摘要:
This invention relates to an apparatus attachable to a small-scale purification unit for precipitating phosphorus from waste water, said apparatus comprising a pumping vessel (1), a discharge pump (2) for unloading the pumping vessel, a chemical tank (6), a chemical metering pump (5) for dispensing a chemical from the chemical tank (6) into waste water to be discharged from the pumping vessel (1), whereby a separation of the resulting chemical precipitate from water draining out of the purification unit is arranged to be accomplished in a settling tank (12) of the small-scale purification unit. In this invention, the metering pump (5) is arranged to supply a chemical coagulant into an effluent flow discharged by the discharge pump (2) over an entire or almost entire operating cycle of the discharge pump (2).