2.2.3 Domestic (Household) Wastes
The increased urbanization, population, and fast economic
growth resulted in increased food consumption, which leads
to an increase in kitchen waste production (Zhao et al. 2017).
Domestic wastes are typically generated from households,
dining centers, public cafes, institute and factory canteens,
etc. (Zhao et al. 2017; Liu et al. 2019). Usually, kitchen
waste consists of vegetables, fruits, eggshells, meat, cooked
food wastes, oil, and grease. Mainly, it contains polysaccharides (such as cellulose, hemicellulose, starch, etc.), lignin, protein, fats, inorganic salts, and a few organic acids
(Chen et al. 2017). At present, China generates over 30
million tonnes of domestic remaining per annum. The
European Union (EU) has been producing approximately 2.5
billion tonnes of food waste every year (Li et al. 2017). The
conventional approaches to decompose kitchen waste
including incineration, land-filling, composting, and discharge into the wastewater create harmful ecological health
problems (Chen et al. 2019). Domestic wastes mostly contain biodegradable material which consists of high moistness
and leads to the development of pathogenic microorganisms
due to easy decomposition and breeding. This waste can be
converted into valuable end-products including nutraceuticals, dietary fiber, antioxidants, fructose based syrup,
single-cell protein, xanthan gum, etc. and are concurrently
diminishing environmental pollution (Liu et al. 2019).
2.2.4 Animal Wastes
Animal waste is one of the most underutilized resources,
especially the poultry and meat industries which are the
leading sectors of a food chain system. As per statistics, the
EU alone produces around 11 million tonnes of meat per
annum. In 2006, Canada produced over 1500 metric tonnes
of beef, which contributed about $26 billion to its total
wealth. However, the production of such a large quantity of
meat produced a huge amount of wastes such as abattoir and
water (Ning et al. 2018). The animal waste mostly includes
waste from poultry, pork, lambs, sheep, and cattle and is
usually non-edible (Adhikari et al. 2018). Mostly, animal
waste which comprises wool, feathers, skin, hoofs, horns,
soft meat, bones, etc. is generating from the meat industries
(slaughterhouse or abattoir). Owing to the nutritious composition, abattoir waste could be useful for numerous valued
product yields including biomass for fish feeding (Yaakob
et al. 2019), biogas produced from poultry, and animal litter
(Adhikari et al. 2018), as well as methane gas generated
through the anaerobic digestion of wastewater (Ning et al.
2018). Similarly, biodiesel was prepared from chicken
manure and pork fatty waste using pseudo catalytic transesterification reactions (Marques et al. 2016). Besides that,
animal waste also possesses versatile applications for cosmetic production development and the pharmaceutical
industries. The conversion of animal waste into energy is a
manure manage response for the ecosystem.
2.2.5 Industrial Wastes
A huge amount of waste and left-over cellulosic materials
are being generated from industrial processing and other
actions. The industrial waste mostly occurs in the form of
pulp sludge from the production of paper, coffee grounds,
cane sugar (bagasse pith), etc. Most of these materials
comprise cellulose, hemicellulose, and lignin. This combination is known to be lignocellulose (Mathews et al. 2015).
Nowadays, lignocellulose is used as a virtuous feedstock in
many lignocellulosic industries for the advancement of
numerous high-priced materials like pulp, paper, edible
microbial protein, fuels, and chemicals using various bioconversion processes. On the other hand, India and other
countries have been producing a huge quantity of cassava
bagasse solid waste from sago industries. India has alone
produced around 600 tonnes of cassava bagasse waste from
the sago industry per day (Sugumaran et al. 2014). Owing to
the minimal ash content, well nutritious composition (50%
of starch), and high organic content, cassava bagasse works
as an economical feedstock for a number of bioconversion
procedures (Carta et al. 1999). Consequently, the bioconversion of these solid waste produces a variety of valued
products like grain distiller, pullulan (polysaccharide polymer consisting of maltotriose), etc. and are useful to the
society to diminish the environmental pollution (Sugumaran
et al. 2014). The production of various biowastes and their
possible usages in bio-industrial applications are presented
in Table 1.
2.3 Various Bioconversion Processes
Compared to existing chemical and thermal pretreatment
processes, the biological pretreatment process is green as
well as energy-efficient. This part of the chapter focuses on
the bioconversion technologies for converting biowaste to
biofuels and chemicals, particularly the scientific models,
possibilities, as well as future applications are discussed. The
emergent advancements in bioconversion processes of four
primary conversion pathways, including microbial, enzymatic, fermentation, and composting conversion techniques,
are evaluated (Fig. 5).
2.3.1 Microbial Bioconversion Process
The microbial bioconversion technique gained huge attraction and has been progressively used to overcome the
restrictions and environmental problems associated with the
traditional chemical processes. This process involves a
variety of microbes (microorganisms), for example, bacteria,
yeasts, fungi, and microalgae (known as microbial enzymes)
6
A. M. Palve et al.
The increased urbanization, population, and fast economic
growth resulted in increased food consumption, which leads
to an increase in kitchen waste production (Zhao et al. 2017).
