Human excreta contain valuable plant nutrients as well as organic matter and can be converted into fertiliser and soil conditioner for agriculture. Thus, reuse of human excreta reduces the production of chemical fertiliser which is energy intensive, causes environmental problems and draws on very limited fossil resources. Additionally, the surface water is preserved which is otherwise polluted by discharging human excreta into it. Because of high dilution, it is hardly possible to recover good amount of nutrients in conventional sanitation systems. Even modern wastewater treatment plants that are hardly affordable for developing countries emit nutrients into water bodies where they cause eutrophication. Also, pathogens contained in faeces can spread to the aquatic Environment causing disease to people.

A high amount of nutrient recovery is possible with source control in households. With the application of Resource Management sanitation it is possible to keep human excreta in non-diluted or little diluted form which provides good condition for high levels of nutrient recovery as well as for effective sanitisation. The systems that are applied in Resource Management sanitation for the source control are composting/dehydration toilets, sorting or no-mix toilets as well as vacuum toilets . In compos­ting/de­hy­dra­tion toilet systems either a toilet with urine diversion or no urine diversion is used. In case of no urine diversion toilet, faeces and urine with or without toilet paper depending on the user’s habit drop into the composter located just below the toilet. In urine diversion toilet, urine is collected separately and kept in a storage tank until it is ready for use in agriculture. Urine diversion is crucial for dehydration toilets. The non-diluted faecal materials are dehydrated with the help of heat (solar radiation), ventilation and the addition of dry materials.

The no mix toilet usually has two bowls, the front one for urine and the rear one for faeces. Each bowl has its own outlet from where the respective flow is piped out and treated separately. Urine is stored in an underground tank for sanitisation prior to its reuse in agriculture whereas faeces with toilet paper if used are discharged either into Aquatron system or Rottebehaelter system for solid liquid separation and treatment. The end product of both systems requires post-treatment prior to its reuse. The vacuum toilet uses only 1 litre flush water to flush faeces, urine and toilet paper and the mixer called black water is transported to the biogas plant with the help of a vacuum system. Biogas can be used for heating and lighting whereas sludge can be used in agriculture after sanitisation. Resource Management sanitation systems have been increasingly used around the world. In this lesson, some applications worldwide are presented as well. Also treatment methods for other domestic wastewater that originates from kitchen, shower, wash basin and laundry are discussed.