David R Kamperman

46247904, Nov 25, 1986

Nov 19, 1981

6/322998

David R. Kamperman - Harmony PA
Leslie E. Lancy - Ellwood City PA
Claire A. Swank - Butler PA

Lancy International, Inc. - Zelienople PA

C02F 164

210665

The residual metal content of tightly chelated heavy metal-containing effluents is reduced by carrying out a sulfide precipitation process in the presence of a seed material comprising an added unchelated soluble heavy metal salt, preferably with an adjustment of pH to at least above about 9. 0, with optional variations including passage through a mixed filter media comprising at least two particulate ingredients and regeneration of the used filter media.

44054629, Sep 20, 1983

Aug 9, 1982

6/406561

David R. Kamperman - Harmony PA

Lancy International, Inc. - Zelienople PA

C02B 120

210709

A system and process has been devised for measuring and constantly maintaining a desired concentration of soluble sulfides in a processing solution for the purpose of fully maintaining its function. Sulfide regenerating solution is automatically introduced into the processing solution in an amount as constantly determined by concentration variations in the processing solution, to thus provide the processing solution with its most effective sulfide content. A constant take-off flow of processing solution is thoroughly mixed with a sulfide stabilizing solution flow to provide a tempered solution flow that is passed through a flow block having a sulfide measuring electrode and a reference electrode. Variable negative voltage generated on the sulfide electrode is sensed and compared with a substantially constant voltage generated on the reference electrode and is amplified in a controller assembly. The amplified energy is then employed to electrically control the introduction of a sulfide regenerating solution into the processing solution in accordance with a predetermined desired sulfide concentration thereof.

49484761, Aug 14, 1990

Jul 20, 1989

7/384153

David R. Kamperman - Bend OR
Dwayne T. Friesen - Bend OR

Bend Research, Inc. - Bend OR

C25B 100

204 89

There are disclosed method and apparatus for recovering chromium from chromium-containing wastes, using an electrolytic oxidation cell divided by an anion exchange membrane and a coupled transport module containing a membrane containing a chromium(VI) complexing agent.

39458652, Mar 23, 1976

Jul 22, 1974

5/490456

David Robert Kamperman - Harmony PA

Dart Environment and Services Company - Los Angeles CA

C23F 100
C09K 1304

156 18

Evolution of NOx fumes during dissolution of metal values in mineral acid solutions of nitric acid can be eliminated by the addition of small quantities of hydrogen peroxide to the acid solution.