Nitrification of yellow waters in bed percolating of sand

ABSTRACT Ecological sanitation awares about the importance of a more efficient water reuse and the use of decentralized wastewater treatment systems. This paper describes the results of yellow waters’ nitrification in a biological reactor made up of simple materials, like sand as support material, aiming to make this liquid waste available for the use of mineralized nitrogen in sustainable agriculture. The experimental system was monitored through pH, dissolved oxygen (DO), total alkalinity (ALK), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), ammonia nitrogen (AN), nitrite (NO- 2) and nitrate (NO- 3). The system showed good removal of organic matter and excellent conversion of nitrogen to nitrite and nitrate, with efficiency of transformation of TKN to nitrate of about 93%.