OZONE CASE STUDY Military Installation Central Georgia Ex-Situ Ozone System. Background. The Challenge. The Solution. Piper Environmental Group, Inc.

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1 OZONE CASE STUDY Military Installation Central Georgia Ex-Situ Ozone System Background The impacted site is a former military landfill, located on a Military Installation in Central Georgia, where several Contaminants of Concern (COC) had been identified within the phreatic zone which require continuous remediation. Currently, a groundwater treatment plant located approximately two miles from the former landfill treats groundwater and some additional wastewater streams (typically decon water or purge water). The current groundwater treatment plant is fed groundwater by 7 extraction wells and by 10 Leachate Collection and Dual Phase wells. DNAPL is collected in a wet well and disposed. Groundwater is transferred to the current groundwater treatment plant (GWTP) for treatment. 1 The existing GWTP was inefficient and had very high operation and maintenance costs. CAPE Environmental proposed to improve their existing plant by removal of existing UV treatment system and adding ozone to treat source landfill wastewater streams. The Challenge Criteria 1: Offer innovative treatment solution package that will surpass effectiveness of existing processes. Criteria 2: Reduce operation and maintenance costs significantly. Criteria 3: Premier solution must treat 50GPM and attain contaminant reduction to non-detect or below acceptable levels based on NPDES permit and Georgia In-Stream Water Quality Criteria (GA ISWQC). The Solution Design a pilot study to demonstrate effectiveness and viability of innovative alternative to traditional methodology. Analyze results and design-build a full scale ozone treatment system to fulfill challenges noted above and reduce Operation & Maintenance costs associated with frequent Granular Activated Carbon (GAC) media change outs and UV bulb maintenance. Piper Environmental Group, Inc. Ozone equipment installed inside existing Groundwater treatment plant in Central Georgia

2 Piper Environmental Group, Inc. Pilot Study Piper Environmental Group, Inc. (Piper) proposed a pilot study to prove the effectiveness of ozone at reducing Contaminants of Concern (COC). The Pilot study supplied a turn-key ozone system for Volatile Organic Carbon (VOC) and Semi-Volatile Organic Carbon (SVOC) contaminant reduction and a separate iron filtration system for iron reduction. A pilot study consisted of a two week on-site test period with longer, subsequent data evaluation. This data collection and analysis was invaluable as it allowed or a high degree of accuracy in determining the ozone system size necessary to reach cleanup goals. Cape prepared the batch of water to be used during the pilot study. This water was intended to be representative of the total loading that would be seen by the full-scale system. The groundwater actually consisted of the worst water quality possible, with higher levels of contaminants and iron than what was originally specified. Typically, this water quality is a sidestream of the typical total waste water to be processed by the future full-scale system. The pilot system also involved precipitation iron chemistry. This can be a challenging process as ideal blends are achieved. Iron chemistry is very site specific and there are many different iron molecules, compounds, configurations, and structures. Some iron chemistry is dependent on ph, ORP and other water quality conditions. Some iron compounds have good flocculation, bonding, and/or settling characteristics and some do not. It was vastly important to perform a pilot study which determined a proven approach for controlling the iron. As desired by Cape, preliminary testing with ozone without addition of hydrogen peroxide or UV indicated a variety of results with both the ozone and iron control agents. The pictures on the following page indicate the variety of tests using flocculent polymer, coagulants and sequestering agents to assist with high levels of iron. One of the goals was to reduce suspended solids loading and maintain the iron in solution to reduce ozone demand and eliminate additional filtration following ozone generator. Pilot System Components 1. Oxygen concentrator (14 grams per hour) 2. Ozone generator produces.7 pounds per day 1% 3. Mazzei injector for gas injection 4. Pressurized contacting vessel 5. Recirculation loop - 1 GPM 6. Degas valve for venting excess ozone (flows to destruct unit) Not pictured: UV lamp and H2O2 injection This unit accepts flows up to one gallon per minute, with recirculation rates up to 10 gpm. The unit is powered by a single phase 120-volt circuit, drawing about 12 amps. Rotameters indicate various flows and recirculation rate. Various controls are used to operate and adjust the oxygen and ozone generators. Figure 1: Ozone Pilot Skid Mounted System UV lamp and H2O2 injection are not pictured here and were not utilized for this pilot study, but available for test purposes. 2

