Improved valorization of sewage sludge in the circular economy by anaerobic digestion: Impact of an innovative pretreatment technology.

Waste Manag

Bioproducts, Sciences and Engineering Laboratory, Washington State University, Tri-Cities, Richland, WA 99354, United States; The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99163, United States; Department of Biological Systems Engineering, Washington State University, Pullman, WA 99163, United States. Electronic address:

Published: December 2022

Anaerobic digestion (AD) of sewage sludge shows low carbon conversion efficiency (CCE) due to the poor biodegradability of sewage sludge. The lack of digestibility is specifically linked to the waste-activated sludge (WAS) making up the majority of sewage sludge along with a smaller portion of primary sludge, depending on the wastewater treatment plant configuration. In this study, we examine the Advanced Wet Oxidation & Steam Explosion process (AWOEx) for improving the CCE of digested sewage sludge (DSS) by thermophilic AD. The effect of the pretreatment temperature in the range between 160 and 185 °C at a fixed residence time of 20 min with and without oxygen added at a dosage of 5 % of the organics present was tested. Methane yield improved by 97.92 % to 183.91 ± 4.93 mL/g vS over the untreated DSS (control), whose methane yield was 92.92 ± 9.07 mL/g vS We have demonstrated for the first time that 84 % of the organics in sewage sludge can successfully be transformed into biogas following AWOEx pretreatment, which can contribute significantly to the circular economy instead of greenhouse gas emissions from landfilling.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wasman.2022.09.035DOI Listing

Publication Analysis

Top Keywords

sewage sludge
24
sludge
8
circular economy
8
anaerobic digestion
8
methane yield
8
sewage
6
improved valorization
4
valorization sewage
4
sludge circular
4
economy anaerobic
4

Similar Publications

Investigating the effects of inoculum temperature and characteristics on cellulose and sewage sludge biodegradability: A comparative study of three inocula.

Chemosphere

January 2025

BioEngine Research team on green process engineering and biorefineries, Chemical Engineering Department, Université Laval, Pavillon Adrien-Pouliot 1065, av. de la Médecine Québec (Québec), Canada; CentrEau, Centre de recherche sur l'eau, Université Laval, 1065 Avenue de la Médecine, Québec, QC, G1V 0A6, Canada. Electronic address:

The role of inoculum in initiating anaerobic digestion (AD), and accelerating the start-up of anaerobic digesters has been well-documented. However, the effect of aligning the origin temperature of the inoculum with the operational temperature of the new digester remains underexplored. This study investigates how the origin temperature and characteristics of the inoculum affect the kinetics and biodegradability of sewage sludge (SS) and microcrystalline cellulose (MCC) under mesophilic and thermophilic conditions.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the degradation of ciprofloxacin (CIP) using a photocatalyst made from CoFeO@3D-TiO and graphene aerogel, achieving complete removal under specific conditions within 60 minutes while showing high reusability.
  • Intermediate products from the degradation process were found to be non-toxic to E. coli, and total organic carbon (TOC) analysis showed 86% mineralization of CIP, indicating successful transformation of non-biological sewage to biodegradable effluent.
  • The research emphasizes the effectiveness of photocatalysis over simple adsorption with a significantly faster reaction rate, showcasing the potential environmental benefits of using the synthesized photocatalyst under visible light.
View Article and Find Full Text PDF

Environmental contamination by pharmaceuticals has become a matter of concern as they are released in sewage systems at trace levels, thus impacting biological systems. Increasing concerns about the low-level occurrence of pharmaceuticals in the environment demands sensitive and selective monitoring. Owing to their high sensitivity and specificity carbon dots (CDs) have emerged as suitable fluorescent sensors.

View Article and Find Full Text PDF

Myxobacteria, belonging to the phylum Myxococcota, are ubiquitous in soil, marine, and other environments. A recent metagenomic sequencing ana-lysis showed that Myxococcota are predominant in activated sludge systems; however, their metabolic traits remain unclear. In the present study, we exami-ned the potential biological functions of 46 metagenomic bins of Myxococcota reconstructed from activated sludge samples from four municipal sewage treatment plants.

View Article and Find Full Text PDF

High production rates of chlorinated paraffins (CPs) and their widespread use resulted in a global contamination. Since 2017, short-chain CPs (SCCPs, C-C) are listed as persistent organic pollutants (POPs) in the Stockholm Convention. Technical CP mixtures contain hundreds of homologues and side products such as chlorinated olefins (COs), diolefins (CdiOs) and triolefins (CtriOs).

View Article and Find Full Text PDF

Want 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!