Bio-electrochemical sensor, system and method for monitoring and controlling organic carbon levels in a wastewater treatment process

Abstract

The present disclosure generally relates to a system for monitoring and/or controlling the delivery of one or more organic carbon compounds to a wastewater treatment system. The system comprises a bio-electrochemical sensor to monitor metabolic activity of a population of exo-electrogenic bacteria and provide an electrical output corresponding with the metabolic activity, the bio-electrochemical sensor comprising an electrode pair and a power source to deliver a voltage across the electrode pair, and an electrical output analyzer to analyze the electrical output and correlate the electrical output with a value representing the amount of the one or more organic carbon compounds in the wastewater treatment system. A method and sensor for monitoring and/or controlling the delivery of one or more organic carbon compounds to a wastewater treatment system are also provided.

1 . A system for monitoring one or more organic carbon compounds in a wastewater treatment system, the system comprising:
 a bio-electrochemical sensor to monitor metabolic activity of a population of exo-electrogenic bacteria and provide an electrical output corresponding with the metabolic activity, the bio-electrochemical sensor comprising an electrode pair and a power source to deliver a voltage across the electrode pair; and   an electrical output analyzer to analyze the electrical output and correlate the electrical output with a value representing the amount of the one or more organic carbon compounds in the wastewater treatment system.   
     
     
         2 . The system of  claim 1 , wherein the wastewater treatment system is an anaerobic digestion system, an anoxic digestion system, a denitrifying tank, or a phosphorous removal tank, and the bio-electrochemical sensor is located within the anaerobic digestion system, anoxic digestion system, denitrifying tank, or phosphorous removal tank. 
     
     
         3 . The system of  claim 1  wherein the wastewater treatment system comprises nitrate at a concentration from about 5 mg/L to about 100 mg/L; bio-available carbon at a concentration from 0 mg/L to about 100 mg/L; oxygen at a concentration of about ≤2 mg/L; or a combination thereof. 
     
     
         4 . The system of  claim 1 , wherein the one or more organic carbon compounds comprises a volatile fatty acid, an organic acid, a complex organic compound, acetic acid, propionic acid, butyric acid, or a combination thereof. 
     
     
         5 . The system of  claim 1  for controlling the delivery of one or more organic carbon compounds to the wastewater treatment system, the system further comprising: a controller; and a pump operably coupled to the controller, wherein the electrical output analyzer provides a signal to the controller, and the pump controls the delivery of the one or more organic carbon compounds in response to the signal. 
     
     
         6 . The system of  claim 5  which permits real time adjustments in the delivery of the one or more organic carbon compounds, wherein a change in electrical output beyond a threshold produces a signal to adjust the delivery of the one or more organic carbon compounds. 
     
     
         7 . The system of  claim 6 , wherein the threshold represents a change in a ratio of the value representing the amount of one or more organic carbon compounds to a value representing the amount of nitrogen and/or phosphorous in the system, and wherein the delivery of the one or more organic carbon compounds initiates, adjusts, maintains, or stops a nitrification process, a simultaneous nitrification and denitrification process, a denitrification process, and/or a carbon addition process. 
     
     
         8 . The system of  claim 7 , wherein:
 the ratio of the value representing the amount of one or more organic carbon compounds to a value representing the amount of nitrogen is: about 0:1; about 1:1, about 2:1; about 3:1; about 4:1; about 5:1; about 6:1; about 7:1; about 8:1; about 9:1; or about 10:1, or greater than about 4:1; greater than about 5:1; greater than about 6:1; greater than about 7:1; greater than about 8:1; greater than about 9:1; greater than about 10:1; greater than about 11:1; or greater than about 12:1; and   the ratio of the value representing the amount of one or more organic carbon compounds to a value representing the amount of phosphorous is less than about 10:1; less than about 15:1; less than about 20:1; less than about 25:1; less than about 30:1; less than about 35:1; less than about 40:1; less than about 45:1; or less than about 50:1.   
     
     
         9 . The system of  claim 5  comprising a pump to deliver nitrogen and/or phosphorous to the to the wastewater treatment system in response to the signal. 
     
     
         10 . The system of  claim 1 , wherein the electrode pair comprises an anode electrode and a cathode electrode, the cathode electrode being in electrical communication with a non-dioxygen terminal acceptor within the treatment system. 
     
     
         11 . The system of  claim 1 , wherein the electrode pair are within one chamber of the treatment system.