Abstract: Method for treating impurities contained in exhaust gases of ships to reduce sulphur oxide and other emissions. In order for the method to purify wash water exiting from an exhaust gas scrubber sufficiently enough to be directly dischargeable to sea, and in order for a purification unit used to be small enough to be easily placed onboard a ship, exhaust gases are scrubbed in the exhaust gas scrubber and wash water containing impurities and exiting from the scrubber is supplied to the purification unit, circulated in an effluent circuit, and filtered through a semipermeable membrane of a filter to obtain purified effluent and a residue containing impurities, when necessary, the pH value of the purified effluent is adjusted to be at least 6.5, after which it is discharged into the sea or recycled to the scrubber while the residue containing impurities is led back to the effluent circuit.

Abstract: A method for treating impurities contained in exhaust gases of ships to reduce sulphur oxide and other emissions, includes scrubbing the exhaust gases in an exhaust gas scrubber and supplying wash water effluent exiting from the scrubber and containing impurities to a purification unit onboard a ship. In order for the method to purify wash water exiting the scrubber sufficiently enough to be discharged directly to sea, the purification unit includes a moving filter band, whereby an aqueous fluid containing impurities originating from the effluent is together with a precipitating agent fed to a surface of the inclined filter band and filtered there through to concentrate impurities onto the surface of the band filter as a precipitate. When necessary, the pH of the purified effluent is adjusted so that it is at least 6.5 before discharging the purified effluent into the sea or returning it to the exhaust gas scrubber.

Abstract: A method for treating impurities contained in exhaust gases of ships to reduce sulphur oxide and other emissions, includes scrubbing the exhaust gases in an exhaust gas scrubber and supplying wash water effluent exiting from the scrubber and containing impurities to a purification unit onboard a ship. In order for the method to purify wash water exiting the scrubber sufficiently enough to be discharged directly to sea, the purification unit includes a moving filter band, whereby an aqueous fluid containing impurities originating from the effluent is together with a precipitating agent fed to a surface of the inclined filter band and filtered there through to concentrate impurities onto the surface of the band filter as a precipitate. When necessary, the pH of the purified effluent is adjusted so that it is at least 6.5 before discharging the purified effluent into the sea or returning it to the exhaust gas scrubber.

Abstract: Method for treating impurities contained in exhaust gases of ships to reduce sulphur oxide and other emissions. In order for the method to purify wash water exiting from an exhaust gas scrubber sufficiently enough to be directly dischargeable to sea, and in order for a purification unit used to be small enough to be easily placed onboard a ship, exhaust gases are scrubbed in the exhaust gas scrubber and wash water containing impurities and exiting from the scrubber is supplied to the purification unit, circulated in an effluent circuit, and filtered through a semipermeable membrane of a filter to obtain purified effluent and a residue containing impurities, when necessary, the pH value of the purified effluent is adjusted to be at least 6.5, after which it is discharged into the sea or recycled to the scrubber while the residue containing impurities is led back to the effluent circuit.