DEVELOPMENT OF URINE TREATMENT TECHNOLOGY FOR ITS REUSE APPLICATION

Abstract

Application of treated human urine as flush water is one of the most promising solutions to combat water scarcity. A grown-up human flushes out nearly 1.5-1.8 L of urine per day. However, this small volume is multiplied 10 times by flush water used to flush this urine making it 15-18 L/Capita/Day. Human urine consists of approximately 91-96% (w/w) water and remaining portion is comprised of organics and inorganics mainly urea which is converted to ammonia by bacteria and makes it difficult to store because of obnoxious odor and color. Electrochemical treatment of urine is performed in 2 L lab scale reactor using Ti-RuO2 electrodes and NaCl electrolyte. Various operating parameters like applied current (1-4 Ampere), treatment time (60-240 min), and electrolyte dose (100-400 mg/L) were studied. Analytical parameters tested were ammonical nitrogen, chemical oxygen demand (COD), odor, turbidity, free chlorine and color. Results revealed that 69% COD, 88% ammonical nitrogen, 95% color, almost 99% turbidity could be removed in 180 minutes of treatment time by applying 4 Ampere current in presence of 300 mg/L of NaCl dose. Available free chlorine was 137 mg/L at the end of treatment which serves as disinfectant. Moreover, electrochemically treated water does not have any unpleasant odor, which makes it suitable for reusing as flush water. Thus, onsite electrochemical treatment can be proposed to recycle human urine to be used as flush water.