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Production of NMOCs and Trace Organics During the Decomposition of Refuse and Waste Components Under Anaerobic and Aerobic Conditions Morton Barlaz, Stephen J. Cowie, Bryan Staley North Carolina State University Gary R. Hater Waste Management Inc. Introduction Limited understanding of factors affecting NMOC production Increasing interest among state regulators – potential for over estimates based on US EPA defaults z NMOC increases as Lo increases Research Objectives Measure an ultimate NMOC yield for individual components Study the relationship between gas production and NMOC release Compare anaerobic and aerobic conditions Identify specific trace organic compounds Evaluate the contribution of household hazardous waste (HHW) compounds to NMOC emissions Experimental Design • aerobic operation for 44/68 days prior to the onset of anaerobic conditions ( I& II) • traditional anaerobic operation (I & II) • traditional anaerobic operation plus household hazardous waste (HHW) • anaerobic decomposition of residential food waste (I & II) • anaerobic decomposition of mixed paper (I) • control for background NMOC production from the leachate seed • anaerobic decomposition of yard waste (I) • aerobic decomposition of yard waste (II) • abiotic conditions (II) Waste Composition Paper: 20% ONP, 42% OCC, 15% OFF, 7% OMG, and 16% 3rd class mail Yard: 25% leaves, 25% branches, 50% grass Food : Residential kitchen scraps MSW: Residential HHW components z Paint remover – 25 – 30% toluene – 25 – 30% acetone – 20 – 25% methylene chloride z Motor oil – 6880 ug/kg toluene z Nail polish remover – 100% acetone Reactor Setup Reactor Operation z z z Triplicate 8-L reactors Seeded with leachate to initiate decomposition Operated with leachate recycle and neutralization at 37°C 1.2 1 0.78 0.8 AP-42: 0.48 0.35/0.03 0.23/0.23 0.4 t ic io Ab . SW -A er W HH M SW + M od Fo . rd -A er n. -A rd Ya SW 0.11/0.14 0.17 0.038 Ya 0.016 r 0 0.15 pe 0.2 M 0.6 Pa N M O C (m g -C /d ry m g m ) NMOC Yields for Individual Components NMOC Yields Under Different Operating Conditions NMOC (mg-C/dry gm) 0.4 0.35 0.23/0.23 0.3 0.25 0.15 0.2 0.11/0.14 0.15 0.1 0.038 0.05 0 Yard-An. Yard-Aer. MSW MSW-Aer. Paper MSW 0.80 mL CH4/day-dry gm 0.60 0.40 0.20 1.00 M2 0.80 0.60 0.40 0.20 100 200 Day 300 400 500 NMOC Rate 1.E-03 mg NMOC-C/day-dry gm 8.E-04 7.E-04 P1 P2 P3 6.E-04 5.E-04 4.E-04 3.E-04 2.E-04 1.E-04 0.E+00 0 100 200 300 400 200 100 0 0 100 200 300 Day 400 500 0.20 50 100 150 200 Day 250 300 350 8.E-03 M1 M2 2.E-03 1.E-03 MH1 MH2 6.E-03 4.E-03 2.E-03 0.E+00 0 mg NMOC-C/m3 mg NMOC-C/m3 300 0.40 NMOC Rate NMOC Rate 100 Day 200 300 0 400 NMOC Conc. M1 M2 1500 1000 500 0 100 Day 200 300 400 NMOC Conc. 4000 2000 P1 P2 P3 0.60 400 3.E-03 2500 400 300 0.E+00 500 NMOC Conc. 500 Day 200 4.E-03 Day 600 100 5.E-03 9.E-04 0.80 0 0 600 mg NMOC-C/day-dry gm 0 MH2 1.00 0.00 0.00 0.00 MH1 1.20 M1 mg NMOC-C/m3 mL CH4/day-dry gm P1 P2 P3 Methane Rate 1.40 1.20 1.00 mg NMOC-C/day-dry gm Methane Rate 1.40 mL CH4/day-dry gm Methane Rate 1.20 MSW + HHW 3000 MH1 2000 MH2 1000 0 0 100 Day 200 300 400 0 100 Day 200 300 400 Percent Yields for Methane and NMOCs After First Two Samples 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Paper Yard MS MSW + Percent Yields for Methane and NMOCs at Midway Point of Operation 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Paper Yard MSW MSW + Relationship Between Gas Production & NMOC Yield 0.50 Aerobic Food Paper yard (an) MSW MSW+HHW yard (ae) Food (II) mg NMOC-C/dry-gram 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 180 230 280 330 380 430 Gas Yield (mL/gm) 480 Individual Organic Compounds Alkane Alkene Alcohol OH