Biocomplex textile as an alternative daily cover for the simultaneous mitigation of methane and malodorous compounds
Introduction
Landfill gases (LFGs) generated during the anaerobic decomposition process of organic matter consist of 45–60% methane (CH4), 40–55% carbon dioxide (CO2), and trace malodorous compounds (United States Environmental Protection Agency (USEPA), 2011, United States Environmental Protection Agency (USEPA), 2015). CH4 is a representative greenhouse gas (GHG) that accelerates climate change because its global warming potential (GWP) is 25 times higher than that of CO2 over 100 years (IPCC, 2014). Huber-Humer et al. (2008) has reported that a significant amount of CH4 (35–69 Tg-CH4 y−1) is released to the atmosphere from operational landfill sites. Since the flammability limit of CH4 in the air is 5–15%, CH4 can cause landfill fires (Bagchi and Bhattacharya, 2015). Malodorous compounds (e.g. H2S, methanethiol (MT), dimethyl sulfide (DMS), dimethyl disulfide) are also released from landfills and can cause not only unpleasantness, but also physical disabilities such as gastroenteric trouble, headache and cardiatic disease (Fang et al., 2012, Shon et al., 2005). CH4 and non-methane volatile organic compounds among LFGs contribute to the global warming (Collins et al., 2002).
Biological treatment systems for the reduction of LFGs emissions, such as biowashers, biomembranes, biofilters, biowindows, and biocovers, have been studied by many researchers (Abushammala et al., 2014, Huber-Humer et al., 2008, Kim et al., 2013, Lee et al., 2014, Moon et al., 2014). Among these systems, the representative system is a biocover composed of a waste layer, a gas distribution layer, and a microbial layer (Abushammala et al., 2014). Gas distribution layers consisting of core sand or gravel are an essential part of biocovers because they can transmit LFGs from the lower waste layers to the upper microbial layers (Abushammala et al., 2014). Organic matter, such as soil, compost, and sludge, is commonly used as a packing material for microbial layers. These materials have abundant nitrogen (N) and phosphorus (P), which are vital nutrients for microbial growth; hence, microorganisms inhabiting the microbial layers can efficiently degrade LFGs (Ganendra et al., 2015).
However, biocovers cannot installed in operational landfills, and they can be applied only in inactive cells or layers of landfill where landfilling of waste has finished. To eliminate LFGs emitted from engaged landfills, the working area is covered with a 15-cm-thick soil layer, which is called the daily cover (DC), in many countries. These days, a variety of alternative daily cover (ADC) materials are used in place of soil: municipal waste compost, composting yard waste, construction & demolition fines, commercial & industrial fines, woodchips, and modified sewage sludge (sludge: lime: cement: silt: tire-derived aggregate = 100:15:5:70:15, w/w) (He et al., 2015, Hurst et al., 2005, Solan et al., 2010, Van Haaren et al., 2010). The LFG removal efficiency (RE) of ADCs reaches only 30–40%, and the volume of ADCs required results in a narrow space for waste filling (Huber-Humer et al., 2008). ADCs that have high organic matter content are easily degraded by microorganisms during prolonged use and cause channeling (Nikiema and Heitz, 2010).
To overcome the limitations of conventional ADCs, it is necessary to develop a new ADC that has satisfactory LFGs removability, resistance to biological deterioration, and long-term stable performance. In this study, space-saving biocomplex textiles, which can be used as covers or rolled up as needed, were designed as ADCs. The biocomplex textiles were made by inserting biocarriers between nonwoven fabrics. Perlite, tobermolite, and a mixture of perlite and tobermolite were used as the biocarriers for immobilizing microorganisms. CH4 and DMS were used as model compounds for GHGs and malodorous compounds emitted from landfills, respectively. The degradation rates and simultaneous removal of CH4 and DMS by biocomplex textiles in a lab-scale were investigated according to type of biocarrier and storage period. In addition, the effects of starvation on the performance of the reactor were evaluated. Methanotrophic dynamics were quantitatively monitored using a quantitative real-time polymerase chain reaction (qRT-PCR) method to clarify the effect of starvation and operation period on methanotrophic activity.
Section snippets
Cultivation of a CH4/DMS co-degrading microbial consortium
Earthworm casts obtained from the Nanji water recycling center (Goyang, Kyunggi, South Korea) were used as an inoculation source for the CH4/DMS co-degrading microbial consortium. Properties of earthworm casts were measured according to the Korean standard methods for soil (2013). Water content, organic matter content, and the pH of earthworm casts were 64.3 ± 0.4%, 71.2 ± 0.1%, and 7.7 ± 0.0, respectively. Earthworm casts were passed through a 2-mm sieve and placed in an air permeable sack
Effect of nonwoven fabric on the activity of the CH4/DMS co-degrading consortium
Fig. 3 shows the effect of nonwoven fabric on the CH4/DMS degradation activity of the consortium. Without the nonwoven fabric, the CH4/DMS co-degrading consortium could degrade 50,000 μL·L−1 of CH4 over 10 days (Fig. 3A). With the nonwoven fabric, the consortium could degrade 50,000 μL·L−1 of CH4 over 14 days after a 4-day lag phase. When CH4 degradation rates were compared under conditions without and with nonwoven fabric, CH4 degradation rates were 160.6 μmol·g−1-cell·d−1 and 119.5 μmol·g−1
Conclusions
Novel biocomplex textile can be used for removal of GHGs and odors in operational landfills. For best performance of the biocomplex textile, the perlite and tobermolite mixture should be used as biocarrier for the CH4/DMS co-degrading microbial consortium. The biocomplex textile is storable and can be used under transient conditions in the field. Compared with conventional ADCs, the biocomplex textile had high CH4 and DMS removability, resistance to biological deterioration, and long-term
Acknowledgements
This research was supported by the Korea Ministry of Environment as a “Converging Technology Project (201500164003)”.
