Unlike most of our competition, at Wärtsilä Water & Waste we don’t believe in the use of plastic biomedia or habitats in our bioreactors and other advanced wastewater solutions. We do not use bio-media or habitats in our systems at all. When draining or flushing a ship’s bioreactor tank the risk of a potential hazard of bio-media pollutants ending up in our oceans is too big. Moreover: the replacement of these bio-media is costly. and can be a very dirty and unhygienic operation.
Bio-media are typically used in ‘Moving Bed Biofilm Reactors’ (MBBR) technology. It is a given that there is loss of bio-media within these MBBRs as the fluidized bed is designed to improve oxygen transfer by abrasive action among the plastic media. MBBR systems include replacing bio-media in their planned maintenance programmes. In many cases no guarantees are given that the broken pieces of plastic bio-media or PP/PVC matrix - as result of wear & tear - are caught at the last treatment stage.
Our own Wärtsilä membrane bioreactors as well as our sewage treatment plants use a form of suspended growth active aeration in order to get oxygen into the decomposition process. Once filtered by our membranes at the end of the cycle, we can guarantee that all micro plastics are hold back and don’t end up in our oceans during discharge.