Mesophilic co-digestion of municipal solid waste and sewage sludge: Effect of mixing ratio, total solids, and alkaline pretreatment

In the case of sewage sludge, as direct landfilling was recently prohibited, it is treated through incineration. Among the air pollutants discharged through the incineration of sewage sludge, NOx and SOx are considered secondary substances of PM2.5 and are being managed accordingly. However, NH3, another of the secondary substances of PM2.5, is not well managed, and the amount of NH3 discharged from sewage sludge incineration facilities has not been calculated. Therefore, in this study, we sought to determine whether NH3 is discharged in the exhaust gas of a sewage sludge incineration facility, and, when discharged, the NH3 emission factor was calculated, and the necessity of the development of the emission factor was reviewed. As a result of the study, it was confirmed that the amount of NH3 discharged from the sewage sludge incineration facility was 0.04 to 4.47 ppm, and the emission factor was calculated as 0.002 kg NH3/ton. The NH3 emission factor was compared with the NH3 emission factor of municipal solid waste proposed by EMEP/EEA (European Monitoring and Evaluation Programme/European Environment Agency) because the NH3 emission factor of the sewage sludge incineration facility had not been previously determined. As a result of the comparison, the NH3 emission factor of EMEP/EEA was similar to that of municipal solid waste, confirming the necessity of developing the NH3 emission factor of the sewage sludge incineration facility. In addition, the evaluation of the uncertainty of the additionally calculated NH3 emission factor was conducted quantitatively and the uncertainty range was presented for reference. In the future, it is necessary to improve the reliability of the NH3 emission factor of sewage sludge incineration facilities by performing additional analysis with statistical representation. In addition, the development of NH3 emission factors for industrial waste incineration facilities should be undertaken.

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Thermal cotreatment of municipal solid waste incineration fly ash with sewage sludge: Phases transformation, kinetics and fusion characteristics, and heavy metals solidification

Journal of Cleaner Production ◽

10.1016/j.jclepro.2021.128429 ◽

2021 ◽

pp. 128429

Author(s):

Xiaoqing Lin ◽

Tieying Mao ◽

Zhiliang Chen ◽

Jie Chen ◽

Sheng Zhang ◽

...

Keyword(s):

Heavy Metals ◽

Fly Ash ◽

Sewage Sludge ◽

Municipal Solid Waste ◽

Solid Waste ◽

Waste Incineration ◽

Municipal Solid Waste Incineration ◽

Transformation Kinetics ◽

Waste Incineration Fly Ash

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Performance of co-composting sewage sludge and organic fraction of municipal solid waste at different proportions

Bioresource Technology ◽

10.1016/j.biortech.2017.08.136 ◽

2018 ◽

Vol 250 ◽

pp. 853-859 ◽

Cited By ~ 39

Author(s):

Difang Zhang ◽

Wenhai Luo ◽

Yun Li ◽

Guoying Wang ◽

Guoxue Li

Keyword(s):

Sewage Sludge ◽

Municipal Solid Waste ◽

Solid Waste ◽

Organic Fraction

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Enhancement in hydrogen production by thermophilic anaerobic co-digestion of organic fraction of municipal solid waste and sewage sludge – Optimization of treatment conditions

Bioresource Technology ◽

10.1016/j.biortech.2014.05.013 ◽

2014 ◽

Vol 164 ◽

pp. 408-415 ◽

Cited By ~ 36

Author(s):

Vinay Kumar Tyagi ◽

Rubén Angériz Campoy ◽

C.J. Álvarez-Gallego ◽

L.I. Romero García

Keyword(s):

Sewage Sludge ◽

Hydrogen Production ◽

Municipal Solid Waste ◽

Solid Waste ◽

Organic Fraction ◽

Treatment Conditions

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

Waste Management & Research ◽

10.1177/0734242x19833161 ◽

2019 ◽

Vol 37 (5) ◽

pp. 542-550 ◽

Cited By ~ 3

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.

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Stabilization of Municipal Solid Waste Fly Ash, Obtained by Co-Combustion with Sewage Sludge, Mixed with Bottom Ash Derived by the Same Plant

Applied Sciences ◽

10.3390/app10176075 ◽

2020 ◽

Vol 10 (17) ◽

pp. 6075

Author(s):

Ahmad Assi ◽

Fabjola Bilo ◽

Alessandra Zanoletti ◽

Laura Borgese ◽

Laura Eleonora Depero ◽

...

Keyword(s):

Heavy Metals ◽

Fly Ash ◽

Sewage Sludge ◽

Municipal Solid Waste ◽

Solid Waste ◽

Coal Fly Ash ◽

Bottom Ash ◽

Solid Material ◽

Flue Gas Desulfurization ◽

Stabilization Method

This study presents an innovative stabilization method of fly ash derived from co-combustion of municipal solid waste and sewage sludge. Bottom ash, obtained from the same process, is used as a stabilizing agent. The stabilization method involved the use of two other components—flue gas desulfurization residues and coal fly ash. Leaching tests were performed on stabilized samples, aged in a laboratory at different times. The results reveal the reduction of the concentrations of heavy metals, particularly Zn and Pb about two orders of magnitude lower with respect to fly ash. The immobilization of heavy metals on the solid material mainly depends on three factors—the amount of used ash, the concentrations of Zn and Pb in as-received fly ash and the pH of the solution of the final materials. The inert powder, obtained after the stabilization, is a new eco-material, that is promising to be used as filler in new sustainable composite materials.

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