A new dissolved air flotation (DAF) system aimed at improving the treatment of industrial and municipal wastewater was among the technologies showcased by water solutions company Xylem at Electra Mining Africa 2026.

Xylem launched the system in March, with a pilot unit demonstrated at the exhibition.

“It’s a DAF system that removes suspended solids, fats, oils and grease (FOG), and particulate-associated chemical oxygen demand (COD) and biochemical oxygen demand (BOD) from wastewater streams,” says Xylem director: sales and service, WSS (AMETI) in Africa Bennie Thiart.

The technology is designed to remove contaminants from wastewater before further treatment.

The process can reduce particulate COD and BOD loading before downstream treatment using chemical or ozone treatment, making the water easier to treat for reuse.

“Its functions as a pre-treatment and solids-separation step support downstream treatment processes,” he adds.

Xylem’s product information notes that its RT Series DAF systems are designed to remove total suspended solids, FOG, and particulate-associated BOD from industrial and municipal wastewater streams. The systems can also remove proteins, fine particles, and particulate-bound metals following appropriate chemical conditioning.

The process involves injecting air into a pressurised recycle stream of clarified DAF effluent (‘white water’). The air-saturated stream is combined with incoming wastewater, with the pressure then normalising to create millions of microscopic bubbles.

These bubbles attach to suspended solids and conditioned contaminants in the wastewater and cause them to rise to the surface, where they form a floating layer that is removed by a surface skimmer.

The technology can be used for several treatment purposes, including product recovery and reuse, pretreatment to support site-specific discharge objectives, the reduction of loading on downstream biological treatment systems, the polishing of biological treatment effluent, and thickening and clarifying biosolids.

Xylem is also offering the DAF technology through pilot and rental applications. “We [are] negotiating [a rental project] with the end-user, and then we’ve . . . a really good pipeline that we’ve built up since March, where we have all of these pretreatments that we can do with the DAF system,” adds Thiart.

The rental units are intended to provide rapid, on-site deployment where temporary treatment capacity is required, including when an existing DAF system is out of service.

Thiart says the RT Series is skid-mounted, which significantly reduces field assembly and simplifies installation. Its stainless steel tank is available in 304 or 316 stainless steel grades, while the design does not use plate packs, which can foul, collapse or clog.

The system also incorporates an internal float hopper, automated float hopper and settled solids auger, while an integral flocculation tube has three chemical injection ports for mixing coagulants and flocculants.