Poor dewaterability is a bottleneck of the disposal of digestate from food waste (DFW). However, the dewatering mechanism remains unclear due to the complex composition of DFW. Understanding the dewatering mechanism, as well as the transformation of organic/inorganic matters is essential for the DFW management and valorization. In this study, the distribution, transformation, and complex interplay of organic and inorganic matters at different Hydrothermal treatment (HTT) temperatures were comprehensively analyzed to explore the hydrothermal dewatering mechanism of DFW. When HTT was conducted in the temperature range of 120-180 °C, the interstitial water was released as surface or free water because of membrane breaking and size reduction of the solid substrate. Releasing divalent cations increased the Zeta potential of the bulk solution. The weaker electrostatic repulsion between suspended particles made them easier to settle as the centrifugation cake. When the temperature of HTT was above 180 °C, polymerization and aromatization reactions took place gradually for organic matters, and the bound water was further removed. The generated humic substances were more hydrophobic than the raw material. In addition, the humic substance could combine with cationic metals, which decreased the zeta potential of the bulk solution but promoted the aggregation of nanoparticles and enhance the dewaterability of DFW.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.scitotenv.2021.150145 | DOI Listing |
Polymers (Basel)
January 2025
Department of Chemical and Metallurgical Engineering, School of Chemical Engineering, Aalto University, 02150 Espoo, Finland.
Alginate hydrogels have gathered significant attention in biomedical engineering due to their remarkable biocompatibility, biodegradability, and ability to encapsulate cells and bioactive molecules, but much less has been reported on the kinetics of gelation. Scarce experimental data are available on cross-linked alginates (AL) with bioactive components. The present study addressed a novel method for defining the crosslinking mechanism using rheological measurements for aqueous mixtures of AL and calcium chloride (CaCl) with the presence of hydroxyapatite (HAp) as filler particles.
View Article and Find Full Text PDFChemosphere
February 2025
Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, United States. Electronic address:
In agricultural and waste management systems, dairy manure wastewater is often recycled for irrigation. However, a key challenge lies in handling suspended solids (SS) and effectively dewatering sludge. To address this, an innovative polycationic soybean protein-based flocculant (SPI+) was developed and applied to enhance flocculation and sludge dewatering efficiency.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China; Jiaxing-Tongji Environmental Research Institute, Jiaxing, 314000, China. Electronic address:
Deep dewatering is crucial for effectively reducing the volume of organic waste and facilitating its downstream transportation and disposal. An in-depth understanding of the occurrence states, composition, and morphological characteristics of moisture in organic waste is the basis for optimizing the dewatering process, improving dewatering efficiency, and reducing energy consumption. Given the common problems of time-consuming, low sensitivity, and poor parallelism of traditional methods, this work reviews the advanced in-situ analysis methods for moisture distribution of organic waste.
View Article and Find Full Text PDFEnviron Res
February 2025
School of Civil and Environmental Engineering, Ningbo University, Ningbo, 315211, China; Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 2W2, Canada.
Microalgae-bacterial granular sludge (MBGS) process has great potential in achieving carbon neutrality and energy neutrality, but rapidly cultivating MBGS remains challenging. To address this challenge, this study proposes a new strategy to develop MBGS systems using pre-made granules from microalgae and dewatered sludge. The results indicate that using pre-made microalgae-dewatered sludge granules (M-DSG) as inoculants can directly develop MBGS system, with M-DSG maintaining a relatively stable granular structure, and ultimately achieving pollutant removal efficiencies of 94.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Department of Environmental and Water Resources Engineering, School of Civil Engineering, VIT, Vellore, Tamilnadu, India. Electronic address:
Currently, Advanced Reduction Process (ARP) is gaining popularity as an alternative to Advanced Oxidation Process (AOP). Though UV/Sulfite process is effective in degrading organic compounds, no investigation has been done using ARP to improve sludge dewaterability. Here, effect of two different ARP's (UV/Sulfite; UV/Sulfide) that generates hydrated electron (e) and hydrogen atom (H•) in enhancing sludge dewatering was explored.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!