Wastewater FOX monitors emissions into water in real time

Metsä Fibre and VTT have developed Wastewater FOX, a method for calculating the wastewater load from a pulp mill. It enables the real-time monitoring of the chemical oxygen demand (COD) of wastewater generated in the mill process.
“Previously, we monitored COD in wastewater by taking samples, which we analysed once a day. By the time the results were in, they were already outdated,” says project leader Ari Poukka.

Using Wastewater FOX, the mill process can be controlled in a manner that reduces the environmental load.
“We are able to identify the ultimate causes of deviations even before they arise. Compared to the old systems, this method is outstanding.”

Wastewater FOX was first implemented at Metsä Fibre’s Rauma mill in December 2014.

Pleasant surprises at a pulp mill

​Shortly before the end of the school year, Year 9 pupils from schools in Rauma visited Metsä Fibre’s Rauma pulp mill. These traditional spring visits are popular, as they allow the pupils to see and experience what it is like to work in a pulp mill.

Metsä Fibre’s Rauma mill has been hosting visits by pupils since 1997. The programme has remained practically unchanged.  The visit begins with a presentation in the auditorium, where mill guides discuss the company and pulp production while the pupils enjoy fizzy drinks and doughnuts. The speakers also include an employee discussing their employment history, educational background and work in the mill. Then the pupils take a tour of the production department and finally a vehicle tour of the mill area.

The feedback from the pupils shows how little they knew about the forest industry and pulp production before their visit. They are always pleasantly surprised: they were expecting a boring theory lesson. Instead, they are provided with a concise briefing that they think is interesting and clear. Judging from the feedback, the visit to the production department is the most popular, surprising and memorable part of the day.

Some of the pupils will later be hired as summer trainees and perhaps even as permanent employees.

Reusing production side streams

Metsä Fibre, Stora Enso and UPM Kymmene have established a consortium to find reuses for production side streams generated at pulp mills. The first steps have already been taken, and the journey continues.

NSPPulp is a project that involves Ekokem, Outotec, Biolan, Tyynelän Maanparannus, Aalto University and Lappeenranta University of Technology, in addition to the three forest industry giants. Funded by industrial companies and Tekes, the project began in late 2014 and will run until autumn 2017. The participants are seeking solutions for reusing side streams from pulp mills that would otherwise be delivered to landfill sites.

Efficient use of raw materials

The forest industry makes optimal use of raw materials. However, substances are still generated during the process that end up in industrial landfill sites. A legal amendment to be implemented at the beginning of 2016 prohibits organic waste from being delivered to landfill sites.
This means that non-recurring waste must no longer be taken to landfill sites. Side streams include fly ash, green liquor sludge and rejects from the recovery boiler, among other substances.

The project plans will be completed during 2015 and tested in 2016. The results of the project will be examined and summarised during 2017.

The project is based on first-hand information about the needs of end users. After their needs had been identified, project implementation was discussed to ensure that the desired results would be achieved.

Green liquor sludge

Landfill waste from pulp mills mainly consists of green liquor sludge, which is the primary research topic within the project. The metallic content of green liquor sludge continues to be too high. Through research, the project seeks to find a way to remove metals from the sludge. Once a solution has been discovered, it will be possible to use the material as a fertiliser, for example.

Tyynelän Maanparannus, a company that owns Tyynelä Farm and specialises in organic farming, started a three-year field experiment in its area in summer 2015. The experiment is studying the possibility of replacing artificial fertilisers with mixed sludge and improving soil quality. Information about the effects will be available once the experiment is completed.

Other experiments and tests will be carried out within the project as well. Some solutions have already been found. Metsä Fibre’s Rauma mill has signed a bark supply agreement with Biolan.  Bark from wood processing is delivered from the mill to Biolan to be used as a raw material for its soil.