Abstract:The increasing amount of municipal sludge in China requires safe and effective management to protect human health and ensure environmental sustainability. Pyrolysis is a thermochemical process that that decompose organic matter at elevated temperature and under anaerobic conditions, and it has attracted an increasing attention in sludge treatment in the recent years. However, comprehensive environmental and economic assessment of sludge pyrolysis in China's context is rare, due to the small quantities of fulls… Show more
“…Investors determine whether projects are viable through the initial cost analysis and finance projections. In this study, we assumed the lifetime of the sewage sludge recycling facility to be 30 years [2]. The unit initial cost decreased with an increase in implementation scale.…”
Section: The Unit Initial Costmentioning
confidence: 99%
“…Due to the acceleration of economic development and urbanization, the number of wastewater treatment plants has increased significantly, resulting in a rapid accumulation of sludge. The amount of sewage sludge generated with an 80% moisture content reached 39.04 Mt in 2019 in China [1,2]. This sludge requires immense space and causes greenhouse gas (GHG) emissions in landfills [1].…”
Section: Introductionmentioning
confidence: 99%
“…Other studies showed that energy consumption and operation cost are related to the implementation scale, and therefore the analyses were conducted on a large-scale sewage sludge recycling system (STRS) to avoid scale effects [9,15]. Luo et al [2] presented the results of environmental and economic analysis for full-scale sludge pyrolysis systems and proved that a larger pyrolysis system for centralized sludge handling was more economically favorable. Kumar et al [16] discussed the relationship between the payback period, return of investment, and plant capacity of biodiesel production generated by municipal sludge.…”
With China’s ongoing economic development and increasing emphasis on environmental protection, the number and treatment capacity of sewage plants is increasing annually. Simultaneously, sludge production is increasing. In recent years, researchers have investigated various approaches to the environmental and economic analysis of sludge treatment and recycling systems (STRS). These investigations did not take the universal law of different capacities for environmental impact and STRS economics into account. The aim of this study was to analyze the scale effect of STRS with different technologies (i.e., incineration, aerobic composting, used in material (brick), anaerobic digestion) on the environment and economy. Moreover, the cost–benefit impact of introducing a carbon- trading mechanism into the STRS to achieve carbon neutrality was analyzed. After reducing carbon emissions through by-products of STRS, the carbon emission quota can be sold, which will generate income. The results show that the break-even scales for incineration, anaerobic composting, used in building material (brick), and anaerobic digestion are 54,899, 6707, 48,775, and 4425 t/y, respectively. The break-even scale of each system decreased after the introduction of the carbon trading system into the STRS. These findings could provide critical technical information for superior decision-making in sewage sludge recycling systems.
“…Investors determine whether projects are viable through the initial cost analysis and finance projections. In this study, we assumed the lifetime of the sewage sludge recycling facility to be 30 years [2]. The unit initial cost decreased with an increase in implementation scale.…”
Section: The Unit Initial Costmentioning
confidence: 99%
“…Due to the acceleration of economic development and urbanization, the number of wastewater treatment plants has increased significantly, resulting in a rapid accumulation of sludge. The amount of sewage sludge generated with an 80% moisture content reached 39.04 Mt in 2019 in China [1,2]. This sludge requires immense space and causes greenhouse gas (GHG) emissions in landfills [1].…”
Section: Introductionmentioning
confidence: 99%
“…Other studies showed that energy consumption and operation cost are related to the implementation scale, and therefore the analyses were conducted on a large-scale sewage sludge recycling system (STRS) to avoid scale effects [9,15]. Luo et al [2] presented the results of environmental and economic analysis for full-scale sludge pyrolysis systems and proved that a larger pyrolysis system for centralized sludge handling was more economically favorable. Kumar et al [16] discussed the relationship between the payback period, return of investment, and plant capacity of biodiesel production generated by municipal sludge.…”
With China’s ongoing economic development and increasing emphasis on environmental protection, the number and treatment capacity of sewage plants is increasing annually. Simultaneously, sludge production is increasing. In recent years, researchers have investigated various approaches to the environmental and economic analysis of sludge treatment and recycling systems (STRS). These investigations did not take the universal law of different capacities for environmental impact and STRS economics into account. The aim of this study was to analyze the scale effect of STRS with different technologies (i.e., incineration, aerobic composting, used in material (brick), anaerobic digestion) on the environment and economy. Moreover, the cost–benefit impact of introducing a carbon- trading mechanism into the STRS to achieve carbon neutrality was analyzed. After reducing carbon emissions through by-products of STRS, the carbon emission quota can be sold, which will generate income. The results show that the break-even scales for incineration, anaerobic composting, used in building material (brick), and anaerobic digestion are 54,899, 6707, 48,775, and 4425 t/y, respectively. The break-even scale of each system decreased after the introduction of the carbon trading system into the STRS. These findings could provide critical technical information for superior decision-making in sewage sludge recycling systems.
“…The annual increase in the volume of municipal wastewater treatment presents a major environmental problem: the treatment and disposal of municipal sludge. The term “municipal sludge” refers to a glutinous, aqueous substance produced during the aerobic or anaerobic biological treatment of municipal wastewater (Luo et al, 2021 ; Stefanakis et al, 2014 ). Fig.…”
Section: Introductionmentioning
confidence: 99%
“…Municipal sludge typically has a water content of more than 80%, which leads to complications in its safe handling and disposal (Kacprzak et al, 2017 ). The disposal of such large quantities of sludge in a safe manner has become an environmental concern (Li et al, 2011 ; Luo et al, 2021 ).…”
Due to the annual increase in wastewater treatment in most Chinese cities, a major environmental issue has arisen: safe treatment, disposal, and recycling of municipal sludge. Municipal sludge has a high content of carbon and essential nutrients for plant growth; hence, it has gained interest among researchers as a soil fertilizer. This study discusses the potential usage of municipal sludge as soil fertilizer (indicators include nitrogen (N), phosphorus (P), and trace elements) along with its shortcomings and drawbacks (potentially toxic elements (PTEs), organic matter (OM), pathogens, etc.) as well as reviews the latest reports on the role of municipal sludge in land use. The use of municipal sludge as a soil fertilizer is a sustainable management practice and a single application of sludge does not harm the environment. However, repeated use of sludge may result in the accumulation of harmful chemicals and pathogens that can enter the food chain and endanger human health. Therefore, long-term field studies are needed to develop ways to eliminate these adverse effects and make municipal sludge available for agricultural use.
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