scholarly journals Variations of sludge characteristics during the advanced anaerobic digestion process and the dewaterability of the treated sludge conditioning with PFS, PDMDAAC and synthesized PFS-PDMDAAC

2018 ◽  
Vol 78 (5) ◽  
pp. 1189-1198 ◽  
Author(s):  
Jinghui Zhang ◽  
Hong Yang ◽  
Wei Li ◽  
Yang Wen ◽  
Xingmin Fu ◽  
...  
Keyword(s):  
Particle Size ◽  
Anaerobic Digestion ◽  
Extracellular Polymeric Substances ◽  
Three Dimensional ◽  
Sludge Treatment ◽  
Capillary Suction ◽  
Excitation Emission Matrix ◽  
Digestion Process ◽  
Sludge Dewaterability ◽  
Polyferric Sulfate

Abstract Anaerobic digestion with thermal hydrolysis pretreatment (THP), also called advanced anaerobic digestion (AAD), is a mainstream technology for sludge treatment. AAD changes sludge, it can degrade extracellular polymeric substances (EPS), release EPS from the sludge, and alter the particle size distribution. We synthesized PFS–PDMDAAC from the inorganic coagulant polyferric sulfate (PFS) and the organic coagulant polymer polydimethyldiallylammonium chloride (PDMDAAC) in various PFS:PDMDAAC weight ratios. We investigated the effects of PFS–PDMDAAC pretreatment on AAD sludge dewaterability, and developed an explanation for them. Capillary suction time (CST) was used as a measure of sludge dewaterability. Dissolved organic matter, the three-dimensional excitation emission matrix, particle size (d0.5), zeta potential, and sludge microstructure were observed in order to explain changes in sludge dewaterability that resulted from different compositions and dosages of coagulants. Treatment with PFS alone gave no significant improvement in sludge dewaterability. PDMDAAC used alone greatly improved sludge dewaterability. Synthesized PFS–PDMDAAC which had a relatively high proportion of PDMDAAC by weight performed similarly to PDMDAAC. PFS–PDMDAAC synthesized in the ratio (PDF:PDMDAAC) 1:5 by weight provided good dewaterability. The dosage can be reduced by 16.7% of the dosage for conditioning by PDMDAAC alone.

scholarly journals Performance and mechanism of sludge dewaterability enhanced by potassium ferrate pretreatment and calcium chloride addition

2016 ◽  
Vol 7 (2) ◽  
pp. 136-141 ◽  
Author(s):  
Yali Liu ◽  
Xiaorong Kang ◽  
Xin Li ◽  
Zheng Wang ◽  
Zhaoqian Jing
Keyword(s):  
Calcium Chloride ◽  
Extracellular Polymeric Substances ◽  
Three Dimensional ◽  
Negative Relationship ◽  
Potassium Ferrate ◽  
Optimal Parameters ◽  
Capillary Suction ◽  
Potential Benefits ◽  
Sludge Dewaterability ◽  
Microscopy Images

The potential benefits and mechanisms of potassium ferrate pretreatment and calcium chloride addition on sludge dewaterability were investigated in this study. The capillary suction time (CST) was used to evaluate sludge dewaterability. Results indicated that potassium ferrate of 0.1 g/g total solids (TS) and calcium chloride of 0.4 g/g TS were optimal parameters, and corresponding CST reached 43.7 s. Soluble organics in extracellular polymeric substances (EPS) were determined by three-dimensional excitation-emission matrix fluorescence spectroscopy, which was used to explain the mechanism of sludge dewaterability. The fluorescence intensities of protein-like and humic-like substances in EPS had a negative relationship with the CST. Scanning electron microscopy images indicated that calcium chloride neutralized the surface charge of particles, making the soluble protein-like substances agglomerate and form bigger flocs, consequently enhancing sludge dewaterability.

scholarly journals Insight into the comparison of thermally and Fe(II) activated persulfate on sludge dewaterability and disintegration

2021 ◽  
Author(s):  
Shaodong Guo ◽  
Long Zhou ◽  
Yuxin Huang ◽  
Xinghu Huang
Keyword(s):  
Extracellular Polymeric Substances ◽  
Three Dimensional ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Fluorescence Excitation ◽  
Capillary Suction ◽  
Extracellular Polymer Substance ◽  
Sludge Dewaterability ◽  
Oxidation Efficiency ◽  
Degradation Effect

