Farmer Centred Approach to Wastewater Treatment
and Resource Recovery
agriculture had sustained its production with organic matter recycling
methods over the past 60 centuries. The productivity, however, started
reducing in this century, primarily due to environmental pollution,
arising through burning of fossil fuels. Farmers had to switch
over to the use of chemical fertilisers (and pesticides) to sustain
food production. The old method is referred to as organic farming
whereas the new method is termed as chemical farming. The latter
method, however, has now been found to be unsustainable due to its
negative impact on the environment and increasing costs to the farmers
as well as to the national economy. Scientists are now rediscovering
the secrets of organic farming, with modern knowledge of soil biology
and ecology. Vermiculture ecotechnology has been found to facilitate
the conversion from chemical farming to organic farming without
drop in the agricultural output. This paper discusses a farmer centred
approach to wastewater treatment and resource recovery, to facilitate
What is chemical farming?
farming involves the use of chemical fertilisers and pesticides
to increase the agricultural output, a method that was promoted
during the past four decades to boost the food production.
limiting nutrient of plants is carbon dioxide, next comes nitrogen
and other nutrients. The output is controlled by the limiting nutrient,
that is, by the availability of carbon dioxide. Modern greenhouses
show spectacular results primarily due to increased supply of carbon
dioxide. It should be noted that one needs to supply carbon dioxide
in the plant vicinity, without polluting the whole atmosphere. The
latter produces global warming that disturbs the climate and food
chemical farming one has to use excessive amounts of nitrogenous
fertilisers (such as urea or ammonium nitrate) to start the denitrifying
reaction in the soil. This involves converting the nitrates back
into nitrogen gas, quite a wasteful reaction for nature. This reaction
also cracks the capital reserve of the soil organic matter and produces
the carbon dioxide that increases food production. Obviously this
cannot be a sustainable method because it exploits the soil's organic
reserves created over the centuries. These reserves need to be maintained
and built up because they give the soil its ability to hold moisture
and nutrients. After a few decades of chemical farming, we have
witnessed a drop in the soil fertility and hence reducing yields.
Soil organic content has been depleted and even the response to
the chemical fertilzers is poor nowadays.
chemical farming, farm residues (such as straw) cannot be used to
build up the soil organic matter. Uncomposted organics rob the nitrates
and delay the denitrifying reaction necessary for the production
of carbon dioxide. Hence farmers have to compost the organic residues
first, even if they are well stabilized (they are non-polluting
and are not in the stage of decomposition). Composting process burns
50-90 percent of organic matter wastefully, producing carbon dioxide
that can pollute the atmosphere. Composting also produces leachate
that pollutes the groundwater. Chemical farming cannot sustain without
an input of compost, about 20 tons per hectare per year, a recommendation
evolved out of research at the agricultural universities. Farmers
cannot get the raw materials to produce this amount and hence, farmers
neglected this aspect, only to lose the soil productivity. Such
soils with depleted organic matter cannot hold moisture and nutrients
and farmers have to spend more on irrigation and fertilizers. If
irrigation or rain is in deficit, there is a crop failure.
promote the denitrification in the soil, chemical farming involves
the use of excessive amount of inorganic nitrogen fertilisers, much
more than the actual needs of the plants. This results in pollution
of ground and surface water with nitrates, that have a negative
impact on physical and mental health of humans and pet animals.
Each year the farmer needs to increase fertiliser use to sustain
output because soil develops its ability to denitrify more speedily.
All beneficial soil life gets destroyed in the denitrification region.
The farmer has to spend more each year and the nation has
to import more oil to produce these fertilisers. The Punjab farmers
produced higher yields, no doubt, but got reducing profits each
more than required nitrogen is supplied, the plants get surplus
nitrates in their sap. This has harmful effect on plant growth because
each plant grows well only in a narrow bandwidth of soil nitrates.
