The new solution works by treating wastewater through a three-stage process before it is supplied to the Ingolstadt plant for reuse. It first passes through a chemical-physical process. This neutralizes alkaline and acidic components and removes heavy metals. Here’s where the bioreactor comes in. The water is mixed with sanitary wastewater and freed from organic components. The MBR then removes bacteria and viruses from the wastewater using pore-fine membranes – this is going one step further than conventional sewage treatment plants, which don’t use the process. Finally, reverse osmosis removes residual salts. The treated wastewater is then returned to the production process.
The new treatment supplements other sustainable initiatives by Audi. For instance, the brand is increasingly using rainwater for service water purposes at its Ingolstadt plant. Rainwater from over 450,000 square meters of roof and parking space is collected in underground cisterns. Depending on weather conditions, up to 260,000 cubic meters of rainwater can be used annually.