文档介绍：Effects of Upflow Liquid Velocity on Performance of Expanded Granular Sludge Bed (EGSB) System
Seni Karnchanawong and Wachara Phajee
Abstract
The effects of upflow liquid velocity (ULV) on performance of expanded granular sludge bed (EGSB) system were investigated. The EGSB reactor, made from galvanized steel pipe m diameter and 5 m height, had been used to treat piggery wastewater, after passing through acidification tank. It consisted of l working volume in reaction zone and 122 l working volume in sedimentation zone, at the upper part. The reactor was seeded with anaerobically digested sludge and operated at the ULVs of 4, 8, 12 and 16 m/h, consecutively, corresponding anic loading rates of – kg COD/ (m3·d). The average COD concentrations in the influent were 9,601 – 13,050 mg/l. The COD removal was not significantly different, . % - %, except at ULV 12 m/h where SS in the influent was exceptionally high so that VSS washout had occurred, leading to low COD removal. The FCOD and VFA concentrations in the effluent of all experiments were not much different, indicating the same range of treatment performance. The biogas production decreased at higher ULV and ULV of 4 m/h is suggested as design criterion for EGSB system.
Keywords—Expanded granular sludge bed system, piggery wastewater, upflow liquid velocity
I. INTRODUCTION
Anaerobic digestion (AD) of wastewater can concurrently anic matter as well as produce biogas which is the renewable energy. The application of AD as pretreatment step for high chemical oxygen demand (COD) wastewater, preferably higher than 2,000 mg/l, is economically suitable while higher COD also results in higher biogas production [1]. In Thailand, piggery wastewater is increasingly treated by AD technology such as upflow anaerobic sludge blanket (UASB) system, anaerobic pond, channel (plug flow) digester and anaerobic covered lagoon. The biogas is generally used for on-farm electricity generation via inducti