@article{cruz_setz_barlaz_varsho_2023, title={Landfill Codisposal of On-Site Vegetation and Coal Combustion Residuals: Implications for Gas Management}, volume={3}, ISSN={["2690-0645"]}, url={https://doi.org/10.1021/acsestengg.2c00332}, DOI={10.1021/acsestengg.2c00332}, abstractNote={Historically, ash from coal combustion has been disposed of in ponds that were not designed with engineered containment systems. As a result of regulatory changes, it is estimated that coal combustion residuals (CCRs) from hundreds of unlined ponds will have to be excavated and disposed of in new lined landfills or the existing CCR ponds will have to been closed in-place with an engineered final cover system. The excavated or in-place CCR may contain vegetative matter that has the potential to decompose to CH4 and CO2. The objective of this study was to demonstrate a framework to assess the need for a gas collection system to accommodate the disposal of a mixture of CCR and vegetation in a lined landfill. Methane generation rates and yields for vegetative matter mixed with CCR were measured in biochemical methane potential and specific methane activity tests at 15, 20, and 37 °C. The data were then used to parameterize a methane generation model to estimate the gas flux at the landfill surface for a series of hypothetical disposal scenarios. Results showed that the specific decay rate constant (k) ranged from 0.00037 to 0.00872 yr–1, while the methane yield (L0) ranged from 84 to 120 mL CH4/dry g. Temperature was the most important determinant of the decomposition behavior. Simulations of gas flux for several disposal scenarios showed that the modeled flux from the decomposition of vegetation was below the CH4 and CO2 transmission rates reported for a geomembrane liner final cover system, suggesting that an active gas collection will not be necessary under the modeled disposal conditions.}, journal={ACS ES&T ENGINEERING}, author={Cruz, Florentino and Setz, Melissa and Barlaz, Morton and Varsho, Jesse}, year={2023}, month={Mar} }
 @article{titaley_cruz_barlaz_field_2023, title={Neutral Per- and Polyfluoroalkyl Substances in In Situ Landfill Gas by Thermal Desorption-Gas Chromatography-Mass Spectrometry}, volume={10}, ISSN={["2328-8930"]}, url={https://doi.org/10.1021/acs.estlett.3c00037}, DOI={10.1021/acs.estlett.3c00037}, abstractNote={Landfills receive over half of the municipal solid waste generated in the U.S. Wastes in landfills include consumer products, some of which are known to contain of per- and polyfluoroalkyl substances (PFAS). Although the occurrence of nonvolatile (ionic) PFAS in landfill leachate is established and volatile (neutral) PFAS are found in ambient air near landfills, the neutral PFAS composition of landfill gas (LFG) collected in situ from landfills is unknown. A thermal desorption–gas chromatography–mass spectrometry (TD-GC-MS) sampling and analysis approach was optimized for the quantification of 25 target neutral PFAS, including fluorotelomer alcohols (FTOHs) and five other PFAS classes, in landfill from a gas well or header pipe. Optimized LFG sampling parameters included the use of an explosion-proof pump, a 100 mL/min flow rate through a sorbent tube, and a LFG volume of 350 mL. The method was applied to LFG samples collected from southeastern U.S. landfills for method demonstration. Fluorotelomer alcohols were found at the highest levels, ranging from 830,000–4,900,000 pg/m3, which is approximately 2 orders of magnitude greater than FTOH levels reported in ambient air collected near landfills.}, number={3}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS}, author={Titaley, Ivan A. and Cruz, Florentino B. and Barlaz, Morton A. and Field, Jennifer A.}, year={2023}, month={Mar}, pages={214–221} }
 @article{doyle_odenkirk_stewart_nelson_baker_cruz_2022, title={Assessing the Fate of Dissolved Organic Compounds in Landfill Leachate and Wastewater Treatment Systems}, volume={11}, ISSN={["2690-0637"]}, url={https://doi.org/10.1021/acsestwater.2c00320}, DOI={10.1021/acsestwater.2c00320}, abstractNote={Landfill leachate and municipal wastewater are major sources of chemical pollutants that contaminate our drinking water sources. Evaluating the dissolved organic chemical composition in wastewater treatment plants is therefore essential to understand how the discharge impacts the environment, wildlife, and human health. In this study, we utilized a nontargeted analysis method coupling liquid chromatography and tandem mass spectrometry (LC-MS/MS) to