Full-scale aerobic granular sludge technology under the trade name Nereda® has been implemented for municipal, as well as industrial wastewater treatment. Owing to the operational reactor procedures, two types of waste aerobic granular sludge can be clearly distinguished: 1) aerobic granular sludge selection discharge (AGS-SD) and 2) aerobic granular sludge mixture (AGS-RTC). This study systematically compared the anaerobic biodegradability of AGS-SD and AGS-RTC under mesophilic conditions. Results were further compared with the anaerobic conversion of waste activated sludge (WAS) as well as primary sludge (PS) from full-scale municipal wastewater treatment plants. Analysis showed similar chemical characteristics for AGS-SD and PS, which were both characterized by a high carbohydrate content (429 ± 21 and 464 ± 15 mg glucose/g VS sludge, respectively), mainly cellulosic fibres. Concurrently, AGS-RTC exhibited chemical properties close to WAS, both characterized by a relatively high protein content, which were individually 498 ± 14 and 389 ± 15 mg/g VS sludge. AGS-SD was characterized by a high biochemical methane potential (BMP) (296 ± 15 mL CH/g VS substrate), which was similar to that of PS, and remarkably higher than that of AGS-RTC and WAS. Strikingly, the BMP of AGS-RTC (194 ± 10 mL CH/g VS substrate) was significantly lower than that of WAS (232 ± 11 mL CH/g VS substrate). Mechanically destroying the compact structure of AGS-RTC only accelerated the methane production rate but did not significantly affect the BMP value. Results indicated that compared to WAS, the proteins and carbohydrates in AGS-RTC were both more resistant to anaerobic bio-degradation, which might be related to the presence of refractory microbial metabolic products in AGS-RTC.
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http://dx.doi.org/10.1016/j.watres.2020.115617 | DOI Listing |
J Environ Manage
December 2024
Department of Environmental Science and Engineering, Zhejiang Ocean University, No.1 Haida South Road, Zhoushan, 316022, PR China; Zhejiang Provincial Key Laboratory of Petrochemical Environmental Pollution Control, Zhoushan, 316022, PR China. Electronic address:
In order to study the resistance mechanisms of biofilm and granular sludge to various dissolved oxygen (DO) exposures in anaerobic ammonium oxidation (anammox) process, a biofilm - granular sludge anammox reactor was established and operated. Experimental results showed that DO levels of ≤0.41 mg L hardly affected the total nitrogen removal efficiency (TNRE).
View Article and Find Full Text PDFEnviron Res
December 2024
School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing, 400054, China. Electronic address:
Microbial loss significantly affects wastewater treatment efficiency. This study simulated the inoculation area of a self-developed biological doubling reactor (BDR) to evaluate the retention efficiency of seven different fillers for aerobic denitrifying bacteria. Over 90 days of continuous operation, the porous filler R3 demonstrated excellent performance, with OD values consistently exceeding 1.
View Article and Find Full Text PDFEnviron Res
December 2024
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, People's Republic of China. Electronic address:
Diffusible signal factor (DSF)-c-di-GMP-mediated strategies have been proposed as an effective regulatory approach for signal molecules in aerobic granular sludge (AGS). The increase in temperature from low to normal levels had a significant impact on AGS stability. In this study, two reactors were established to investigate the effects of different temperature rise modes (abrupt or gradual) on AGS stability.
View Article and Find Full Text PDFJ Environ Manage
December 2024
College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China.
With the widespread use of typical antibiotics such as sulfamethazine (SMT), it leads to their accumulation in the environment, increasing the risk of the spread of antibiotic resistance genes (ARGs). Aerobic granular sludge (AGS) has shown great potential in treating antibiotic wastewater. However, the long cultivation period of AGS, the easy disintegration of particles and the poor stability of degradation efficiency for highly concentrated antibiotic wastewater are still urgent problems that need to be solved, and it is important to explore the migration and changes of ARGs and microbial diversity in AGS systems.
View Article and Find Full Text PDFHeliyon
December 2024
Department of Applied and Environmental Chemistry, University of Szeged, Szeged, Hungary.
Currently, the increasing use of nickel metal-organic frameworks (Ni-MOF) and nickel oxide nanoparticles (NiO NPs) has raised concerns regarding their potential environmental impact on wastewater treatment systems. Herein, the responses of aerobic granular sludge (AGS) and algal-bacterial aerobic granular sludge (AB-AGS) to Ni-MOF and NiO NPs were investigated. The results showed that Ni-MOF concentrations of 50, 100, and 200 mg/L significantly reduced nutrient removal in both systems, particularly affecting ammonia, nitrite, and phosphorus removal, while denitrification processes remained stable.
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