vermicomposting period (Suthar 2006). Moreover, T 2 produces 21.9 and 645.5% more cocoon than T 1 and T 2 mixtures, respectively. Therefore, the research concluded that T 2
mixture is ideal for enhancing vermicomposting coefficient
and producing higher mean biomass.
Jjagwe et al. have studied the potential of vermicomposting for effective cattle manure management in Uganda
(Jjagwe et al. 2019). During the experiment, 1 kg earthworms were added to 10 kg of cattle manure, and the batch
had undergone an 84 days period of vermicompost. Using
the sprinkling water system, the moisture content inside the
vermicomposting unit was maintained between 60 and 70%.
After the harvesting period, based on dry basis, 46% of the
mass was successfully converted into vermicompost, 2%
was consumed by earthworms, and 52% dissipated to the
environment. According to substance flow, 30% of the total
carbon content was part of vermicompost, 2% was used by
earthworms and rest was released to the environment.
Similarly, 75% of nitrogen was converted into vermicompost, 7% was used by earthworms, and 18% entered the
atmosphere. Their research also revealed that vermicompost
significantly reduces the greenhouse gas emission from
cattle manure. Data show that cumulative emission from
vermicompost was only 102 g CO 2 , 7.6 g CH 4 and
3.94 Â 10
−5 g N 2 O from per kg of manure. Therefore,
vermicompost can be considered as an effective advanced
application of cow dung waste. Since this technology is
inexpensive and easy to maintain, it can be recommended for
low-income developing and least developed countries.
5.2 Anaerobic Co-digestion of Cow Dung
Anaerobic digestion is a type of biodegradation process of
organic materials using microorganisms in a sealed, air-tight,
and oxygen-free chamber (Masud et al. 2019). This is a
promising method of converting organic industrial and
domestic waste into biofuels. Anaerobic digestion has
environmental benefits as it actively reduces groundwater
and soil pollution as the volume of disposable materials is
reduced (Ananno et al. 2021). The produced biogas also
maintains the balance among the greenhouse gases in the
atmosphere (Masud et al. 2020). From an economic perspective, the system delivers a low-cost and rather simplistic
approach to provide the rural areas of under-developed and
developing countries with suitable energy generating methods. Inexpensive biogas generated from cow dung can be
used for food drying and residential heating purposes
(Ananno et al. 2020; Masud et al. 2019a, b, 2020).
Singh et al. have investigated the potential of anaerobic
co-digestion of cow dung with different types of non-edible
oil cakes such as safflower, karanja and jatropha (Singh and
Mandal 2011). By using a one litter batch reactor and mixed
inoculum technology, the production of methane-enriched
biogas was observed. Different mixture ratio of cow dung
and non-edible oil cakes was tested to identify optimum
methane production condition. The digestion period for all
experiments was 41 days at 35 °C temperature. The average
yield of methane was recorded as 0.23 to 0.36 Lg-1VS (Litre
per gram Volatile Solid Content); biogas 0.49 to 0.52
Lg-1VS and CO 2 generation 0.13 to 0.18 Lg-1VS. The study
found that a 1:1 feed material mixture produced maximum
methane yield. Anaerobic co-digestion of cow dung and
karanja was most effective; yielding an average of 0.36
Lg-1VS methane and 0.52 Lg-1VS biogas. Whereas the
combination of cow dung and jatropha was least effective,
producing an average of 0.32 Lg-1VS methane and 0.51
Lg-1VS biogas. Moreover, the experiments also showed a
14.8% increase in methane production from 1:1 combination
cow dung and karanja compared to cow dung alone (0.31
Lg-1VS). Therefore, it can be concluded in terms of
methane-enriched biogas production; anaerobic co-digestion
is significantly more effective than anaerobic digestion of
only cow dung.
5.3 Reinforcement of Friction Composites
In order to produce an automotive braking system, friction
composites containing reinforcing fibres, binders and friction
modifiers are widely used (Yun et al. 2010). The traditional
materials used for automotive braking system have
long-term adverse effect on the environment due to the use
of toxic materials. Hence, the modern automotive industry is
testing organic lignocellulosic fibres such as bamboo, jute,
coir and betelnut for the production of reinforcing fibres (Ma
et al. 2012; Nahar et al. 2011; Tran et al. 2011; Yousif et al.
2010). Since these fibres are biodegradable, they are not
detrimental to the environment. Moreover, renewability,
mass availability and inexpensive production cost have
made organic fibres a popular choice for friction composite
production. Primarily composed of hemicellulose, cellulose
and lignin—these organic fibres have acceptable, friction
coefficient, noiseless, low fade and satisfactory resistance to
corrosion (Singh et al. 2017).
Ma et al. have studied the possibility of cow dung fibre
reinforced friction composite (Ma et al. 2019). Using
detailed study and exhaustive experimentation, they have
concluded that cow dung positively affects the wear properties of friction composites. Additionally, they have concluded that friction composites reinforced with cow dung
have pronounced wear resistance and stable friction coefficient. The experimental analysis shows that friction composite containing 6 wt% cow dung fibre produced the most
satisfactory results. Considering the overall performance
cow dung fibre reinforced friction composite displayed a
Multi-utilisation of Cow Dung as Biomass
225
mixture is ideal for enhancing vermicomposting coefficient
and producing higher mean biomass.
