3 research outputs found
Control Of Hydrogen Sulfide Emissionsusing Autotrophic Denitrificationlandfill Biocovers
Hydrogen sulfide (H2S), a major odorous component emitted from construction and demolition debris landfills, has received increasing attention. Besides its unpleasant odor, long-term exposure to a very low concentration of H2S can cause a public health issue. Although cover materials such as soil and compost are recommended to be used routinely to control an odor problem from the landfills, the problem still remains. Autotrophic denitrification may have environmental applications including treatment of water, groundwater, wastewater or gaseous streams contaminated with sulfur and/or nitrogen compounds. However, there have been no studies reported in the literature on H2S removal using autotrophic denitrification from landfills. This study, therefore, investigated the application of autotrophic denitrification incorporated into landfill covers in order to evaluate the feasibility of controlling H2S emissions generated from landfills. Research was investigated by two techniques, microcosm and laboratory-scale column studies. The microcosm experiments were conducted to evaluate the kinetics of autotrophic denitrification in various cover materials with H2S-nitrate as electron donor-acceptor couple. Cover materials including soil, compost and sand were tested and nitrate was added. Based on the microcosm study results, the addition of nitrate into soil and compost can stimulate indigenous autotrophic denitrifying bacteria which are capable of H2S oxidation biologically under anoxic conditions. Results also demonstrated that some amount of H2S can be removed physically and chemically by soil or compost. There was no H2S removal observed in sand microcosms. Rapid H2S oxidation to sulfate was achieved, especially in soil. Zero-order kinetics described the H2S oxidation rate in soil and compost microcosms. The rates of sulfide oxidation under autotrophic denitrification in soil and compost were 2.57 mg H2S/d-g dry soil and 0.17 mg H2S/d-g dry compost, respectively. To further explore H2S removal in a landfill biocover, two sets of column experiments were run. The first set of columns contained seven cm of soil. The autotrophic column was prepared with 1.94 mg KNO3/g dry soil; an identical control column was prepared without nitrate. A gas stream was introduced to the columns with a H2S concentration of 930 ppm. The second set contained seven cm of soil, with both an autotrophic (0.499 mg KNO3/g dry soil) and a control column. Influent H2S concentration was 140 ppm for the second set. Column studies supported the results of microcosm studies; removal of H2S was observed in all columns due to the capacity for soil to absorb H2S, however autotrophic columns removed significantly more. The higher