Excess sludge contains large amounts of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs), posing a risk for human health. However, most current studies usually ignored their abundance and removal in excess sludge. Therefore, this study aimed to reduce ARGs/MGEs in sludge by Fenton process, and applied single-factor experiment (SFE) and response surface methodology (RSM) to optimize the Fenton reaction condition for higher removal rates of ARGs/MGEs. The results demonstrated that the removal rates of target genes by SFE optimized condition ranged from 10.91% to 66.86%, while the removal rates caused by RSM optimized condition were 48.02% - 76.36%, indicating RSM was a useful tool to improve the removal rates of ARGs in excess sludge. Additionally, the scanning electron microscope and cell apoptosis results suggested that the Fenton treatment altered the structure of sludge and reduced the numbers of normal cells, thus causing the reductions of target genes.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147889 | DOI Listing |
Water Res X
May 2025
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
Although the treatment of sludge with free nitrous acid can effectively recover short chain fatty acids, the feasibility of sequential nitrite reduction and methane recovery without acidic pH adjustment is still scarcely studied. Therefore, this study aimed to provide insights into the effect of nitrite at different levels on nitrite reduction and methane production. The results showed that the nitrite concentrations of 100, 200, 400 and 800 mg/L were completely reduced in 1, 2, 2 and 4 days, respectively.
View Article and Find Full Text PDFChemosphere
January 2025
DICAR University of Pavia, Pavia, 27100, Italy. Electronic address:
Excess biological sludge processing and disposal have a significant impact on the energy balance and economics of wastewater treatment operations, and on receiving environments. Anaerobic digestion is probably the most widespread in-plant sludge processing method globally, since it stabilizes and converts biosolids organic matter into biogas, allowing partial recovery of their embedded chemical energy. A considerable number of studies concerning applicable techniques to improve biogas production, both in quantity and quality, include pre-treatment strategies to promote biosolids disintegration aimed at the release and solubilization of intracellular energy compounds, inorganic/biological amendments aimed at improving process performance, and sludge thermal pre-treatment.
View Article and Find Full Text PDFSci Total Environ
January 2025
Environmental Science and Engineering Program, Guangdong Technion-Israel Institute of Technology, 241 Daxue Road, Shantou, Guangdong 515063, China.
Extracellular polymeric substances (EPS) significantly influence the properties and performance of waste activated sludge. Various pretreatment protocols with different extraction efficiency and characteristics of EPS have been reported, which markedly impact subsequent treatment and disposal of sewage sludge. This study systematically assesses the EPS properties from twelve extraction pretreatment methods.
View Article and Find Full Text PDFChemosphere
February 2025
Guangxi Key Laboratory of Environmental Processes and Remediation in Ecologically Fragile Regions, Guangxi Normal University, 15 Yucai Road, Guilin, 541004, PR China; Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, 15 Yucai Road, Guilin, 541004, PR China. Electronic address:
Garlic and chili are widely used as food flavoring agents in food cooking, therefore might be accumulated in large amounts in food waste (FW). The effects of garlic and chili on the dissolution, hydrolysis, acidification and methanation in an anaerobic co-digestion system were investigated during the combined co-digestion of FW and excess sludge (ES). Additionally, the transformation of phosphorus form and microbial metabolism changes during the process were analyzed.
View Article and Find Full Text PDFFront Biosci (Elite Ed)
December 2024
Polytechnic School, University of Vale do Itajaí (Univali), Itajaí, SC 88302-202, Brazil.
Background: Enhanced biological phosphorus removal (EBPR) systems utilize phosphorus-accumulating organisms (PAOs) to remove phosphorus from wastewater since excessive phosphorus in water bodies can lead to eutrophication. This study aimed to characterize a newly isolated PAO strain for its potential application in EBPR systems and to screen for additional biotechnological potential. Here, sequencing allowed for genomic analysis, identifying the genes and molecules involved, and exploring other potentials.
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