Use of Streaming Current and Other Parameters for Polymer Dose Control in Sludge Conditioning

1994 ◽  
pp. 373-381 ◽  
Author(s):  
Steven K. Dentel ◽  
Kathleen M. Wehnes ◽  
Mohammad M. Abu-Orf
Keyword(s):  
Streaming Current ◽  
Dose Control ◽  
Sludge Conditioning

Fundamental Considerations in Use of the Streaming Current Detector for Chemical Dose Control

1992 ◽  
pp. 165-179 ◽  
Author(s):  
Mark L. Elicker ◽  
John J. Resta ◽  
James W. Hunt ◽  
Steven K. Dentel
Keyword(s):  
Streaming Current ◽  
Dose Control

Application of the Streaming Current Detector in Sludge Conditioner Selection and Control

1993 ◽  
Vol 28 (1) ◽  
pp. 169-179 ◽  
Author(s):  
S. K. Dentel ◽  
M. M. Abu-Orf
Keyword(s):  
Positive Charge ◽  
Mixing Time ◽  
Dose Range ◽  
Digested Sludge ◽  
Capillary Suction ◽  
Streaming Current ◽  
Polymer Addition ◽  
Dose Control ◽  
Anaerobically Digested Sludge ◽  
And Control

The streaming current detector (SCD) can be utilized to measure charge characteristics of a suspension or sludge which can be related to zeta potential. In this study, the SCD was used as a tool for polymer selection and dose control toward improved sludge conditioning prior to centrifugation. In laboratory studies, polymer addition to sludges was followed by controlled mixing then measurement of streaming current (SC) and capillary suction time (CST). Plant studies employed facilities at an 18.8 MGD wastewater treatment facility in Warminster, PA, USA. Anaerobically digested sludge was conditioned with varying doses of cationic polymer and dewatered using two parallel solid-bowl centrifuges. The polymer caused a transition from negative to positive charge in both conditioned sludge and centrate. The polymer dose range for optimum dewaterability, as indicated by CST and solids recovery, corresponded to near-zero SC in all cases. Even when greater mixing intensities or times increased the polymer demand, the charge transition was similarly related. This correspondence was used to successfully confirm a calculation method establishing velocity gradient and mixing time similitude between jar tests and in-line mixing prior to the centrifuge.

How to use alum with cationic dispersed rosin size

TAPPI Journal ◽  
2016 ◽  
Vol 15 (5) ◽  
pp. 331-335 ◽  
Author(s):  
LEBO XU ◽  
JEREMY MYERS ◽  
PETER HART
Keyword(s):  
Zeta Potential ◽  
Colloidal Particles ◽  
Streaming Potential ◽  
Excessive Amount ◽  
Paper Machine ◽  
Optimum Amount ◽  
Potential Measurement ◽  
Streaming Current ◽  
Wide Range ◽  
Laboratory Results

Retention of cationic dispersed rosin size was studied via turbidity measurements on stock filtrate with different alum and dispersed rosin size dosages. Stock charge characteristics were analyzed using both an analysis of charge demand determined via a streaming current detector and an evaluation of zeta potential of the fibers by streaming potential measurement. The results indicated that an optimum amount of alum existed such that good sizing retention was maintained throughout a wide range of dispersed rosin size dosages. However, when an excessive amount of alum was used and fines and colloidal particles were transitioned from anionic to cationic, the cationic size retention was reduced. Laboratory results were confirmed with a paper machine trial. All data suggested that a stock charge study was necessary to identify optimal alum dosage for a cationic dispersed rosin sizing program.

Modern Trends in Sludge Management: Sludge Conditioning

1983 ◽  
Vol 15 (1) ◽  
pp. 37-48 ◽  
Author(s):  
G E Eden
Keyword(s):  
Relative Efficiency ◽  
Sludge Management ◽  
Chemical Methods ◽  
Laboratory Techniques ◽  
Sludge Conditioning

The origins and characteristics of sludges are described in relation to the need to dewater them for ultimate disposal. Various methods for conditioning sludge to facilitate subsequent dewatering are discussed, including physical, thermal and chemical methods. The special features of conditioning by polyelectrolytes are described and an account is given of laboratory techniques for comparing the relative efficiency of conditioners.

