At MANN+HUMMEL, we not only transform paper into high-performance filters; our very own waste water treatment system also converts our dirty water into clean water. In the past, we simply removed the oil from our waste water and fed it into the waste water system via a pump station.  However, since August we have been running our own waste water treatment system.

At the heart of the system are two ceramic filters, which remove micro-sized particles. But let’s start at the beginning: all production areas have a designated waste water container, where all the dirty water from floors, machines and systems is collected. The water contains solid particles, chemicals, heavy metals and oil concentrates. Just one drop of oil will contaminate 1000 litres of water, meaning it cannot be drained away.

The dirty water from the collection containers is fed into the storage containers of our waste water treatment system. There, a large sieve is used to filter out coarse dirt particles before the water is passed through a band of non-woven fabric, designed to collect fine particles and shavings, and into the working container. Once used, the non-woven fabric is rolled up and disposed of together with the sludge. In the working container, the oil is sucked out and the odours neutralised using biocides. After this preliminary cleaning step, the waste water is piped into the heart of the System.

The two ceramic filters are like fine spaghetti; only clean water (the permeate) comes through, while dirt is pressed to the outside under pressure. The fresh water is then ready to be disposed of through the municipal sewage system. It is not crystal clear and has a different colour depending on the substances in it, but all iron parts and oils have been removed. This is verified by regular checks.