3 Military Installation, Central Georgia The pilot study extended an extra week to try various combinations of iron filtration, coagulants, and flocculants that are ozone resistant. A successful combination was found to maintain the 60 ppm iron in solution. One gpm of groundwater was fed to the ozone pilot system, with the picture on the left indicating clear water at the effluent. Foaming was evident in the relief valve purge line post the ozone contact chamber. This was alleviated by altering the chemical injection. Figure 2: Sequential Water Samples during Pilot Water Samples taken during Pilot Test demonstrating optimization of iron control (Left to Right) 1. Raw water (cloudy, red suspended particles) 2. Coagulant only (fluffy, slowly settling pinfloc) 3. Too much flocculent polymer (iron, sludge) 4. Just right flocculent polymer (tight sludge, large floc) 5. Too little flocculent polymer (green iron, but not dense) 6. Feed to ozone contacting skid The success of the pilot study paved the way for full scale implementation of full scale ozone system. Summary Pilot ozone system operational for 2 weeks, June 13-29, 2012 Final Pilot Study report issued August 28, 2012 Approximately 1500 gallons of water was treated with ozone and iron filtration. Significant reductions in COC s observed in post ozone groundwater samples. Equipment performed safely, effectively, reliably, and produced desired results. The initial, quick evaluation of results above indicated we did not achieve results expected. This is due to two factors: (1) Groundwater received during pilot study was more concentrated with contamination and iron than expected. Cape intended to operate with a low ozone mass to contaminant ratio in order to fully evaluate formation of daughter products. Pilot Study VOC Percent Reduction Data Table Sample Location Influent Effluent Influent Effluent Influent Effluent Influent Effluent Date 6/19/12 6/19/12 6/20/12 6/20/12 6/21/12 6/21/12 6/26/12 6/26/12 ug/l ug/l % ug/l ug/l % ug/l ug/l % ug/l ug/l % Chlorobenzene 3,030 1,170 61% 3,220 1,050 67% 3,330 1,470 56% 2, % 1,2-Dichlorobenzene 26,700 8,130 70% 22,700 6,370 72% 23,800 8,320 65% 17,600 6,530 63% 1,3-Dichlorobenzene 1, % 1, % 1, % ,4-Dichlorobenzene 4,250 1,080 75% 4, % 4,020 1,070 73% 2, % cis-1,2-dichloroethene 6,730 3,300 51% 6,330 3,170 50% 6,870 3,650 47% 6,680 4,030 40% Methylene chloride 3,980 2,390 40% 3,600 1,950 46% 3,700 2,110 43% 2,600 1,720 34% Toluene 2, % 1, % 1, % 1, % Trichloroethene 38,400 12,100 68% 34,600 10,100 71% 35,400 12,900 64% 25,900 9,980 61% Total VOCs / % Reduction 86,360 29,128 66% 77,340 23,498 70% 80,160 30,623 62% 59, % Figure 3: Data Summary Table for VOC Reduction Pilot Study Results (June 19-28, 2012) (2) It was clear some contaminants were only partially oxidized. However, an extensive analysis of data was performed and the data interpretation followed this analysis. The purpose of the thorough analysis was to confirm initial design-build concept validity, verify iron sequestering chemical and injection methodology, and ensure complete COC oxidation occurred. 3

4 Piper Environmental Group, Inc. Interpretation of Pilot Study Results Much of what we know about the degradation pathways,which define organic contaminant breakdown in reactions with ozone, are derived from the application of Ozonolysis. This is an analytical method, in which organics are broken down to elucidate their molecular structure. The degradation pathway during ozonation involves at least two reactions in series. Specifically alkenes (all of the primary contaminants analyzed in this study are chlorinated alkenes) react with ozone through two possible pathways forming either (1) a ketone and an aldehyde or (2) a ketone and an organic acid. 3 Breakdown of organics occurs along