Wastewater treatment method and apparatus

Claim 1

Water treatment apparatus, for the treatment of polluted water, wherein: the apparatus comprises a treatment station, which includes a container, in which is contained a body of a foam material; the treatment station includes a water-throughflow-control-means, including an inlet and an outlet, for conveying water through the container; the apparatus includes a means for admitting polluted water into the container, through the inlet, and onto the body of foam material; the treatment station includes means for enabling the polluted water, so admitted, to percolate gradually down through the body of foam material; the foam material is of a sponge-like, open, cellular structure, in which the cells are mutually interconnected; the cells are so small that water does not, in substance, drain from the cells, whereby the foam material remains substantially constantly saturated with water; the cells are so small that water present in the cells is retained in the cells by sponge action, being action in which water is drawn into and retained in the cells by surface tension, and is spread from cell to cell by capillary action; the foam material is elastomeric, flexible, soft, and resiliently deformable; the foam material in the container is in the form of many separate blocks; the blocks are arranged in a loose, open, heap in the container, and the blocks in the heap touch each other at places of contact; the blocks in the heap form large, free, open, interconnected voids and spaces, through which air can circulate smoothly and freely, around and between the blocks; the voids are so large that water cannot, in substance, support itself in the voids by surface tension, whereby water in the voids drains from the voids, leaving the voids substantially freely open and clear to the circulation of air therethrough; the water-throughflow-control-means includes means for moving water through the container in such a way that the said voids and spaces are maintained substantially open and clear of water; the blocks are so resiliently soft and deformable that, at the said places of contact between the blocks, the material of the blocks deforms and spreads resiliently, whereby, at the places of contact, the blocks lie in water-transmitting contact with each other over a substantial contact area; the block size, and the porosity of the foam, are so selected as to form means for retaining, between dosings, a body of water, to undergo further biological treatment, inside the block, between dosings.