Abstract: A method and control unit for controlling a ballast water treatment system are disclosed. In the method, a prevailing operational condition value relating to the filter unit and/or the treatment unit is determined by means of a sensor. Based on the determined prevailing condition value, a modifying action is performed. The method further includes, when repeated during a determined time interval, tracking a trend for the development of the prevailing operational condition values and/or a frequency for the modifying actions. Based on the tracked trend, a moment in time where a critical value for the prevailing operational condition value is predicted. The ballast water treatment system is controlled by performing the modifying action on the basis of the prediction and/or the value for the determined prevailing condition.

Abstract: A liquid treatment module (2), configured for ultraviolet (UV)-light treatment of a liquid (4) flowing through a first treatment chamber (6) defined as a first elongated circumferential hollow cavity (8) between an outer surface (10) of a first translucent inner sleeve (12) and an inner surface (16) of a first outer sleeve (18?) configured to enclose said first translucent sleeve (12). The inner sleeve (12) is arranged to protect and include a UV-light treatment lamp (14). The module comprises a module inlet connection (20) configured to receive liquid to be treated and a module outlet connection (22) configured to expel liquid treated by the liquid treatment module.

Abstract: A liquid treatment module (2), configured for ultraviolet (UV)-light treatment of a liquid (4) flowing through a first treatment chamber (6) defined as a first elongated circumferential hollow cavity (8) between an outer surface (10) of a first translucent inner sleeve (12) and an inner surface (16) of a first outer sleeve (18?) configured to enclose said first translucent sleeve (12). The inner sleeve (12) is arranged to protect and include a UV-light treatment lamp (14). The module comprises a module inlet connection (20) configured to receive liquid to be treated and a module outlet connection (22) configured to expel liquid treated by the liquid treatment module.

Abstract: A fluid treatment system (2) for treating a fluid (4), the system (2) comprises: —a translucent sleeve (6) surrounding at least one light source (8) and mounted within a cell (10) of the system (2); —a housing (12) configured to receive the sleeve (6) therein, a hollow cavity (18) is defined between an outer surface (14) of the sleeve (6) and an inner surface (16) of the housing (12) defining a cavity for flowing the fluid (4) therein. The system (2) further comprises: —a fluid flowing device (22) to flow said fluid (4) through the hollow cavity (18) at a velocity of 3 m/s or higher such that the velocity of the fluid in relation to the outer surface (14) prevents fouling and/or scaling from aggregating on the outer surface (14) of the sleeve (6), —a recirculation assembly (24) configured to recirculate said fluid (4) through said hollow cavity (18). In addition a method is provided for treatment of a fluid in the fluid treatment system.