concentration of H2S resulted in partial oxidation to elemental sulfur, while sulfate was found at levels predicted by stoichiometric relationships at the lower concentration. H2S oxidation in the column with higher loading was found to follow zero-order kinetics. The rate of H2S oxidation was 0.46 mg H2S removed/d-g dry soil. Economic comparison of cover systems including autotrophic denitrification, soil amended with lime, fine concrete, and compost covers were analyzed. Based on a case-study landfill area of 0.04 km2, the estimated H2S emissions of 80,900 kg over the 15-year period and costs of active cover system components (ammonium nitrate fertilizer, lime, concrete and compost), autotrophic denitrification cover was determined to be the most cost-effective method for controlling H2S emissions from landfills
Control Of Hydrogen Sulfide Emissions Using Autotrophic Denitrification Landfill Biocovers: Engineering Applications
Hydrogen sulfide (H2S) emitted from construction and demolition waste landfills has received increasing attention. Besides its unpleasant odor, longterm exposure to a very low concentration of H2S can cause a public health issue. In the case of construction and demolition (C&D) waste landfills, where gas collection systems are not normally required, the generated H2S is typically not controlled and the number of treatment processes to control H2S emissions in situ is limited. An attractive alternative may be to use chemically or biologically active landfill covers. A few studies using various types of cover materials to attenuate H2S emissions demonstrated that H2S emissions can be effectively reduced. In this study, therefore, the costs and benefits of H2S-control cover systems including compost, soil amended with lime, fine concrete, and autotrophic denitrification were evaluated. Based on a case-study landfill area of 0. 04 km2, the estimated H2S emissions of 80900 kg over the 15-year period and costs of active cover system components (ammonium nitrate fertilizer for autotrophic denitrification cover, lime, fine concrete, and compost), ammonium nitrate fertilizer is the most cost effective, followed by hydrated lime, fine concrete, and yard waste compost. Fine concrete and yard waste compost covers are expensive measures to control H2S emissions because of the large amount of materials needed to create a cover. Controlling H2S emissions using fine concrete and compost is less expensive at landfills that provide on-site concrete recovery and composting facilities; however, ammonium nitrate fertilizer or hydrated lime would still be more cost effective applications. ÂĐ 2011 Higher Education Press and Springer-Verlag Berlin Heidelberg
