Forming aerobic granulation in SBR technology at the laboratory

Abstract

Transplanting and application of aerobic granulation in SBR technology have been developed since 1970. In recent years, this technology has been extensively researched with different substances such as glucose, acetate, ethanol, molasses, sugar, starch, phenol, phthalic acid, chloroanilines, tert-butyl alcohol, and synthetic wastewater. This article describes the process of formation and development of aerobic granulation with acetate at the laboratory in Vietnam. Activated sludge for the study was obtained from Yen So (Hanoi) wastewater treatment plant with MLSS 900-1200 mg/l. The research was carried out on two reactors of the same SBR technology with 0.110 m in diameter and 1 m in height, water level height 0.8 m, working volume of 2.5 l with respective names of A and B. The reactors were sequentially operated 6 cycles/day, each cycle was divided into 4 periods, lasting 4 hours: 1-2 mins of influent filling, 180 mins of aeration, 20-30 mins of settling, and 10-15 mins of effluent. The input wastewater for model A was wastewater with low strength has OLR from 1.0-1.2 kg COD/m³.day. The input wastewater for model B was wastewater with high strength has OLR from 2.7-3.0 kg COD/m³.day, time for research was 120 days. The result showed that the formation and development of granular sludge in model A were very difficult. Meanwhile, granular sludge was formed and developed after 30-45 days of experimentation in model B.