certain preferential pathways in which the weakest bonds are broken first (or more rapidly and in greater numbers). In the case of chlorinated alkenes these bonds are (1) double bonds, which are converted to single bonds, and (2) chlorine/carbon bonds, which are converted to hydrogen/ carbon bonds. This latter process (dechlorination) is less preferential and a much slower reaction. Knowing these few facts, we surmise degradation pathways to divide contaminants into likely primary reactants and likely daughter products or secondary reactants. Analytes were divided into primary reactants and daughter products in order to analyze the degree of incomplete oxidation. This was used to determine theoretical ozone demand, which is then used to extrapolate a full scale design, based on pilot data. It is also utilized to estimate total ozone contact time with groundwater. It is critical to note in pilot studies where oxidation is complete, full-scale design basis cannot be accurately predicted, since degree of oxidation cannot be quantified. This situation can result in an unnecessary, but common, over sizing of full scale ozonation systems. As higher concentration ozone generators (16 % concentration by weight) are utilized, it is suspected the rate of contaminant reaction will increase and overall ozone demand will decrease. Depending upon the relative reaction rate of two reactions in series, the concentration of daughter products may increase in the reaction solution. The concentration of primary reactants cannot increase in the reaction solution. With this information, we can conclude that daughter products, including ketones and other reactants, have concentrations which increase with statistical significance. We can also surmise that a chemical could theoretically be a daughter product by verifying that its molecular structure is (in a physical sense) a component of the molecular structure of a primary ( parent or superior ) reactant. Primary reactants can be identified in at least two ways: (1) they are the most complex (or larger ) molecules and (2) they are known to have been a chemical that was likely to have been disposed of on site. As part of the process to identify primary reactants, several compounds presented a challenge. In some cases, this was because compounds could be daughter products, based upon their molecular structure or primary contaminants, based upon their commercial significance, potential use and/or subsequent disposal at the site. In other cases, compounds could be considered primary contaminants, based upon their molecular structure, but relative concentrations suggested they were not. In all cases, distinguishing between primary and daughter compounds required an understanding of 1) the historical use of the compound, and 2) the chemical makeup and unintended chemical reaction byproducts which are supplied with all commercial chemicals. An example to illustrate this process: 1,2 dichlorobenzene (Ortho DCB or ODCB) which is present at some of the highest concentrations at the site, but based upon current commercial use, it would not be deemed a primary reactant. Closely related Chlorobenzene seems to be a degradation product of ODCB, based upon its molecular structure, and its concentration increased in one data set. However, Chlorobenzene is a used as a solvent today, with ODCB as a trace contaminant in the commercially available product. An important detail in this analysis was the finding that ODCB was widely used in the past for a very specific application: to soften and remove carbon deposits from metal parts, such as in engine rebuilding operations. In this product the other two DCB s (also found at the site at lesser concentrations) are common minor contaminants. Percent removal of individual organic compounds were accurately estimated. Removal of primary contaminants, was good, but not complete. Removal of daughter products varied greatly. Ketones (acetone, 2-butanone and 4-methyl-2-pentanone) had poor overall removal as these are primary structural daughter products of various primary reactants, and with insufficient oxidizer, they are generated as fast or faster than they are degraded. Chlorobenzene and1,2 dichloroethane are also daughter products that are 4