Domestic wastes are typically generated from households,
dining centers, public cafes, institute and factory canteens,
etc. (Zhao et al. 2017; Liu et al. 2019). Usually, kitchen
waste consists of vegetables, fruits, eggshells, meat, cooked
food wastes, oil, and grease. Mainly, it contains polysaccharides (such as cellulose, hemicellulose, starch, etc.), lignin, protein, fats, inorganic salts, and a few organic acids
(Chen et al. 2017). At present, China generates over 30
million tonnes of domestic remaining per annum. The
European Union (EU) has been producing approximately 2.5
billion tonnes of food waste every year (Li et al. 2017). The
conventional approaches to decompose kitchen waste
including incineration, land-filling, composting, and discharge into the wastewater create harmful ecological health
problems (Chen et al. 2019). Domestic wastes mostly contain biodegradable material which consists of high moistness
and leads to the development of pathogenic microorganisms
due to easy decomposition and breeding. This waste can be
converted into valuable end-products including nutraceuticals, dietary fiber, antioxidants, fructose based syrup,
single-cell protein, xanthan gum, etc. and are concurrently
diminishing environmental pollution (Liu et al. 2019).
2.2.4 Animal Wastes
Animal waste is one of the most underutilized resources,
especially the poultry and meat industries which are the
leading sectors of a food chain system. As per statistics, the
EU alone produces around 11 million tonnes of meat per
annum. In 2006, Canada produced over 1500 metric tonnes
of beef, which contributed about $26 billion to its total
wealth. However, the production of such a large quantity of
meat produced a huge amount of wastes such as abattoir and
water (Ning et al. 2018). The animal waste mostly includes
waste from poultry, pork, lambs, sheep, and cattle and is
usually non-edible (Adhikari et al. 2018). Mostly, animal
waste which comprises wool, feathers, skin, hoofs, horns,
soft meat, bones, etc. is generating from the meat industries
(slaughterhouse or abattoir). Owing to the nutritious composition, abattoir waste could be useful for numerous valued
product yields including biomass for fish feeding (Yaakob
et al. 2019), biogas produced from poultry, and animal litter
(Adhikari et al. 2018), as well as methane gas generated
through the anaerobic digestion of wastewater (Ning et al.
2018). Similarly, biodiesel was prepared from chicken
manure and pork fatty waste using pseudo catalytic transesterification reactions (Marques et al. 2016). Besides that,
animal waste also possesses versatile applications for cosmetic production development and the pharmaceutical
industries. The conversion of animal waste into energy is a
manure manage response for the ecosystem.
2.2.5 Industrial Wastes
A huge amount of waste and left-over cellulosic materials
are being generated from industrial processing and other
actions. The industrial waste mostly occurs in the form of
pulp sludge from the production of paper, coffee grounds,
cane sugar (bagasse pith), etc. Most of these materials
comprise cellulose, hemicellulose, and lignin. This combination is known to be lignocellulose (Mathews et al. 2015).
Nowadays, lignocellulose is used as a virtuous feedstock in
many lignocellulosic industries for the advancement of
numerous high-priced materials like pulp, paper, edible
microbial protein, fuels, and chemicals using various bioconversion processes. On the other hand, India and other
countries have been producing a huge quantity of cassava
bagasse solid waste from sago industries. India has alone
produced around 600 tonnes of cassava bagasse waste from
the sago industry per day (Sugumaran et al. 2014). Owing to
the minimal ash content, well nutritious composition (50%
of starch), and high organic content, cassava bagasse works
as an economical feedstock for a number of bioconversion
procedures (Carta et al. 1999). Consequently, the bioconversion of these solid waste produces a variety of valued
products like grain distiller, pullulan (polysaccharide polymer consisting of maltotriose), etc. and are useful to the
society to diminish the environmental pollution (Sugumaran
et al. 2014). The production of various biowastes and their
possible usages in bio-industrial applications are presented
in Table 1.
2.3 Various Bioconversion Processes
Compared to existing chemical and thermal pretreatment
processes, the biological pretreatment process is green as
well as energy-efficient. This part of the chapter focuses on
the bioconversion technologies for converting biowaste to
biofuels and chemicals, particularly the scientific models,
possibilities, as well as future applications are discussed. The
emergent advancements in bioconversion processes of four
primary conversion pathways, including microbial, enzymatic, fermentation, and composting conversion techniques,
are evaluated (Fig. 5).
2.3.1 Microbial Bioconversion Process
The microbial bioconversion technique gained huge attraction and has been progressively used to overcome the
restrictions and environmental problems associated with the
traditional chemical processes. This process involves a
variety of microbes (microorganisms), for example, bacteria,
yeasts, fungi, and microalgae (known as microbial enzymes)
6
A. M. Palve et al.