Three birds with one stone: Lower volatile fatty acids (VFAs) reduction, higher phosphorus (P) removal, and lower alkali consumption via magnesium dosing after waste activated sludge (WAS) alkaline fermentation. (10th June 2020)

• Record Type: Journal Article
• Authors: Chen, Yun; Ruhyadi, Roby; Shen, Nan; Wu, Yuanyuan; Yan, Wang; Liang, Zhu; Huang, Jinjin; Wang, Guoxiang
• Is Part Of: Journal of cleaner production. Volume 258(2020)
• Publication Date: 2020-06-10
• Subjects: Dosing methods -- Magnesium chloride -- Alkaline fermentation -- Nutrient removal; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2020.120687
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Magnesium (120 mmol/L) was dosed to investigate the effects of different methods and times on performance of waste activated sludge (WAS) alkaline fermentation. The investigation revealed that maximum soluble chemical oxygen demand (SCOD) was achieved without magnesium addition, indicating magnesium addition, regardless of dosing method or time, could constrain the sludge hydrolysis process. Fermented sludge dewaterability was improved with magnesium addition, as based on results of capillary suction time (CST) and bound water. The optimal magnesium dosage was reached following WAS alkaline fermentation, in which little volatile fatty acids (VFAs) reduction (67 mg COD/L), higher PO4 3- -P removal efficiency (95.41%), and lower alkali consumption were achieved. Further, 682.19 mg chemical oxygen demand (COD)/L of the released protein was precipitated, suggesting that soluble protein was effectively recovered from sludge with magnesium addition after fermentation. In conclusion, dosing magnesium after WAS alkaline fermentation has multiple merits and warrants further study. Graphical abstract: Image 10020 Highlights: Effects of different Mg dosing strategies on WAS alkaline fermentation were studied. Mg addition was able to improve alkaline fermented sludge dewaterability. Dosing magnesium after WAS alkaline fermentation has plurality merits. Little VFAs reduction and higher P removal efficiency were achieved. 37.33% of release protein was recovered and lower alkali was consumed.