Liquid purification or separation – Processes – Liquid/liquid solvent or colloidal extraction or diffusing...
Patent
1992-06-24
1994-04-19
Spear, Frank
Liquid purification or separation
Processes
Liquid/liquid solvent or colloidal extraction or diffusing...
210638, 21050042, 210639, B01D 6502
Patent
active
053043090
ABSTRACT:
An improved, continuous, cyclic process for selective coagulant recovery from clarifier sludge in water treatment plants. The improvement comprises several steps. First, the pH of the clarifier sludge is adjusted to about 3.5. Next, a composite membrane is provided having a chelating exchanger enmeshed in porous polymeric thin sheets. That composite membrane is placed in contact with the acidified sludge for selectively sorbing metal ion from the acidified sludge onto the composite membrane. The composite membrane, now carrying the metal ion, is withdrawn from contact with the acidified sludge and introduced into a stirred regeneration tank containing acid. In that tank, the chelating exchanger of the composite membrane is regenerated by desorbing the metal ion, thereby recovering the coagulant substantially devoid of organic material and undesirable metals. Finally, the regenerated composite membrane is recycled into contact with more acidified sludge while, at the same time, the acid is recirculated through the regeneration tank. In short, the improved cyclic process recovers alum selectively from clarifier sludge with insignificant carry-over of undesirable substances like organics, manganese, and heavy metals.
REFERENCES:
patent: 3872001 (1975-03-01), Davis et al.
patent: 3910842 (1975-10-01), Karlson
patent: 3959133 (1976-05-01), Fulton
patent: 4067802 (1978-01-01), Cronberg et al.
patent: 4153661 (1979-05-01), Ree et al.
patent: 4203837 (1980-05-01), Hooe et al.
patent: 4334999 (1982-06-01), Cornwell
patent: 4448696 (1984-05-01), White, Jr.
patent: 4460642 (1984-07-01), Errede
patent: 4500494 (1985-02-01), Scher
patent: 4530963 (1985-07-01), DeVoe et al.
patent: 4612122 (1986-09-01), Ambrus et al.
patent: 4676908 (1987-06-01), Clepiela et al.
patent: 4741831 (1988-05-01), Grinstead
patent: 4902308 (1990-02-01), Mallouk et al.
patent: 5026481 (1991-06-01), Paul et al.
W. Waitz, "Ion Exchange in Heavy Metals Removal and Recovery", Amber-Hi-Lites, 162 (Rohm and Haas Co., Philadelphia, PA).
T. Roy, "Chelating Polymers: Their Properties and Applications", Master's Thesis, Lehigh University, Bethlehem, PA, pp. 25-39 (1989).
M. Bishop et al., "Testing of Alum Recovery for Solids Reductions and Reuse", J. AWWA, 79:76 (1987).
D. Cornwell & J. Zoltek, "Recycling of Alum Used for Phosphorus Removal in Domestic Wastewater Treatment", J. WPCF, 49:600 (1977).
Y. Zhu et al., "Toward Separation of Toxic Metal Ions by Chelating Polymers; Some Noteworthy Observations", Reactive Polymers, 13:241 (1990).
W. Holl, "Optical Verification of Ion Exchange Mechanisms in Weak Electrolyte Resin", Reactive Polymers, 2:93 (1984).
G. Schmuckler, "Kinetics of Moving-Boundary Ion-Exchange Processes", Reactive Polymers, 2:103 (1984).
I. Najm et al., "Effect of Particle Size and Background Natural Organics on the Adsorption Efficiency of PAC", J. AWWA, 82:1:65 (Jan. 1990).
A. Sengupta et al., "Metal (II) Ion Binding Onto Chelating Exchangers with Nitrogen Donor Atoms: Some New Observations and Related Implications", Environmental Science & Technology, 25:3:481 (Mar. 1991).
D. Cornwell et al., "Demonstration Testing of Alum Recovery by Liquid Ion Exchange", J. AWWA, 73:6:326 (Jun. 1981).
D. Cornwell et al., "Feasibility Studies on Liquid Ion Exchange for Alum Recovery From Water Treatment Plant Sludges", J. AWWA, 72:1:64 (Jan. 1980).
A. Sengupta et al., "Selective Alum Recovery from Clarifier Sludge", J. AWWA, p. 96 (Jan. 1992).
Lehigh University
Spear Frank
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