analyze chemical features at different points along two landfill leachate treatment plants (LLTPs) and two municipal wastewater treatment plants (WWTPs) in the Southeastern United States. Significant feature differences were observed for the WWTPs where activated sludge clarification was employed versus the LLTPs utilizing reverse osmosis. Specifically, even though both LLTPs had the largest number of features in their influent water, their effluent following reverse osmosis yielded a lower number of features than the WWTPs. Additionally, the clarification processes of each WWTP exhibited different efficiencies as chemical disinfection removed more features than UV disinfection. Feature identification was then made using the LC, MS, and MS/MS information. Analysis of the identified molecules showed that lipids were the most effectively removed from all plants, while alkaloid and organic nitrogen compounds were the most recalcitrant.}, journal={ACS ES&T WATER}, author={Doyle, Michael G. and Odenkirk, Melanie T. and Stewart, Allison K. and Nelson, Jacob P. and Baker, Erin S. and Cruz, Florentino}, year={2022}, month={Nov} }
 @article{muensterman_cahuas_titaley_schmokel_cruz_barlaz_carignan_peaslee_field_2022, title={Per- and Polyfluoroalkyl Substances (PFAS) in Facemasks: Potential Source of Human Exposure to PFAS with Implications for Disposal to Landfills}, volume={9}, ISSN={["2328-8930"]}, url={https://doi.org/10.1021/acs.estlett.2c00019}, DOI={10.1021/acs.estlett.2c00019}, abstractNote={Facemasks are important tools for fighting against disease spread, including Covid-19 and its variants, and some may be treated with per- and polyfluoroalkyl substances (PFAS). Nine facemasks over a range of prices were analyzed for total fluorine and PFAS. The PFAS compositions of the masks were then used to estimate exposure and the mass of PFAS discharged to landfill leachate. Fluorine from PFAS accounted only for a small fraction of total fluorine. Homologous series of linear perfluoroalkyl carboxylates and the 6:2 fluorotelomer alcohol indicated a fluorotelomer origin. Inhalation was estimated to be the dominant exposure route (40%-50%), followed by incidental ingestion (15%-40%) and dermal (11%-20%). Exposure and risk estimates were higher for children than adults, and high physical activity substantially increased inhalation exposure. These preliminary findings indicate that wearing masks treated with high levels of PFAS for extended periods of time can be a notable source of exposure and have the potential to pose a health risk. Despite modeled annual disposal of ~29-91 billion masks, and an assuming 100% leaching of individual PFAS into landfill leachate, mask disposal would contribute only an additional 6% of annual PFAS mass loads and less than 11 kg of PFAS discharged to U.S. wastewater.}, number={4}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS}, publisher={American Chemical Society (ACS)}, author={Muensterman, Derek J. and Cahuas, Liliana and Titaley, Ivan A. and Schmokel, Christopher and Cruz, Florentino B. and Barlaz, Morton A. and Carignan, Courtney C. and Peaslee, Graham F. and Field, Jennifer A.}, year={2022}, month={Apr}, pages={320–326} }
 @article{de la cruz_cheng_call_barlaz_2021, title={Evidence of thermophilic waste decomposition at a landfill exhibiting elevated temperature regions}, volume={124}, ISSN={0956-053X}, url={http://dx.doi.org/10.1016/j.wasman.2021.01.014}, DOI={10.1016/j.wasman.2021.01.014}, abstractNote={There have been several reports of landfills exhibiting temperatures as high as 80 to 100 °C. This observation has motivated researchers to understand the causes of the elevated temperatures and to develop predictive models of landfill temperature. The objective of this research was to characterize the methanogenic activity of microbial communities that were derived from landfill samples excavated from a section of a landfill exhibiting gas well temperatures above 55 °C. Specific objectives were to: (1) determine the upper temperature limit for methane production; (2) evaluate the kinetics of methane generation when landfill-derived microcosms are incubated above and below their excavation temperature and derive a temperature inhibition function; and (3) evaluate microbial community shifts in response to temperature perturbations. Landfill microcosms were derived from 57 excavated landfill samples and incubated within ±2.5 °C of their excavation temperature between 42.5 °C and 87.5 °C. Results showed an optimum temperature for methane generation of ~57 °C and a 95% reduction in methane yield at ~72 °C. When select cultures were perturbed between 5 °C below and 15 °C above their in-situ temperature, both the rate and maximum methane production decreased as incubation temperature increased. Microbial community characterization using 16S rRNA amplicon sequencing suggests that thermophilic methanogenic activity can be attributed to methanogens of the genus Methanothermobacter. This study demonstrated that from a microbiological standpoint, landfills may maintain active methanogenic processes while experiencing temperatures in the thermophilic regime (<72 °C).