2.1.1 Daily Spreading
A large number of farms are using this option. The spreading
of manure is undertaken on a daily basis as they are generated during the year (Petersen 2018; Wright 2017). Figure 1 presents a summary including the strengths and the
weaknesses of this operation. The process has the reputation
of being cost-effective with flexibility in the management
(Polprasert and Koottatep 2017). It is a practice that is done
on a daily basis by many farmers as mentioned earlier.
Nutrients management to decrease the use of fertilizer can be
challenging unless efficient procedures are used (Drinkwater
et al. 2017). When the practice of spreading is completed
nearby the manure source, the soil absorbs excess of phosphorous which causes its contamination and reduce mobility
of other minerals in the soil due to excess of phosphorous.
Another consequence of high levels of phosphorous in the
soil is the contamination of groundwater by migration of
phosphorous. Although smelling problems are usually not a
major concern on sites under spreading operation, runoff and
leaching losses in saturated conditions may contribute to the
discharging of nutrients to a watershed (Kleinman et al.
2017).
2.1.2 Liquid Effluent Storage
This operation is completed when there is a need to decrease
dissemination of manure during high losses times and periods when fields are not accessible. Effluent storage is
mandatory in various areas and usually supported for all
areas. Figure 2 presents a summary involving the strengths
and weaknesses of the liquid storage operation.
The storage of solid particles of manure and the manure
effluents for the spreading at a correct time may decrease the
nutrients discharging to a watershed; it has an advantage of
protecting the water resources and soil from pollution
(Chadwick et al. 2020; Rosov et al. 2020). Nutrients monitoring done by spreading from storage to decrease the use of
fertilizers is a very effective and sustainable process (Svanbäck et al. 2019). Records keeping and spreading trends for
each site are very important to be assured of the uniformity
of coverage. There is a possibility of cost savings both in the
reduction of fertilizers usage and operational use of processing plant from the process of spreading manure from
storage (Fournel et al. 2018). Odour generation is a major
concern when dealing with storage of manure.
2.1.3 Solid Separation
The separation of liquid effluent and solids from manure is
an important operation when it comes to physical treatment.
This separation is completed with the use of a filtration
system used for solid/liquid separation such as a sedimentation tank or a filter-press. The physical separation between
the solid and liquid fractions of manure effluents generates
30% dry matter (DM) from the solid fraction while the liquid
represents only 4–8%. Figure 3 presents a summary of some
advantages and disadvantages related to the separation of the
solids from manure effluents. The separation and hauling of
solids fraction has the potential of allowing the spread of
almost 20% of phosphorus (Kumaragamage and Akinremi
2018). There are various types of separators available on the
market that are very efficient in the way of performing the
separation process. Many of them need additional water to
operate adequately. However, screw press separator operates
with no added water and it can generate a satisfactory dry
product.
Fig. 1 Summary of advantages
and disadvantages of daily
spreading operation
Treatment and Bioconversion of Manure Effluents
301
A large number of farms are using this option. The spreading
of manure is undertaken on a daily basis as they are generated during the year (Petersen 2018; Wright 2017). Figure 1 presents a summary including the strengths and the
weaknesses of this operation. The process has the reputation
of being cost-effective with flexibility in the management
(Polprasert and Koottatep 2017). It is a practice that is done
on a daily basis by many farmers as mentioned earlier.
Nutrients management to decrease the use of fertilizer can be
challenging unless efficient procedures are used (Drinkwater
et al. 2017). When the practice of spreading is completed
nearby the manure source, the soil absorbs excess of phosphorous which causes its contamination and reduce mobility
of other minerals in the soil due to excess of phosphorous.
Another consequence of high levels of phosphorous in the
soil is the contamination of groundwater by migration of
phosphorous. Although smelling problems are usually not a
major concern on sites under spreading operation, runoff and
leaching losses in saturated conditions may contribute to the
discharging of nutrients to a watershed (Kleinman et al.
2017).
2.1.2 Liquid Effluent Storage
This operation is completed when there is a need to decrease
dissemination of manure during high losses times and periods when fields are not accessible. Effluent storage is
mandatory in various areas and usually supported for all
areas. Figure 2 presents a summary involving the strengths
and weaknesses of the liquid storage operation.
The storage of solid particles of manure and the manure
effluents for the spreading at a correct time may decrease the
nutrients discharging to a watershed; it has an advantage of
protecting the water resources and soil from pollution
(Chadwick et al. 2020; Rosov et al. 2020). Nutrients monitoring done by spreading from storage to decrease the use of
fertilizers is a very effective and sustainable process (Svanbäck et al. 2019). Records keeping and spreading trends for
each site are very important to be assured of the uniformity
of coverage. There is a possibility of cost savings both in the
reduction of fertilizers usage and operational use of processing plant from the process of spreading manure from
storage (Fournel et al. 2018). Odour generation is a major
concern when dealing with storage of manure.
2.1.3 Solid Separation
The separation of liquid effluent and solids from manure is
an important operation when it comes to physical treatment.
This separation is completed with the use of a filtration
system used for solid/liquid separation such as a sedimentation tank or a filter-press. The physical separation between
the solid and liquid fractions of manure effluents generates
30% dry matter (DM) from the solid fraction while the liquid
represents only 4–8%. Figure 3 presents a summary of some
advantages and disadvantages related to the separation of the
solids from manure effluents. The separation and hauling of
solids fraction has the potential of allowing the spread of
almost 20% of phosphorus (Kumaragamage and Akinremi
2018). There are various types of separators available on the
market that are very efficient in the way of performing the
separation process. Many of them need additional water to
operate adequately. However, screw press separator operates
with no added water and it can generate a satisfactory dry
product.
Fig. 1 Summary of advantages
and disadvantages of daily
spreading operation
Treatment and Bioconversion of Manure Effluents
301