āļĻāļąāļāļĒāļ āļēāļāļāļēāļĢāļāļĨāļīāļāļāđāļēāļāļĄāļĩāđāļāļāđāļĨāļ°āļāļĨāļāļāļĨāļĻāļēāļŠāļāļĢāđāļāļāļāļāļēāļĢāļŦāļĄāļąāļāļĢāđāļ§āļĄāļĢāļ°āļŦāļ§āđāļēāļāđāļĻāļĐāļāļēāļŦāļēāļĢāđāļĨāļ°āļāļĨāļīāļāļ āļąāļāļāđāđāļĒāļ·āđāļāļāļĩāļ§āļ āļēāļāļāļĢāļĢāļāļļāļāļēāļŦāļēāļĢ Biochemical Methane Potential and Kinetics on Anaerobic Co-digestion of Food Waste and Cellulose-based Food Packaging Product
āļāļēāļĢāļĒāđāļāļĒāļŠāļĨāļēāļĒāļ āļēāļĒāđāļāđāļŠāļ āļēāļ§āļ°āđāļĢāđāļāļēāļāļēāļĻāđāļāļĒāļāļēāļĢāļŦāļĄāļąāļāļĢāđāļ§āļĄāđāļāđāļĢāļąāļāļāļēāļĢāļāļīāļŠāļđāļāļāđāđāļĨāđāļ§āļ§āđāļēāđāļāđāļāļāļĩāļāđāļāļāđāļāđāļĨāļĒāļĩāļŦāļāļķāđāļāļāļĩāđāļāđāļ§āļĒāđāļāļīāđāļĄāļāļĢāļīāļĄāļēāļāļāļēāļĢāļāļĨāļīāļāļāđāļēāļāļĄāļĩāđāļāļāđāļŦāđāļŠāļđāļāļāļķāđāļāđāļāđ āļāļēāļĢāļĻāļķāļāļĐāļēāļāļĩāđāļāļķāļāļāļģāļāļēāļĢāļāļĢāļ§āļāļŠāļāļāļāļķāļāļĻāļąāļāļĒāļ āļēāļāđāļāļāļēāļĢāļāļĨāļīāļāļāđāļēāļāļĄāļĩāđāļāļāđāļāļĒāļāļēāļĢāļŦāļĄāļąāļāļĢāđāļ§āļĄāļĢāļ°āļŦāļ§āđāļēāļāđāļĻāļĐāļāļēāļŦāļēāļĢ (Food Waste, FW) āđāļĨāļ°āļāļĨāļīāļāļ āļąāļāļāđāđāļĒāļ·āđāļāļāļĩāļ§āļ āļēāļāļāļĢāļĢāļāļļāļāļēāļŦāļēāļĢ (Cellulose-based Food Packaging Product, CFPP) āļāļĩāđāļāļļāļāļŦāļ āļđāļĄāļīāļĢāļ°āļāļąāļāļāļēāļāļāļĨāļēāļ (35 Âą 2 āļāļāļĻāļēāđāļāļĨāđāļāļĩāļĒāļŠ) āđāļāļĢāļđāļāđāļāļāļāļ° (Batch Experiment) āđāļāđāļāļĢāļ°āļĒāļ°āđāļ§āļĨāļē 45 āļ§āļąāļ āđāļāļĒāļāļąāļāļĢāļēāļŠāđāļ§āļāļĢāļ°āļŦāļ§āđāļēāļāļ§āļąāļŠāļāļļāļāļąāđāļāļāđāļāļāļąāđāļ 2 āļāļāļīāļāļāļĩāđāļāļģāļāļēāļĢāļĻāļķāļāļĐāļēāļĄāļĩ 3 āļāļąāļāļĢāļēāļŠāđāļ§āļ (FW/CFPP 100:0, 40:60 āđāļĨāļ° 0:100 (āđāļāļĒāļāđāļģāļŦāļāļąāļāļāļāļāđāļāđāļāļĢāļ°āđāļŦāļĒāļāđāļēāļĒ)) āđāļĨāļ°āļĄāļĩāļāļēāļĢāđāļāđāļāļąāļāļĢāļēāļŠāđāļ§āļāļĢāļ°āļŦāļ§āđāļēāļāļ§āļąāļŠāļāļļāļāļąāđāļāļāđāļāđāļĨāļ°āļŦāļąāļ§Âāđāļāļ·āđāļāļāļļāļĨāļīāļāļāļĢāļĩāļĒāđāđāļāđāļēāļāļąāļ 0.5 āļĢāļ§āļĄāļāļąāđāļāļĄāļĩāļāļēāļĢāđāļāļīāļĄāđāļāđāļāļĩāļĒāļĄāđāļāļāļēāļĢāđāļāļāđāļāļ (NaHCO3) āđāļāļ·āđāļāđāļŦāđāļāļĢāļ°āļāļ§āļāļāļēāļĢāļĒāđāļāļĒāļŠāļĨāļēāļĒāļ āļēāļĒāđāļāđāļŠāļ āļēāļ§āļ°āđāļĢāđāļāļēāļāļēāļĻāļāļĒāļđāđāđāļāļŠāļ āļēāļ§āļ°āļŠāļĄāļāļļāļĨ āļāļāļāļāļēāļāļāļĩāđāđāļāđāļĄāļĩāļāļēāļĢāļāļģāđāļĄāđāļāļĨāļāļēāļāļāļāļīāļāļĻāļēāļŠāļāļĢāđ āļāļģāļāļ§āļ 4 āđāļĄāđāļāļĨ (Modified Gompertz Model, First-order Model, Monod Model āđāļĨāļ° Cone Model) āļĄāļēāđāļāđāđāļāļāļēāļĢāļāļĢāļ°āđāļĄāļīāļāļāļ§āļēāļĄāđāļŦāļĄāļēāļ°āļŠāļĄāļāļāļāļāļēāļĢāļāļģāļāļēāļĒāļāļĨāļāļĨāļīāļāļāđāļēāļāļĄāļĩāđāļāļāļāļĩāđāđāļāļīāļāļāļķāđāļāļāļēāļāļ§āļąāļŠāļāļļāļāļąāđāļāļāđāļāļāļąāļāļĢāļēāļŠāđāļ§āļāļāđāļēāļ āđ āļāđāļ§āļĒ āļāļĨāļāļēāļĢāļĻāļķāļāļĐāļē āļāļāļ§āđāļē āļāļąāļāļĢāļēāļŠāđāļ§āļ FW/CFPP 100:0 āđāļŦāđāļāļĨāļāļĨāļīāļāļāđāļēāļāļĄāļĩāđāļāļāļŠāļ°āļŠāļĄāļŠāļđāļāļāļĩāđāļŠāļļāļ āļĢāļāļāļĨāļāļĄāļēāļāļ·āļ 40:60 āđāļĨāļ° 0:100 āđāļāļĒāļĄāļĩāļāđāļēāļāļĨāļāļĨāļīāļāļāđāļēāļāļĄāļĩāđāļāļ āđāļāđāļēāļāļąāļ 459.15, 381.79 āđāļĨāļ° 355.60 āļĄāļīāļĨāļĨāļīāļĨāļīāļāļĢāļĄāļēāļāļĢāļāļēāļāļāđāļāļāļĢāļąāļĄāļāļāļāđāļāđāļāļĢāļ°āđāļŦāļĒāļāđāļēāļĒ āļāļēāļĄāļĨāļģāļāļąāļ āđāļĨāļ°āļāļēāļāđāļĄāđāļāļĨāļāļēāļāļāļāļīāļāļĻāļēāļŠāļāļĢāđāļāļĩāđāļāļģāļāļēāļĢāļĻāļķāļāļĐāļēāļāļąāđāļāļŦāļĄāļ āļāļāļ§āđāļē Modified Gompertz Model