Jjagwe et al. have studied the potential of vermicomposting for effective cattle manure management in Uganda
(Jjagwe et al. 2019). During the experiment, 1 kg earthworms were added to 10 kg of cattle manure, and the batch
had undergone an 84 days period of vermicompost. Using
the sprinkling water system, the moisture content inside the
vermicomposting unit was maintained between 60 and 70%.
After the harvesting period, based on dry basis, 46% of the
mass was successfully converted into vermicompost, 2%
was consumed by earthworms, and 52% dissipated to the
environment. According to substance flow, 30% of the total
carbon content was part of vermicompost, 2% was used by
earthworms and rest was released to the environment.
Similarly, 75% of nitrogen was converted into vermicompost, 7% was used by earthworms, and 18% entered the
atmosphere. Their research also revealed that vermicompost
significantly reduces the greenhouse gas emission from
cattle manure. Data show that cumulative emission from
vermicompost was only 102 g CO 2 , 7.6 g CH 4 and
3.94 Â 10
−5 g N 2 O from per kg of manure. Therefore,
vermicompost can be considered as an effective advanced
application of cow dung waste. Since this technology is
inexpensive and easy to maintain, it can be recommended for
low-income developing and least developed countries.
5.2 Anaerobic Co-digestion of Cow Dung
Anaerobic digestion is a type of biodegradation process of
organic materials using microorganisms in a sealed, air-tight,
and oxygen-free chamber (Masud et al. 2019). This is a
promising method of converting organic industrial and
domestic waste into biofuels. Anaerobic digestion has
environmental benefits as it actively reduces groundwater
and soil pollution as the volume of disposable materials is
reduced (Ananno et al. 2021). The produced biogas also
maintains the balance among the greenhouse gases in the
atmosphere (Masud et al. 2020). From an economic perspective, the system delivers a low-cost and rather simplistic
approach to provide the rural areas of under-developed and
developing countries with suitable energy generating methods. Inexpensive biogas generated from cow dung can be
used for food drying and residential heating purposes
(Ananno et al. 2020; Masud et al. 2019a, b, 2020).
Singh et al. have investigated the potential of anaerobic
co-digestion of cow dung with different types of non-edible
oil cakes such as safflower, karanja and jatropha (Singh and
Mandal 2011). By using a one litter batch reactor and mixed
inoculum technology, the production of methane-enriched
biogas was observed. Different mixture ratio of cow dung
and non-edible oil cakes was tested to identify optimum
methane production condition. The digestion period for all
experiments was 41 days at 35 °C temperature. The average
yield of methane was recorded as 0.23 to 0.36 Lg-1VS (Litre
per gram Volatile Solid Content); biogas 0.49 to 0.52
Lg-1VS and CO 2 generation 0.13 to 0.18 Lg-1VS. The study
found that a 1:1 feed material mixture produced maximum
methane yield. Anaerobic co-digestion of cow dung and
karanja was most effective; yielding an average of 0.36
Lg-1VS methane and 0.52 Lg-1VS biogas. Whereas the
combination of cow dung and jatropha was least effective,
producing an average of 0.32 Lg-1VS methane and 0.51
Lg-1VS biogas. Moreover, the experiments also showed a
14.8% increase in methane production from 1:1 combination
cow dung and karanja compared to cow dung alone (0.31
Lg-1VS). Therefore, it can be concluded in terms of
methane-enriched biogas production; anaerobic co-digestion
is significantly more effective than anaerobic digestion of
only cow dung.
5.3 Reinforcement of Friction Composites
In order to produce an automotive braking system, friction
composites containing reinforcing fibres, binders and friction
modifiers are widely used (Yun et al. 2010). The traditional
materials used for automotive braking system have
long-term adverse effect on the environment due to the use
of toxic materials. Hence, the modern automotive industry is
testing organic lignocellulosic fibres such as bamboo, jute,
coir and betelnut for the production of reinforcing fibres (Ma
et al. 2012; Nahar et al. 2011; Tran et al. 2011; Yousif et al.
2010). Since these fibres are biodegradable, they are not
detrimental to the environment. Moreover, renewability,
mass availability and inexpensive production cost have
made organic fibres a popular choice for friction composite
production. Primarily composed of hemicellulose, cellulose
and lignin—these organic fibres have acceptable, friction
coefficient, noiseless, low fade and satisfactory resistance to
corrosion (Singh et al. 2017).
Ma et al. have studied the possibility of cow dung fibre
reinforced friction composite (Ma et al. 2019). Using
detailed study and exhaustive experimentation, they have
concluded that cow dung positively affects the wear properties of friction composites. Additionally, they have concluded that friction composites reinforced with cow dung
have pronounced wear resistance and stable friction coefficient. The experimental analysis shows that friction composite containing 6 wt% cow dung fibre produced the most
satisfactory results. Considering the overall performance
cow dung fibre reinforced friction composite displayed a
Multi-utilisation of Cow Dung as Biomass
225