Here we have our focus on factories handling pulp, paper, cardboard, etc. The paper industry is one of the largest consumers of water. Processes consuming serious amounts of clean water, mostly (~85%) as high-quality process water. In total it’s about volumes of over 10 times more (waste)water then finished products. On the downstream side, paper mills also create difficult-to-manage wastewater and sludge. As a result, environmental issues must be prevented. Resulting in challenges for wastewater and sludge treatment.

The process water becomes contaminated during the manufacturing processes. With contaminants like sediments, effluent solids, chlorinated organic compounds, organic halides (AOX), salinisation and chemical oxygen demand (COD) and biological oxygen demand (BOD) contaminants. Fibres as cellulose, wood and recovered paper are involved too. But also ink from de-inking could be applicable.

On-site treatment is mostly mandatory due to the volume and type of wastewater. Common treatment technologies include clarification for removal of solids and particles. On the other hand, biological treatment for removal of biodegradable organics and for diminishing of toxicity is a key solution. Sometimes the effluent is further treated with UV disinfection, and membrane, ion exchange, and activated carbon systems.

For the wastewater we must overcome issues from particles/fibres, salinization, odour, bleaching processes, scaling, foam, and many more. Positive aspect is that often huge amounts of biogas can be produced too.

Many of our realised solutions therefor are based on a proper pre-treatment, anaerobic treatment and biological treatment.