The Bio-works, Kolding, Denmark As part of an urban renewal project, a rundown area behind several housing blocks in Kolding was redeveloped for an ecological waste water treatment plant powered by electricity from photovoltaic cells. The heart of the Bio-works is this four-storey pyramid containing a series of ponds on different levels stocked with algae, plankton and fish. Waste water from neighbouring houses filters down through the ponds to end up purified in an adjoining reed bed. Some of the cleaned water is recycled back to the houses (but not for drinking). The ponds inside the Bio-works grow plants and flowers for sale. Photo source: Still Pictures Ref No: 1116957 << Previous Image | Next Image >> Back to gallery