ARUP K SENGUPTA
Engineers in Bethlehem, PA

6495047, Dec 17, 2002

Mar 21, 2001

09/813469

Arup K. SenGupta - Bethlehem PA 18017
Prakhar Prakash - Bethlehem PA

Arup K. SenGupta - Bethlehem PA

B01D 6100

210638, 210644, 210649, 210639, 210723, 210711

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.

2012023, Sep 20, 2012

Mar 14, 2012

13/420262

Arup K. SenGupta - Bethlehem PA, US
Sudipta Sarkar - West Bengal, IN
Prasun K. Chatterjee - West Bengal, IN

LEHIGH UNIVERSITY - Bethlehem PA

C02F 1/42, B01D 1/00, B01D 15/04, C02F 103/10

210670, 210681, 210180

Provided herein are systems and methods for use in wastewater treatment. In some examples, the systems and methods involve different combinations of ion exchange and membrane based systems and processes that can be used to remove radium and recover and purify barium and strontium salts to render the wastewater depleted of those regulated toxic metals. Treated wastewater having less than 12000 pCi/L of any of radium, barium or strontium is then subjected to tertiary treatment where it is subjected to processes in an evaporator/crystallizer which drives out water in the form of vapor, leaving behind salts of innocuous metals such as sodium, calcium, and magnesium, among others. In some examples, water vapor from the processes is condensed to produce water suitable for reuse, such as reuse in the hydro-fracturing process.

2013027, Oct 17, 2013

Apr 11, 2013

13/860984

Arup K. SenGupta - Bethlehem PA, US

Lehigh University - Bethlehem PA

B01J 41/12

521 26, 521 28

Polymeric anion exchanger are used as host materials in which sub-micron sized hydrated Zr(IV) oxides (HZrO) particles are irreversibly dispersed within the ion exchange medium, such as beads or fibers. The HZrO can be impregnated into the pore structure of resin by mixing the parent anion exchange resin with zirconium solution prepared by pre-calcined zirconium oxide dissolved in concentrated mixture of alcohol and acid, and then followed by precipitation of HZrO particles within the resin by using alkaline solution. Since the anion exchangers have positively charged such as quaternary ammonium functional groups, anionic ligands such as arsenate, fluoride can transport in and out of the gel phase without subjected to the Donnan exclusion effect. Consequently, anion exchanger-supported HZrO submicron particles exhibit significantly greater capacity to remove arsenic and fluoride in comparison with parent anon exchange resins. Known cation exchange resins as support materials do not offer high arsenic or fluoride removal capacity.

5304309, Apr 19, 1994

Jun 24, 1992

7/904434

Arup K. Sengupta - Bethlehem PA

Lehigh University - Bethlehem PA

B01D 6502

210636

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.

7291578, Nov 6, 2007

Aug 24, 2004

10/925600

Arup K. SenGupta - Bethlehem PA, US
Luis H. Cumbal - Quito, EC

B01J 20/26

502402, 502406, 210683

Polymeric anion exchangers are used as host materials in which hydrated Fe(III) Oxides (HFO) are irreversibly dispersed within the exchanger beads. Since the anion exchangers have positively charged quaternary ammonium functional groups, anionic ligands such as arsenates, chromates, oxalates, phosphates, phthalates can permeate in and out of the gel phase and are not subjected to the Donnan exclusion effect. Consequently, anion exchanger-supported HFO micro particles exhibit significantly greater capacity to remove arsenic and other ligands in comparison with cation exchanger supports. Loading of HFO particles is carried out by preliminary loading of the anion exchange resin with an oxidizing anion such as MnO or OCl, followed by passage of a Ferrous Sulfate solution through the resin.

8187890, May 29, 2012

Jun 4, 2008

12/602523

Arup K. Sengupta - Bethlehem PA, US

Lehigh University - Bethlehem PA

G01N 33/20

436 80, 436 73, 436 81

Methods for rapid sensing of dissolved toxic heavy metals use a hybrid inorganic material (“HIM”), which is synthesized from hydrated iron oxide (“HFO”) and calcium magnesium silicate. HIM thus synthesized is used in sensing dissolved toxic heavy metals. Water containing toxic heavy metals (e. g. , lead, copper, zinc, nickel, etc. ) is passed through a sorbent bed of HIM, whereupon it shows a sharp drop in pH after a certain length of time. The presence of HFO and calcium magnesium silicates in HIM synergistically provide a precipitous drop in pH, which is characteristic of the concentration and type of toxic heavy metal. Therefore, observing a change in pH indicates the presence and identity of heavy metal ions in a test water sample.

2010028, Nov 11, 2010

Nov 24, 2009

12/624917

Arup K. SenGupta - Bethlehem PA, US
Sudipta Sarkar - Bethlehem PA, US

LEHIGH UNIVERSITY - Bethlehem PA

C02F 1/42, B01D 65/02

210636, 210687, 210638, 2101982

Desalination is accomplished by subjecting feed saline water to a cation exchanger in magnesium form where sodium and scale-forming cations are at least partially exchanged for non-scale-forming magnesium ions. This ion exchange also reduces the osmotic pressure of the solution. When the resultant solution is subjected to a pressure-driven membrane desalination process, scaling is reduced and desalinated water is efficiently produced at a lower pressure. After desalination, the concentrated waste water, which contains higher concentrations of ions such as magnesium and sodium, is used to regenerate the depleted cation exchanger back into magnesium form. This regeneration permits the process to be self-sustainable.

6136199, Oct 24, 2000

Dec 7, 1998

9/206446

Arup SenGupta - Bethlehem PA
Dongye Zhao - Blacksburg VA

C02F 142

210670

Phosphates and chromates are selectively removed from contaminated water by a new class of sorbent, referred to as a Polymeric Ligand Exchanger (PLE). The exchanger bed comprising a styrene-divinylbenzene or polymethacrylate matrix having an electrically neutral chelating functional group with nitrogen or oxygen donor atoms, and a Lewis-acid type metal cation, such as copper, bonded to the chelating functional group in a manner that the positive charges of the metal cation are not neutralized. PLEs are very selective toward phosphates and chromates, chemically stable, and also amenable to efficient regeneration.

7540965, Jun 2, 2009

Apr 2, 2004

10/551578

Arup K. Sengupta - Bethlehem PA, US
Ping Li - Bethlehem PA, US
Brendan J. Murray - Kesington, AU
Stuart D. Harrison - Box Hill North, AU
Gregory M. Vero - Camberwell, AU

Orica Australia Pty Ltd - Melbourne

C02F 3/00

210661, 210663, 210667, 210670, 210692

A process for removing DOC (dissolved organic carbon) from a concentrated salt solution containing DOC by contacting the salt solution with a coagulant/flocculant such that the DOC becomes insoluble and removing the insoluble DOC from the salt solution.