scholarly journals FLOCCULATION DYNAMICS OF SYNTHETIC AND ACTIVATED SLUDGE IN WASTEWATER TREATMENT

2009 ◽  
Vol 12 (2) ◽  
pp. 74-84
Author(s):  
Phong Tan Nguyen ◽  
Nidal Hilal ◽  
John T Novak
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Cationic Polyelectrolyte ◽  
Sludge Dewatering ◽  
Critical Effect ◽  
Cation Concentration ◽  
Floc Characteristics ◽  
Synthetic Sludge ◽  
Sludge Conditioning ◽  
The Relationship

This study has investigated in a comparative fashion the effect of cation, polysaccharide, and Polyelectrolyte on the flocculation dynamics and final properties of both synthetic and activated sludge. The results from experiments indicate that cation, polysaccharide, and Polyelectrolyte could influence sludge floc characteristics as they relate to sludge conditioning. The relationship between polysaccharide and cation concentration was examined at laboratory scale during flocculation with both synthetic and activated sludge; an increase in feed cation concentration led to a decrease in final polysaccharide concentration of the supernatant. The effects of a polyelectrolyte conditioner on sludge conditioning were determined. The results indicated that the cationic Polyelectrolyte had the critical effect on sludge dewatering, and made the improvement of the final properties of sludge. A qualitative link exists between polyelectrolyte conditioner dosage and sludge conditioning for both types of sludge. The two types of sludge also have very similar sludge conditioning. Thus synthetic and activated sludge behave very similarly in terms of their characteristics and sludge conditioning, and synthetic sludge can be used as a surrogate in activated sludge studies.

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.

Zoogleal Clusters and Sludge Dewatering Potential in an Industrial Activated-Sludge Wastewater Treatment Plant

2000 ◽  
Vol 72 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Curtis A. Lajoie ◽  
Alice C. Layton ◽  
Ingrid R. Gregory ◽  
Gary S. Sayler ◽  
Don E. Taylor ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Sludge Dewatering

Optimizing Polymer Consumption in Sludge Dewatering Applications

1990 ◽  
Vol 22 (7-8) ◽  
pp. 261-267
Author(s):  
P. M. Crawford
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Operating Performance ◽  
Water Systems ◽  
Full Scale ◽  
Sludge Dewatering ◽  
The Past ◽  
Sludge Conditioning ◽  
Original Objective ◽  
Device Operation

As we move into the 1990's, upgrading of existing wastewater treatment plants is becoming a very important consideration. Although upgrading can take many forms, one of the most economic is to optimize the performance of the existing equipment and structures. In the realm of sludge dewatering, also an increasingly important topic, an area which has received little attention in the past is the control of the sludge conditioning process prior to dewatering. In conjunction with the Wastewater Technology Centre in Burlington, Canada, ZENON Water Systems Inc. has developed the Sludge Conditioning Controller (SCC) to fulfill this need in the wastewater marketplace. A description of both the hardware and software aspects of the SCC are presented. In addition, typical operating performance of the microprocessor-based system is shown. Experience with full scale systems has revealed that the benefits associated with the SCC far exceed the original objective of saving polymer. The others include automation of the dewatering device operation, increased capacity, and more uniform performance of the dewatering machine.

The fate and impact of coagulants/flocculants in sludge treatment system

2021 ◽  
Author(s):  
qizi fu ◽  
xuran liu ◽  
yanxin Wu ◽  
Dongbo Wang ◽  
Qiuxiang Xu ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Treatment System ◽  
Waste Activated Sludge ◽  
Sludge Dewatering ◽  
High Accumulation ◽  
Sludge Treatment

Coagulants and flocculants have been widely used in various applications, especially in wastewater treatment and sludge dewatering, which result in their high accumulation in waste activated sludge (WAS). In the...

Sludge conditioning by using alumina nanoparticles and polyelectrolyte

2007 ◽  
Vol 56 (8) ◽  
pp. 125-132 ◽  
Author(s):  
Z.S. Wang ◽  
M.T. Hung ◽  
J.C. Liu
Keyword(s):  
Activated Sludge ◽  
Paper Industry ◽  
Cationic Polyelectrolyte ◽  
Alumina Nanoparticles ◽  
Waste Activated Sludge ◽  
Capillary Suction ◽  
Floc Size ◽  
Combined Use ◽  
Retention Aids ◽  
Sludge Conditioning

