The bound water in waste activated sludge (WAS) is trapped in extracellular polymeric substances (EPS) in the form of gel-like structure, leading to a great challenge in the sludge deep dewatering. Traditional flocculation conditioning is unable to destroy EPS and ineffective to remove the bound water in WAS. In this study, we employed integration of Fe(II)-sulfite oxidation and polyacrylamide flocculation (F/S-PAM) treatment for removing the bound water and improving sludge dewaterability under aerobic conditions. Meanwhile, the floc microstructure and EPS properties were examined to understand the mechanisms of F/S-PAM conditioning. F/S produced SO radicals which could decompose the EPS in sludge, releasing bound water into free water. In addition, the formed Fe(III) from F/S led to re-coagulation of decomposed EPS, and C=O groups of tryptophan played the leading role in Fe-EPS association binding, causing transformation of the secondary structure of proteins (especially β-sheets and α-helices). Then, the introduction of PAM caused re-flocculation of disintegrated sludge flocs, enhancing the sludge filterability. This work provides a novel and cost-effective method for efficient removal of bound water in sludge, and subsequence improvement in sludge dewaterability.
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http://dx.doi.org/10.1016/j.watres.2020.116652 | DOI Listing |
Int J Biol Macromol
January 2025
Technical University of Munich (TUM), TUM School of Life Sciences Weihenstephan, Alte Akademie 8, 85354 Freising, Germany; Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser Str. 35, 85354 Freising, Germany. Electronic address:
Macauba fruit pulp (Acrocomia aculeata) is an emerging oil source. After de-oiling, the macauba pulp meal (MPM) offers a dietary fiber content of 40-50 %, which mainly comprises cell wall polysaccharides (CWP). The present work aimed to assess the potential of MPM as an innovative source of sustainable food polysaccharides.
View Article and Find Full Text PDFSci Rep
January 2025
Pacific Northwest National Laboratory, Richland, WA, USA.
Enewetak Atoll underwent 43 historical nuclear tests from 1948 to 1958, including the first hydrogen bomb test, resulting in a substantial nuclear material fallout contaminating the Atoll and the lagoon waters. The radionuclide fallout material deposited in lagoon sediments and soil on the islands will remain for decades to come. With intensifying climate and extreme weather events, the possibility of redistribution of deposited radionuclide material has become a great concern.
View Article and Find Full Text PDFFood Chem
January 2025
School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou 510641, China.
Lycium barbarum polysaccharide (LBP) is a prebiotic that promotes the proliferation of beneficial bacteria, but lacks of regulatory function on harmful bacteria. In this study, chlorogenic acid (CGA) was used to achieve the functional enhancement of two LBPs (LBP-A and LBP-M). The combination of CGA resulted in changes in the solution properties of LBPs, manifested as increased pseudoplasticity, viscosity, turbidity, and decreased water mobility, absolute potential value, pH value.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Section of Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Stevinweg 1, 2628 CN Delft, The Netherlands.
Photochemical weathering and eco-corona formation through natural organic matter (NOM) adsorption play vital roles in the aggregation tendencies of nanoplastics (NPs) in aquatic environments. However, it remains unclear how photochemical weathering alters the adsorption patterns of NOM and the conformation of the eco-corona, subsequently affecting the aggregation tendencies of NPs. This study examined the effect of Suwannee River NOM adsorption on the aggregation kinetics of pristine and photoaged polystyrene (PS) NPs in monovalent electrolyte solutions.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
Host-guest binding plays a crucial role in the functionality of various systems, and its efficiency is often quantified using the binding free energy, which represents the free-energy difference between the bound and dissociated states. Here, we propose a methodology to compute the binding free energy based on the energy representation (ER) theory of solution, which enables us to evaluate the free-energy difference between the systems of interest with the molecular dynamics (MD) simulations. Unlike the other free-energy methods, such as the Bennett acceptance ratio (BAR), the ER theory does not require the MD simulations for hypothetical intermediate states connecting the systems of interest, leading to reduced computational costs.
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