Understanding synergistic mechanisms of ferrous iron activated sulfite oxidation and organic polymer flocculation for enhancing wastewater sludge dewaterability

Ai, Jing; Wang, Zhiyue; Dionysiou, Dionysios D.; Liu, Ming; Ruan, Wenquan; Tang, Mingyue; Liao, Gang; Hu, Aibin; Zhang, Weijun

doi:10.1016/j.watres.2020.116652

Cited by 73 publications

(9 citation statements)

References 52 publications

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“…After AOP treatment, the zeta potential rose to − 12.4 mV within 5 min. However, over time, the best zeta potential of WAS after the AOP treatment remained at − 10.4 mV, which differs from previous results (Ai et al 2021 ; Wang et al 2021 ; Zhu et al 2018 ). This situation might have resulted from the continuous release of negatively charged organic matter from internal sludge cells and flocs to the outer space of the sludge and the release of biopolymers with the same charge, which repel each other in the AOP.…”

Section: Resultscontrasting

confidence: 98%

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Pyrite activated peroxymonosulfate combined with as a physical–chemical conditioner modified biochar to improve sludge dewaterability: analysis of sludge floc structure and dewatering mechanism

Gao

Song

Wang

et al. 2022

Environ Sci Pollut Res

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In this study, we proposed an advanced oxidation process of pyrite (FeS 2 ) and peroxymonosulfate (PMS) and prepared a modified polyaluminum chloride biochar (P-BC). The motivation is to use the combination of FeS 2 + PMS + P-BC to improve waste activated sludge (WAS) dewaterability. The method to improve the sludge dewatering effect with the combination of FeS 2 + PMS + P-BC is as follows: in the first step, pour 0.75 g/g TSS FeS 2 and 0.6 g/g TSS PMS into the sludge, and stir for 15 min. Then, add P-BC and stir for 5 min; complete the entire WAS processing process. The vacuum filtration test was used to evaluate the dehydration effect. The water content (Wc) and specific resistance to filtration (SRF) of the raw sludge can be reduced from the original values of 92% and 2.36 × 10 13 m/kg to 67% and 9.89 × 10 11 m/kg, respectively. The results showed that the combination of FeS 2 + PMS + P-BC can effectively improve the sludge dewatering effect through oxidation. A laser particle size analyzer is used to observe changes in sludge particle size. The median diameter of sludge particles increased from 55.37 to 64.56 μm. A zeta analyzer to is used observe changes in sludge zeta potential. The zeta potential of sludge particles increased from − 15.8 to 0.4 mV. In the analysis of extracellular polymeric substances (EPS) of sludge, it was found that protein (PN) and polysaccharide (PS) in EPS decreased significantly. To further analyze the phenomenon of PN and PS drop, excitation-emission-matrix spectra (3D-EEM) was used. To observe the changes of sludge functional group, X-ray photoelectron spectroscopy was used. It was found that FeS 2 + PMS + P-BC can destroy the functional groups of sludge, such as O–H, C–C, and O═C—NH– related to proteins and polysaccharides. Graphical abstract Supplementary Information The online version contains supplementary material available at 10.1007/s11356-022-21074-4.

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Section: Resultscontrasting

confidence: 98%

“…Before P-BC flocculation, the AOP pretreatment decomposed EPS and caused the release of BW into the liquid phase, resulting in a high degree of dispersion of sludge particles. Then, the cracked sludge flocs were easily bridged by P-BC and re-flocculated to form a more porous structure (Ai et al 2021 ).Fig. 7 e and Fig.…”

Section: Resultsmentioning

confidence: 99%

Pyrite activated peroxymonosulfate combined with as a physical–chemical conditioner modified biochar to improve sludge dewaterability: analysis of sludge floc structure and dewatering mechanism

Gao

Song

Wang

et al. 2022

Environ Sci Pollut Res

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“…The C 1s XPS spectra can be deconvoluted into three main peaks at 284.8, 286.3, and 288.6 eV, which correspond to C–(C, H) (lipids or AAs), C–(O, N) (amide), and CO/O–C–O (amine), respectively . The N 1s peak at 400.0 eV correlated with protein-N, and the other N 1s peak at 401.5 eV is commonly associated with inorganic-N, while the O 1s signal included two peaks at 532.5 and 531.5 eV, which are attributed to CO (proteins/polysaccharides) and C–OH/C–O (glycoside), respectively . Two peaks identified at 168.9 and 163.7 eV were assigned to the −SO 3 and S–S bond, respectively …”

