Treatment of Primary Settled Wastewater Using Anaerobic Sequencing Batch Reactor Seeded with Activated EM

Abstract

The biologic treatment process using effective microorganisms (EM) in an anaerobic sequencing batch reactor (ASBR) for primary settled wastewater treatment was investigated. Activated EM was formed from raw EM to increase its efficiency by ensuring that the microorganisms were in an exponential phase of growth. A bench-scale ASBR (volume 2.6 l) was seeded with activated EM and the characteristics of the influent and effluent wastewater were investigated under different temperatures and reaction times. This system achieved good removal efficiency for all the analyzed parameters. The removal efficiency of the chemical oxygen demand (COD), soluble COD, biochemical oxygen demand, total suspended solids, ammonia, and total phosphorus increased with increasing reaction time and temperature, and reached 72.1%, 61.5%, 75.7%, 80.9%, 50.4%, and 62.5% respectively, at a reaction time of 24 h and at 35 °C. The system showed good removal of total coliform and salmonella and a reduction in ammonia and sulfate-reducing bacteria. Biogas can also be obtained using this system.

Keywords: Anaerobic treatment; ASBR; Effective microorganisms; Pathogens; Wastewater treatment