy of the plant performance. If there is not a laboratory on-site, Watericon can provide a standard laboratory in a container, as well as portable kits for smaller plants.
CA Watericon Laboratories is part of the Watericon Group and is SANAS 17025 accredited. We do a lot of lab analysis of our customers’ effluent in our R&D laboratory. We trial different technologies on the effluent and run the analysis. We can also monitor changes in effluent over time. The plants that we install are designed for a very specific process. Therefore, if any other type of effluent is added to the plant other than that which it was designed for, it may not work. It is very important to consider what effluent you want to treat right at the beginning of the design process.
What advice can you give, when investigating/using a water treatment plant?
CA Watericon Laboratories does a lot of upfront test work – this provides parameters around which a plant is designed. Where possible, we have even used a trial plant on-site that processes small volumes of effluent. This provides important data and a proof of concept for the client. It is key for successful effluent projects. There is no silver bullet that can fix all your water treatment problems. I have personally seen many ‘white elephants’, where millions have been spent on a plant that is simply not fit for purpose. Every industry is different, and every factory generates different wastewater. Make sure that you have a plant that will work on a bench scale.
Are Watericon’s technologies scalable?
BP Most definitely. Watericon provides water treatment solutions to individual homes as well as large mining projects. We have turnkey solutions for all water-related issues for households, mines, industries and municipalities.
Water treatment plants require a lot of capital. There must be many companies that need a plant but have no funds.
CA With Covid-19, capex is very tight. We can offer a BOOT (build, own, operate and transfer) contract. This is where Watericon will finance a project and install a plant, operate and maintain it, and then sell the water (at an agreed-upon amount and quality) back to a company over a 10-year (or longer) period. At the end of the contract, the plant is transferred to the company. This is a trend that more customers are opting for. They typically want to focus on their core business and outsource all waterrelated issues.
What are some of the challenges and opportunities experienced in the water treatment space?
BP Waste is generated whenever water is treated, and waste recovery has become important. There is an increased focus on zero liquid discharge units or zero effluent discharge. There are an increased number of requests for brine treatment, sludge treatment and sludge beneficiation. Sludge is treated to compost, brine sludge has been used to create bricks, and biogas is a viable option for sewage treatment plants.