Patents by Inventor Bengt G. Hansson

Bengt G. Hansson 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).

  • Method of treating peroxide-containing wastewater
    Patent number: 4663043
    Abstract: It was found difficult to carry out anaerobic treatment of peroxide-containing wastewater. According to the invention, the problem is solved in that the peroxide content of the water is reduced in a catalytic pretreatment step (1), preferably an enzymatic pretreatment step.
    Type: Grant
    Filed: August 6, 1984
    Date of Patent: May 5, 1987
    Assignee: Purac Aktiebolag
    Inventors: Nils L. Molin, Thomas G. Welander, Bengt G. Hansson, Per-Erik Andersson, Bengt A. G. Olsson
  • Method of controlling an anaerobic treatment process
    Patent number: 4659471
    Abstract: The invention relates to a method of treating wastewater from the manufacture of peroxide bleached mechanical or chemi-mechanical pulp. The method comprises a hydrolysis step, a methane fermentation steps and an aerobic step. After the hydrolysis and methane fermentation steps, sludge is separated from the wastewater and partially recycled to the hydrolysis step. The redox potential of the outgoing water from the hydrolysis step is continuously measured and controlled to a value between -400 and -260 mV by regulating the amount of sludge recycled or by passing ingoing wastewater directly to the aerobic treating step.
    Type: Grant
    Filed: August 6, 1984
    Date of Patent: April 21, 1987
    Assignee: Purac Aktiebolag
    Inventors: Nils L. Molin, Thomas G. Welander, Bengt G. Hansson, Per-Erik Andersson, Goran E. Annergren