Estimating evolution of δ13CH4 during methanization of municipal solid waste based on chemical reactions, isotope accumulation in products and microbial ecology

2012 ◽  
Vol 65 (2) ◽  
pp. 270-276 ◽  
Author(s):  
V. A. Vavilin
Keyword(s):  
Municipal Solid Waste ◽  
Microbial Ecology ◽  
Solid Waste ◽  
Chemical Reactions ◽  
Final Stage ◽  
Sharp Decrease ◽  
Hydrogenotrophic Methanogenesis ◽  
13C Isotope ◽  
Aceticlastic Methanogenesis ◽  
Thermophilic Conditions

Natural isotopic composition in substrate may be used to reveal the metabolic pathways of substrate transformation by microbial community. In this paper, a change in δ13CH4 during methanization of reconstituted municipal solid waste was described using a mathematical model based on stoichiometric chemical reactions, equation for the 13C isotope accumulation in products at the low natural C13/C12 ratio and microbial ecology. A set of experimental data used in the model was taken from Qu et al. (2009a). According to the model, during mesophilic municipal solid waste methanization initially hydrogenotrophic and further aceticlastic methanogenesis dominated. At the final stage hydrogenotrophic methanogenesis followed by acetate oxidation dominated again. In spite of rather high measured values of δ13C for CO2 above −21‰, a sharp decrease in δ13CH4 from −20‰ to −60‰ at the final stage was explained by a larger fractionation against 13C during methanogenesis from H2/H2CO3 due to a kinetic isotope effect when hydrogenotrophic methanogens preferentially take down light 12C. The model also confirmed that in thermophilic conditions a comparatively stable value of δ13CH4 about −60‰ measured earlier (Qu et al. 2009b) was due to a dominance of hydrogenotrophic methanogenesis during all methanization process of cardboard waste.

Stabilisation of municipal solid waste after autoclaving in a passively aerated bioreactor

2019 ◽  
Vol 37 (5) ◽  
pp. 542-550 ◽  
Author(s):  
Irena Wojnowska-Baryła ◽  
Dorota Kulikowska ◽  
Katarzyna Bernat ◽  
Sławomir Kasiński ◽  
Magdalena Zaborowska ◽  
...  
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Order Kinetic ◽  
Respiration Activity ◽  
Total Solids ◽  
Gas Formation ◽  
Volatile Solids ◽  
Thermophilic Conditions ◽  
Solids Content ◽  
Solids Removal

Autoclaving of unsorted municipal solid waste is one of the solutions in waste management that maximises the amount of waste for recycling. After autoclaving, however, a large part of the waste is composed of unstabilised biodegradable fractions (organic remaining fraction, ORF), which may comprise up to 30% of autoclaved waste and cannot be landfilled without further stabilisation. Thus, the aim of this study was to investigate the effectiveness of aerobic stabilisation in a passively aerated reactor of organic remaining fraction after full-scale autoclaving of unsorted municipal solid waste. The organic remaining fraction had a volatile solids content of ca. 70%, a 4-day respiration activity test (AT4) of ca. 26 g O2 kg–1 total solids and a 21-day gas formation test (GP21) of ca. 235 dm3 kg–1 total solids. Stabilisation was conducted in a 550 L reactor with passive aeration (Stage I) and a periodically turned windrow (Stage II). The feedstocks consisted entirely of organic remaining fraction, or of organic remaining fraction with 10% inoculum (ORF + I). Inoculum constituted product of stabilisation of organic remaining fraction. During stabilisation of organic remaining fraction and ORF + I, thermophilic conditions were achieved, and the decreases of volatile solids, AT4 and GP21 could be described by 1 order kinetic models. The rate constants of volatile solids removal (kVS) were 0.033 and 0.068 d–1 for organic remaining fraction and ORF + I, respectively, and the thermophilic phase was shorter with ORF + I (25 days vs. 45 days). The decrease in GP21 corresponded to volatile solids decrease, but AT4 decreased sharply during the first 10 days of waste stabilisation in the reactor, indicating that the content of highly biodegradable organic matter decreased during this time.

EDS (Energy Sipersive Spectrometer) Analysis of Sintered Construction Material

2013 ◽  
Vol 849 ◽  
pp. 257-260
Author(s):  
Hai Ying Zhang ◽  
Shu Zhen Li
Keyword(s):  
Fly Ash ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Considerable Increase ◽  
Construction Material ◽  
Sharp Decrease ◽  
Waste Incineration ◽  
Mswi Fly Ash ◽  
Eds Analysis ◽  
Mg Content

This study aims to analyze elementary variation of fly ash from one Shanghai municipal solid waste incineration (MSWI) plant using EDS (Energy Sipersive Spectrometer) as a function of sintering temperature. MSWI fly ash was firstly sintered at 700°C, 800°C, 900°C, 1,000°C and 1,100°C respectively for 30 minutes, and then underwent EDS analysis. It was found that element content follows the decreasing sequence of Cl > Ca > O > K > Na > S > Fe > Cu > Si > Al > Zn >Mg. Content of Ca and O rose with increase of temperature, while Cl has a relatively reverse trend. Fly ash sintered at temperatures over 1000°C sees a sharp decrease of Cl, K, Na and S, and a considerable increase of Ca and O. Therefore, sintering temperatures over 1000°C is recommended for treatment of municipal solid waste fly ash.

