Stability of aerobic granular sludge in a pilot scale sequencing batch reactor enhanced by granular particle size control. (June 2019)

• Record Type: Journal Article
• Authors: Long, Bei; Xuan, Xinpeng; Yang, Changzhu; Zhang, Linan; Cheng, Yuanyuan; Wang, Jianqi
• Is Part Of: Chemosphere. Volume 225(2019)
• Page Start: 460
• Page End: 469
• Publication Date: 2019-06
• Subjects: Aerobic granular sludge -- Pilot scale -- Particle size -- Selective sludge discharge -- Stability; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.03.048
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Aerobic granulation was successfully achieved in a pilot scale sequencing batch reactor within 40 days. Then, stability of different particle size granules was explored according to their activity and resistance to ultrasonic crushing. Different particle size granules (0.3–0.6 mm, 0.6–1 mm, 1–1.43 mm, 1.43–2 mm, 2–3 mm and 3–4 mm) were exposed under different ultrasonic power separately. It was found that the granules with 2–3 mm always had the maximum granulation rates after ultrasonic crushing. Meanwhile, activity data showed that the 2–3 mm granules had the lowest specific oxygen utilization rates, which indicated that they were easier to maintain stability as the increase of their particle sizes was the slowest. So, 500 mL mixed liquid of the reactor were taken out and sieved to obtain the 2–3 mm granules, which were subsequently returned to the reactor to increase their proportion. Through the manual regulation, the proportion of 2–3 mm granules kept increasing which gradually became dominant in the reactor. Under the strategy of 86 days of operation, the aerobic granules were regular and compact, which had good removal effects of the real wastewater. The results indicated that the stability of the system could be greatly enhanced by the method, which provided a new strategy to maintain the granular stability. Graphical abstract: Image 1 Highlights: Stability of different particle size granules was investigated. The optimal particle size was determined according to granular activity and structural stability. Stability of the reactor was enhanced by improving the proportion of the granules with optimal particle size.