Theoretical Principles of Streaming Current Detection

1989 ◽  
Vol 21 (6-7) ◽  
pp. 443-453 ◽  
Author(s):  
S. K. Dentel ◽  
K. M. Kingery
Keyword(s):  
Velocity Profile ◽  
Electrophoretic Mobility ◽  
Double Layer ◽  
Initial Attempt ◽  
Streaming Current ◽  
Coagulant Dosage ◽  
Model Predictions ◽  
Double Layer Model ◽  
Simplifying Assumptions ◽  
Current Detection

In spite of the increased use of streaming current detectors (SCDs) as a means of monitoring and/or controlling coagulant dosage, knowledge regarding fundamental workings is incomplete. This paper provides an initial attempt at predicting and verifying functioning compared to electrophoretic mobility. The instrument's components -- the sensor and the signal processor -- are first described. Equations modelling electro-double layer behavior in its sensor are then developed. Simplifying assumptions include the use of a capacitance model of the double layer and a triangular velocity profile for fluid within the sensor's annulus. More complex modelling approaches are also suggested which incorporate the Gouy-Chapman electro-double layer model and an exact solution for the velocity profile. Experimental results confirm predictions of the simplified model under conditions of low potential. A monotonic relationship exists between streaming current electrophoretic mobility, which is required for its use as a control parameter. Deviations from model predictions are suggested to be due to charge characteristics of the sensor surfaces themselves.

Development of New Polymer Dosage Control Method for Sludge Dewatering Process

1993 ◽  
Vol 28 (11-12) ◽  
pp. 263-272 ◽  
Author(s):  
Chiaki Igarashi ◽  
Kazunari Tanaka ◽  
Teruaki Kitamura ◽  
Kazuo Fujita ◽  
Kazuaki Arai ◽  
...  
Keyword(s):  
Control Method ◽  
Sludge Dewatering ◽  
Proportional Control ◽  
Sludge Characteristics ◽  
Streaming Current

In a sludge dewatering process using polymer, controlling the polymer dosage is an important factor for upgrading performance and achieving a saving on costs. A new automatic polymer dosage control method has been developed by the authors, which features the use of a streaming current detector or a colloid titrator. These detectors detect the colloidal charge of the filtrate from sludge. The said method was used with actual dehydrators and the following advantages were confirmed.(1) The said method is applicable for various types of dehydrators.(2) The said method is effective even when there are changes in sludge characteristics.(3) The said method is more economical than a conventional solids proportional control method in that less polymer is used.

Changes of some sewage sludge parameters prepared with an ultrasonic field

1997 ◽  
Vol 36 (11) ◽  
pp. 101-106 ◽  
Author(s):  
January Bien ◽  
Lidia Wolny
Keyword(s):  
Sewage Sludge ◽  
Microscopic Analysis ◽  
Chemical Compounds ◽  
Ultrasonic Field ◽  
Water Removal ◽  
Vacuum Filter ◽  
Additional Criterion ◽  
New Methods ◽  
Sludge Conditioning

Studies of sewage sludge conditioning by ultrasonic field concentrate on determination of the increase of water removal effect, which depends on kind of sludge and chemical compounds used in the dewatering process. An attempt was made to find new methods of sludge preparation before dewatering. Tests presented here focused on digested and difficult dewatered sludge. The sludge was dewatered on a vacuum filter after conditioning with polyelectrolytes and the ultrasonic field. The microscopic analysis was an additional criterion to evaluate changes in the sludge structure after preparation. The polyelectrolyte dose of 3 mg/g d.m. sonicated within 15 sec. resulted in the 50% decrease of sludge volume. Results presented confirmed our previous experiences, concerning the relation between conglomerates of sludge and the effect of dewatering.

Fuzzy control of coagulation reaction through streaming current monitoring

1997 ◽  
Vol 36 (4) ◽  
pp. 127-134 ◽  
Author(s):  
J. C. Liu ◽  
M. D. Wu
Keyword(s):  
Fuzzy Logic Controller ◽  
Treatment Plant ◽  
Control Process ◽  
Water Treatment Plant ◽  
Critical Parameters ◽  
Flow Mode ◽  
Raw Water ◽  
Streaming Current ◽  
On Line ◽  
Current Monitoring

A fuzzy logic controller (FLC) incorporating the streaming current detector (SDC) was utilized in the automatic control of the coagulation reaction. Kaolinite was used to prepare synthetic raw water, and ferric chloride was used as the coagulant. The control set point was decided at a streaming current (SC) of −0.05 and pH of 8.0 from jar tests, zeta potential and streaming current measurements. A bench-scale water treatment plant with rapid mix, flocculation, and sedimentation units, operated in a continuous-flow mode, was utilized to simulate the reaction. Two critical parameters affecting the coagulation reaction, i.e., pH and streaming current, were chosen as process outputs; while coagulant dose and base dose were chosen as control process inputs. They were on-line monitored and transduced through a FLC. With raw water of initial turbidity of 110 NTU, residual turbidity of lower than 10 NTU before filtration was obtained. Results show that this combination functions satisfactorily for coagulation control.

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