Zero Wastewater Discharge in Papermaking: Voith's AquaLineZero Hits 1.5 m³ Fresh Water per Tonne in First Trial Run

●Voith widens its AquaLine water-management family with AquaLineZero, a solution that brings fresh water use down to 1.5 m³ per tonne of paper and reduces wastewater discharge to zero

For paper producers, two questions never go away: how to curb fresh water intake, and how to stay on a sustainable path. Voith's AquaLine water-management series now offers two new answers — AquaLineFlex and AquaLineZero — which sharply reduce fresh water consumption in papermaking and, in the case of AquaLineZero, push the water circuit all the way to a fully closed loop.

The innovative AquaLineZero solution, developed jointly by Voith and German paper manufacturer Progroup, has just completed a successful first trial run.

Running on this system, a tonne of paper calls for only 1.5 m³ of fresh water, while carbon emissions fall by roughly 10%.

Eckhard Gutsmuths

Product Manager, Voith

Progroup's aim is to keep resource consumption as low as possible without compromising production quality.

The company turns out 750,000 tonnes of containerboard and corrugated board each year, and the closed-loop water treatment unit integrated into AquaLineZero saves it around 8,500 tonnes of fresh water every day.

AquaLine

AquaLine wastewater treatment technology applies anaerobic and aerobic biological treatment to papermaking process water at the same time, putting water management on a sustainable footing. Under this technology, each tonne of packaging paper takes only 5.5 to 7 m³ of fresh water, and purified process water discharged per tonne of paper amounts to just 4 to 5.5 m³.

AquaLineFlex

AquaLineFlex lifts the performance of the water-management system another notch. An additional filtration system built into the paper machine's water loop purifies process water for reuse, which in turn reduces fresh water demand. Thanks to the biological treatment unit working alongside the filtration system, fresh water consumption per tonne of paper drops below 5.5 m³, while wastewater discharge per tonne of paper stays below 4 m³.

AquaLineZero closed-loop water circuit

The biological treatment unit in AquaLineZero relies entirely on an anaerobic process — the so-called “biological kidney” — to close the water loop completely. All purified water returns to the pulping process, taking wastewater discharge to zero. Filtered purified water can also stand in for fresh water, cutting fresh water consumption dramatically. The substantial volume of biogas produced by the fully anaerobic process serves as a primary energy source, helping to lower both energy use and carbon emissions.

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

Bringing down chemical oxygen demand in papermaking

When process water is treated, the single most important 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 comes mainly from sludge, starch and additives. Anaerobic and aerobic treatment strip those COD components out of the water. Once biologically treated, process water is purified and circulated back into use, saving resources.

AquaLine and AquaLineFlex not only lower operating costs but also give paper producers a clear sustainability boost, allowing them to raise capacity even as environmental requirements tighten.

AquaLineZero delivers the best results for a paper mill: fresh water consumption down to 1.5 m³ per tonne and zero wastewater discharge.

Voith keeps pressing ahead on sustainability and decarbonization performance for the paper industry.

Voith Paper is a division of the Voith Group. As a full-line supplier to the paper industry, it offers the market's broadest portfolio of technologies, services and products, delivering overall solutions to paper manufacturers from a single source. Voith Paper is committed to continuous innovation and resource-saving production, and to helping customers minimize their corporate carbon footprint. With leading automation products and Papermaking 4.0 digital solutions, Voith Paper equips customers with advanced digital technology that raises availability and efficiency at every stage of paper production.

Voith is a global high-tech group. Its broad range of solutions — systems, products, services and digital applications — 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