Pump station arrangement and method for removing harmful fluids from wastewater

A pump station arrangement in a wastewater transportation system, wherein the pump station arrangement comprises:

• a pre-chamber having an inlet for influent wastewater connected to one or more households and an outlet,
• a pump sump having an outlet connected to a sewage system or to a sewage treatment plant for effluent wastewater, and an inlet that is in fluid communication with the outlet of the pre-chamber by an intermediate conduit such that wastewater is transported from the pre-chamber to the pump sump under the influence of gravity through the intermediate conduit,
• at least one pump connected to the outlet of the pump sump and to a recirculation channel extending from the pump sump to the pre-chamber, and
• a gas sensor arranged in the pump sump and configured to measure the content of hydrogen sulphide (H2S) in the form of gas in the pump sump,
• wherein the pump station arrangement is configured to remove hydrogen sulphide (H2S) in gaseous phase or in liquid phase from the wastewater by transformation of the H2S by oxidation to an oxidized sulphuric species by recirculating wastewater via the recirculation channel from the pump sump to the pre-chamber if the measured content of H2S in the form of gas in the pump sump exceeds a predetermined value.