}, journal={Waste Management}, publisher={Elsevier BV}, author={De la Cruz, Florentino B. and Cheng, Qiwen and Call, Douglas F. and Barlaz, Morton A.}, year={2021}, month={Apr}, pages={26–35} }
 @article{titaley_cruz_field_2020, title={Comment on “Release of Volatile Per- and Polyfluoroalkyl Substances from Aqueous Film-Forming Foam”}, volume={7}, url={https://doi.org/10.1021/acs.estlett.0c00591}, DOI={10.1021/acs.estlett.0c00591}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVCorrespondenceNEXTComment on “Release of Volatile Per- and Polyfluoroalkyl Substances from Aqueous Film-Forming Foam”Ivan A. Titaley*Ivan A. TitaleyDepartment of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States*Email: [email protected]. Phone: (541) 737-9208. Fax: (541) 737-0497.More by Ivan A. Titaleyhttp://orcid.org/0000-0003-4683-1160, Florentino B. De la CruzFlorentino B. De la CruzDepartment of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, North Carolina 27695-7908, United StatesMore by Florentino B. De la Cruzhttp://orcid.org/0000-0002-0936-3778, and Jennifer A. Field*Jennifer A. FieldDepartment of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States*Email: [email protected]. Phone: (541) 737-2265. Fax: (541) 737-0497.More by Jennifer A. Fieldhttp://orcid.org/0000-0002-9346-4693Cite this: Environ. Sci. Technol. Lett. 2020, 7, 11, 866–868Publication Date (Web):September 2, 2020Publication History Received30 July 2020Accepted25 August 2020Revised6 August 2020Published online2 September 2020Published inissue 10 November 2020https://doi.org/10.1021/acs.estlett.0c00591Copyright © 2020 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1858Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (914 KB) Get e-AlertsSUBJECTS:Chromatography,Degradation,Desorption,Fragmentation,Mixtures Get e-Alerts}, number={11}, journal={Environmental Science & Technology Letters}, publisher={American Chemical Society (ACS)}, author={Titaley, Ivan A. and Cruz, Florentino B. De and Field, Jennifer A.}, year={2020}, month={Nov}, pages={866–868} }
 @article{schupp_de la cruz_cheng_call_barlaz_2020, title={Evaluation of the Temperature Range for Biological Activity in Landfills Experiencing Elevated Temperatures}, volume={1}, ISSN={2690-0645}, url={http://dx.doi.org/10.1021/acsestengg.0c00064}, DOI={10.1021/acsestengg.0c00064}, abstractNote={There have been reports of municipal solid waste landfills with waste and gas wellhead temperatures of at least 80–100 °C, which is in excess of temperatures reported at typical landfills. Landfill...}, number={2}, journal={ACS ES&T Engineering}, publisher={American Chemical Society (ACS)}, author={Schupp, Sierra and De la Cruz, Florentino B. and Cheng, Qiwen and Call, Douglas F. and Barlaz, Morton A.}, year={2020}, month={Oct}, pages={216–227} }
 @article{lopez_de la cruz_barlaz_2016, title={Chemical composition and methane potential of commercial food wastes}, volume={56}, ISSN={0956-053X}, url={http://dx.doi.org/10.1016/j.wasman.2016.07.024}, DOI={10.1016/j.wasman.2016.07.024}, abstractNote={There is increasing interest in anaerobic digestion in the U.S. However, there is little information on the characterization of commercial food waste sources as well as the effect of waste particle size on methane yield. The objective of this research was to characterize four commercial food waste sources: (1) university dining hall waste, (2) waste resulting from prepared foods and leftover produce at a grocery store, (3) food waste from a hotel and convention center, and (4) food preparation waste from a restaurant. Each sample was tested in triplicate 8 L batch anaerobic digesters after shredding and after shredding plus grinding. Average methane yields for the university dining, grocery store, hotel, and restaurant wastes were 363, 427, 492, and 403 mL/dry g, respectively. Starch exhibited the most complete consumption and particle size did not significantly affect methane yields for any of the tested substrates. Lipids represented 59–70% of the methane potential of the fresh substrates.}, journal={Waste Management}, publisher={Elsevier BV}, author={Lopez, Victoria M. and De la Cruz, Florentino B. and Barlaz, Morton A.}, year={2016}, month={Oct}, pages={477–490} }
