Disclosed herein is a method for treating odors in wastewater treatment bodies. The pH of the body is preferably established above about 6 and most preferably above about 7, usually by adding a base to the body. The oxidation reduction potential of the body is established at about -300 mV or higher and more preferably about -200 mV or higher, usually by adding an oxidizing agent such as oxygen or nitrates. After these conditions are established, sulfur oxidizing bacteria are added to the body. These preferably include Paracoccus denitrificans (formerly called Thiosphaera pantotropha) ATTC number 35,512. The sulfur oxidizing bacterial population should be established at levels of at least about 1.times.10.sup.4 cfu/mL and more preferably at levels of 1.times.10.sup.5 to 1.times.10.sup.6 cfu/mL or higher. The increased ORP and pH levels make sulfate reduction thermodynamically unfavorable. Additionally, the presence of an alternative electron acceptor such as oxygen or nitrate allows the sulfur oxidizing bacteria to oxidize organic acids.
HISTORY OF THE APPLICATION
This is a continuation of U.S. application Ser. No. 09/400,229, filed Sep. 21, 1999, which is hereby incorporated by reference in its entirety, now abandoned.
A synergistic composition is provided for controlling odor from waste products. The composition comprises a combination of nitrate salt, sulfide-consuming compound, pH-elevating compound, sulfide-oxidizing, nitrate-reducing bacteria, and sulfide-oxidizing enzyme. The method includes adding a sufficient amount of the composition to a waste stream to provide sufficient sulfide-consuming compound to effect immediate removal of sulfide. The composition incorporates a pH elevating compound, which both decreases the amount of gaseous H.sub.2S and puts the aqueous phase into a pH range where naturally occurring bacteria can more easily metabolize the sulfide. The composition also includes one or more nitrate salts which will accomplish longer term prevention of odors. Specific bacteria are incorporated into the formulation to insure that the nitrate has the right type and amount of bacteria present to prevent formation of and/or consume sulfide. Specific enzymes are incorporated into the formulation to promote oxidation of sulfide.
