Benefits of On-line Monitoring of Carbon, Nitrogen and Phosphorus

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1 Benefits of On-line Monitoring of Carbon, Nitrogen and Phosphorus New Jersey Water Environment Association Dan Davis Shimadzu Scientific Instruments

2 Benefits of On-Line Monitoring Environment Consumers Treatment Facilities

3 Environmental Impact Why Carbon, Nitrogen and Phosphorus? Because of their environmental impact These elements are nutrients and can enrich aquatic systems The problem is when we over enrich: Eutrophication Potomac River

4 Drinking Water: TOC EPA established two drinking water Regulations: Stage 1 Disinfection Byproducts Rule (DBPR)1 Protects customers from disinfectants and disinfectant byproducts (DBP) Enhanced Surface Water Treatment Rule (IESWTR)1 Reduce microbial contamination in drinking water Federal Register, December 16, 1998, Volume 63, Number 241, or 40 CFR Parts 9, 141, and142

5 Response by EPA: Nitrogen & Phosphorus States & EPA : issue permits to all wastewater treatment facilities that regulate pollutants such as nitrogen and phosphorus Nutrient Criteria Technical Guidance Manual for Lakes & Reservoir (EPA-822-B ), released 5/2000 Rivers & Streams (EPA-822-B ), released 7/2000 Estuarines and Coastal Waters (EPA-822-B ), released 10/2001

6 Total Organic Carbon TOC (Total Organic Carbon): Organic carbon bonding with hydrogen or oxygen to form organic compounds Consists of: Purgeable Organic Carbon (POC) Non-purgeable Organic Carbon (NPOC) i.e. TOC = POC + NPOC Analysis: There are 2 methods, Difference method : TOC = (TC IC) Direct method : TOC NPOC (if no POC)

7 Total Organic Carbon Measurement Measure the sample (dilute) Inorganic Carbon Removal Hydrochloric Acid Solution Agitate Removal of CO 2 Decomposition : 680 with Pt catalyst Formation of CO 2 Obtain the TOC Result

8 Total Nitrogen TN (Total Nitrogen): Sum of Both Organic Nitrogen and Inorganic Nitrogen: Organic Nitrogen (R-N) (Inorganic) Nitrate (NO3) (Inorganic) Nitrite (NO2) (Inorganic) Ammonia (NH3) Does not include: Nitrogen Gas (N2) Chemical unreactive and not very reactive biologically Not detected by TN Method

9 Total Nitrogen Measurement Measure the sample (dilute) O 2 Decomposition : 720 with Pt catalyst Electricity Formation of NO Formation of NO 2*, -> NO 2, Photon Emission Ozone Obtain the TN Result Relaxation of NO 2* to NO 2 by emitting light

10 Total Phosphorous Measurement Measure(dilute) the sample Sulfuric acid solution Decomposition : 95 with UV irradiation and air Sodium hydroxide solution for ph control L-ascorbic acid solution Sulfuric acid ammonium molybdate Color the solution to blue Obtain the TP Result Measure 880nm absorbance of Phosphomolybdate blue

11 COD, BOD & TOC Permits are usually written on COD, BOD, or TOC TOC can be used in place of COD or BOD after conversion trends (correlation) have been made. Running COD or BOD and TOC in parallel

12 COD, BOD & TOC What is the difference between BOD, COD or TOC? Why do I have to measure them? All treatment plants are required to measure one of these three items as a measure of the pollution value water. COD or Chemical Oxygen Demand is the total measurement of all chemicals in the water that can be oxidized. BOD or Biological Oxygen Demand is supposed to measure the amount of food (or organic carbons) that bacteria can oxidize. TOC or Total Organic Carbon is the measurement of organic carbons.

13 COD, BOD & TOC COD - COD is a chemically chelated/thermal oxidation reaction and can be measured in 2 hours. False Lows and False Highs A COD test measures all organic carbon with the exception of certain aromatics (benzene, toluene, phenol, etc.) which are not completely oxidized in the reaction, other reduced substances such as sulfides, sulfites, and ferrous iron will also be oxidized and reported as COD. NH3-N (ammonia) will NOT be oxidized as COD. No indication for nitrogen loading

14 COD, BOD & TOC BOD Two Types C-BOD & BOD BOD5 measures the oxidation of carbons and possibly nitrogenous compounds present in a water sample. CBOD only measures oxidation of carbons. 5-day test Need to do Both Places where the nitrification of ammonia may not be complete (i.e., incomplete conversion of ammonia (NH3) to nitrate (NO3)) or where high levels of amines or ammonia are present, false BOD readings may occur. This can occur in municipal lagoons, wineries and general industry.

15 COD, BOD & TOC BOD Uses and Limitations BOD testing has its widest application in measuring waste loadings of treatment plants, and in evaluating the efficiency of treatment processes. It is usually seeded with the type of bacteria found in municipal plants. The types of bacteria needed in wineries and general industry usually differ in species. The hard to degrade organics found in some of these systems also may take longer than five days to break down, so a BOD test will give an inaccurate measurement.

