Advanced nutrient removal and external sludge reduction: Demonstration in a pilot‐scale sequencing batch reactor. (22nd January 2023)

• Record Type: Journal Article
• Authors: Yang, Shenhua; Chang, Haibin; Peng, Yongzhen; Zhang, Shujun; Han, Xiaoyu; Sun, Shihao; Liu, Jinjin; Zhang, Liang
• Is Part Of: Water environment research. Volume 95:Number 1(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-22
• Subjects: anaerobic/oxic/anoxic process -- excess sludge reduction -- pilot scale -- sludge fermentation; Water quality management -- Periodicals; Water -- Purification -- Periodicals; Water -- Pollution -- Periodicals; Water -- Pollution; Water -- Purification; Water quality management; Sewage; Water Pollution; Periodicals; Electronic journals; Periodicals; 628.16
• DOI: 10.1002/wer.10837
• Languages: English
• ISSNs: 1061-4303

Abstract

Abstract: Although the addition of excess sludge fermentation products to improve nutrient removal from sewage is cost‐effective, its application has rarely been demonstrated. In this study, the external sludge was first collected and fermented under a sludge retention time of 10 days, then introduced into SBR with a 1:15 sewage ratio. The results revealed a gradual increase in the nitrite accumulation ratio to 34.7% in the SBR at the end of the oxic stage after 64 days of adding fermented sludge products. In addition, the average effluent total nitrogen and phosphorous decreased to 7.3 and 0.5 mg/L, corresponding to removal efficiencies of 86.7% and 95.5%, respectively. On the other hand, the use of the fermented sludge products as external organic carbon sources in the SBR increased the external sludge reduction ratio to 42.5%. High‐throughput sequencing demonstrated that the increase in the endogenous denitrifier community, polyphosphate‐accumulating organisms, and fermentation bacteria were the main factors contributing to the increase in nutrient removal and excess sludge reduction. The economic evaluation indicated that the operational cost of the pilot‐scale system saves 0.011$/m 3 of sewage treated. Practitioner Points: Fermented sludge addition effectively enhanced nutrient removal in pilot‐scale SBR. Average effluent TN and PO4 3− –P decreased to 7.3 and 0.5 mg/L, respectively. Highest external sludge reduction rate was 42.5% in pilot‐scale reactor. Sewage treatment cost can save 0.011$/m 3 under advanced nutrient removal. Abstract : Considering the bottleneck of mainstream simultaneous removal of nitrogen and phosphorus caused by the insufficient carbon source of sewage, fermented sludge products were used in this study to replace organic carbon sources and induce partial nitritation, as well as establish a pilot‐scale AOA process to enhance postposition denitrification pathway.