Abstract: A combination of a biological dry toilet and a biological waste water purifying plant. The combination comprises a tank for composting waste, a means for change of air in the tank, and a sludge sedimentation tank. A biofilter is provided through which the water to be purified is circulated. The combination comprises in addition a means for change of air in the biolfilter, a means for circulating the water to be purified in the biofilter, a means for removing the purified water from the sludge sedimentation tank, a means for removing the sludge from the lower part of the sedimentation tank, a means for feeding the water to be purified through the dry toilet, and a means for mechanically purifying said water in the dry toilet. An equalizing basin is included in the waste water purifying plant, the dry toilet being at least partly submerged in said basin.

Abstract: A combination of a biological dry toilet and a biological waste water purifying plant. In the combination the heat and coarse sludge of the so called grey water from households is recovered in the dry toilet to which also the fine sludge from the waste water purifying plant is pumped. The heat obtained is used for heating the compost and both sludges collected in the filters are from time to time combined to compost them together with the other waste in the dry toilet. A suction fan in the dry toilet also sucks the air needed by the biofilter through the filter bed. The purified water obtained from the waste water purifying plant is absorbed in the soil.