16 COD, BOD & TOC What is Total Organic Carbon? Organic matter content is typically measured as total organic carbon and dissolved organic carbon, which components of the carbon cycle. The Total Organic Carbon test measures all organic carbon as CO 2 TOC does not differentiate between the source of organic carbon, which can be metabolized (assimilated). Total organic carbon is a more accurate indication of pollutants that cause problems with BOD testing.

17 Sampling Scheme Collection Analysis Reporting Sampling Physical Treatment Report Generation Preserving Chemical Treatment Review/React Storage Batch Measurement

18 Sampling Scheme Collection Analysis Reporting Sampling Physical Treatment Report Generation Preserving Chemical Treatment Review/React Storage Measurement

19 On-Line Sampling Considerations When selecting a sampling device Consider: Particulates Are there a lot of particulates? Do I need to include them in my reading? Concentration of Analyte Are there special precautions based on level? Do I need to consider environmental influences? Number of Sampling Points Can I monitor all necessary points?

20 On-Line Sampling Considerations Particulates can add to the complexities of collecting and analyzing samples. Do you have particulates? If yes will they interfere with the analysis Do I need to consider them in my analysis? Do they contribute to your analysis?

21 On-Line Sampling Considerations Performing low level analysis can be influenced by environmental influences such as contact with air or water used in the process. Concentration of Analyte Are there special precautions based on level? Do I need to consider environmental influences?

22 Multi-Stream Suspended Solids Unit Sample flows in the top and drains out the bottom Actuators move the sampling arm into the stream Sample flows down into the sampling chamber through the strainer removing larger particles Mixing blades homogenizes the sample System back flushes then washes Movie

23 Multi-Stream Sample Switching Unit Sample flows in the bottom and out the top Some sample flows in lower chamber on the outside of the sample collection cup Actuators move the stream to the sample collection chamber. Reduces Sample-Air Contact Eliminates need for washing

24 Backwash Strainer Sampling Unit Sample flows in the bottom and out the top Air pressure prevents sample from entering inner chamber until sampling Air is turned off and sample is filtered as it enters chamber Sample flow dynamics self clean the sample mechanism Movie

25 Field Application: Waste Water Facility

26 Wastewater Treatment Facility A X X Points of Monitoring (A) Currently (X) Future

27 Onsite Installation

28 Water Treatment Utility WATER SOURCE MONITORING TECHNIQUE AUTOMATIC TECHNIQUE MANUAL TECHNIQUE CHEMICALS COST (per Analysis) Labor AUTOMATIC ADDITION REDUCE ERROR LAST LONGER (per Analysis) Time (per Analysis) Variability Frequency Hourly/Weekly/ Monthly TREATMENT Biweekly

29 Manual vs Automatic Total Nitrogen TKN vs TN TKN TN Average Total Nitrogen (mg/l/day) /19/04 11/29/04 12/9/04 12/19/04 12/29/ /8/05 Date Average Total Nitrogen (mg/l/day) Comparable Data TN 12/9/04 12/19/04 12/29/04 Date TN

30 Manual vs Automatic Total Phosphorus TPK vs TP TP Manual TP Average Total Phosphorus (mg/l/day) /19/04 11/29/04 12/9/04 12/19/04 12/29/04 1/8/05 Comparable Data TP TP Date 5 Average Total Phosphorus (mg/l/day) /9/04 12/19/04 12/29/04 Date

31 Monitoring Why Biweekly vs. Hourly? Manual: To reduce cost To reduce labor To reduce time Automatic: Reduces labor Reduces time Reduces cost BIWEEKLY HOURLY/DAILY/WEEKLY/ MONTHLY REDUCES COST OF POST TREATMENT FASTER RESPONSE IMPROVE WATER QUALITY

32 Manual vs Automatic Total Phosphorus Relative TPK (mg/l) per day Hourly : Relative TPK (mg/l) More information Less labor Better quality Biweekly 0 10/4/04 11/3/04 12/3/04 TOC 1/2/05 Date TN TP 180 Hourly Relative Concentration (mg/l/day) TOC/TN/TP Relative mg/l/day 7:34 18:34 5:34 Time (hrs)

33 Hourly vs Biweekly..Allows FASTER RESPONSE 7 Biweekly Monitor Biweekly TPK Relative TP (mg/l) /4/ /24/ /13/ /3/ /23/2004 Date Relative TP (mg/l) Hourly Monitor Sudden Changes Hourly TP 0 8:32 19:32 6:32 19:32 6:32 18:32 16:32 14:32 Time (Hrs)

34 Benefits of On-Line Monitoring Automatic Sampling Pretreatment Digestion Analysis Report Flexibility of Sampling Hourly Daily Weekly Monthly Reduce Labor Time Money Achieve Maximum Efficiency Faster Response Better Treatment Cost Reduction

35 Thank You! Special Thanks to