A wastewater treatment plant has a flow of 35,000 m3/day. Calculate the mass of sludge wasted each day (QwXw, expressed in kg/day) for an activated-sludge system operated at a solids retention time (SRT) of 5 days. Assume an aeration tank volume of 1,640 m3 and an MLSS concentration of 2,000 mg/L.