 @article{cruz_green_hater_chanton_thoma_harvey_barlaz_2016, title={Comparison of Field Measurements to Methane Emissions Models at a New Landfill}, volume={50}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.6b00415}, abstractNote={Estimates of methane emissions from landfills rely primarily on models due to both technical and economic limitations. While models are easy to implement, there is uncertainty due to the use of parameters that are difficult to validate. The objective of this research was to compare modeled emissions using several greenhouse gas (GHG) emissions reporting protocols including: (1) Intergovernmental Panel on Climate Change (IPCC); (2) U.S. Environmental Protection Agency Greenhouse Gas Reporting Program (EPA GHGRP); (3) California Air Resources Board (CARB); and (4) Solid Waste Industry for Climate Solutions (SWICS), with measured emissions data collected over three calendar years from a young landfill with no gas collection system. By working with whole landfill measurements of fugitive methane emissions and methane oxidation, the collection efficiency could be set to zero, thus eliminating one source of parameter uncertainty. The models consistently overestimated annual methane emissions by a factor ranging from 4-31. Varying input parameters over reasonable ranges reduced this range to 1.3-8. Waste age at the studied landfill was less than four years and the results suggest the need for measurements at additional landfills to evaluate the accuracy of the tested models to young landfills.}, number={17}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, publisher={American Chemical Society (ACS)}, author={Cruz, Florentino B. and Green, Roger B. and Hater, Gary R. and Chanton, Jeffrey P. and Thoma, Eben D. and Harvey, Tierney A. and Barlaz, Morton A.}, year={2016}, month={Sep}, pages={9432–9441} }
 @article{de la cruz_osborne_barlaz_2016, title={Determination of Sources of Organic Matter in Solid Waste by Analysis of Phenolic Copper Oxide Oxidation Products of Lignin}, volume={142}, ISSN={0733-9372 1943-7870}, url={http://dx.doi.org/10.1061/(ASCE)EE.1943-7870.0001038}, DOI={10.1061/(asce)ee.1943-7870.0001038}, abstractNote={AbstractThe decomposition behavior of lignocellulosic materials is related to the taxonomic classes of the parent plant tissues. Thus, methods to characterize the composition of mixtures of lignocellulosic materials such as municipal solid waste (MSW) according to different taxonomic classes of plants are useful. The copper oxide (CuO) oxidation products of lignin provide molecular markers that allow for characterization of the initial plants. The objective of this study was to determine if the chemical composition of the monomers present after CuO oxidation can be used to infer information on the content of woody angiosperms (hardwood—HW), non-woody angiosperms (leaves and grasses—LG), woody gymnosperms (softwood—SW), and non-woody gymnosperms (needles—GN). Results showed that the composition of HW and SW in synthetic mixtures can be estimated from CuO oxidation products of lignin within an error of ±60% of the expected values. The high uncertainty in the estimate of composition in synthetic mixtures can...}, number={2}, journal={Journal of Environmental Engineering}, publisher={American Society of Civil Engineers (ASCE)}, author={De la Cruz, Florentino B. and Osborne, Jason and Barlaz, Morton A.}, year={2016}, month={Feb}, pages={04015076} }
 @article{wang_cruz_ximenes_barlaz_2015, title={Decomposition and carbon storage of selected paper products in laboratory-scale landfills}, volume={532}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2015.05.132}, abstractNote={The objective of this study was to measure the anaerobic biodegradation of different types of paper products in laboratory-scale landfill reactors. The study included (a) measurement of the loss of cellulose, hemicellulose, organic carbon, and (b) measurement of the methane yields for each paper product. The test materials included two samples each of newsprint (NP), copy paper (CP), and magazine paper (MG), and one sample of diaper (DP). The methane yields, carbon storage