High Salinity Wastewater Treatment Study Using an Automated Pilot Combining Anaerobic and Aerobic Biofilm Processes

Abstract

A 20-ft containerized biological pilot system consisting of both an anaerobic expended granular sludge bed (EGSB) and an aerobic biofilm continuous flow intermittent clean (CFIC®) system has been designed, constructed, and delivered onsite at a pharmaceutical wastewater producer for a wastewater treatment study. The pilot was operated for a total of 317 days, including 147 days of adaptive phase and 170 days of testing phase. A pilot adaptive phase feeding wastewater COD concentration from 2 to 50 g/L with salinity up to 16 g/L was carried out, achieving EGSB where COD removal reached over 80 to 95% at OLR up to 22 kg COD/m3·d. In the testing phase, with repressive practical wastewater, the EGSB can remove over 97% of feed COD (with up to 82% acetic acid) at an average 16.3 kg COD/m3·d. The high wastewater salinity at 20 g/L did not inhibit COD removal efficiency by the system. The complete system with EGSB and aerobic stage was very stable and removed over 90–97% of the total COD dependent on the wastewater composition. The pilot was demonstrated as a valuable tool because of its user-friendly nature with high automation level, as well as its high efficiency in treating specific wastewater under varying operational conditions. This study provides critical information for full-scale system design and offers training for the customer in handling a previously unfamiliar process in a confident manner.