āđāļāđāļāđāļĄāđāļāļĨāļāļĩāđāļĄāļĩāļāļ§āļēāļĄāđāļĄāđāļāļĒāļģāđāļĨāļ°āđāļŦāļĄāļēāļ°āļŠāļĄāļĄāļēāļāļāļĩāđāļŠāļļāļāđāļāļāļēāļĢāđāļāđāļāļģāļāļēāļĒāļāļĨāļāļĨāļīāļāļāđāļēāļāļĄāļĩāđāļāļāļāļāļāļāļąāļāļĢāļēāļŠāđāļ§āļ FW/CFPP 100:0 āđāļĨāļ° 0:100 āđāļāđāļŠāļģāļŦāļĢāļąāļāļāļąāļāļĢāļēāļŠāđāļ§āļ FW/CFPP 40:60 āļāļāļ§āđāļē First-order Model āđāļāđāļāđāļĄāđāļāļĨāļāļĩāđāļĄāļĩāļāļ§āļēāļĄāđāļĄāđāļāļĒāļģāđāļĨāļ°āđāļŦāļĄāļēāļ°āļŠāļĄāļĄāļēāļāļāļ§āđāļē Modified Gompertz Model āļāļāļāļāļēāļāļāļĩāđ āļāļēāļĢāļēāļĄāļīāđāļāļāļĢāđāļāļēāļāļāļĨāļāļāļĨāļĻāļēāļŠāļāļĢāđ āđāļāđāđāļŠāļāļāđāļŦāđāđāļŦāđāļāļ§āđāļē āļāļēāļĢāļŦāļĄāļąāļāļĢāđāļ§āļĄāļĢāļ°āļŦāļ§āđāļēāļāđāļĻāļĐāļāļēāļŦāļēāļĢāđāļĨāļ°āļāļĨāļīāļāļ āļąāļāļāđāđāļĒāļ·āđāļāļāļĩāļ§āļ āļēāļāļāļĢāļĢāļāļļāļāļēāļŦāļēāļĢ (FW/CFPP 40:60) āļĄāļĩāļāļēāļĢāļāļĨāļīāļāļāđāļēāļāļĄāļĩāđāļāļāđāļāļāļąāļāļĢāļēāļāļĩāđāđāļĢāđāļ§āļāļ§āđāļēāļāļēāļĢāļŦāļĄāļąāļāđāļāļĒāđāļāđāđāļĻāļĐāļāļēāļŦāļēāļĢāļŦāļĢāļ·āļāļāļĨāļīāļāļ āļąāļāļāđāđāļĒāļ·āđāļāļāļĩāļ§āļ āļēāļāļāļĢāļĢāļāļļāļāļēāļŦāļēāļĢāđāļāļĩāļĒāļāļāļĒāđāļēāļāđāļāļĩāļĒāļ§Anaerobic co-digestion is proven to be a promising technology for enhancing the production of methane. In this study, the biochemical methane potential (BMP) from anaerobic co-digestion of food waste (FW) and cellulose-based food packaging product (CFPP) was carried out under mesophilic (35 Âą 2°C) condition in a batch mode for 45 days. Three mixing ratios of these two substrates (FW/CFPP 100:0, 40:60, and 0:100 based on volatile solids (VS)) were studied with a substrate-to-inoculum ratio of 0.5. Sodium bicarbonate (NaHCO3) was also added to establish a stable anaerobic digestion process. In addition, four mathematical models (Modified Gompertz model, First-order model, Monod model, and Cone model) were employed to evaluate their suitability for predicting the methane production of the examined substrates. Based on the obtained results, it is found that the maximum cumulative methane yield was observed in FW/CFPP 100:0, followed by 40:60 and 0:100 with the values of 459.15, 381.79, and 355.60 NmL/gVS, respectively. Among all the studied kinetic models, it can be seen that the Modified Gompertz model was the most accurate and appropriate in predicting the methane production of FW/CFPP 100:0 and 0:100. However, in the case of FW/CFPP 40:60, the First-order model was found to be a better fit than the Modified Gompertz model. Besides, their kinetic parameters reveal that the co-digestion of FW/CFPP 40:60 had a faster methane production rate than the mono-digestion of FW or CFPP.Keywords: āļĻāļąāļāļĒāļ āļēāļāļāļēāļĢāļāļĨāļīāļāļāđāļēāļāļĄāļĩāđāļāļ; āđāļĻāļĐāļāļēāļŦāļēāļĢ; āļāļĨāļīāļāļ āļąāļāļāđāđāļĒāļ·āđāļāļāļĩāļ§āļ āļēāļāļāļĢāļĢāļāļļāļāļēāļŦāļēāļĢ; āļāļēāļĢāļŦāļĄāļąāļāļĢāđāļ§āļĄ; āļāļĨāļāļāļĨāļĻāļēāļŠāļāļĢāđ; Biochemical methane potential; Food waste; Cellulose-based food packaging product; Co-digestion; Kinetic