Other plant nutrients, such as phosphorous, potassium and other
major and micronutrients, are required to counter the harmful effect
of extra supply of nitrogen. Again, an extra cost to the farmers
and to the nation as many of these need to be imported. There is
also pollution of water bodies due to leaching of soluble nutrients.
having surplus nitrates are unsuitable for human consumption. Nature
has developed pests to attack such plants and check the food quality.
Not knowing this, farmers were advised to use (spend for) pesticides
that poisoned the whole ecology and only produced resistant pests,
forcing farmers to use a stronger (more toxic) pesticide each year,
adding to the burden on his pocket. Use of pesticides also resulted
in the production of food polluted with pesticides and nitrates,
both harmful for human consumption. Such plant produce also has
more moisture, making the extra food production superfluous. This
produce also has a poor shelf life due to the nitrate content. It
is found that food spoilage due to fungi, insects or rodents is
due to residual nitrates in food. These are nature's mechanisms
to destroy the faulty food.
from the extra input costs, one needs to use higher irrigation in
chemical farming, just to adjust the nitrate level to the plant's
required bandwidth. Increase in chemical farming has depleted (and
polluted) our water resources.
treatment needs to be planned differently for organic and chemical
farming. In organic farming, free nitrates (nitrites and ammonia)
need to be locked, while conserving the organic content because
the latter is the base of organic farming. In chemical farming,
however, organic matter in the wastewater needs to be biologically
incinerated in the wastewater treatment plants, using electricity,
which is often produced by techniques that are polluting. Current
pollution control laws are formulated with chemical farming in mind.
The treated wastewater, without the organic content (COD) and enriched
with inorganics, is suitable only for the chemical farming, but
highly harmful to the nature and natural organic farming. High inorganics
to organics ratio, which is characteristic of the secondary treated
wastewater, is ideal food for water hyacinth, mosquitoes and pathogens.
It is found that while raw sewage may lead to the breeding of ordinary
mosquitoes in the water bodies, the secondary treated sewage encourages
breeding of malaria and dengue mosquitoes. It is also an ideal food
for other pathogens. Allowing the secondary treated sewage and other
wastewaters in the water bodies should not be permitted unless the
inorganic content, too, is removed. This is very costly (called
tertiary treatment), hence not practiced.
Eco-friendly Wastewater Treatment:
need to understand nature's requirements and treat wastes (solid
wastes and wastewaters). Fish can utilise organic matter in water
if the inorganic content is reduced. Use of cowdung in fisheries
is a good example. Use of poultry manure (this has higher inorganic
to organic ratio) leads to mosquito production after the fish get
killed due to the nitrate toxicity. Human excreta and urine, too,
has high inorganic content that is harmful to the environment.
soil, too, needs the supply of organic matter, with minimal inorganic
load. The soil life is managed by the earthworms that aerate the
soil, maintain the pH and cull the harmful soil pathogens, encouraging
the beneficial soil microorganisms that use organic matter and rock
soil minerals, to produce the plant nutrients as per the plants'
genuine needs. This leads to healthy plant production, without the
need to use polluting agrochemicals.
fertilizer factory, thus is managed by the earthworms that process
the rock particles to produce the plant nutrients. The energy source
is organic matter, available from dead roots and organic inputs
to the soil (in the form of organic fertilizers). The earthworms,
however, cannot tolerate salinity of soil and the water used for
irrigation.. Hence wastewater needs to be processed to produce a
high organic to salt ratio and only the toxic organic content needs
to be removed. Use of BioSanitizer makes this an easy task.
concept was developed by Dr Uday S. Bhawalkar of Bhawalkar Ecological
Research Institute (BERI), Pune. It is based on the following concepts:
(solid or liquid, the latter being known as wastewaters) are actually
resources if they are treated to become food for the ecology.
toxic organics and inorganics are managed, nontoxic organics (sugars,
starch, cellulose, etc.) are food for the ecology and need not be
bioincinerated, as done in the conventional secondary treatment
of wastewaters and in composting.
