Page 28 - Refining Biomass Residues for Sustainable Energy and Bioproducts

Solid waste biorefineries 7

1.2.4 Animal manure

Animal manure is one of the SWs that could be obtained from different cattle ani-
mals as wastes, and it has wide applications in various fields. Animal manure is
generally used to provide additional organic matter for enhancing soil structure and
supplement for product development. As most fertilizers from animal feeding ordi-
narily contain high salt content, they may be adverse to soil conglomeration and the
environment. Animal manure can immobilize both abiotic and biotic nitrogen in an
acidified soil. The most important application of animal manure is that it could be
used as an organic fertilizer, which means that they can act as a carbon source and
could alter soil nitrogen transformation. C/N ratio is the key organic fertilizer qual-
ity parameter, and it is inversely proportion to the nitrogen immobilization in soil.
Those compounds having higher C/N ratio could exhibit lower N immobilization.
The lower N immobilization occurs due to the acidification of soil, which can also
affect the bacterial abundance and diversity in biotic environment in soil. Due to
higher alkalinity, animal manures are more efficient in mitigating soil acidification
and also increase microbial activity than other materials (Wang et al., 2019). Apart
from these applications, animal manure is also most commonly used for the produc-
tion of biogas.

1.2.5 Sewage sludge
In biological waste water treatment process, sewage sludge is formed by the con-
version of chemical oxygen demands removed to biosolids. In a clean landfill the
edge of discharge water content is 60% from the point of view of prosperity con-
trols. The inappropriate exchange causes the decadent of resources just as it
accomplishes a movement of assistant catastrophes (e.g., landslide and pollution
of environment). Sewage discharge floc is a multiphase medium and contains big-
ger pieces of fragments including microbial populace, filamentous bacterial
strains, regular and inorganic particles, extracellular polymeric substances, and
enormous proportion of water. The techniques are utilized most frequently for
sewage waste handling and transferring incorporate dewatering, composting,
anaerobic digestion, drying incineration, and sanitary landfill. The major purpose
behind slop dewatering is to reduce discharge volume by clearing anyway as
much water as could sensibly be normal from the muck. The water in slop flocs
is usually divided into four orders: free water (65% 85% of the outright water),
interstitial water (15% 25%), vicinal water (7%), and water of hydration (3%).
Anaerobic ingestion incorporates a couple of dynamic natural methodology (i.e.,
hydrolysis, acidogenesis, acetogenesis, and methanogenesis) in which microorgan-
isms separate biodegradable materials and convey them into methane-rich biogas
(60 70 vol.% CH4); in this manner the significant residual solids concentrations
were reduced by pummeling the pathogens present in the ooze and discarding
antagonistic scents.