Treatment of high strength pharmaceutical wastewaters in a Thermophilic Aerobic Membrane Reactor (TAMR)

Abstract

In the present work we studied the thermophilic biological treatability of high strength liquid wastes from a pharmaceutical industry (rich in organic matter - COD: Chemical Oxygen Demand, nutrients and salinity). Different mixtures (with concentrations of COD, phosphorus and chloride up to 57,000 mg L(-1), 2000 mg L(-1) and 9000 mg L(-1), respectively) were tested. The pilot plant used in this work was designed and built with dimensions comparable to a semi-industrial unit. The results are therefore representative for full-scale applications. During four months of experimentation, the pilot plant (TAMR - Thermophilic Aerobic Membrane Reactor) was operated at 49 ± 1 °C and the organic loading rate was 1.5-5.5 kgCOD m(-3) d(-1) with a hydraulic retention time of 5-10 days. Main results are the following: a) extremely high COD removal rate (up to 98%); b) very low sludge production (∼0.016 kgVSS produced kgCOD removed(-1)); c) suitability as a pre-treatment to a conventional (e.g. activated sludge) biological treatment (the studied pharmaceutical industrial wastewaters are discharged into the sewer system for final polishing in a centralized municipal wastewater treatment plant) and d) high phosphorus removal (up to 99%).

Keywords: Salinity; Sludge minimization; Thermophilic Aerobic Membrane Reactor (TAMR); Ultrafiltration.