Chlorinated organic Cl Cl Cl Cl Terpene O Ketone O Volatile Fatty Acid OH Aromatic Sources of Organics z HHW – z chlorinated compounds, aromatics, alkanes, alkenes Vegetative Matter – terpenes release after plant death z z present in citrus peels Decomposition Intermediates – alcohols, ketones and fatty acids Types of Organics Released from Waste Components Chlorinateds Ketones Alkenes Alkanes Alcohols Aromatics Terpenes Fraction of Individually Quantified Organics 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.002 0.12 1.13 Paper Waste Yard Waste Food Waste 0.13 0.44 0.20 0.10 0.00 MSW MSW + HHW Paper Specific Compounds 97 74 208 171 Ethanol 197 Terpenes OH Aromatics Alcohols 280 Alkanes Alkenes 1-Butanol Ketones Chlorinateds 1462 OH Yard Waste 1150 605 Specific Compounds 7 Terpenes 5166 z Aromatics Alcohols Alkanes 13162 Alkenes Ketones 1861 Chlorinateds 611 z z α-pinene Terpenes − α-pinene − β-pinene − Camphene − Limonene 1-Butanol 2-Methylhexane Food Waste 1328 Specific Compounds Limonene 2664 602 5223 z 56407 149635 Terpenes Aromatics Alcohols Alkenes Ketones Chlorinateds Alkanes z z Terpenes − a-pinene − b-pinene − Camphene − Limonene − g-Terpinine 1-Methyl-4-isopropylbenzene Ethanol, 1-Butanol, 2Butanone MSW 565 Specific Compounds 4 997 8083 z 9202 z 2292 Terpenes Alcohols Alkenes Chlorinateds 3419 z Alkanes – Pentane – 2-Methylhexane 1-Butanol Limonene, α-Pinene Aromatics Alkanes Ketones 2-Methylhexane MSW + HHW Specific Compounds 466 2658 1712 15241 8978 2062 z Toluene z Acetone O 63903 Terpenes Alkanes Chlorinateds Aromatics Alkenes Alcohols Ketones z 2-Butanone O MSW Aerobic 546 Specific Compounds 20044 21068 z z 1121 495 z Ethyl Acetate Pentane Terpenes 8540 15997 Terpenes Aromatics Alcohols Alkanes Alkenes Ketones O Ethyl Acetate Chlorinateds O Importance of Fatty Acids VFAs as % of NMOCs 20 15.3 15 10 5 5.6 5.3 Yard Waste Paper Waste 2.6 0.1 0.2 0 Food Waste MSWAerobic MSWAnaerobic MSW + HHW Based on selected high COD time points Speciated Organics in MSW: Aerobic vs. Anaerobic 1.0E+06 Anaerobic Aerobic Terpenes 1.0E+05 Alcohols Ketones Yield (ng/dry gm) Alkanes Alkenes 1.0E+04 Aromatics Chlorinated 1.0E+03 1.0E+02 1.0E+01 1.0E+00 Alkanes Alkenes Aromatics Alcohols Ketones Terpenes CAH Contribution of HHW to Speciated Organics 1.E+07 --MSW --MSW + HHW --Food Waste Mass (ng/dry gram) 1.E+06 1.E+05 Alkanes 1.E+04 1.E+03 1.E+02 1.E+01 1.E+00 Terpenes Aromatics Alcohols Alkenes Ketones Chlorinated 5.48 6 5 4 3 SP S 0.48 N er . 0.78 Ab io tic + SW M SW -A H HW SW M 0.23 0.17 0.11 M 0.22 Fo od Ya rd -A er . n. -A 0 0.15 0.04 0.02 Ya rd 1 AP -4 2 2 Pa pe r NMOC (mg-C/dry gm) Lab-Scale NMOC Yields vs. Regulatory Estimates Comparison of AP-42 and Measured HAP Yields for MSW MSW 10000 AP-42 1000 100 10 H ex a ne E TC Xy le ne s Et hy lb en ze ne To lu en e en z en e 1 B Yield (ng/dry gm) 100000 Conclusions Ultimate NMOC yields vary substantially among MSW components Lab-scale NMOC and HAP yields are considerably lower than regulatory estimates NMOC production is characterized by an initial “burst”, followed by much more gradual release Conclusions High gas production tends to correlate with high NMOC production with the exceptions of paper and yard waste Decomposition intermediates (fatty acids) do not appear to be major contributors to NMOC yields Conclusions Aeration results in higher NMOC release compared to anaerobic decomposition HHW constituents do not dominate NMOC yields Food waste can be high in NMOCs, but is not a source of HAPs Additional Work Explanation for large variation in food waste yields Evaluate how to merge with data from Waste Industry Air Coalition Acknowledgement z Waste Management Inc. for the support of this research