Abstract The effects of thermally and Fe(II) activated potassium persulfate (PPS) on sludge dewatering performance were compared systematacially. Sludge dewaterability was monitored by measuring capillary suction time (CST) and sludge specific resistance to filtration (SRF), and the degradation effect was characterized by Chemical oxygen demand (COD), total organic carbon (TOC), ammonia nitrogen (NH4+-N) and extracellular polymeric substances (EPS). The Change of extracellular polymer substance (EPS) including soluble, loosely bound and tightly bound EPS (S-EPS, LB-EPS and TB-EPS) with time and PPS dosage was monitored to discuss the oxidation efficiency of thermally and Fe(II) activated PPS. Sludge supernate were analyzed by three dimensional fluorescence excitation-emission spectrum (3D-EEM) to confirm the proteins transformation. The result showed that sludge dewaterability in terms of CST and SRF were enhanced with increasing PPS dosage and condition time of both two activated methods. While Fe(II) activated PPS could reduce sludge CST and SRF to preferred values at low PPS dosage and short condition time. Maenwhile, sludge degradation effect was also more obvious. Mechanically, sludge TB-EPS in proteins and polysaccharides converted to SB-EPS was more quickly with Fe(II) activated PPS. Besides, thermally activated PPS tended to oxidize the protein in the supernatant first.

scholarly journals Improvement of sludge dewaterability and disintegration efficiency using electrolytic zero-valent iron activated peroxymonosulfate

2021 ◽  
Author(s):  
Shaodong Guo ◽  
Yuxin Huang ◽  
Long Zhou ◽  
Xinghu Huang
Keyword(s):  
Extracellular Polymeric Substances ◽  
Specific Resistance ◽  
Three Dimensional ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Zero Valent Iron ◽  
Organic Substances ◽  
Fluorescence Excitation ◽  
Capillary Suction ◽  
Sludge Dewaterability

Abstract Electrolysis zero-valent iron activated peroxymonosulfate (EZVI-PMS) was applied to enhance sludge dewaterability and disintegration performance. Sludge dewaterability was characterized by capillary suction time (CST), specific resistance to filtration (SRF), and disintegration performance was explored by measuring sludge DNA content, ammonia nitrogen, chemical oxygen demand (COD), extracellular polymeric substances (EPS) and dissolved organic carbon (DOC). EPS including soluble EPS (SB-EPS), loosely bound EPS (LB-EPS), tightly bound EPS (TB-EPS) were analyzed by three dimensional fluorescence excitation-emission spectrum (3D-EEM) to confirm the proteins transformation tendency. DOC, protein and polysaccharide in EPSs were quantified to investigate the conditioning mechanism. The results showed that sludge CST and SRF were reduced significantly when the current was 0.2 A and PMS dosage was 130 mg/gDS with the reductions of 43.8% and 74.1%, respectively, and DNA was released from sludge cells to liquid phase. Mechanically, sludge TB-EPS converted to SB-EPS with DOC in TB-EPS decreasing from 367.0 mg/L to 210 mg/L, while DOC in SB-EPS increased from 44 mg/L to 167.4 mg/L. Besides, the changes of proteins and polysaccharides contents in SB-EPS and TB-EPS were similar to DOC, and protein in TB-EPS transformed to other protein-like or organic substances obviously.

scholarly journals The influence of different sludge concentrations on its dewaterability during bioleaching

2020 ◽  
Vol 81 (12) ◽  
pp. 2585-2598
Author(s):  
Wenfeng Yang ◽  
Liyuan Zeng ◽  
Weihao Zhang ◽  
Qiyong Yang ◽  
Tianfeng Wang ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances ◽  
Reduction Potential ◽  
High Efficiency ◽  
Specific Resistance ◽  
Principal Component ◽  
Buffering Capacity ◽  
Capillary Suction ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Sludge Dewaterability

Abstract Bioleaching, a technologically and economically feasible technology, is considered as the high efficiency method to improve dewaterability in sewage sludge. The objective of this study was to investigate the effect of different sludge concentrations on bioleaching dewaterability and understand the mechanism of the effect of bioleaching on sludge dewaterability. Variation in pH, oxidation-reduction potential (ORP), capillary suction time (CST), specific resistance to filtration (SRF) and different fractions of extracellular polymeric substances (EPS) including slime EPS (S-EPS), loosely bound EPS (LB-EPS), and tightly bound EPS (TB-EPS) were determined. Different sludge concentrations (5, 10, 15, 20 and 30 g·L−1) were selected to investigate during bioleaching. Results indicated that sludge buffering capacity significantly inhibited bioleaching efficiency as sludge concentrations increased. Optimum enhancements in sludge dewaterability were observed during the 10 g·L−1 sludge concentration treatment, and reached a maximum when the pH was 2.11. The variation of different fractions of EPS revealed that the ratio of S-EPS/TB-EPS significantly affected sludge dewaterability. Principal component analysis and Pearson's correlation analysis both provided evidence that the higher TB-EPS followed by a very large reduction was positively correlated with sludge dewaterability. However, the increase of protein and DNA in S-EPS content was negatively correlated with sludge dewaterability.

