ChemScan. com © 2006 ASA, Inc. On-line Nutrient Monitoring Strategies in Eastern US and Canada 2009 Wuhan International Conference on the Environment Wuhan, Hubei Province, China October 17, 2009 Wei Zhang Regional Manger – Eastern US & Canada ASA Analytics, Inc.

ChemScan. com © 2006 ASA, Inc. Outlines Historical biological nutrient removal (BNR) overview in the region Current municipal discharge regulations Monitoring technologies Application/Case Studies Question & Answers

ChemScan. com © 2006 ASA, Inc. Historical Perspective 1800’s wastewater treatment concept : development of biological treatment 1960: milestone – 50% of population covered. 1972: Clean Water Act Point source. NPDES discharge permitting program Non-point source Mid 1990 – current: nutrients focus Great Lakes (treaty obligations) Chesapeake Bay Delaware River Basin

ChemScan. com © 2006 ASA, Inc. Great Lakes Region

ChemScan. com © 2006 ASA, Inc. Chesapeake Bay.

ChemScan. com © 2006 ASA, Inc. Delaware River Basin

ChemScan. com © 2006 ASA, Inc. Where in the Map

ChemScan. com © 2006 ASA, Inc. AppliedSpectrometry Associates, Inc.

ChemScan. com © 2006 ASA, Inc. Why On-line Nutrient Today? Technology is more mature/proven Tighter TN/TP discharge limits Verify process performance Operation cost saving: Chemical, Energy If You Want to Control Process Chemistry, you need to Measure Process Chemistry

ChemScan. com © 2006 ASA, Inc. On-line Analyzer Category In-Situ Type –Galvanic, polaorgraphic, luminescent type of “sensor” or “probe” immersed in the treatment process. –Most have single parameter Central Type –Sample extracted from multiple process locations and analysis in a centralized flow through device in a analyzer –Allow multiple sample lines –Allow multiple parameters at each sample line

ChemScan. com © 2006 ASA, Inc. Comparison: Pros & Cons Single locations vs. multiple locations Single parameter vs. multiple parameters Calibration issues Cycle time issues

ChemScan. com © 2006 ASA, Inc. Polarography (pō'lərŏg'rəfē), in chemistry, method for analyzing the composition of a dilute electrolyte. Two electrodes are placed in the solution: One has a fixed potential (voltage) and is called the reference electrode, and the other has a variable potential and is called the polarizable electrode. As voltage is applied to the polarizable electrode, the resulting change in the current through the solution is monitored. By plotting the pairs of values for voltage and current, a series of current-voltage curves (polarograms) can be generated. The general name for this method is voltametry; the term polarography was formerly restricted to those cases where the polarizable electrode is a dropping mercury electrode, though now this distinction is often disregarded. Current-voltage curves, which look like a series of steps called polarographic waves, can be used to determine the reduction potentials of any reducible species present in the solution, e.g., inorganic ions or complex organic intermediates. Conversely, unknown substances can be identified by their characteristic reduction potentials. Quantitative titrations of an oxidizing agent by a reducing agent can be performed using a polarographic cell to determine the equivalence point by monitoring changes in the current.titrations

ChemScan. com © 2006 ASA, Inc. AppliedSpectrometry Associates, Inc.

ChemScan. com © 2006 ASA, Inc. 2. Application and Performance

ChemScan. com © 2006 ASA, Inc. Typical Application Denitrification/phosphorus removal bio-filter Chemical feed control scheme using nutrient parameter is well developed Denitrification Filter BOD Removal Nitrification Methanol

ChemScan. com © 2006 ASA, Inc. A ENR Process Flow Diagram using DynaSand Continuous Backwash Filter

ChemScan. com © 2006 ASA, Inc. BNR Process Schematic Nitrification/Denitrification. No supplemental carbon Similar to Modified Ludzack Ettinger (MLE) process Some simultaneous nitrification/denitrification (SND) Final Clarifier Oxidation Ditch AXPrimary Eff. WAS RAS

ChemScan. com © 2006 ASA, Inc. Application in Advanced BNR Advanced BNR Processes –Discharge limits on either total N or total P or both; –Treatment process involves more than one stand-alone BNR process Advantages to use centralized analyzer –Confirming process performance between parallel treatment trains –Providing process profile for overall plant –Avoid possible calibration errors between individual sensors

ChemScan. com © 2006 ASA, Inc.. BNR Process Schematic Step-feed BNR with supplemental carbon RAS WAS Final Clarifier Primary Effluent Methanol Feed AX Aerobic AX

ChemScan. com © 2006 ASA, Inc. BNR Process Schematic Bardenpho Process with post denitrification filter Two on-line nutrient analyzers AX Aerobic AX Anaerobic Primary Sludge Final Clarifier Methanol RAS WAS Denitrification Filter

ChemScan. com © 2006 ASA, Inc. Back River WWTP City of Baltimore, Maryland Existing 180 mgd plant MLE Process Expect new discharge requirements Evaluation of treatment alternatives Modeling/Pilot testing

ChemScan. com © 2006 ASA, Inc. AppliedSpectrometry Associates, Inc.

ChemScan. com © 2006 ASA, Inc. AppliedSpectrometry Associates, Inc.

ChemScan. com © 2006 ASA, Inc.

ChemScan. com © 2006 ASA, Inc.

ChemScan. com © 2006 ASA, Inc.

ChemScan. com © 2006 ASA, Inc.

ChemScan. com © 2006 ASA, Inc.

ChemScan. com © 2006 ASA, Inc. AppliedSpectrometry Associates, Inc. Case Study: Bonnybrook WWTP Calgary, Alberta Orthophosphate 4 Month Average Error 3.0 %Ammonia 4 Month Average Error 3.0 %

ChemScan. com © 2006 ASA, Inc. AppliedSpectrometry Associates, Inc. Case Study: Bonnybrook WWTP Calgary, Alberta Nitrate 4 Month Average Error 1.7 %TSS 4 Month Average Error 3.3 %

ChemScan. com © 2006 ASA, Inc. Summary If you want to control process chemistry, measure process chemistry Proven technology using nutrient parameter for process control/optimization Advantages of multi-parameter multi- sample line analyzer system Pay attention to Cost of Ownership Pay attention to Maintenance Requirement

ChemScan. com © 2006 ASA, Inc. Questions