Binzhou Yuyue Home Textile commissions 15,000 m3/d near-zero liquid discharge line for dyeing wastewater, plant-wide water reuse rate exceeds 96%

According to Dazhong Daily, republished by Xinhua Net's Shandong channel, Binzhou Yuyue Home Textile in Shandong is reshaping traditional textile manufacturing with artificial intelligence and digital technologies, with circular water use forming one pillar of that transformation.

Source reduction: moving salt and emission control upstream

Dyeing and printing consume large volumes of water and involve dyestuffs, auxiliaries, salts and alkali. Yuyue upgraded its digitally intelligent spinning line and carried out water-saving, salt-control and emission-reduction retrofits, combining process optimisation, equipment renewal and resource recycling. Before any wastewater is generated, low-temperature pretreatment, salt-free dyeing and digital inkjet printing reduce resource intensity; project data indicate that associated washing wastewater can be cut by up to 40%. Salt-free dyeing also shifts salt control upstream into the production process itself.

Three-tier reuse: matching water quality to each process step

For wastewater that is generated, the company matches available water quality to the demand of each process step through a three-tier reuse system spanning inter-process, cross-workshop and plant-wide levels, extracting maximum value from water before it enters advanced treatment.

• High-alkali wastewater: an independently developed membrane technology achieves closed-loop recycling of alkaline water, saving 3,150 tonnes of fresh alkali per year. The related achievement won a first-class Science and Technology Progress Award from the China National Textile and Apparel Council.
• Near-zero liquid discharge demonstration line: a 15,000 m3 per day facility for printing and dyeing wastewater applies a combined physicochemical, biological and multi-stage membrane salt-splitting plus evaporative crystallization process, progressively purifying the stream so that reclaimed water can be reused in core operations such as dyeing and printing.
• Overall performance: plant-wide water reuse now exceeds 96%, with 4.07 million m3 of wastewater reused annually.

Water savings on the spinning side

In spinning, the company's proprietary digital coloured spinning technology reaches a target shade with only 10% to 20% coloured fibre, saving 67% of water compared with conventional yarn dyeing. Because less fibre needs to be pre-dyed, consumption of dyestuffs and chemical auxiliaries falls accordingly.

From using less water at the front end, to multiple rounds of intermediate reuse, to advanced treatment at the tail end, water use is shifting from one-way consumption to circulation.