Preliminary results for start-up and adaptation of an EGSB reactor for valorization and treatment of fresh urine

Processing of the liquid phase remaining after nutrient recovery from source separated urine using clinoptilolite is an important issue regarding environmental protection. Possibility of anaerobic treatment using an expanded granular sludge bed reactor for this purpose is investigated as an option to remove organic matter together with possible biogas generation. To start this investigation, an anaerobic granular sludge from a confectionery industry was adapted to source separated fresh urine, which is highly saline with an electrical conductivity of 8,000 mu S/cm, has a high ammonium concentration (900 mg NH4+-N/L) and relatively high organic content of 1,200 mg COD/L. In a period of observation which exceeded 2 months, 75% and 60% of removal could be achieved for soluble and total COD, respectively, together with minor amounts of NH4+ release into the liquid phase. The amount of CH4 to be produced was calculated from COD removal as 1.3 L CH4/d and 0.24 L CH4/L urine. The preliminary results obtained in this work were motivating for further investigation upon the subject matter with emphasis on the effect of high salinity content.