factors and the extent of cellulose and hemicellulose decomposition all consistently show that papers made from mechanical pulps (e.g., NPs) are less degradable than those made from chemical pulps where essentially all lignin was chemically removed (e.g., CPs). The diaper, which is not only made from chemical pulp but also contains some gel and plastic, exhibited limited biodegradability. The extent of biogenic carbon conversion varied from 21 to 96% among papers, which contrasts with the uniform assumption of 50% by the Intergovernmental Panel on Climate Change (IPCC) for all degradable materials discarded in landfills. Biochemical methane potential tests also showed that the solids to liquid ratio used in the test can influence the results.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, publisher={Elsevier BV}, author={Wang, Xiaoming and Cruz, Florentino B. and Ximenes, Fabiano and Barlaz, Morton A.}, year={2015}, month={Nov}, pages={70–79} }
 @article{de la cruz_dittmar_niggemann_osburn_barlaz_2015, title={Evaluation of Copper Oxide Oxidation for Quantification of Lignin in Municipal Solid Waste}, volume={32}, ISSN={1092-8758 1557-9018}, url={http://dx.doi.org/10.1089/ees.2014.0402}, DOI={10.1089/ees.2014.0402}, abstractNote={Abstract The ability to quantify lignin is an important tool for characterizing the extent of decomposition of municipal solid waste (MSW). Traditionally, acid insoluble Klason lignin (KL) has been used to measure lignin. However, synthetic organic materials such as plastics and rubber present in MSW interfere with the traditional KL method, resulting in artificially high measurements. Another method for lignin analysis is CuO oxidation, in which lignin is oxidatively hydrolyzed into phenolic monomers that are quantified by high-performance liquid chromatography or gas chromatography–mass spectrography. The objective of this study was to evaluate the applicability of CuO oxidation to measure the lignin content of MSW. The study demonstrated that analysis of lignin monomers can be simplified by skipping the ethyl acetate extraction step and that ball milling is not necessary to optimize CuO oxidation. Neither the MSW components (e.g., plastics and metals) nor extractives affected CuO oxidation. The ratio o...}, number={6}, journal={Environmental Engineering Science}, publisher={Mary Ann Liebert Inc}, author={De la Cruz, Florentino Banaag and Dittmar, Thorsten and Niggemann, Jutta and Osburn, Christopher L. and Barlaz, Morton A.}, year={2015}, month={Jun}, pages={486–496} }
 @article{cruz_yelle_gracz_barlaz_2014, title={Chemical Changes during Anaerobic Decomposition of Hardwood, Softwood, and Old Newsprint under Mesophilic and Thermophilic Conditions}, volume={62}, ISSN={["1520-5118"]}, DOI={10.1021/jf501653h}, abstractNote={The anaerobic decomposition of plant biomass is an important aspect of global organic carbon cycling. While the anaerobic metabolism of cellulose and hemicelluloses to methane and carbon dioxide are well-understood, evidence for the initial stages of lignin decomposition is fragmentary. The objective of this study was to look for evidence of chemical transformations of lignin in woody tissues [hardwood (HW), softwood (SW), and old newsprint (ONP)] after anaerobic decomposition using Klason and acid-soluble lignin, CuO oxidation, and 2D NMR. Tests were conducted under mesophilic and thermophilic conditions, and lignin associations with structural carbohydrates are retained. For HW and ONP, the carbon losses could be attributed to cellulose and hemicelluloses, while carbon loss in SW was attributable to an uncharacterized fraction (e.g., extractives etc.). The 2D NMR and chemical degradation methods revealed slight reductions in β-O-4 linkages for HW and ONP, with no depolymerization of lignin in any substrate.}, number={27}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, publisher={American Chemical Society (ACS)}, author={Cruz, Florentino B. and Yelle, Daniel J. and Gracz, Hanna S. and Barlaz, Morton A.}, year={2014}, month={Jul}, pages={6362–6374} }