The combined use of nanoparticle and polyelectrolyte as retention aids in pulp and paper industry tend to give better flocculation (retention) and drainage (dewatering) than conventional polyelectrolyte flocculation. The combined use of alumina nanoparticle and polyelectrolyte in conditioning waste activated sludge was investigated in the current study. Alumina with three different sizes (139.5, 241.7, and 326.4 nm) was utilized in combination with a cationic polyelectrolyte (T3052) of molecular weight of 1.1 × 107 and charge density of 2.1 meq/g. It was found from capillary suction time (CST) and specific resistance to filtration (SRF) measurement that sludge conditioned with alumina/polyelectrolyte showed a better dewaterability than polyelectrolyte alone. In addition, it was found that the better dewaterability was obtained as alumina became smaller. Floc size and fractal dimension of flocs were examined as well. The mechanism of enhanced dewaterability was proposed that alumina nanoparticles became adsorbed onto sludge and positive patches were formed. The electrostatic repulsion made the polyelectrolyte more stretched, and resulted in more effective flocculation and bridging as polyelectrolyte was added. Dosing sequence also affected the conditioning effectiveness. However, the combined use of silica nanoparticles and a cationic polelectrolyte, KP-201C, or alumina nanoparticles and an anionic polyelectrolyte, AP410, did not result in improved dewaterability of waste activated sludge. Possible explanation was discussed. Preliminary results show that some in-depth work is needed regarding the introduction of nanoparticles in sludge conditioning.

scholarly journals Enhancement the conditioning of waste activated sludge through a sequence of freeze/thaw-electro-Fenton process

2018 ◽  
Vol 20 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Narjes Shahheidar ◽  
Sahand Jorfi ◽  
Afshin Takdastan ◽  
Neemat Jaafarzadeh ◽  
Mehdi Ahmadi
Keyword(s):  
Activated Sludge ◽  
Specific Resistance ◽  
Current Intensity ◽  
Freezing Process ◽  
Waste Activated Sludge ◽  
Fenton Process ◽  
Solution Ph ◽  
Sludge Dewatering ◽  
Freeze Thaw ◽  
Sludge Conditioning

Abstract Sludge conditioning is an important stage in sludge management. In the present study, a sequence of freeze/thaw-electro-Fenton process was designed and specific resistance filtration (SRF) was monitored during sludge conditioning as an important factor in sludge dewaterability. Furthermore, protein and polysaccharide concentrations were measured during the experiments. Results showed that the lowest SRF value contributed to −10°C in freezing process which showed a reducing trend by decreasing solution pH. In addition, results revealed that solution pH less than 3 caused a significant improvement in sludge dewatering; so the lowest SRF has been registered at pH = 2. By increasing current intensity from 0.5 to 1A, SRF values were reduced and then followed by an enhancement with increasing current intensity to 3.2 A. The lowest SRF value (6.1 × 104 m/kg) was obtained at H2O2 = 30 mg/L which was the best conditions for sludge dewatering.

Chitosan use in chemical conditioning for dewatering municipal-activated sludge

2014 ◽  
Vol 71 (6) ◽  
pp. 810-816 ◽  
Author(s):  
H. Zemmouri ◽  
N. Mameri ◽  
H. Lounici
Keyword(s):  
Activated Sludge ◽  
Treatment Plant ◽  
Cationic Polyelectrolyte ◽  
Solid Content ◽  
Test Method ◽  
Optimum Dose ◽  
Optimal Dosage ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Jar Test

This work aims to evaluate the potential use of chitosan as an eco-friendly flocculant in chemical conditioning of municipal-activated sludge. Chitosan effectiveness was compared with synthetic cationic polyelectrolyte Sedipur CF802 (Sed CF802) and ferric chloride (FeCl3). In this context, raw sludge samples from Beni-Messous wastewater treatment plant (WWTP) were tested. The classic jar test method was used to condition sludge samples. Capillary suction time (CST), specific resistance to filtration (SRF), cakes dry solid content and filtrate turbidity were analyzed to determine filterability, dewatering capacity of conditioned sludge and the optimum dose of each conditioner. Data exhibit that chitosan, FeCl3 and Sed CF802 improve sludge dewatering. Optimum dosages of chitosan, Sed CF802 and FeCl3 allowing CST values of 6, 5 and 9 s, were found, respectively, between 2–3, 1.5–3 and 6 kg/t ds. Both polymers have shown faster water removal with more permeable sludge. SRF values were 0.634 × 1012, 0.932 × 1012 and 2 × 1012 m/kg for Sed CF802, chitosan and FeCl3 respectively. A reduction of 94.68 and 87.85% of the filtrate turbidity was obtained with optimal dosage of chitosan and Sed CF802, respectively. In contrast, 54.18% of turbidity abatement has been obtained using optimal dosage of FeCl3.

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