A thermal cycle engine having a heat exchanger for transferring thermal energy across the heater head from a heated external fluid to the working fluid. The master-detail provider has a query analyzer, a master-detail link handler, a master query handler and a detail query handler. The here presented invention refers to a method and device refer also to the extraction of nutrient salts from toilet andor urinal waste waters, whereas the method comprises the steps urea cleavage, removal of ammonium, and reuse of the toilet flushing water for toilet flushing and these steps are executed preferably in separated devices.