The dewaterability and particle size distribution of activated and digestion sludge were studied. Meanwhile, the related mechanism was explored through analyzing the extracellular polymeric substances (EPS) content and microbe characteristic of activated and digestion sludge. The dewaterability was evaluated using the capillary suction time (CST) and settling property. The CST of activated sludge and digestion sludge are 9.84 s and 607.5 s, respectively. The settling time of the solids of digestion sludge is longer than that of activated sludge. The major reason of poor dewaterability of digestion sludge is the degradation of carbohydrate and protein parts of EPS. In addition, the quantity of protozoan in digestion sludge is less than that of activated sludge, resulting in reducing the excretion of certain matters benefiting the agglomeration between microbes. The EPS content of digestion sludge is 123 mg/g, which was 77% less than that of activated sludge. The degradation of EPS during the digestion process leads to the smaller particle size of digested sludge, and then the poorer dewaterability. The particle size that occupied maximum volume in activated sludge is 133 microm, while it is 44.6 microm in digestion sludge. The mean particle size of activated sludge is 132.6 microm which is larger than that of digestion sludge (70.48 microm).
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Miliary Tuberculosis Initially Presenting as an Isolated Hepatic Abscess.
Korean J Gastroenterol
January 2025
Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Hepatic tuberculosis, typically associated with miliary tuberculosis, can occasionally present as localized liver lesions. This case report describes a 77-year-old male presenting with persistent abdominal pain and fever, following an endoscopic retrograde cholangiopancreatography for bile duct sludge removal. Subsequent computed tomography revealed focal liver lesions.
View Article and Find Full Text PDFHeavy metal(loid)s and nutrients in sewage sludge in Portugal - Suitability for use in agricultural soils and assessment of potential risks.
Sci Total Environ
January 2025
LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal. Electronic address:
The presence of heavy metal(loid)s in sewage sludge is a cause of concern and an obstacle to its agricultural valorisation. This study analysed the elemental composition of sewage sludge from 42 Portuguese wastewater treatment plants (WWTPs) during summer and winter, investigating heavy metal(loid) contamination, nutrient content, and potential risks related to sludge application to agricultural soils. Levels of 8 heavy metal(loid)s were investigated, ranging from not detected (Hg) to 5120 mg kg dw (Zn), decreasing in the order Zn > Cu > Cr > Ni > Pb > As>Cd > Hg.
View Article and Find Full Text PDFLong-term effects of combining anaerobic digestate with other organic waste products on soil microbial communities.
Front Microbiol
January 2025
Agroécologie, French National Institute for Agriculture, Food, and Environment (INRAE), Institut Agro, Université Bourgogne, Université Bourgogne Franche-Comté, Dijon, France.
Introduction: Agriculture is undergoing an agroecological transition characterized by adopting new practices to reduce chemical fertilizer inputs. In this context, digestates are emerging as sustainable substitutes for mineral fertilizers. However, large-scale application of digestates in agricultural fields requires rigorous studies to evaluate their long-term effects on soil microbial communities, which are crucial for ecosystem functioning and resilience.
View Article and Find Full Text PDFHow to combine SBR and A/O process for pollutant removal in treating digested effluent of swine wastewater.
J Environ Manage
January 2025
Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041, PR China; Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Chengdu, 610041, PR China. Electronic address:
To solve the problem of low chemical oxygen demand (COD)/N and poor efficiency of single-stage sequencing batch reactor (SBR) or anoxic/oxic process (A/O) in treatment of digested effluent of swine wastewater, combined SBR-A/O and A/O-SBR processes were employed in the addition ratios of 0, 10%, 30%, and 40% (V/V)) of raw swine wastewater (RS). Analysis of pollutants removal performance of SBR-A/O and A/O-SBR systems showed no significant difference between the two systems without RS addition. However, after adding RS, the pollutants removal efficiency of the two systems increased with the increase in the ratio of RS, with SBR-A/O system presenting better pollutants removal performance than A/O-SBR system.
View Article and Find Full Text PDFGeographical distribution and risk of antibiotic resistance genes in sludge anaerobic digestion process across China.
J Hazard Mater
January 2025
School of Environment, Tsinghua University, Beijing 100084, PR China. Electronic address:
Anaerobic digestion (AD) is gaining increasing attention as the central reservoir of antibiotic resistance genes (ARGs), while the geographical distribution of ARGs in AD is neglected. Accordingly, a sampling scheme on full-scale AD plants across China was implemented, and the resistome therein was excavated. The abundance of ARGs in AD sludge ranged from 0.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!