Microbial ecology of the leach bed anaerobic digestion of unsorted municipal solid waste

2000 ◽  
Vol 41 (3) ◽  
pp. 9-16 ◽  
Author(s):  
P. Silvey ◽  
P.C. Pullammanappallil ◽  
L. Blackall ◽  
P. Nichols
Keyword(s):  
Anaerobic Digestion ◽  
Municipal Solid Waste ◽  
Microbial Ecology ◽  
Solid Waste ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Phospholipid Fatty Acid ◽  
Ether Lipid ◽  
Bacterial Biomass ◽  
Start Up ◽  
Gradient Gel Electrophoresis

The microbial ecology of the sequential, leach-bed, mesophilic anaerobic digestion of unsorted, coarse municipal solid waste (MSW) was examined over 80 days. The methane yield was approximately 75% of the ultimate biochemical methane potential (BMP) of the waste loaded into the digesters. The operational strategy involved a sequence of two digesters containing fresh and anaerobically stabilised MSW respectively. Cell wall phospholipid fatty acid (PLFA) and ether lipid (PLEL) analysis was used to monitor changes in microbial biomass. Both Bacterial and Archaeal biomass were heavily influenced by pH during the two-week start up period. Archaeal biomass peaked just before the methane production rate reached a maximum whereas Bacterial biomass peaked at a later stage. Changes in the phylogenetic diversity of the population were monitored by denaturing gradient gel electrophoresis (DGGE). An analysis of the changes in DGGE banding patterns suggested that rapid start-up of a new reactor was effected byinoculation as well as the provision of buffering capacity from the mature reactor leachate.

Two-phase anaerobic digestion of source sorted OFMSW (organic fraction of municipal solid waste): performance and kinetic study

2000 ◽  
Vol 41 (3) ◽  
pp. 111-118 ◽  
Author(s):  
P. Pavan ◽  
P. Battistoni ◽  
F. Cecchi ◽  
J. Mata-Alvarez
Keyword(s):  
Municipal Solid Waste ◽  
Kinetic Study ◽  
Solid Waste ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Phase System ◽  
Total System ◽  
Organic Fraction ◽  
Two Phase ◽  
Thermophilic Conditions

The results of a two-phase system operated in different conditions, treating the source-sorted organic fraction of municipal solid waste (SS-OFMSW), coming mainly from fruit and vegetable markets, are presented. Hydraulic retention time (HRT) in the hydrolytic reactor and in the methanogenic reactor and also the temperature in the hydrolytic reactor (mesophilic and thermophilic conditions) are varied in order to evaluate the effect of these factors. The methanogenic reactor is always operated within the thermophilic range. Optimum operating conditions are found to be around 12 days (total system) using the mesophilic range of temperature in the first reactor. Specific gas production (SGP) in these conditions is around 0.6 m3/kgTVS. A kinetic study is also carried out, using the first and the step diffusional models. The latter gives much better results, with fitted constants comparable to other studies. Finally, a comparison with a one-phase system is carried out, showing that a two-phase system is much more appropriate for the digestion of this kind of highly biodegradable substrate in thermophilic conditions.

Co-digestion of bovine slaughterhouse wastes, cow manure, various crops and municipal solid waste at thermophilic conditions: a comparison with specific case running at mesophilic conditions

2013 ◽  
Vol 67 (5) ◽  
pp. 989-995 ◽  
Author(s):  
J. Pagés-Díaz ◽  
I. Sárvári-Horváth ◽  
J. Pérez-Olmo ◽  
I. Pereda-Reyes
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Crop Residues ◽  
Effect Of Temperature ◽  
Cow Manure ◽  
Digestion Process ◽  
Thermophilic Conditions ◽  
Study Case ◽  
Mesophilic Conditions ◽  
Mesophilic Condition

A co-digestion process was evaluated when mixing different ratios of agro-industrial residues, i.e. bovine slaughterhouse waste (SB); cow manure (M); various crop residues (VC); and municipal solid waste (MSW) by anaerobic batch digestion under thermophilic conditions (55 °C). A selected study case at mesophilic condition (37 °C) was also investigated. The performance of the co-digestion was evaluated by kinetics (k0). The best kinetic results were obtained under thermophilic operation when a mixture of 22% w/w SB, 22% w/w M, 45% w/w VC and 11% w/w MSW was co-digested, which showed a proper combination of high values in rsCH4 and k0 (0.066 Nm3CH4/kgVS*d, 0.336 d−1) during the anaerobic process. The effect of temperature on methane yield (YCH4), specific methane rate (rsCH4) and k0 was also analyzed for a specific study case; there a mixture of 25% w/w of SB, 37.5% w/w of M, 37.5% of VC and 0% of MSW was used. Response variables were severely affected by mesophilic conditions, diminishing to at least 45% of the thermophilic values obtained for a similar mixture. The effect of temperature suggested that thermophilic conditions are suitable to treat these residues.

