Concentrated organic manures
Sewage and sludge
Dr. P. K. Mani
Bidhan Chandra Krishi Viswavidyalaya
Concentrated organic manures
Oil cake, Bone meal, blood meal, fish manure, meat meal etc.
Oilcakes: is the residue left after the oil is extracted from oil bearing seeds
Edible oil Cakes : feed to
Coconut cake : 3.0% N
Mustard Cake : 5.2% N
Ground nut cake : 7.2% N
Safflower cake : 7.9% N
Sesame cake : 6.2% N
OC should be well powdered
application for quick decomposition
nutrients are liberated after
decomposition of oil cakes,
nitrifies quickly, nearly 50-80%
N is available within 2-3 months,
Used as top dressing
Toxic substances: (Saponin)
Castor Cake : 4.3% N Muhua cake- poorest
: 5.2% N N available after 2 months of
Mahua Cake : 2.6% N
Suitable for orcahrd , Long Day
Crop like Sugarcane, Tapioca
Neem cake: used for controlling
nematodes @ 1 t /ha
Concentrated organic manures has no residual effect
Except Mahua Cake Oil Cake may apply as top dressing
Use as a fertilizer:
Neem cake organic manure protects plant roots
from Nematodes, soil grubs and White ants probably due
to its residual limonoid content.
It also acts as a natural fertilizer with pesticidal properties.
Neem cake is widely used in India to fertilize paddy ,
cotton and sugarcane.
Neem seed cake also reduce alkalinity in soil, as it
produces organic acids on decomposition.
Being totally natural, it is compatible with soil microbes,
improves rhizosphere microflora and hence ensures
fertility of the soil.
The cake contains salannin, nimbin, azadirachtin and
azadiradione as the major components.
Hoof and Horn Meal organic fertilizer is a great source
of N (12%) for organic garden plants, especially high feeders
like corn, tomato and lettuce. It also has a small amount
of P (2%) for healthy roots and stems.
It is made from cooked ground dehydrated cattle hooves
and horns obtained from slaughterhouses.
H&H Meal is equivalent to Blood Meal in N content, but
the nutrient availability is slower, which is better for
organic crops and with less "leaf burn" damage and it
It nutrient availability starts at around 4-6 weeks and can
lasts 12 months.
Essentially P fertilizer, slow acting manure, apply at the time
of planting or sowing, suitable for acid soil, rich in sesquioxides
Bones consisits of Ca3 (PO4)2 together with
some organic substances like fats and protiens.
So, good source of Lime, phosphoric acid
The presence of fat hinders the process of decomposition.
Therefore, bones are sometimes treated with steam to remove fat
before they crushed. Steamed bone meals are more brittle, and easy
to crush and decomposes quickly.
Steamed bone meal
Sewage sludge –a potential threat to heavy
metal pollution in Indian soils
200 major cities in India generate 2600 million m3 of
raw sewage per year
Production of sludge is estimated to be around 1200
tonnes per day, potentiality is 4000 tonnes per day
Delhi city produces 600 Mm3 of waster water per
day, 175 Mm3 untreated
Five major sewage treatment plants in Delhi
produce 1200 M lit treated effluents per day-used to
Sewage has two components,
Solid portion technically known as sludge
Liquid portion, commonly known as
sewage water or effluent . The raw or crude
sewage consists mainly of water carrying various solids
partly in soln and partly in suspension
Both the components of sewage are used in increasing
crop production but due to bacterial contamination
untreated sewage is not advocated for growing
Bacterial contamination is reduced by fermentation and
Settled sludge :Produced by plain sedimentation
Digested sludge:- Digested sludge is obtained from raw
sewage through settling by gravity and sedimentation.
The solid parts subsequently digested anaerobically for
period of 10-15 days. This digested material is then pumped
in suitable beds for drying out. This sludge’s
usually gave an
offensive odour but they are free from pathogenic
organisms present in unprocessed sludges
Activated sludge: produced by a special rapid aerobic
treatment of sewage that results in coagulation and
settling of suspended materials. This pdt is superior to
digested sludge and has no offensive adour.
