ABSTRACT:
Biological hydrolysis of urea was studied in an upflow anaerobic sludge blanket (UASB) reactor. Methanol was used as the source of carbon. Modified diacetyl monoxime method was used for the determination of urea in samples having a high background of ammoniacal nitrogen to hydrolyse 100% urea at loadings of 7.09 kg/m3bed vol/d and below. The reactor could be operated at 100% efficiency with NH4+‐N loading of 3.43 kg NH4+‐N/m3bed vol/d. The highest COD utilization rate was 2.32 kg/m3bed vol/d. The advantages of the UASB reactor over the fixed film‐fixed bed (FFFB) and the continuous flow stirred tank reactor (CFSTR) are discussed in the paper.