The Beijiao Xinhe river in China

The Beijiao Xinhe river in China

The ZDHC Roadmap to Zero Programme has published guidance on wastewater treatment technologies as part of its goal of achieving zero discharge of hazardous chemicals in the textile, leather and footwear supply chain.

The industry uses huge amounts of water in production processes, after which the water is often discharged in a way that harms the environment and surrounding communities, ZDHC says. This has become a huge problem over the last few years, especially in China, South and Southeast Asia and other production countries around the world.

To try and improve wastewater management in the industry, ZDHC released the first Wastewater Guidelines for the apparel, textile and footwear industry in 2016. These set unified expectations on wastewater quality.

"When we released the ZDHC Wastewater Guidelines, we took the first step for the industry to treat wastewater in a harmonised way," says Frank Michel, ZDHC executive director. "The guidelines present an aligned set of parameters, limit values and test methods to ensure brands and suppliers are working to the same set of expectations."

The new ZDHC Wastewater Treatment Technologies document is now designed to support the supply chain in implementing the guidelines and to help improve the quality of wastewater discharge.

The document includes guidance on pretreatment, primary treatment, secondary and tertiary treatment, colour and antimony removal, water reuse and resource recovery, and sludge production.

"Wastewater treatment is a complex process, and ZDHC hopes that in combination with regional training programmes and other relevant references, this technical overview of wastewater treatment technologies will help the supply chain to close the knowledge gap," ZDHC says.

"It is also intended to motivate wet processing facilities and elevate their knowledge to implement the necessary treatment systems in order to meet the requirements of the ZDHC Wastewater Guidelines."