Management of Macroalgae from Venice Lagoon through Anaerobic Co-Digestion and Co-Composting with Municipal Solid Waste (MSW)

1993 ◽  
Vol 27 (2) ◽  
pp. 159-168 ◽  
Author(s):  
F. Cecchi ◽  
G. Vallini ◽  
P. Pavan ◽  
A. Bassetti ◽  
J. Mata-Alvarez
Keyword(s):  
Anaerobic Digestion ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Venice Lagoon ◽  
Bulking Agent ◽  
Organic Fraction ◽  
Lagoon Of Venice ◽  
Digested Sludge ◽  
Thermophilic Conditions

The paper gives information on the behaviour of a digester operating under semi-dry thermophilic conditions when algae are co-digested together with the organic fraction of municipal solid waste (OFMSW) at different ratios. These results are compared with those obtained digesting OFMSW alone at similar operative conditions. 25-30 % is the contribution that this approach can give to the disposal of harvested algae from the lagoon of Venice. Since after anaerobic digestion a bio-oxidative step is needed for agricultural utilization of digested sludge, this process has been studied and the performance of this step reported using the OFMSW as bulking agent.

scholarly journals Bio-Delignification of Green Waste (GW) in Co-Digestion with the Organic Fraction of Municipal Solid Waste (OFMSW) to Enhance Biogas Production

2021 ◽  
Vol 11 (13) ◽  
pp. 6061
Author(s):  
Bruno Semeraro ◽  
Daniela Summa ◽  
Stefania Costa ◽  
Federico Zappaterra ◽  
Elena Tamburini
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Biogas Production ◽  
White Rot Fungi ◽  
White Rot ◽  
Organic Fraction ◽  
Green Waste ◽  
Biogas Yield ◽  
Thermophilic Conditions ◽  
Chemical Pretreatments

The organic fraction of municipal solid waste (OFMSW) is recognized as a suitable substrate for the anaerobic digestion (AD) process and is currently considered a mature technology. A promising strategy to enhance biogas yield and productivity is the co-digestion of OFMSW with other organic biomass, such as green waste (GW), a mixture of leaves, grass, and woody materials originated from private yards and public greenspace management. The main limitation to the use of GW for biogas production is the high percentage of the lignocellulosic fraction, which makes necessary a pretreatment of delignification to dissolve the recalcitrant structure. In this study, a new strategy of sustainable bio-delignification using the white-rot fungi Bjerkandera adusta (BA) in comparison with other chemical pretreatments were investigated. Untreated and treated GW were, respectively, submitted to anaerobic co-digestion with OFMSW. AD processes were carried out in a lab-scale plant for 30 days in thermophilic conditions (55 °C). Biogas cumulative production was increased by about 100% in the case of treated GW compared with that of just OFMSW, from 145 to 289 Nm3 CH4/ton SV, and productivity almost doubled from 145 to 283 Nm3/ton FM * day. The measured average methane content values in the cumulative biogas were 55% from OFMSW and 54% from GW. Moreover, over 95% of the biogas was produced in 20 days, showing the potential opportunity to reduce the AD time.

scholarly journals Formation of soot in the disposal of municipal solid waste

2021 ◽  
Vol 274 ◽  
pp. 08001
Author(s):  
Olga Barysheva ◽  
Alina Mokhova
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Chemical Reactions ◽  
Power Plants ◽  
Combustion Process ◽  
Combustion Products ◽  
High Energy ◽  
Household Waste ◽  
Solid Domestic Waste ◽  
Composition Of Combustion Products

In power plants intended for the disposal of solid household waste, the processes take place at a high temperature. For such installations, nonequilibrium processes are characteristic of a change in the composition of combustion products caused by the final rates of the ongoing chemical reactions. This affects the basic characteristics of the combustion process of municipal solid waste. A mathematical model has been created for calculating the chemically nonequilibrium composition of the fuel. Solid household and industrial waste is a high-energy fuel. It is a high energy fuel. The process of thermal neutralization of solid household waste is considered. An alternative calculation method is presented that allows one to find the composition of combustion products under conditions of nonequilibrium in the process of thermal utilization of solid domestic waste. The data on the composition and properties of solid household waste obtained by the developed method of calculation allow predicting the yield of super Eco toxicants in combustion products. On the basis of the equations of formal chemical kinetics, an alternative was created, which consists in determining the composition of combustion products taking into account the kinetics of chemical reactions. The assumption is introduced that transformations in the gas phase are elementary, one-stage. Various chemical interactions can be represented by a set of elementary stages. The most probable are mono-, biand three molecular chemical reactions. The method allows predicting the yield of Eco toxicants by finding the composition of the fuel combustion products prior to its utilization.

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