Section: Resultsmentioning

confidence: 99%

“…The C 1s XPS spectra can be deconvoluted into 50 The N 1s peak at 400.0 eV correlated with protein-N, and the other N 1s peak at 401.5 eV is commonly associated with inorganic-N, while the O 1s signal included two peaks at 532.5 and 531.5 eV, which are attributed to C�O (proteins/polysaccharides) and C− OH/C−O (glycoside), respectively. 51 Two peaks identified at 168.9 and 163.7 eV were assigned to the −SO 3 and S−S bond, respectively. 52 As shown in Figure 7, there was a slight increase of protein-N after thermal treatment only, and similar results were also reported with thermal treatment.…”

Section: Impact Of Process Parameters Of Nades-based Treatment On Dew...mentioning

confidence: 99%

Simultaneously Enhanced Dewaterability and Biopolymer Release of Sludge by Natural Deep Eutectic Solvents: Performance, Mechanisms, and Insights of Theoretical Calculations

Zhai

Zhu

et al. 2022

ACS Sustainable Chem. Eng.

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The dewatering and resource recovery of wasteactivated sludge (WAS) seemed to be two contradictory processes due to the high moisture content induced by the extracellular polymer substances, which mainly consist of proteins and polysaccharides. Natural deep eutectic solvents (NADESs) were proposed to synergistically enhance dewaterability and biopolymer release of WAS. It showed that NADES with low-temperature pretreatment can significantly improve the dewaterability and release of valuable resources. With the addition of 1.0 mL of NADES combined with 60 °C thermal treatment for 120 min, the capillary suction time (CST) of sludge significantly decreased from 75.9 ± 7.5 to 30.5 ± 1.6 s, and 11.83 mg/L of the total amino acids (AAs) was obtained. The protein and polysaccharide contents were increased to 876.48 and 213.42 mg/L, respectively. This study indicated that NADES combined with low-temperature pretreatment is a green, cost-effective, and environmentally friendly method to improve sludge dewaterability and resource recovery simultaneously. The theoretical calculation results suggested that the generation of NADES•••AAs aggregates is an exothermic reaction and proceeds nonspontaneously. A good correlation is also found between the theoretically calculated free-energy change and the concentrations of AAs. On the basis of this study, the biopolymers from WAS can be recovered as value-added resources, enabling a recycling concept within the circular economy vision. The theoretical calculation can be used to guide future experiments for screening highly selective and effective NADES toward resource recovery from WAS.

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“…If this kind of wastewater is discharged directly or treated improperly, it would cause serious harm to environmental safety and human health. At present, many techniques, including biological process 4,5 , physical chemical combination method 3,6 , adsorption [7][8][9] , membrane separation 10,11 , advanced oxidation [12][13][14] , photocatalytic degradation 15,16 , could be used to treat organic wastewater. Each of these approaches has its own advantages and disadvantages.…”

Section: Introductionmentioning

confidence: 99%

Sliver Doped Sodium Antimonate with Greatly Reduced the Band Gap for Efficiently Enhanced Photocatalytic Activities Under Visible Light (Experiment and DFT Calculation)

et al. 2021

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In this work, Ag doped NaSbO 3 (ANS) was successfully synthesized and applied an efficient visible light photocatalyst. The properties of catalyst were fully characterized, and DFT (the density functional theory) computation was utilized to investigate the photocatalytic mechanism. The various characterization findings proved that Ag atoms were perfectly doped into NaSbO 3 crystals, which greatly reduced the band gap, and made ANS catalyst exhibit excellent visible light absorption performance. In addition, ANS appeared great photocatalytic activities and remarkable stability. Also, electrochemical characterizations illustrated that ANS possessed stronger ability of generating and transferring electrons and holes under visible light, and the doping of Ag atoms reduced the resistance of charge transfer, thus effectively accelerated the photocatalysis reaction. Moreover, through ESR characterization and scavengers coexistent experiments, •OH and •O 2 were considered to be active radicals that played a crucial role in the photodegradation process. Furthermore, DFT calculation demonstrated that ANS displayed obvious visible light excitation performance via reducing the band gap. The improvement of work function enhanced the oxidation ability of photogenerated holes, forming more hydroxyl radicals, thus boosted the photodegradation of pollutants.

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Understanding synergistic mechanisms of ferrous iron activated sulfite oxidation and organic polymer flocculation for enhancing wastewater sludge dewaterability

Cited by 73 publications

References 52 publications

Pyrite activated peroxymonosulfate combined with as a physical–chemical conditioner modified biochar to improve sludge dewaterability: analysis of sludge floc structure and dewatering mechanism

Pyrite activated peroxymonosulfate combined with as a physical–chemical conditioner modified biochar to improve sludge dewaterability: analysis of sludge floc structure and dewatering mechanism

Simultaneously Enhanced Dewaterability and Biopolymer Release of Sludge by Natural Deep Eutectic Solvents: Performance, Mechanisms, and Insights of Theoretical Calculations

Sliver Doped Sodium Antimonate with Greatly Reduced the Band Gap for Efficiently Enhanced Photocatalytic Activities Under Visible Light (Experiment and DFT Calculation)

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