Enhancing anaerobic digestion of waste activated sludge by the combined use of NaOH and Mg(OH)2: Performance evaluation and mechanism study.
In this study, the combination treatment of NaOH and Mg(OH)2 was applied to anaerobic digestion of waste activated sludge (WAS) for simultaneously enhancement of volatile fatty acids (VFAs) production, nutrients removal and sludge dewaterability. The maximum VFAs production (461mg COD/g VSS) was obtained at the NaOH/Mg(OH)2 ratio of 75:25, which was much higher than that of the blank or sole NaOH. Moreover, nutrients removal and sludge dewaterability were improved by the combined using of NaOH and Mg(OH)2. Mechanism investigations revealed that the presence of Mg(OH)2 could maintain alkaline environment, which contributed to inhibit the activity of methanogens. Also, the bridging between Mg(2+) and extracellular polymeric substances (EPS) plays an important role in the solubilization and dewatering of sludge. High-throughput sequencing analysis demonstrated that the abundance of bacteria involved in sludge hydrolysis and VFAs accumulation was greatly enriched with the mixtures of NaOH and Mg(OH)2.
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province, China.
Cheng
C
Huang
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province, China.
Jia
J
Lai
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province, China. Electronic address: sunxyun@njust.edu.cn.
Xiuyun
X
Sun
Engineering Research Center for Chemical Pollution Control (Ministry of Education), School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province, China.
Jiansheng
J
Li
Engineering Research Center for Chemical Pollution Control (Ministry of Education), School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province, China.
Jinyou
J
Shen
Engineering Research Center for Chemical Pollution Control (Ministry of Education), School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province, China.
Weiqing
W
Han
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province, China; Engineering Research Center for Chemical Pollution Control (Ministry of Education), School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province, China.
Lianjun
L
Wang
D064751:Ammonium Compounds / Q000302:isolation & purification; D000693:Anaerobiosis / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism; D057919:Biological Oxygen Demand Analysis; D001704:Biopolymers / Q000737:chemistry; D005232:Fatty Acids, Volatile / Q000096:biosynthesis; D006863:Hydrogen-Ion Concentration; D008276:Magnesium Hydroxide / Q000494:pharmacology*; D010758:Phosphorus / Q000302:isolation & purification; D012722:Sewage / Q000382:microbiology*; D012972:Sodium Hydroxide / Q000494:pharmacology*; D012995:Solubility; D055672:Static Electricity; D014866:Waste Products; D062065:Wastewater / Q000382:microbiology; D014867:Water; D018508:Water Purification
D064751:Ammonium Compounds; D001704:Biopolymers; D005232:Fatty Acids, Volatile; D008276:Magnesium Hydroxide; D010758:Phosphorus; D012722:Sewage; D012972:Sodium Hydroxide; D014866:Waste Products; D062065:Wastewater; D014867:Water
Alkaline digestion; Dewaterability; Magnesium hydroxide; Nutrients removal; Volatile fatty acids; Waste activated sludge