Enhancing waste activated sludge dewaterability by reducing interaction energy of sludge flocs

Wenbo Yu; Yanlei Wan; Yu Wang; Yuwei Zhu; Shuangyi Tao; Qi Xu; Keke Xiao; Sha Liang; Bingchuan Liu; Huijie Hou; Jingping Hu; Jiakuan Yang

doi:10.1016/j.envres.2020.110328

Enhancing waste activated sludge dewaterability by reducing interaction energy of sludge flocs

Wenbo Yu, Yanlei Wan, Yu Wang, Yuwei Zhu, Shuangyi Tao, Qi Xu, Keke Xiao, Sha Liang, Bingchuan Liu, Huijie Hou^*, Jingping Hu, Jiakuan Yang^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

35 Scopus citations

Abstract

How to efficiently improve waste activated sludge (WAS) dewaterability is a common challenge in WAS treatment and management throughout world. The interaction energy of sludge flocs is of great importance for sludge dewaterability. In this study, the relationship among the repulsive force of sludge flocs, hydrophilic/hydrophobic characteristics of sludge flocs, and sludge dewaterability have been quantitatively and qualitatively investigated based on extended Derjaguin–Landau–Verwey–Overbeek theory for the first time. The energy barrier of sludge flocs has good correlations with sludge dewaterability (p < 0.05). Trivalent cations (Al³⁺ and Fe³⁺) and Fenton's reagent reduced the interfacial free energy (ΔG) from 9.4 mJ/m² of raw sludge to −34.2 (Al³⁺), −60.5 (Fe³⁺), and −63.2 (Fenton) mJ/m², respectively, indicating that the hydrophilic surfaces of the sludge flocs converted to hydrophobic (△G < 0), and decreasing Lewis acid–base interaction energy (W_AB) of sludge flocs. In addition, most of the trivalent cations (Al³⁺ and Fe³⁺) were attached to sludge flocs, leading to neutralize negative charges and mitigate electrostatic interaction energy (W_R) of sludge flocs. The reduction of W_AB and W_R eliminated energy barrier of sludge flocs and repulsive force between sludge flocs. In comparison, monovalent (Na⁺ and K⁺) and bivalent (Ca²⁺ and Mn²⁺) cations cannot completely change the hydrophilic surface characteristic and negative charge of sludge flocs. The existed energy barrier prevented sludge flocs to agglomerate with each other, thus resulting in a worse dewaterability. This study illustrated that reducing interaction energy of sludge flocs played a critical role to improve sludge dewaterability.

Original language	English
Article number	110328
Journal	Environmental Research
Volume	196
DOIs	https://doi.org/10.1016/j.envres.2020.110328
State	Published - May 2021
Externally published	Yes

Keywords

Cations
Dewaterability
Energy barrier
Extended DLVO theory
Waste activated sludge

Access to Document

10.1016/j.envres.2020.110328

Cite this

@article{35f5f80746254d39b7818ef3fae882d5,

title = "Enhancing waste activated sludge dewaterability by reducing interaction energy of sludge flocs",

abstract = "How to efficiently improve waste activated sludge (WAS) dewaterability is a common challenge in WAS treatment and management throughout world. The interaction energy of sludge flocs is of great importance for sludge dewaterability. In this study, the relationship among the repulsive force of sludge flocs, hydrophilic/hydrophobic characteristics of sludge flocs, and sludge dewaterability have been quantitatively and qualitatively investigated based on extended Derjaguin–Landau–Verwey–Overbeek theory for the first time. The energy barrier of sludge flocs has good correlations with sludge dewaterability (p < 0.05). Trivalent cations (Al3+ and Fe3+) and Fenton's reagent reduced the interfacial free energy (ΔG) from 9.4 mJ/m2 of raw sludge to −34.2 (Al3+), −60.5 (Fe3+), and −63.2 (Fenton) mJ/m2, respectively, indicating that the hydrophilic surfaces of the sludge flocs converted to hydrophobic (△G < 0), and decreasing Lewis acid–base interaction energy (WAB) of sludge flocs. In addition, most of the trivalent cations (Al3+ and Fe3+) were attached to sludge flocs, leading to neutralize negative charges and mitigate electrostatic interaction energy (WR) of sludge flocs. The reduction of WAB and WR eliminated energy barrier of sludge flocs and repulsive force between sludge flocs. In comparison, monovalent (Na+ and K+) and bivalent (Ca2+ and Mn2+) cations cannot completely change the hydrophilic surface characteristic and negative charge of sludge flocs. The existed energy barrier prevented sludge flocs to agglomerate with each other, thus resulting in a worse dewaterability. This study illustrated that reducing interaction energy of sludge flocs played a critical role to improve sludge dewaterability.",

keywords = "Cations, Dewaterability, Energy barrier, Extended DLVO theory, Waste activated sludge",

author = "Wenbo Yu and Yanlei Wan and Yu Wang and Yuwei Zhu and Shuangyi Tao and Qi Xu and Keke Xiao and Sha Liang and Bingchuan Liu and Huijie Hou and Jingping Hu and Jiakuan Yang",

note = "Publisher Copyright: {\textcopyright} 2020 Elsevier Inc.",

year = "2021",

month = may,

doi = "10.1016/j.envres.2020.110328",

language = "英语",

volume = "196",

journal = "Environmental Research",

issn = "0013-9351",

publisher = "Academic Press Inc.",

}

TY - JOUR

T1 - Enhancing waste activated sludge dewaterability by reducing interaction energy of sludge flocs

