Abstract: A pump station arrangement for removing harmful fluids from wastewater and a method for removing harmful fluids from wastewater in such a pump station arrangement. The pump station arrangement includes a pre-chamber, a pump sump, 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 harmful fluids in the form of gas in the pump sump. The pump station arrangement is configured to recirculate the wastewater via the recirculation channel from the pump sump to the pre-chamber if the measured content of harmful fluids in the form of gas in the pump sump exceed a predetermined value. Also disclosed is.

Abstract: A pump station arrangement for removing harmful fluids from wastewater and a method for removing harmful fluids from wastewater in such a pump station arrangement. The pump station arrangement includes a pre-chamber, a pump sump, 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 harmful fluids in the form of gas in the pump sump. The pump station arrangement is configured to recirculate the wastewater via the recirculation channel from the pump sump to the pre-chamber if the measured content of harmful fluids in the form of gas in the pump sump exceed a predetermined value. Also disclosed is.

Abstract: One end of a dual-ended housing is closed off by a plug formed of a first constituent which is a water-soluble material and a second constituent which is a thermosetting resin and forms a readily-frangible structure in the plug. An electrical switch which has an actuating plunger is set, in the housing against the plug, so that the latter holds the plunger depressed/retracted. Moisture expands the water-soluble material which, in turn, destroys the plug integrity and, subsequently, the plug is so weakened that the plunger breaks through the frangible structure to actuate the switch.