References (50)
- et al.
Bio-tarp alternative daily cover prototypes for methane oxidation atop open landfill cells
Waste Manage.
(2011) - et al.
Methane emission from a landfill and the methane oxidising capacity of its covering soil
Soil Biol. Biochem.
(1996) - et al.
Odor compounds from different sources of landfill: characterization and source identification
Waste Manage.
(2012) - et al.
Biofiltration of methane from ruminants gas effluent using autoclaved aerated concrete as the carrier material
Chem. Eng. J.
(2015) - et al.
Modified sewage sludge as temporary landfill cover material
Water Sci. Eng.
(2015) - et al.
Removal kinetics of hydrogen sulfide, methanethiol and dimethyl sulfide by peat biofilters
J. Ferment. Bioeng.
(1990) - et al.
Assessment of municipal waste compost as a daily cover material for odour control at landfill sites
Environ. Pollut.
(2005) - et al.
Characterization of tobermolite as a bed material for selective growth of methanotrophs in biofiltration
J. Biotechnol.
(2014) - et al.
Assessing effects of earthworm cast on methanotrophic community in a soil biocover by concurrent use of microarray and quantitative real-time PCR
Appl. Soil Ecol.
(2011) - et al.
Long-term performance and bacterial community dynamics in biocovers for mitigating methane and malodorous gases
J. Biotechnol.
(2017)
Depth profiles of methane oxidation potentials and methanotrophic community in a lab-scale biocover
J. Biotechnol.
Removal of benzene and toluene in polyurethane biofilter immobilized with Rhodococcus sp. EH831 under transient loading
Bioresour. Technol.
Isolation and characterization of a facultative methanotroph degrading malodor-causing volatile sulfur compounds
J. Hazard. Mater.
Use of bacteria-immobilized cotton fibers to absorb and degrade crude oil
Int. Biodeterior. Biodegrad.
Earthworm cast as a promising filter bed material and its methanotrophic contribution to methane removal
J. Hazard. Mater.
Photochemistry of reduced sulfur compounds in a landfill environment
Atmos. Environ.
Evaluation of the odour reduction potential of alternative cover materials at a commercial landfill
Bioresour. Technol.
Biofilter based on a biofilm immobilized on geo-textile sheets for rapid atrazine biodegradation
Int. Biodeterior. Biodegrad.
LCA comparison of windrow composting of yard wastes with use as alternative daily cover (ADC)
Waste Manage.
Methanotrophic communities in a landfill cover soil as revealed by [13 C] PLFAs and respiratory quinones: Impact of high methane addition and landfill leachate irrigation
Soil Biol. Biochem.
Methane oxidation in landfill cover soils: a review
Asian J. Atmos. Environ.
Post-closure care of engineered municipal solid waste landfills
Waste Manage. Res.
Methanotrophic production of extracellular polysaccharide in landfill cover soils
Water Sci. Technol.
The oxidation of organic compounds in the troposphere and their global warming potentials
Clim. Change
Influence of the water content and water activity on styrene degradation by Exophiala jeanselmei in biofilters
Appl. Microbiol. Bbiotechnol.
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2018, Bioresource TechnologyCitation Excerpt :Some biologically-inactive materials that have been studied as potential packing materials include paper pellets (Haubrichs and Widmann, 2006), glass cullet (Pawłowska, 2010), stone (Avalos Ramirez et al., 2012a; Ferdowsi et al., 2016), clay and polypropylene spheres (Avalos Ramirez et al., 2012b), ceramsite (Pawłowska, 2010), gravel (Girard et al., 2011; Karthikeyan et al., 2017), activated carbon (Karthikeyan et al., 2017; Wu et al., 2017), biochar and lava rock (La et al., 2018b), plastic bio-balls (Karthikeyan et al., 2017), perlite (Kim et al., 2014a), tobermolite (Kim et al., 2014b), Biobob® sponge, blast furnace slag, and expanded vermiculite (Brandt et al., 2016), polyethylene rings (Cáceres et al., 2017), graphite granules (Xie et al., 2016), and Kaldnes rings (López et al., 2018). More recently, Choi et al. (2018) experimented with polypropylene nonwoven fabric that was fashioned as pockets containing inert medium of perlite, tobermolite, or mixtures of the two, for the purpose of applying it to landfill biocovers that could then be easily removed and stored. Wood-based materials such as wood fibers (Streese and Stegmann, 2003), woodchips (Haubrichs and Widmann, 2006), and sawdust (Perdikea et al., 2008) have previously been used as bulking agents especially in combination with soil or compost in order to prevent excessive compaction of the latter.
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