AU - Yu, Wenbo

AU - Wan, Yanlei

AU - Wang, Yu

AU - Zhu, Yuwei

AU - Tao, Shuangyi

AU - Xu, Qi

AU - Xiao, Keke

AU - Liang, Sha

AU - Liu, Bingchuan

AU - Hou, Huijie

AU - Hu, Jingping

AU - Yang, Jiakuan

PY - 2021/5

Y1 - 2021/5

N2 - How to efficiently improve waste activated sludge (WAS) dewaterability is a common challenge in WAS treatment and management throughout world. The interaction energy of sludge flocs is of great importance for sludge dewaterability. In this study, the relationship among the repulsive force of sludge flocs, hydrophilic/hydrophobic characteristics of sludge flocs, and sludge dewaterability have been quantitatively and qualitatively investigated based on extended Derjaguin–Landau–Verwey–Overbeek theory for the first time. The energy barrier of sludge flocs has good correlations with sludge dewaterability (p < 0.05). Trivalent cations (Al3+ and Fe3+) and Fenton's reagent reduced the interfacial free energy (ΔG) from 9.4 mJ/m2 of raw sludge to −34.2 (Al3+), −60.5 (Fe3+), and −63.2 (Fenton) mJ/m2, respectively, indicating that the hydrophilic surfaces of the sludge flocs converted to hydrophobic (△G < 0), and decreasing Lewis acid–base interaction energy (WAB) of sludge flocs. In addition, most of the trivalent cations (Al3+ and Fe3+) were attached to sludge flocs, leading to neutralize negative charges and mitigate electrostatic interaction energy (WR) of sludge flocs. The reduction of WAB and WR eliminated energy barrier of sludge flocs and repulsive force between sludge flocs. In comparison, monovalent (Na+ and K+) and bivalent (Ca2+ and Mn2+) cations cannot completely change the hydrophilic surface characteristic and negative charge of sludge flocs. The existed energy barrier prevented sludge flocs to agglomerate with each other, thus resulting in a worse dewaterability. This study illustrated that reducing interaction energy of sludge flocs played a critical role to improve sludge dewaterability.

AB - How to efficiently improve waste activated sludge (WAS) dewaterability is a common challenge in WAS treatment and management throughout world. The interaction energy of sludge flocs is of great importance for sludge dewaterability. In this study, the relationship among the repulsive force of sludge flocs, hydrophilic/hydrophobic characteristics of sludge flocs, and sludge dewaterability have been quantitatively and qualitatively investigated based on extended Derjaguin–Landau–Verwey–Overbeek theory for the first time. The energy barrier of sludge flocs has good correlations with sludge dewaterability (p < 0.05). Trivalent cations (Al3+ and Fe3+) and Fenton's reagent reduced the interfacial free energy (ΔG) from 9.4 mJ/m2 of raw sludge to −34.2 (Al3+), −60.5 (Fe3+), and −63.2 (Fenton) mJ/m2, respectively, indicating that the hydrophilic surfaces of the sludge flocs converted to hydrophobic (△G < 0), and decreasing Lewis acid–base interaction energy (WAB) of sludge flocs. In addition, most of the trivalent cations (Al3+ and Fe3+) were attached to sludge flocs, leading to neutralize negative charges and mitigate electrostatic interaction energy (WR) of sludge flocs. The reduction of WAB and WR eliminated energy barrier of sludge flocs and repulsive force between sludge flocs. In comparison, monovalent (Na+ and K+) and bivalent (Ca2+ and Mn2+) cations cannot completely change the hydrophilic surface characteristic and negative charge of sludge flocs. The existed energy barrier prevented sludge flocs to agglomerate with each other, thus resulting in a worse dewaterability. This study illustrated that reducing interaction energy of sludge flocs played a critical role to improve sludge dewaterability.

KW - Cations

KW - Dewaterability

KW - Energy barrier

KW - Extended DLVO theory

KW - Waste activated sludge

UR - http://www.scopus.com/inward/record.url?scp=85093930894&partnerID=8YFLogxK

U2 - 10.1016/j.envres.2020.110328

DO - 10.1016/j.envres.2020.110328

M3 - 文章

C2 - 33075357

AN - SCOPUS:85093930894

SN - 0013-9351

VL - 196

JO - Environmental Research

JF - Environmental Research

M1 - 110328

ER -

Enhancing waste activated sludge dewaterability by reducing interaction energy of sludge flocs

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this