BioSanitizer is a catalyst produced from natural ingredients and
is a simple tool to manage the toxic organics, and inorganics, converting
the waste ingredients into resources. The action is known as biosanitization
and controls the pathogens too, because the pathogens prefer inorganic
and toxic organic pollution.
BioSanitizer can be used to biosanitize both the solid as well as
liquid wastes, only the moisture content is different in these two
catagories. Human excreta, if healthy, is produced as a solid waste.
We pour costly and scarce drinking water to produce sewage. Sewage
is conventionally treated to produce sewage sludge that needs to
be treated as solid waste. Since the inorganic load of sewage sludge
is high, wooden chips are mixed to start composting reaction. Carbon
dioxide is produced in the stages of electricity generation, secondary
sewage treatment and in composting. This is equivalent to loss of
resource (organic matter). Environmental pollution takes place only
when we waste a resource.
BioSanitizer locks the inorganic content of the wastes and cracks
the toxic organics to produce safe organics, retaining food organics
during this treatment. The locked inorganics become safe for the
aquatic life and the soil. These also become a resource in healthy
soil (with earthworms). Plants can derive nutrition from the locked
inorganics in healthy soil. To produce healthy soil, one just has
to feed the soil with wastes that have been biosanitized with BioSanitizer
BioSanitizer harnesses interesting natural mechanisms to convert
wastes into resources. These were learnt after reading the "books
of nature" over the past forty years.
wastes or wastewaters can be stabilized in two ways:
bioincinerating the simple organics, to stop the decomposition reaction
(production of carbon dioxide), or
locking the inorganics. This also stops the carbon dioxide production
and produces stabilized wastes.
BioSanitizer uses the latter method that conserves the resources
stabilize solid wastes, one can add 1 gram BioSanitizer per
10 tons of waste. BioSanitizer is added in the top layer and the mass
sprinkled with water, to produce stabilized waste in 10 days. This
is the time for mixing, not the reaction time. The reaction is quite
fast, over within a few minutes. One can reduce the mixing time
with the use of mechanical mixing methods, if necessary.
treat wastewater, one can add 1 gram BioSanitizer to the
wastewater stream of 10 m3/day. BioSanitizer is added at the
beginning of the sewer line or open nalla carrying wastewater, or
in the first tank of the wastewater treatment unit. BioSanitizer locks
the inorganics, cracks the toxic organics and also produces active
oxygen that takes care of BOD and pathogens. A minimal treatment
time, of few hours, depending upon the level of pollution, is required.
Since no mechanical aeration or mixing is required for BioSanitizer
action, this method is best used for "on-line" treatment while the
wastewater flows in the underground or open channels. It is also
useful for treatment of polluted lakes, rivers and wells/borewells.
1 gram is a good dose for a well/borewell and one gets results within
few hours. Brackish water becomes sweet and one also gets free of
pathogens, toxic organics and heavy metals..
has been used successfully to clean the Powai Lake in Mumbai and
Pashan lake in Pune. BioSanitizer has shown efficacy to clean the Ambil
nalla in Pune. This carries sewage and pours it into the Mutha River.
BioSanitizer also has been used in the sewers in Pune. Several individuals
and industries have used BioSanitizer in their septic tanks to get water
that is an asset for their gardens. Several industries have stopped
mechanical aeration in their activated sludge plants and have found
that BioSanitizer generates no sludge for disposal. The wastewater treatment
plants require no machinery, electricity and operators. Several
farmers have used BioSanitizer to treat their wells/bore wells to manage
the inorganic pollution. and by cities and industries to treat wastewaters
in eco-friendly manner. These methods are also easy to operate and
maintain because BioSanitizer has auto-control action. The
treated water becomes an asset for the soil.
BioSanitizer makes wastewater treatment a simple task. It converts
pollution into an asset. The method pays for itself in a short time
because of value-addition to the wastes. Capital investment is low
and there are no recurring expenses. People accept it readily during
the period of ongoing recession. It also makes sense ecologically.
Dr. Uday S. Bhawalkar