Keywords Fruit and vegetable waste · Excess activated sludge · Vermicomposting ·
Earthworms · Microbial activity
9.1 Introduction
With the rapid economic development, the lack of resources and energy and
environmental issues have become more serious. The concept of recovery, recycling,
and reuse from waste resources has been widely accepted for the sustainable
treatment of wastes in large quantities and attracted the attention of many
researchers. The fruit and vegetable waste (FVW), as one of the major components
of wastes, is generated in large quantities during production, processing, and consumption. The FVW is characterized by high water content and rich biodegradable
organic substances, normally with water content of about 90 and 85% corresponding
to organic matters (Edwiges et al. 2018). These characteristics indicate that the FVW
may contribute to negative environmental issues without proper treatment (e.g.,
leachate and greenhouse gas) and provide a great potential for reuse, recycling,
and recovery (Hartmann and Ahring 2006; Plazzotta et al. 2017). Therefore, it is
important to find a sustainable method for the treatment and recycling of FVW.
Several conventional methods are used for treatment and recycling of FVW, such
as incineration, landfill, anaerobic digestion, and composting. Compared to these
conventional methods, vermicomposting has the advantage of effective stabilization
of the organic wastes through the joint function of earthworms and microorganisms
in decomposition of easily decaying organic constituents and of high utilization
value for its final product as fertilizer. On the other hand, excess activated sludge
(EAS), as the main by-product of sewage treatment process, is an organic waste
mainly consisted of microorganisms which can be treated by vermicomposting. Li
et al. (2020) proposed that the wide variety of microorganisms presented in EAS can
enhance the microbial activity and positively contribute to the decomposition of
FVW since the complex microbial communities play a key role during the
vermicomposting (Chen et al. 2018a, b). In addition, the rich content of nitrogen
and phosphorus in EAS can promote the growth of earthworms and specific bacterial
species, thus improving the stabilization efficiency of FVW and will also improve
the utilization value of the final product.
Accordingly, the main objectives of this chapter are to summarize several conventional treatment methods for FVW and to propose a more feasible and sustainable method for treating FVW with the addition of EAS by vermicomposting.
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W. Li et al.
Earthworms · Microbial activity
9.1 Introduction
With the rapid economic development, the lack of resources and energy and
environmental issues have become more serious. The concept of recovery, recycling,
and reuse from waste resources has been widely accepted for the sustainable
treatment of wastes in large quantities and attracted the attention of many
researchers. The fruit and vegetable waste (FVW), as one of the major components
of wastes, is generated in large quantities during production, processing, and consumption. The FVW is characterized by high water content and rich biodegradable
organic substances, normally with water content of about 90 and 85% corresponding
to organic matters (Edwiges et al. 2018). These characteristics indicate that the FVW
may contribute to negative environmental issues without proper treatment (e.g.,
leachate and greenhouse gas) and provide a great potential for reuse, recycling,
and recovery (Hartmann and Ahring 2006; Plazzotta et al. 2017). Therefore, it is
important to find a sustainable method for the treatment and recycling of FVW.
Several conventional methods are used for treatment and recycling of FVW, such
as incineration, landfill, anaerobic digestion, and composting. Compared to these
conventional methods, vermicomposting has the advantage of effective stabilization
of the organic wastes through the joint function of earthworms and microorganisms
in decomposition of easily decaying organic constituents and of high utilization
value for its final product as fertilizer. On the other hand, excess activated sludge
(EAS), as the main by-product of sewage treatment process, is an organic waste
mainly consisted of microorganisms which can be treated by vermicomposting. Li
et al. (2020) proposed that the wide variety of microorganisms presented in EAS can
enhance the microbial activity and positively contribute to the decomposition of
FVW since the complex microbial communities play a key role during the
vermicomposting (Chen et al. 2018a, b). In addition, the rich content of nitrogen
and phosphorus in EAS can promote the growth of earthworms and specific bacterial
species, thus improving the stabilization efficiency of FVW and will also improve
the utilization value of the final product.
Accordingly, the main objectives of this chapter are to summarize several conventional treatment methods for FVW and to propose a more feasible and sustainable method for treating FVW with the addition of EAS by vermicomposting.
142
W. Li et al.