Efficiency of wastewater treatment by land disposal and its effects on crop productivity

Abstract

Land application of wastewater is one of the oldest methods used for treatment and disposal of wastes.The main advantages of this technique are the low initial and maintenance costs involved,high Nutrieht recyle capacity, and the increase of crop growth. Because of these factors it is believed that land disposal is an advantageous thechnique for deyelooing countries and is strongly recommended for the rural areas of Turkey. in 1984, a 25 meters long channel was constructed by A-Bavsal in Boğaziçi University's Garden.These Channels were filled with sand and gravel domestic wastewater was applied. The variation of wastewater characteristics with timerdistance and effective size of media were investijated through out the anplication period in 1985. Removal efficiencies obtained are given below: Chemical Oxvqen Demand(C0D) 76% in the Sand bed for 35days - 60% in the Gravel bed for 35days -- Nitrogen (N) 70% in the Sand bed for 35 days - 57% in the Gravel bed for 35days -- Phosnhorus (P) 77% in the Sand bed for 35 days - 64% in the Gravel bed for 35days. The study of crop productivity has been performed at Faculty of Forest of Istanbul University. Its aim was to examine the crop productivity of the media through which wastewater has been disnosed.The best result was obtain from a mixture containing 80% of the media and 20% of soil.