Extracellular polymeric substances and dewaterability of waste activated sludge during anaerobic digestion

2014 ◽  
Vol 70 (9) ◽  
pp. 1555-1560 ◽  
Author(s):  
Fenxia Ye ◽  
Xinwen Liu ◽  
Ying Li
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Extracellular Polymeric Substance ◽  
Extracellular Polymeric Substances ◽  
Waste Activated Sludge ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Relationship Analysis ◽  
The Relationship ◽  
Insight Into

Anaerobic digestion of waste activated sludge was conducted to gain insight into the mechanisms underlying change in sludge dewaterability during its anaerobic digestion. Unexpectedly, the results indicated that sludge dewatering properties measured by capillary suction time only deteriorated after 10 days of anaerobic digestion, after which dewaterability recovered and remained stable. The loosely bound extracellular polymeric substance (LB-EPS) content increased three-fold after 20 days of anaerobic digestion, and did not change significantly during the remaining 30 days. The tightly bound EPS (TB-EPS) content reduced slightly after 20 days of anaerobic digestion, and stabilized during the last 30 days. Polysaccharides (PS) and proteins (PN) content in LB-EPS increased after 10 days of anaerobic digestion. However, PS and PN contents in TB-EPS decreased slightly. The relationship analysis showed that only LB-EPS correlated with dewaterability of the sludge during anaerobic digestion.

Fate of nonylphenol polyethoxylates and nonylphenoxy acetic acids in an anaerobic digestion process for sewage sludge treatment

2006 ◽  
Vol 53 (11) ◽  
pp. 221-226 ◽  
Author(s):  
M. Minamiyama ◽  
S. Ochi ◽  
Y. Suzuki
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Treatment Process ◽  
Sludge Treatment ◽  
Testing Apparatus ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Sewage Sludge Treatment ◽  
Acetic Acids

Many environmental problems caused by endocrine disruptors (EDs) have been reported. It is reported that EDs flow into sewage treatment plants, and it has been pointed out that these may be shifted from the wastewater treatment process to the sludge treatment process. Little is known about the fate of EDs accumulated in sewage sludge, so we carried out a study to clarify the fate of EDs in sewage sludge treatment processes, especially in an anaerobic digestion process. In this study, nonylphenol (NP) was selected as a target ED. Nonylphenol ethoxylates (NPnEO) or nonylphenoxy acetic acids (NPnEC), which were the precursor of NP, were added to an anaerobic digestion process, and mass balance was investigated. The following results were obtained from the anaerobic digestion experiments. (1) NP1EO was injected to an anaerobic digestion testing apparatus that was operated at a retention time of approximately 28 d and a temperature of 35 °C with thickened sludge sampled from an actual wastewater treatment plant. Approximately 40% of the injected NP1EO was converted to NP. (2) NP1EC was injected to an anaerobic digestion testing apparatus with thickened sludge. As a result, almost all injected NP1EC was converted to NP. When NP2EC was injected, NP2EC was not converted to NP until the 20th day.

scholarly journals Synergetic Effect of Combined CaO2 and Microwave Treatment on Waste Active Sludge Dewaterability and Organic Contaminants’ Removal

2021 ◽  
Vol 9 ◽  
Author(s):  
Jie Wang ◽  
Kankan Shang ◽  
Liangjun Da ◽  
Xingguo Liu ◽  
Yongjing Zhao ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Superoxide Anion ◽  
Extracellular Polymeric Substances ◽  
Synergetic Effect ◽  
Microwave Treatment ◽  
Sludge Dewatering ◽  
Active Sludge ◽  
Capillary Suction ◽  
Contaminants Removal ◽  
Sludge Dewaterability