Chemically precipitated sludge:- Produced by treatment
of certain chemicals to remove certain poisonous
and heavy metals as also to precipitate the
Digested activated sludge :-
Activated sludge contains :
3-6% N, ~ 2% P2O5 and 1% K2O
in form a that can become readily available when applied
to soil. (ISSS,2009)
On an average, the sewage sludge has the following
composition on oven dry basis
Amount on oven dry weight basis (%)
Basic flow of sewage sludge composting process
Composition of Sludge
(1.5 – 3.5% )
Effluent waters which should be removed from
settlements and industrial enterprises are
known as Sewage
food wastes, various washings and laundry wastes,
waters from lavatories, baths etc.
waste waters are unstable polydispersed system
Inorganic impurities are sand, clay, particles of ore,
slag, chalk, mineral salts, mineral oils
Sewage water : can be used as an irrigation source.
However, it should be treated before application to
Soil sickness: results from excessive organic and N
loading, which causes anaerobiosis and imbalance
C:N and C:P.
Excessive N-loading: also induces production of more
foliage, resulting in less fruiting, particularly in the
case of vegetables like brinjal, okra, chillies.
The yield decline: due to continuous application of
untreated sewage water is primarily due to blocking
soil pore spaces by colloidal matter. The soil
special methods of the treatment are reqd.
(i) NaCN+ H2SO4→ (Na)2SO4 + HCN (260C)
(ii) NaCN + HOCl = CNCl + NaOH
CNCl + H2O → HCNO + HCl
HCNO + Cl2 + H2O → CO2 + N2 + 2HCl
(at pH 10.0)
Crops suitable for sewage irrigation
Fodder crops like Oats, Jowar, Maize, berseem and lucerne
Vegetable crops, like Cabbage, cauliflower, turnip, potato,
brinjal, lady’s finger, beans etc.
Crops unsuitable for sewage irrigation
• Carrot and leafy vegetables
Heavy metal composition of sewage sludge from different
cities in India
Source : Maity et al (1992).
DTPA-extractable heavy metals in soils under different crops
irrigated with sewage and underground water
Source: Sharma and Kansal(1986)
DTPA-extractable heavy metal status in Peri-Urban Soils
(treated with sewage) during Summer of 2001
DTPA-extractable heavy metal content/mg.kg -1
South Mahishtala, Tiljala
Source: Sanyal (2002)
Distillery is one of the most important agri based industries
in India for manufacturing of ethyl alcohol from molasses. A
large volume of foul smelling effluent which is commonly
known as distillery effluent or spent wash is generated.
Usually with 1 L of alcohol production 12-15L spent
wash effluent is generated. Approximately 40 billion Litres of
spent wash is generated/ annum from 285 distilleries in the
country, which is generally discharged in to the water
courses under untreated or partially treated conditions,
causing environmental pollution owing to its very high
In order to reduce its high biological oxygen demand (BOD)
and Chemical Oxygen Demand (COD), many distilleries
recycle these effluents to produce methane by passing them
through biomethanation digesters and the effluent thus
obtained is known as Post methanation effluent (PME)
Let the Hundred flowers bloom
Trypsin inhibitor, goiterogen, tannins,
Mustard or rape Goiterogens (thioglucosides or
seed and its meal glucosinolates), tannic acid, erucic
acid, sinapine (cholinester), pectins
and its meal
Estrogenic factor, Two phenolic
glucosides (Bitter flavour)
and its meal
Sesame seed and Phytate and Oxalates
Linseed and its
Linamarin (cyanogenic glucoside),
Bitterness → Limonoids → Triterpenoids
and its meal
Nonisoprenoid polypenolics- Flavanoids,
Tannins and coumarin viz.
Salannin and Azadirachtin
Mowrin (Saponin) and Tannins
Fish meal and Gizzerosine and histamine
The Activated Sludge Process
Returned Activated Sludge
Classical Oxygenation by sidestream
The OXY-DEP® process
Activated Sludge Basin
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