System for filtering water e.g. rainwater, comprises permeable concrete block comprising water receiving face and filtered water supplying face, substrate layer covering water receiving face, plant, and edge surrounding the substrate layer

摘要

The water filtration system comprises a permeable concrete block (10) comprising a water receiving face (12) and a filtered water supplying face (13), a substrate layer (18) partially covering the water receiving face, a plant (20) consisting of lolium, sorghum, hordeumand trifolium, where roots of the plant extend partly in the substrate layer, and an edge surrounding the substrate layer. The water receiving face comprises a recess (14). The substrate layer is disposed partially in the recess. The water filtration system comprises a permeable concrete block (10) comprising a water receiving face (12) and a filtered water supplying face (13), a substrate layer (18) partially covering the water receiving face, a plant (20) consisting of lolium, sorghum, hordeumand trifolium, where roots of the plant extend partly in the substrate layer, and an edge surrounding the substrate layer. The water receiving face comprises a recess (14). The substrate layer is disposed partially in the recess. The permeable concrete block comprises fresh concrete in cubic meter consisting of: 100-400 kg of a hydraulic binder; 60-400 kg of Portland cement; 0-180 kg of a particulate material or a mixture of materials with average particle size of less than 100 mu m; 0.3-3 kg of a plasticizer; 1300-1800 kg of a gravel or a mixture of gravel with an average size of 3-20 mm; and 40-200 kg of water, and has a hardened density of 1500-2200 kg/m 3>, a porosity of 10-40 vol.% and a compression strength of >= 6 MPa after 28 days.