Ballast water treatment apparatus and methods for preventing foreign aquatic invasive species form entering marine ecological zones by translocation in ship's ballast water. The apparatus includes a housing, a filter member, and UV water treatment chambers. Methods include use of a ship's fire hydrant system for moving ballast water from the ship's ballast tanks into the apparatus for filtration and treatment. In-port service vessels and dock-side service vehicles are equipped with the treatment and filtration apparatus to provided in-port or dock-side ballast water treatment services. Related methods are also provided.
The invention concerns a method for thickening sludge derived from a water treatment plant by flocculation-decantation with floc ballasted with micro-sand or other dense granular material using a liquid cyclone treatment (1) of the decantation sludge. The invention is characterised in that it comprises successive steps which consist in: degassing (3) the overflow sludge of the liquid cyclone treatment (1) from the ballasted flocculation decantation unit, said degassing step being carried out on a corresponding degassing surface at a degassing surface velocity of less than 100 mph; injecting at least a flocculating reagent (4) into said sludge; and thickening said sludge in at least a laminar sludge thickener (6), with a stilling floor load calculated at the thickener floor surface higher than 200 kg of suspended matter per m.sup.2 per day and the extracted sludge concentration higher than 10 g/l.
A drinking water treatment system includes a pump for pumping water from an aquifer, an aerator connected downstream from the pump for generating an outlet water flow and a hydrogen sulfide-containing gas flow, and a hydrogen sulfide scrubber for scrubbing the hydrogen sulfide-containing gas flow from the aerator. The hydrogen sulfide scrubber includes at least one scrubber tank and scrubber media contained therein. A scrubbing solution circulator includes a dispenser for dispensing scrubbing solution into contact with the scrubber media, a sump for collecting the scrubbing solution after contact with the scrubber media, and a circulating pump for circulating the scrubbing solution from the sump back to the dispenser after contact with the scrubber media. A triazine compound supply is provided for supplying a triazine compound to the scrubbing solution. The triazine compound may be used in place of caustic to reduce build-up in the scrubber