US3715308A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and process for treating toxic waste materials
Assignee: Oxy Metal Finishing Corp
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Filing: 1971-06-04
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Granted: 1973-02-06
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Expires: 1991-06-04
Abstract
Abstract An apparatus and method for continuously treating and destroying toxic constituents in effluent waste streams from metal finishing processes such as aqueous rinse solutions containing dissolved hexavalent chromium and cyanide compounds present in concentrations which are lethal to marine ecology. The apparatus and process provide for a two-stage treatment of such waste streams which are continuously recirculated in each stage and their chemical characteristics are continuously monitored and adjusted so as to assure optimum conditions for promoting the desired chemical reactions for effecting a destruction of the toxic constituents and assuring that the effluent continuously discharged from the treating apparatus is devoid of any harmful constituents.
Inventors
- 👤 A Sulfaro
- 👤 A Stein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:21
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; C02F2101/00; C02F2101/10; C02F2101/16; C02F2101/18; C02F2101/20; C02F2101/22
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
301 words
An apparatus for continuously treating waste solutions containing toxic constituents therein comprising a first receptacle including a first compartment and a second compartment, a second receptacle, inlet means for continuously discharging a waste solution into said first compartment at a preselected influx rate and in admixture with a solution therein, transfer means for continuously withdrawing a portion of the admixed said solution at said preselected influx rate from said first compartment at a location remote from said inlet means and for discharging said solution into said second compartment at an outlet point and in admixture with a solution therein, first sensing means for continuously monitoring the chemical characteristics of the admixed said solution withdrawn from said first compartment, first recirculating means for continuously withdrawing a portion of the admixed said solution from said second compartment at a location remote from said outlet point for return to said first compartment for admixture with said solution therein, flow means for continuously withdrawing a portion of the admixed said solution at said preselected rate from said second compartment at a location remote from said outlet point for discharge into said second reCeptacle at a discharge point and in admixture with a solution therein, second sensing means for continuously monitoring the chemical characteristics of said solution being discharged into said second receptacle, second recirculating means for continuously recirculating a portion of the admixed said solution in said second receptacle through a path by which a portion is returned to said discharge point, outlet means for continuously withdrawing a portion of said solution at said preselected rate from said second receptacle at a location remote from said discharge point, and injection means for adding a chemical reagent to said solution in response to said sensing means for converting the toxic ingredients therein to substantially harmless materials.
Claim 2
Independent Claim
301 words
An apparatus for continuously treating waste solutions containing toxic constituents therein comprising a first receptacle including a first compartment and a second compartment, a second receptacle, inlet means for continuously discharging a waste solution into said first compartment at a preselected influx rate and in admixture with a solution therein, transfer means for continuously withdrawing a portion of the admixed said solution at said preselected influx rate from said first compartment at a location remote from said inlet means and for discharging said solution into said second compartment at an outlet point and in admixture with a solution therein, first sensing means for continuously monitoring the chemical characteristics of the admixed said solution withdrawn from said first compartment, first recirculating means for continuously withdrawing a portion of the admixed said solution from said second compartment at a location remote from said outlet point for return to said first compartment for admixture with said solution therein, flow means for continuously withdrawing a portion of the admixed said solution at said preselected rate from said second compartment at a location remote from said outlet point for discharge into said second reCeptacle at a discharge point and in admixture with a solution therein, second sensing means for continuously monitoring the chemical characteristics of said solution being discharged into said second receptacle, second recirculating means for continuously recirculating a portion of the admixed said solution in said second receptacle through a path by which a portion is returned to said discharge point, outlet means for continuously withdrawing a portion of said solution at said preselected rate from said second receptacle at a location remote from said discharge point, and injection means for adding a chemical reagent to said solution in response to said sensing means for converting the toxic ingredients therein to substantially harmless materials.
Claim 3
Dependent Claim
125 words
The apparatus as defined in claim 1, wherein said toxic constituent comprises hexavalent chromium ions and said first sensing means is operative to control said injection means for introducing sulfur dioxide in a quantity sufficient to convert substantially all of the hexavalent chromium present to trichromium sulfate, said first sensing means further including means for introducing mineral acid into said solution in said first receptacle in a quantity to maintain the pH thereof at about 3.5 or less, said second sensing means operable for introducing an alkali hydroxide into said solution in said second receptacle for raising the pH to a level of between about 7 to about 8 for effecting a hydrolysis and conversion of the trivalent chromic acid salt to trivalent chromic hydroxide.
Claim 4
Dependent Claim
115 words
The apparatus as defined in claim 1, wherein said toxic constituent comprises cyanide ions and said first sensing means are operative to control said injection means for introducing chlorine into said solution in said first receptacle in an amount sufficient to form cyanogen chloride and an adjustment of the pH of said solution to a level above about 10 by the controlling addition of an alkali metal hydroxide, said second sensing means being operative to control the pH in said second stage to a level ranging from about 7.5 to less than about 9 by the addition of a mineral acid to effect an oxidation of the cyanate radical to harmless nitrogen and carbon dioxide.
Claim 5
Dependent Claim
23 words
The apparatus as defined in claim 1, wherein the volume of said first receptacle is greater than three times said preselected influx rate.
Claim 6
Dependent Claim
35 words
The apparatus as defined in claim 1, in which the volume of said first receptacle ranges from about ten times to about twenty times said preselected influx rate expressed in terms of gallons per minute.
Claim 7
Dependent Claim
36 words
The apparatus as defined in claim 1, wherein said first recirculating means is controlled to effect a rate of recirculation of said solution at a magnitude of at least about two times said preselected influx rate.
Claim 8
Dependent Claim
34 words
The apparatus as defined in claim 1, wherein said first recirculation means is controlled to effect a recirculation of said solution at a rate of at least about three times said preselected influx rate.
Claim 9
Dependent Claim
53 words
The apparatus as defined in claim 1, further including flow control means operatively associated with said inlet means for halting the flow of said waste solution into said first compartment in response to an imbalance in the chemical characteristics of the treated solution as sensed by said first and said second sensing means.
Claim 10
Dependent Claim
45 words
The apparatus as defined in claim 1, wherein the flow of said solution from said first receptacle to said second receptacle and out through outlet means is achieved by gravitational overflow in response to the entry of said waste solution at said preselected influx rate.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |