FIELD OF THE INVENTION:
This invention relates to the production of potassium rich organic
fertilizer from tanney effluent.
BACKGROUND OF THE INVENTION:
Leather industries generate large amount of wastewater from the
processing units that creates severe environmental pollution. The liquid
effluent contains high concentrations of organic and inorganic
pollutants. The safe disposal of effluent generated from the leather
industries is an issue of concern.
Presently there is no proper sludge disposal system in the tanneries. The
dried sludge is removed from the sludge drying beds and disposed of in
the tannery surroundings indiscriminately without any environmental
consideration.
Sludge is produced from pickling effluent generated from steel and other
alloy production, chrome plating, pigments etc., but these sludges do not
have any fertilizer value.
The pulverized sludge obtained has a composition which is similar to
vermi-compost. Vermi compost is stable, organic manure produced as
the vermicast by earthworm feeding on biological waste materials. It is

preferred balanced nutrient source for organic farming and is eco-
friendly.
The pickling bath from a tannery slightly acidic in nature and so far, no
methods are known in the art, to treat this effluent in order to generate
sludge with fertilizer value.
OBJECTS OF THE INVENTION;
It is therefore an object of this invention to propose a process for the
production of potassium rich organic fertilizer from tannery effluent,
which is simple and cost-effective.
It is a further object of this invention to propose a process for the
production of potassium rich organic fertilizer from tannery effluent,
which is eco-friendly and reduces environmental pollution.
These and other objects and advantages of the invention will be apparent
from the ensuing description.
BRIEF DESCRIPTION OF THE INVENTION:
This invention relates to a method for the production of potassium rich
organic fertilizer from tannery effluent.

The pickling effluent is treated with an optimum dose of a coagulant

such as for example calcium oxide. After treatment with calcium oxide,
the supernatant liquor is filtered using a fine cloth. The sludge is dried
and pulverized to obtain the organic fertilizer.
The pH of the pickling solution is 1.4. An appropriate treatment with
calcium oxide, results in sedimentation of almost all the organic material
rich in inorganic material and generates sludge. Table 1, represents
various properties of the clear liquid after calcium oxide dosing for
different concentrations of calcium oxide. The pH of the feed gradually
increases with calcium oxide concentrations. At 0.1% of calcium oxide dose, the pH is acidic and it is alkaline at 1.0%. The pH is nearly neutral
when it reaches about 0.38 to 0.45% concentration, preferably 0.4% of
calcium oxide. It is shown in the table that the chemical oxygen demand
(COD) decrease initially and then reaches a minimum value at 0.4%
calcium oxide and then increases as the dosage increases gradually. The
properties such as total dissolved solids (TDS), conductivity and total
solids (TS) show similar results with results with 0.4% calcium oxide
dosing. These properties show gradual increase on increasing the
concentration. From these observations, 0.4% of calcium oxide is
selected as optimum concentration for coagulation.

The invention will now be explained in greater detail with the help of the
following non-limiting example.
Example:
100 litres of pickling effluent from tanneries, was taken and it was found
to have a pH of 1.4. To it was added 400g calcium oxide to obtain a
slurry. The supernatant was filtered off using a fine cloth to obtain the
sludge. The sludge was then dried using standard methods and
pulverized to obtain the potassium rich organic the potassium rich
organic fertilizer. The yield was found to be 1.6 kg, which indicates that
the cost of the fertilizer is Rs. 1.5/kg.


- The dry pulverized sludge is analyzed for its fertilizer value. The analysis
results along with the composition of a standard vermi-compost are
presented in Table 2. From this table, it is evident that the produced
sludge can be used as potassium rich organic fertilizer.

This is a very simple and economic method for the production of an eco-
friendly potassium rich organic fertilizer and uses cheap commercially available chemicals and no heavy equipment.
The sludge is analyzed to have extremely high potassium content and
thus can be used as blends with other fertilizers in appropriate
proportion for optimum activity.
The pH and other parameters indicate that it can be used as a safer
organic fertilizer and the process addresses a burning environmental
problem by converting an environmental pollutant into a saleable
product.

WE CLAIM:
1. A process for the preparation of an organic fertilizer from
tannery effluent, comprising providing pickling effluent from
tannery, and treating the same with a coagulant to obtain a
slurry, filtering the supernatant liquor to obtain a sludge,
followed by drying and pulverizing the same to obtain the
organic fertilizer.
2. The process as claimed in claim 1, wherein the coagulant is
calcium oxide.
3. The process as claimed in claim 1, wherein the dose of the
coagulant is 0.38 to 0.45%.

4 The process as claimed in claim 1, wherein the dose of the
coagulant is 0.4%.
5 The process as claimed in claim 1, wherein the supernatant
liquor is filtered using a fine cloth.

ABSTRACT

TITLE: PRODUCTION OF POTASSIUM RICH ORGANIC
FERTILIZER FROM TANNERY EFFLUENT
This invention relates to a process for the preparation of an organic
fertilizer from tannery effluent, comprising providing pickling effluent
from tannery, and treating the same with a coagulant to obtain a
slurry, filtering the supernatant liquor to obtain a sludge, followed by
drying and pulverizing the same to obtain the organic fertilizer.