Patents by Inventor Arup K. SenGupta

Arup K. SenGupta has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6495047
    Abstract: Alum, used as a coagulant in water treatment, is recovered from clarifier sludge by adjusting the pH of the sludge downward to produce an aqueous clarifier sludge solution, and contacting the aqueous clarifier sludge solution with one side of a semi-permeable cation exchange membrane while contacting the other side of the membrane with an acidic sweep solution. By virtue of the Donnan co-ion exclusion phenomenon, aluminum ions, which are trivalent, pass readily through the membrane, in preference to divalent and monovalent cations, and consequently heavy metal carryover is relatively low. Organic matter carryover is substantially excluded, and consequently, the recovered alum can be reused without the potential for trihalomethane formation. The reactor is preferably in the form of a stack of spaced membranes, with the aqueous clarifier sludge solution and the acid sweep solution flowing through alternate spaces. The same process can be used for recovery of ferric iron coagulants.
    Type: Grant
    Filed: March 21, 2001
    Date of Patent: December 17, 2002
    Inventors: Arup K. SenGupta, Prakhar Prakash
  • Publication number: 20020179531
    Abstract: Alum, used as a coagulant in water treatment, is recovered from clarifier sludge by adjusting the pH of the sludge downward to produce an aqueous clarifier sludge solution, and contacting the aqueous clarifier sludge solution with one side of a semi-permeable cation exchange membrane while contacting the other side of the membrane with an acidic sweep solution. By virtue of the Donnan co-ion exclusion phenomenon, aluminum ions, which are trivalent, pass readily through the membrane, in preference to divalent and monovalent cations, and consequently heavy metal carryover is relatively low. Organic matter carryover is substantially excluded, and consequently, the recovered alum can be reused without the potential for trihalomethane formation. The reactor is preferably in the form of a stack of spaced membranes, with the aqueous clarifier sludge solution and the acid sweep solution flowing through alternate spaces. The same process can be used for recovery of ferric iron coagulants.
    Type: Application
    Filed: March 21, 2001
    Publication date: December 5, 2002
    Inventors: Arup K. SenGupta, Prakhar Prakash
  • Patent number: 5304309
    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.
    Type: Grant
    Filed: June 24, 1992
    Date of Patent: April 19, 1994
    Assignee: Lehigh University
    Inventor: Arup K. Sengupta