How to Achieve Zero Wastewater Discharge in Papermaking

●The new AquaLine Zero product in Voith's AquaLine series can reduce fresh water consumption per ton of paper to 1.5 cubic meters, achieving zero wastewater discharge

Reducing fresh water consumption and adhering to sustainable development is one of the main challenges in paper enterprises' operations. The new AquaLine Flex and AquaLine Zero solutions in Voith's AquaLine water management series not only greatly reduce fresh water consumption in the papermaking process but further achieve a fully closed water loop.

Recently, the innovative AquaLine Zero solution jointly developed by Voith and the German paper enterprise Progroup successfully completed its first trial run.

With this system, producing one ton of paper requires only 1.5 cubic meters of fresh water, while carbon emissions are reduced by about 10%.

Eckhard Gutsmuths

Voith Product Manager

Progroup wants to reduce resource consumption as much as possible without affecting production quality.

The company can produce 750,000 tons of containerboard and corrugated board annually. Through the closed-loop water treatment unit integrated in AquaLine Zero, about 8,500 tons of fresh water can be saved every day.

AquaLine

AquaLine wastewater treatment technology can simultaneously carry out anaerobic and aerobic biological treatment of papermaking process water, achieving sustainable water management. With this technology, producing one ton of packaging paper requires only 5.5 to 7 cubic meters of fresh water, and the purified process water discharged per ton of paper produced is only 4 to 5.5 cubic meters.

AquaLine Flex

AquaLine Flex further improves the effectiveness of the water management system. By integrating an additional filtration system into the paper machine's water loop, process water is purified and reused, thus reducing fresh water use. Through the biological treatment unit and filtration system, fresh water consumption per ton of paper is reduced to below 5.5 cubic meters, while wastewater discharge per ton of paper is below 4 cubic meters.

AquaLine Zero closed-loop water loop

The AquaLine Zero biological treatment unit uses a fully anaerobic process (the so-called "biological kidney") to achieve a completely closed water loop. All purified water returns to the pulping process, bringing wastewater discharge down to zero. In addition, the filtered purified water can replace fresh water, greatly reducing fresh water consumption. The large amount of biogas produced by the fully anaerobic biological treatment process can be used as a main energy source, helping reduce energy consumption and carbon emissions.

With AquaLine Zero, all purified water returns to the pulping process, bringing wastewater discharge down to zero

Reducing chemical oxygen demand in the papermaking process

When treating process water, the most critical requirement is to reduce chemical oxygen demand (COD), that is, the content of all oxidizable substances in water under specific conditions. COD in process water mainly comes from sludge, starch and additives. Anaerobic and aerobic treatment can reduce the COD components in water. After biological treatment, process water is purified and reused, thereby saving resources.

AquaLine and AquaLine Flex technologies, while reducing operating costs, significantly improve paper enterprises' sustainability, enabling capacity increases under increasingly strict environmental requirements.

AquaLine Zero can reduce fresh water consumption per ton to 1.5 cubic meters, achieving zero wastewater discharge and thereby the best results for paper mills.

Voith is continuing to move forward in improving the sustainability and decarbonization performance of the paper industry.

Voith Paper is a division of the Voith Group. As a full-line supplier to the paper industry, Voith offers the market's broadest range of technologies, services and products and provides paper manufacturers with overall solutions from a single source. Voith Paper is committed to continuous innovation, resource-saving production and helping customers minimize their corporate carbon footprint. With leading automation products and Papermaking 4.0 digital solutions, Voith Paper provides customers with the most advanced digital technologies to improve availability and efficiency in every link of paper production.

Voith is a global high-tech group. With a broad range of solutions including systems, products, services and digital applications, Voith sets industry standards in the fields of energy, oil and gas, paper, raw materials, and transport and public transport. Founded in 1867, the Voith Group has more than 20,000 employees worldwide, with operations in more than 60 countries and annual sales of EUR 4.2 billion, making it one of Europe's largest family-owned enterprises.

——This article is reproduced from China Packaging Network (pack.cn), original link: http://news.pack.cn/show-377472.html