Petro-chemical wastewater treatment by biological process

In order to study the feasibility of treating petro-chemical wastewater by the combination of anaerobic and aerobic biological process, a research of treating wastewater in UASB reactor and aeration basin has been conducted. The test results shows that under moderate temperature, with 5.2 kgCOD/(m3&middotd) volumetric load of CODCr in the UASB reactor and 24 h of HRT, 85% removal rate of BOD5 and 83% of CODCr and 1.34 m3/(m3&middotd) volumetric gas production rate can be obtained respectively. The aerobic biodegradability can be increased by 20%-30% after the petro-chemical wastewater has been treated by anaerobic process. As Ns = 0.45 kgCOD/(kgMLSS&middotd), HRT = 4 h in the aeration tank, 94% removal rate of BOD5, 93% of CODCr, 98.8% total removal rate of CODCr and 99% removal rate of BOD5 can be reached.