As industry increasingly looks for wastewater treatment solutions, the VDMA (Mechanical Engineering Industry Association), a not-for-profit European industry association, recently explored wastewater treatments in textile dyeing and finishing in a webinar titled ‘Wastewater reduction and treatment in textile dyeing and finishing’.
The webinar, hosted by Boris Abadjieff, head of exhibition & marketing at VDMA, featured contributions from Bertram Stetter, head of application technology at FONG’S EUROPE, a designer of finishing and dyeing machines; Karl Hesse, senior project engineer at Körting Hannover, which develops and builds wastewater treatment machines; and Dr Norbert Müller-Blanke of the TIA (Technologies for Industrial Wastewater Treatment), a company which installs wastewater machinery and optimises plants to improve treatment systems.
Throughout the webinar, the speakers showcased available technologies to reduce and clean wastewater, while addressing key challenges in wastewater treatments.
Müller-Blanke, for example, drew attention to current trends surrounding the treatment of wastewater. Primarily, people treat wastewater to avoid penalties and adhere to new legislation, Müller-Blanke explained. However, contemporarily, more textile dyeing and finishing plants acknowledge their responsibility to their communities and customers.
But when making the decision to improve their wastewater treatment processes, Müller-Blanke said there are many challenges facing textile dyers and finishers. For example, wastewater is often not easily degradable or organic and has varying loads and flow rates that need to be handled.
Additionally, accidents happen in production, he said, which means a simple and safe operation, yet one that is comprehensive enough to treat wastewater effectively.
Müller-Blanke explained that there are many aspects to consider when adopting textile wastewater treatment technologies. There are so many technologies and often they must be combined in conjunction with one another to cater to customer satisfaction, he added.
Firstly, there is pre-treatment technology – precipitation, lamella separators, flotation (DAF) and filters. Then, there is biological treatment, which ranges from activated sludge, aerobic and anaerobic treatments, biofilm carriers, membrane bioreactors and biological adsorption to chemical oxidisation. Often, he added, there are tertiary treatments like filtration, membrane filtration, reverse osmosis to eliminate salt and adsorption technologies to take the colour out of the water.
Despite these challenges, many wastewater treatment companies continue to innovate the technologies.
For example, Hesse explored Körting Hannover’s new mercerising machine, which allows more sustainable wastewater treatment by utilising traditionally wasted energy. The system enables a factory to reuse heated steam and cooling water to recover strong lye, while funnelling vapour condensate back into the system. The company also showcased its peroxide lye cleaning system for recovered dye.
Meanwhile, Stetter of Fong’s Europe explored how traditional ways to reduce water effluent include using yarn with less or no fibre or low fluff tendency (the less fluff put into the process, the less fluff you have to take from the effluent, he explains), using salt with a low amount of impurities, or using dyeing machines with low liquor ratios, such as the company’s Then Airflow Synergy machine, or its Then Supratec LTM and Then Smartflow (TSF) technologies.
Additionally, Stetter explored the company’s BAT wastewater management system, which utilises airflow technologies and reel-less hydraulic machines to reduce water effluent in the textile process.
For more information, visit www.vdma.org.
