Apparatus and associated method for reducing an undesired constituent of gas associated with wastewater

A controller for use with a scrubber apparatus comprising a vessel;

• recirculating spray means for drawing scrubbing solution from a sump, spraying the scrubbing solution in contact with gas being treated within the vessel for reducing hydrogen sulfide (H.sub.2 S) in the gas which also contains moisture, and for returning scrubbing solution back to the sump;
• and treatment chemical supply means for controllably delivering treatment chemical to the scrubbing solution;
• said controller comprising:
• an environmentally resistant housing;
• outlet gas sensor means, positioned with said housing, for sensing H.sub.2 S in gas exiting the vessel after treatment, said outlet gas sensor means comprising a permeable membrane and chamber defining means cooperating with said permeable membrane for defining a sample chamber therewith, and having a gas entry port and a gas exit port opposite said permeable membrane and in spaced relation therefrom;
• outlet sensor vertical mounting means for mounting said outlet gas sensor means in a vertical orientation within said housing so that the gas entry and exit ports are in a lower portion of said sample chamber and spaced beneath said membrane so as to facilitate removal of accumulated liquid within said gas sampling chamber resulting from the moisture in the gas, and while avoiding contact of accumulated liquid with said permeable membrane;
• and
• processor means positioned within said housing and operatively connected to said outlet gas sensor means and operatively connectable to the treatment chemical supply means for controlling a level of treatment chemical in the scrubbing solution responsive to the sensed H.sub.2 S so as to enhance reduction of H.sub.2 S in the gas being treated, and while conserving consumption of treatment chemical.

A controller for use with a scrubber apparatus comprising a vessel;

• recirculating spray means for drawing scrubbing solution from a sump, spraying the scrubbing solution in contact with gas being treated within the vessel for reducing hydrogen sulfide (H.sub.2 S) in the gas, and for returning scrubbing solution back to the sump;
• and treatment chemical supply means for controllably delivering treatment chemical to the scrubbing solution;
• said controller comprising:
• a housing;
• inlet gas sensor means positioned within said housing for sensing H.sub.2 S in gas to be treated;
• outlet gas sensor means positioned within said housing for sensing H.sub.2 S in gas to exiting the vessel after treatment;
• and
• processor means positioned within said housing and operatively connected to said inlet gas sensor means and said outlet gas sensor means, and operatively connectable to the treatment chemical supply means for controlling a level of treatment chemical in the scrubbing solution responsive to sensed H.sub.2 S at said inlet gas sensor means and said outlet gas sensor means so as to enhance reduction of H.sub.2 S in the gas being treated, and while conserving consumption of treatment chemical.

A method for controlling a scrubber apparatus for treating a gas associated with wastewater to reduce H.sub.2 S in the gas, the scrubber apparatus comprising a vessel, and a sump for containing scrubbing solution, the method comprising the steps of:

• flowing gas to be treated from associated wastewater into and through the vessel for treatment, and exiting from the vessel after treatment;
• spraying the scrubbing solution in contact with gas being treated within the vessel for reducing the undesired constituent in the gas, and returning the scrubbing solution to the sump;
• providing a housing, positioning an inlet gas sensor within said housing, and positioning an outlet gas sensor within said housing;
• sensing H.sub.2 S in gas entering the vessel before treatment by the inlet gas sensor;
• sensing H.sub.2 S in gas exiting the vessel after treatment by the outlet gas sensor;
• and
• controlling a level of treatment chemical in the scrubbing solution responsive to the sensed H.sub.2 S from said inlet and outlet sensors so as to enhance reduction of H.sub.2 S in the gas being treated, and while conserving consumption of treatment chemical.