G.R. Pophali, R.S. Dhodapkar, and T. Nandy (India)
PTA effluent, Activated Sludge Process, Anaerobic
reactor, Wastewater treatment, Resource recovery
Wastewater management and energy recovery in
treatment of Purified Terephthalic Acid (PTA) effluent
using anaerobic and aerobic processes is presented.
Activated sludge process (ASP – two stage and single
stage) and upflow anaerobic fixed film fixed bed reactor
(AFFFBR) were used, individually and in combination.
Studies with ASP revealed that the treatment of PTA
effluent using two-stage ASP alone does not meet treated
effluent quality within the prescribed Indian Standards.
However, pretreatment of PTA effluent using upflow
AFFFBR ensured substantial reduction in BOD (63%)
and COD (62%) with recovery of biogas @1.8 – 1.96 l
per l effluent treated at volumetric loading rate (VLR) of
4 – 5 kg COD/m3
.d. Methane content in biogas varied
between 55 and 60%. The pretreated effluent from upflow
AFFFBR was then treated through single stage ASP. The
biomass produced in ASP, after anaerobic treatment had
very good settlability (SVI: 75 –90 ml/g) as compared to
two stage ASP and the treated effluent quality with
respect to BOD, COD and SS was within the prescribed
Indian Standards. The alternative treatment process
comprising AFFFBR and single stage ASP ensured net
energy saving of 257 kW and in addition generated 442
kW energy, through AFFFBR.