Abstract: A denitrification system for denitrified wastewater or nitrified water treatment using a detergent or detergent-like compound comprising available carbon. The system comprises a plurality of interconnected tanks including a mixing tank which feeds detention tanks which in combination provide a detention time period for the effluent. A controller determines the amount of detergent dispensed into the mixing tank in accordance with the measured volume of effluent to be treated. The mixing tank comprises a heater for maintaining the nitrified effluent temperature above 50 degrees F. An optional line filter can be added to the output of the system for further reducing organic nitrogen concentration. An alternate embodiment comprises passing the final denitrified effluent through a pump chamber for pumping of the effluent to a sand filter capable of reducing bacterial populations.

Abstract: An air filtration unit of the type having a liquid filtration medium in a canister with air entering below the level of the liquid, bubbling up into an upper air chamber and thence conducted to a face mask, is simplified for use not only in sedentary occupations but so that it can be used by workmen in strenuous occupations requiring leaning over, lying down, etc. One way valves assure that only scrubbed air enters the face mask, the mask is peripherally sealed and float, or gravity, valves prevent leakage into the mask, or out of the canister, when the unit is in abnormal position. In non-portable form, air filtration masks, peripherally sealed on the wearer's face have a common air chamber with air drawn thereinto from outisde the pollution environment.