6.3.1.5 Vermicomposting
The term vermicomposting applies to the use of earthworms for the composting of
organic residues. Vermicomposting is a joint interaction between earthworm and
microorganisms found in its gut that helps in the breakage and degradation of the
waste. The vermicompost so obtained is considered to be natural fertilizer and is
capable of providing all the types of nutrients to the deficient soil. It not only offers
the nutrient to the soil but also improves the soil structure by maintaining pH and
EC. It is also helpful in detoxification of soil. In this chapter, a special emphasis will
be given on the method that has the least limitations i.e., vermicomposting. The
approach of technology used for waste treatment varies from country to country and
also on the type of waste generated. India is a country where there is a maximum
generation of organic or wet waste and accordingly waste treatment technology
should be used.
6.3.2 Liquid Waste/Wastewater Treatment
6.3.2.1 Preliminary Treatment
The main purpose of preliminary treatment is the elimination of coarse solids and
other large materials frequently present in untreated wastewater. To increase the
operation and maintenance of future treatment, removal of these materials is necessary. Typically coarse screening, grit removal, and, in some situations, large comminution are included in preliminary treatment procedures. In the grit tanks, the
velocity of the water through the container is kept extremely high, or the air is used to
avoid the sedimentation of most organic solids.
6.3.2.2 Primary Treatment
Primary treatment is aimed at removing settleable organic and inorganic solids by
sedimentation and elimination of scum (floating material) by skimming. Primary
treatment involves the use of physical processes like screening, skimming, and
sedimentation, for the removal of unwanted materials that are settleable, floatable,
or too large to pass through the screens. Primary treatment typically eliminates
25–50% of biochemical oxygen demand and 50–70% of total suspended solids,
but it doesn’t affect the colloidal and dissolved constituents. The effluent after the
primary treatment can be used for irrigation of crops that are not consumed by
humans; it can also be used to irrigate orchards and vineyards.
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S. I. Singh et al.
The term vermicomposting applies to the use of earthworms for the composting of
organic residues. Vermicomposting is a joint interaction between earthworm and
microorganisms found in its gut that helps in the breakage and degradation of the
waste. The vermicompost so obtained is considered to be natural fertilizer and is
capable of providing all the types of nutrients to the deficient soil. It not only offers
the nutrient to the soil but also improves the soil structure by maintaining pH and
EC. It is also helpful in detoxification of soil. In this chapter, a special emphasis will
be given on the method that has the least limitations i.e., vermicomposting. The
approach of technology used for waste treatment varies from country to country and
also on the type of waste generated. India is a country where there is a maximum
generation of organic or wet waste and accordingly waste treatment technology
should be used.
6.3.2 Liquid Waste/Wastewater Treatment
6.3.2.1 Preliminary Treatment
The main purpose of preliminary treatment is the elimination of coarse solids and
other large materials frequently present in untreated wastewater. To increase the
operation and maintenance of future treatment, removal of these materials is necessary. Typically coarse screening, grit removal, and, in some situations, large comminution are included in preliminary treatment procedures. In the grit tanks, the
velocity of the water through the container is kept extremely high, or the air is used to
avoid the sedimentation of most organic solids.
6.3.2.2 Primary Treatment
Primary treatment is aimed at removing settleable organic and inorganic solids by
sedimentation and elimination of scum (floating material) by skimming. Primary
treatment involves the use of physical processes like screening, skimming, and
sedimentation, for the removal of unwanted materials that are settleable, floatable,
or too large to pass through the screens. Primary treatment typically eliminates
25–50% of biochemical oxygen demand and 50–70% of total suspended solids,
but it doesn’t affect the colloidal and dissolved constituents. The effluent after the
primary treatment can be used for irrigation of crops that are not consumed by
humans; it can also be used to irrigate orchards and vineyards.
94
S. I. Singh et al.