Rapid start-up of expanded granular sludge bed (EGSB) reactor using granulated anaerobic bacteria in pharmaceutical wastewater treatment: pilot scale

Abstract

The start-up process is one of the most critical processes in wastewater treatment. The performance of a biological agent (bacteria) and/or the system can be predicted when the start-up process is carried out. The purpose of the start-up process is an adaptation of biological agent, and also as a granulation process for bacteria to form granule. The aim of this research was to study the effect of granular sludge in enhancing start-up time. The research was done using a 7 m tall stainless-steel reactor with 1,2 m x 1,2 m cubic shape-based and seeded with granulated anaerobic bacteria. The Reactor was operated continuously with configuration as follows: 4 h of HRT with up-flow velocity (Vup) of 1.75 m/h and recirculation ratio of 1:2. The main parameters observed were pH, alkalinity, and COD. The result showed that the effluent pH increased from 5,1 (inlet) to 6,9 on the first day of start-up and achieved pH 8,2 on the 4th day, the alkalinity also showed an increase from 219,05 CaCO3 mg/l to 470,3 CaCO3 mg/l. and the reduction of COD was 41,1% on the 4th day. It can be concluded that seeding the reactor with granulated anaerobic bacteria had successfully accelerated the start-up process.