5 more chemically stable than the superior product from which they derive, and thus also can be generated faster than they are degraded with insufficient oxidizer. Solution Military Installation, Central Georgia Piper s successful pilot confirmed the proposed innovative design-build ozone solution to effectively destroy Contaminants of Concern (COC). To be successful, a complete, in depth analysis of SVOC, VOC, metals and bacteria was completed. Interpretation of these results included primary contaminants, degradation pathways and daughter product formation. This was extremely critical to determine ozone demand as ozone is non-preferential and will attempt to reduce all oxidizable compounds, including other oxidizers. Determining maximum levels of contamination and predicting daughter product formation (indicating incomplete oxidation) was a complex mathematical model including maximum expected COC levels. This analysis was completed and an ozone generator producing 100 pound per day (PPD) at 10% concentration by weight was verified to be sufficiently sized In order to handle expected 45 55GPM continuous water flow rate with 8 SCFM gas flow rate. Several additional factors were taken into consideration: To ensure complete oxidation of COC and reduction in daughter product formation, a sophisticated contact, mixing, and degassing solution was designed. Liquid to gas ratios were evaluated, optimal injection pressure for eduction determined, and degas relief valves, backflow prevention, ozone destruct units sized for the 8 SCFM maximum flow. Ultimately, Piper doubled the capacity of the ozone contact tank to ensure sufficient contact time due to the information discovered during the pilot study. This particularly relates to extensive daughter product formation. Our experience has shown that waste water and groundwater which has been treated by properly designed ozone systems, followed by Granular Activated Carbon (GAC), extends carbon life significantly. Other ozone + GAC systems have run for eight (8) years without media replacement. This is due to GAC acting 1) as ozone removal/destruct, 2) to eliminate bacteria in the media, and 3) as a polisher and not the primary treatment. This greatly reduces the long term operation and maintenance cost at the groundwater treatment facility. Figure 4: Manufacture & Assembly in California This unique Piper ozone system, mounted solid on two individual steel skid, delivers 100 pounds per day (PPD) of ozone, and processes incoming water at up to 55 GPM. The ozone system was designed to reduce levels of contaminants to below acceptable levels while significantly reducing O&M costs over the long term. Full Scale Ozone Specifications Timeline 100-PPD Ozone 10% concentration by weight 40-HP rotary screw air compressor at 166 SCFM feed gas 750 SCFH Oxygen concentrator Proprietary ozone mixing, contacting, and degassing 1,915-gallon stainless steel ozone contact tank ORP and Ambient Ozone monitors PLC and HMI integrated Control Panel Ozone pilot system :June 13-29, 2012 Ozone full scale system startup: February 27, 2014 Ozone system intended to run for 20 years Payback Estimate This system has been estimated to be eighteen (18) months. 5

6 Concentration, ug/l (PPB) Concentration, ug/l (PPB) Piper Environmental Group, Inc. Results The ozone system was fully functional on February 27, 2014 and testing was initiated. The first Sampling event, noted to the right indicates immediate reductions of all Volatile Organic Compounds (all VOC tests included here via EPA SW-8260B). The below graph (Figure 5) indicates only measureable compounds tested. It was assumed that any nondetect level in effluent was provided a numerical level of VOC Reduction: First Sampling Event INFLUENT POST-OZ POST-GAC Sampled Points Vinyl Chloride Acetone cis-1,2-dichloroethene Benzene Chlorobenzene Ethylbenzene 1,3-Dichlorobenzene 1,4-Dichlorobenzene 1,2-Dichlorobenzene Xylenes (total) The increase in Acetone was consistent throughout sampling and is a daughter product of multiple degra- Figures 5 & 6 indicate immediate reduction post ozone of all measureable COCs. The standard to be met was Georgia s ISWQC. Initial indicator contaminant Trichloroethylene (TCE) was not present. It is believed the new indicator will likely be Chlorobenzene. Figure 6 indicates an average Chlorobenzene and 1,4-Dichlorobenze levels at 0.44 ug/l and 0.08 ug/l respectively post ozone with nondetect post GAC. The ozone sample is taken from sample point on the recirculation skid and the post GAC sample is taken post GAC. Figure 5: First Ozone Sampling Event Average VOC Concentrations Vinyl Chloride 100 Acetone cis-1,2-dichloroethene 10 Benzene Toluene 1 Chlorobenzene Ethylbenzene 0.1 1,2,4-Trimethylbenzene 1,3-Dichlorobenzene ,4-Dichlorobenzene 1,2-Dichlorobenzene Xylenes (total) INFLUENT POST-OZONE POST-GAC Sampled Points Figure 6: Average VOC concentrations through first 5 samples 6