 @article{cruz_chanton_barlaz_2013, title={Measurement of carbon storage in landfills from the biogenic carbon content of excavated waste samples}, volume={33}, ISSN={["0956-053X"]}, DOI={10.1016/j.wasman.2012.12.012}, abstractNote={Landfills are an anaerobic ecosystem and represent the major disposal alternative for municipal solid waste (MSW) in the U.S. While some fraction of the biogenic carbon, primarily cellulose (Cel) and hemicellulose (H), is converted to carbon dioxide and methane, lignin (L) is essentially recalcitrant. The biogenic carbon that is not mineralized is stored within the landfill. This carbon storage represents a significant component of a landfill carbon balance. The fraction of biogenic carbon that is not reactive in the landfill environment and therefore stored was derived for samples of excavated waste by measurement of the total organic carbon, its biogenic fraction, and the remaining methane potential. The average biogenic carbon content of the excavated samples was 64.6 ± 18.0% (average ± standard deviation), while the average carbon storage factor was 0.09 ± 0.06 g biogenic-C stored per g dry sample or 0.66 ± 0.16 g biogenic-C stored per g biogenic C.}, number={10}, journal={WASTE MANAGEMENT}, publisher={Elsevier BV}, author={Cruz, Florentino B. and Chanton, Jeffrey P. and Barlaz, Morton A.}, year={2013}, month={Oct}, pages={2001–2005} }
 @article{wang_padgett_cruz_barlaz_2011, title={Wood Biodegradation in Laboratory-Scale Landfills}, volume={45}, ISSN={["1520-5851"]}, DOI={10.1021/es201241g}, abstractNote={The objective of this research was to characterize the anaerobic biodegradability of major wood products in municipal waste by measuring methane yields, decay rates, the extent of carbohydrate decomposition, carbon storage, and leachate toxicity. Tests were conducted in triplicate 8 L reactors operated to obtain maximum yields. Measured methane yields for red oak, eucalyptus, spruce, radiata pine, plywood (PW), oriented strand board (OSB) from hardwood (HW) and softwood (SW), particleboard (PB) and medium-density fiberboard (MDF) were 32.5, 0, 7.5, 0.5, 6.3, 84.5, 0, 5.6, and 4.6 mL CH(4) dry g(-1), respectively. The red oak, a HW, exhibited greater decomposition than either SW (spruce and radiata), a trend that was also measured for the OSB-HW relative to OSB-SW. However, the eucalyptus (HW) exhibited toxicity. Thus, wood species have unique methane yields that should be considered in the development of national inventories of methane production and carbon storage. The current assumption of uniform biodegradability is not appropriate. The ammonia release from urea formaldehyde as present in PB and MDF could contribute to ammonia in landfill leachate. Using the extent of carbon conversion measured in this research, 0-19.9%, predicted methane production from a wood mixture using the Intergovernmental Panel for Climate Change waste model is only 7.9% of that predicted using the 50% carbon conversion default.}, number={16}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, publisher={American Chemical Society (ACS)}, author={Wang, Xiaoming and Padgett, Jennifer M. and Cruz, Florentino B. and Barlaz, Morton A.}, year={2011}, month={Aug}, pages={6864–6871} }
 @article{cruz_barlaz_2010, title={Estimation of Waste Component-Specific Landfill Decay Rates Using Laboratory-Scale Decomposition Data}, volume={44}, ISSN={["1520-5851"]}, DOI={10.1021/es100240r}, abstractNote={The current methane generation model used by the U.S. EPA (Landfill Gas Emissions Model) treats municipal solid waste (MSW) as a homogeneous waste with one decay rate. However, component-specific decay rates are required to evaluate the effects of changes in waste composition on methane generation. Laboratory-scale rate constants, k(lab), for the major biodegradable MSW components were used to derive field-scale decay rates (k(field)) for each waste component using the assumption that the average of the field-scale decay rates for each waste component, weighted by its composition, is equal to the bulk MSW decay rate. For an assumed bulk MSW decay rate of 0.04 yr(-1), k(field) was estimated to be 0.298, 0.171, 0.015, 0.144, 0.033, 0.02, 0.122, and 0.029 yr(-1), for grass, leaves, branches, food waste, newsprint, corrugated containers, coated paper, and office paper, respectively. The effect of landfill waste diversion programs on methane production was explored to illustrate the use of component-specific decay rates. One hundred percent diversion of yard waste and food waste reduced the year 20 methane production rate by 45%. When a landfill gas collection schedule was introduced, collectable methane was most influenced by food waste diversion at years 10 and 20 and paper diversion at year 40.}, number={12}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, publisher={American Chemical Society (ACS)}, author={Cruz, Florentino B. and Barlaz, Morton A.}, year={2010}, month={Jun}, pages={4722–4728} }