Treatment of Pharmaceutical Wastewater Using Sequencing Batch Reactor

The objective of this study was to determine the optimum operating conditions
for the effective treatment of a pharmaceutical wastewater by sequencing batch reactor.
The wastewater sample was obtained from a pharmaceutical company in Bangi, Kuala
Lumpur. The characteristics of the wastewater: pH 4.36; BOD5 765 mg/L; COD
1352mg/L; TSS 71.3 mg/L; NH3-N 6.8 mg/L; N03-N 30 mg/L; total phosphorus 18.13
mg/L; sulphate 20 mg/L, sulphide 0.28 mg/L and TKN 44.34 mg/L. The wastewater
was treated using sequencing batch reactor process that included the following five
stages: Fill, React, Settle, Decant and Idle. Three different HRT values were tested (12
hr, 24 hr and 48 hr) with each cycle operating under high MLSS and low MLSS
concentrations simultaneously. Both reactors operated with an organic loading rate of
1.35 kg COD/m3. A 24 hr HRT showed the best performance. Optimum operating
conditions resulted in the following effluent characteristics, COD 217±23.2 mg/L, BOD
46±9.8 mg/L, pH 7.7±0.2, TNK 23.35±17 mg/L, N03-N 0.21±0.08 mg/L and NH3-N
4.4±2.1 mg/L. It is recommended to use a pre treatment by chemical or anaerobic
process.