7 Military Installation, Central Georgia It is not known definitely yet if the extended contact time from the ozone skid to the GAC is responsible for total destruction or if the GAC is polishing these contaminants. Regardless, much like sizing waste stream for GAC usage, it is critical to focus on all compounds and ions that contribute to treatment media, ozone requires the same attention to detail and a thorough understanding of all contaminants (metals, bacteria, VOC, SVOC, COD, BOD, etc) to properly size for excellent results. Figure 7: Final installation at Military Installation in Central Georgia 120% 100% 80% 60% 40% 20% 0% Average Percent VOC Reduction Pilot Study and Full Scale Results Pilot Study Results Full Scale Results Figure 8: Average Percent VOC Reduction for Pilot and Full Scale Figure 8 indicates the Average Percent VOC reduction in Pilot Study and Full Scale System. The importance of this is twofold: While able to estimate final full scale system correctly prior to Pilot Study, the pilot study results provided opportunity for indepth analysis of COC, percent reduction, understanding of daughter products observed and confirmed initial sizing need. Ozone was ideal solution even with incomplete oxidation during Pilot. 7

8 Piper Environmental Group, Inc. Challenges Overcome during Startup: 1. Delays in delivery of process feed pumps due to inadequate procurement tracking 2. Power harmonic issues internal to ozone generator prevented ozone production 3. Influent and Effluent flowmeters reading discrepancy 4. Air Compressor experienced low temperature alarms on integrated refrigerated air dryer due to uncharacteristically low temperatures during extreme winter event 5. Demister addition to mitigate excessive moisture carry over from tank off gas into the destruct 6. Back pressure on backflow prevention and destruct 7. Contact tank lost prime, pressure, and volume during water processing 8. Ambient ozone alarms from ozone destructs and GAC sample point 9. Iron precipitation in GAC and neutralization tank, a consequence of iron solution chemical not 100% effective 10. Software upgrades to adjust based on changes above 11. Controls integration took approximately 4 iterations 12. GAC expansion joints 13. Foaming post iron solution injection Summary Overall, reduction of the COC s and daughter products has been extremely successful. Post GAC results indicate this Military Installation in Central Georgia fully meets ISWQC target values and NPDES permit values for cleanup standards. None of the VOC s exceeded the ISWQC s in either the post-ozone water samples or the post-gac water samples. This installation is expected to be a tremendous cost saving move for this Military Installation in Central Georgia. Piper Environmental Group, Inc. With special consideration and appreciation to our innovation seeking project partners: Mr. David Fortune, Mr. John Thomas, and Mr. Nelson Rosa of Cape Visit: Cape is Recognized by their clients as best provider of safe, innovative, cost efficient remediation and construction solutions. Sources 1 Fortune, David, and Miller, Merle. RFQ: Robins AFB Provide an Equipment System Designed to Treat the Landfill 3 Extracted Groundwater, March 09, Print. 2 Piper, Jane and Horn, Brad. Summary Report: Robins Air Force Base Landfill 003, Groundwater Treatment Pilot Test for Ozonation System, August Print. 3 Fessenden, RJ et al, Organic Chemistry, 4th Ed, Brooks/ Cole Publishing, Pacific Grove, CA 1990, pages Company Profile Piper Environmental Group, Inc. offers ozone technology, equipment, and services for a wide-range of environmental applications. The company designs, manufactures, and integrates ozone systems and related equipment for short and long-term projects, offering equipment for rent or purchase. Services include project design assistance, oxidation pilot studies, contract service, equipment repair, consulting. Our area of expertise is large, custom remediation projects within the United States. 500 Pinnacle Court Norcross, GA (770) California Street Castroville, California Phone: Fax: For more information, visit