Solar evaporation of liquid effluent from composting toilets in cool temperate climates

This thesis investigates the design of a solar powered evaporator aimed at reducing visual intrusion of composting toilet infrastructure on the natural landscape. A series of tests were undertaken beginning in the laboratory, progressing to outdoor conditions at the University ofTasmania in Hohart and culminating in a field test in the Mt Field National Park in southern Tasmania. This field test involved the substitution of the field test evaporator for an existing unit at the Government Huts composting toilet facility. A method for gathering the data to enable matching of evaporator size to effluent output rate was also evaluated. The performance related objectives were realized by increasing evaporative efficiency over the existing National Parks and Wildlife Service (NPWS) design and achieving flexibility in siting through good evaporative performance in cold and diffiise light conditions. Over a twelve month period of operation in an alpine location the 1.5m x 1.5m solar evaporator dealt with all the liquid effluent from two public composting toilets. A method for gathering the necessary empirical evidence to properly match evaporator size to toilet loading was also tested at Mt Field resulting in the calculation of average figures for the volume of liquid expelled to the evaporator per toilet use.