title: Enhanced volatile fatty acids production of waste activated sludge under salinity conditions: Performance and mechanisms.
abstract: Volatile fatty acids (VFAs) are essential for removing biological nitrogen and phosphorus in wastewater treatment plants. The purpose of this work was to investigate whether and how the addition of NaCl could improve the production of VFAs from waste activated sludge (WAS). Sludge solubilization was efficiently improved by the addition of NaCl. Both protein and carbohydrate in the fermentation liquid increased with the dosage of NaCl, and it provided a larger amount of organic compounds for the production of the VFAs. NaCl had inhibitory effects on the production of methane and a high dosage of NaCl could severely suppress the growth of methanogens, which decreased the consumption of the VFAs. Consequently, the production of VFAs was significantly enhanced by the addition of NaCl. The maximum production of VFAs was achieved with the highest dosage of NaCl (3316 mg (COD)/L at the NaCl dosage 0.5 mol/L; 783 mg (COD)/L without the addition of NaCl). Therefore, this study indicates that using NaCl could be an efficient method for improving the production of VFAs from WAS.
authors: Key Laboratory of Beijing Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, China; Jiangsu Yulong Environmental Protection Company Limited, Yixing 214214, China.
authors: Gaoqiang
authors: G
authors: Su
authors: Key Laboratory of Beijing Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, China.
authors: Shuying
authors: S
authors: Wang
authors: Key Laboratory of Beijing Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, China; Advanced Water Management Center, The University of Queensland, QLD 4072, Australia.
authors: Zhiguo
authors: Z
authors: Yuan
authors: Key Laboratory of Beijing Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, China. Electronic address: pyz@bjut.edu.cn.
authors: Yongzhen
authors: Y
authors: Peng
mesh_terms: D050260:Carbohydrate Metabolism / Q000187:drug effects; D005232:Fatty Acids, Volatile / Q000096:biosynthesis* / Q000378:metabolism; D005285:Fermentation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis / Q000187:drug effects; D008697:Methane / Q000096:biosynthesis / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D054712:Salinity; D012722:Sewage / Q000737:chemistry*; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D005232:Fatty Acids, Volatile; D011506:Proteins; D012722:Sewage; D010758:Phosphorus; D012965:Sodium Chloride; D009584:Nitrogen; D008697:Methane
keywords: Acidification; Hydrolysis; Sodium chloride; Volatile fatty acid; Waste activated sludge