This study investigated the synergetic effect of the combined calcium peroxide (CaO2) and microwave (MW) treatment on waste active sludge dewatering properties and organic contaminants’ removal. The optimal sludge dewaterability was obtained at CaO2 (20 mg/gVSS)/MW (70°C), and the capillary suction time decreased by 52% compared with raw sludge. Further investigation indicated that total extracellular polymeric substances (EPS), tightly bound EPS, total protein, and protein present in tightly bound EPS were closely correlated with sludge dewaterability. Tryptophan, aromatic protein–like substances and humic acid–like substances were the key compounds that affect sludge dewaterability. The charge neutralization and bridge effect of cation ions were strengthened when combined with MW irradiation. In addition, it was revealed that MW facilitated CaO2 to produce more hydroxyl and superoxide anion radicals. This study confirmed CaO2/MW to be an effective way to improve sludge dewatering and remove organic pollutants from sludge.

Enhancement of sewage sludge dewaterability by fungal conditioning with Penicillium simplicissimum NJ12: From bench- to pilot-scale consecutive multi-batch investigations

2021 ◽  
Author(s):  
Neng Tao ◽  
Xiu Wu ◽  
Feng Zhang ◽  
Zilei Pi ◽  
Jiaqi Wen ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances ◽  
Volume Fraction ◽  
Linear Regression Analysis ◽  
Pilot Scale ◽  
Recycling Rate ◽  
Penicillium Simplicissimum ◽  
Fungal Treatment ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Sludge Dewaterability

Abstract Bench- and pilot-scale successive multi-batch trials were conducted to investigate the performance and sustainability of fungal conditioning with Penicillium simplicissimum NJ12 for improving sludge dewatering. The dominant factors affecting the sludge dewaterability improvement by P. simplicissimum NJ12 were also identified. Fungal treatment with P. simplicissimum NJ12 at a volume fraction of 5% of the inoculum greatly improved the sludge dewaterability. This improvement was characterized by sharp decreases in the specific resistance to filtration from 1.97 × 1013 to 3.52 × 1011 m/kg and capillary suction time from 32 to 12 s within 3 days. Stepwise multiple linear regression analysis showed that a marked decrease (58.8%) in the protein content in slime extracellular polymeric substances and an increase in the zeta potential of the sludge (from − 35 to − 10 mV) were the most important factors that improved the dewaterability of sludge after fungal treatment. Consecutive processes of fungal treatment could be realized by recirculating the fungal-treated sludge with a recycling rate of 1:2 (Vbiotreated sludge/Vtotal sludge). The treatment effectiveness was maintained only over three successive cycles, but replenishment with fresh P. simplicissimum NJ12 would be provided periodically at set batch intervals. These findings demonstrate the possibility of P. simplicissimum NJ12-assisted fungal treatment for enhancing sludge dewatering.

Three-dimensional excitation emission matrix fluorescence spectroscopy and gel-permeating chromatography to characterize extracellular polymeric substances in aerobic granulation

2010 ◽  
Vol 61 (11) ◽  
pp. 2931-2942 ◽  
Author(s):  
Huacheng Xu ◽  
Pinjing He ◽  
Guanzhao Wang ◽  
Liming Shao
Keyword(s):  
Molecular Weight ◽  
Fluorescence Spectroscopy ◽  
Extracellular Polymeric Substances ◽  
Operating Time ◽  
Three Dimensional ◽  
Aerobic Granules ◽  
Aerobic Granulation ◽  
Excitation Emission Matrix ◽  
Two Peaks ◽  
Eem Fluorescence

Three-dimensional excitation emission matrix (EEM) fluorescence spectroscopy and gel-permeating chromatography (GPC) were employed to characterize the extracellular polymeric substances (EPS) in aerobic granulation. EPS matrix in this study was stratified into four fractions: (1) supernatant, (2) slime, (3) loosely bound EPS (LB-EPS), and (4) tightly bound EPS (TB-EPS). The results showed that the dissolved organic carbon was mainly distributed in TB-EPS fraction, and increased with increasing the operating time. The supernatant, slime, and LB-EPS fractions exhibited four fluorescence peaks, an autochthonous signature, unimodal MW distribution and lower molecular weight (MW) (3 < log [MW]<5), whereas the TB-EPS fraction only had two peaks, an allochthonous signature, multiple peaks and higher MW (5 < log [MW]<7). It was deemed that the formation of aerobic granules was correlated with the accumulation of proteins in the TB-EPS fraction. EEM spectroscopy and GPC profiles could be used as appropriate and effective methods to characterize the EPS in aerobic granulation from a micro-view level.

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