Suchergebnisse

ABSTRACTGravel bed hydroponic (GBH) systems planted withemergent hydrophytes, such as Phragmites australis (the common reed), treat domestic sewage effluents to acceptable environmental standards in an economic and efficient manner. Biochemical oxygen demand (BOD), ammonia, and coliform bacteria can be reduced by over 90% and dissolved oxygen (DO) substantially increased. In temperate zones, such as Europe, GBH systems can be used to replace conventional small rural treatment works, and for tertiary treatment of final effluents. In tropical and arid zones, GBH systems can provide locally‐managed, cost‐effective alternatives to hightechnology systems which are inappropriate for use in developing countries. Portsmouth Polytechnic reed‐bed sewage treatment GBH projects in the UK and Egypt are discussed and current progress is assessed.