Posts Tagged ‘fertilizer’


On the sludge management and reuse potential in Bangalore

May 12, 2014

One of the many critical factors affecting productivity in Indian soils is the absence of nutrients such as Nitrogen, Potassium and Phosphates. Even Carbon is in short supply as well as micro-nutrients such as Zinc and Boron.  AA substantial part of our artificial fertilizers is imported and we run up quite a huge bill. Fertilizer prices too are shooting up leading to an imbalance in their application. It has been reported for example that Urea which is relatively cheaper is over applied on soils causing more harm than good.

Cut to urban cities. Sewage treatment plants are coming up in large numbers. The Bangalore Water Supply and Sewerage Board –the utility responsible for sanitation and sewage, will eventually be setting up 25 sewage treatment plants treating nearly 1100 Million Litres Per day of sewage. These plants will mostly be secondary and tertiary treatment plants. Each million litre of sewage generates nearly a Tonne of sludge. Imagine 1100 Tonnes of sludge will be generated in the city of Bangalore alone. This is 120 truckloads of sludge.

There are smaller sewage treatment plants dotting the landscape in apartments and layouts too. These too generate smaller quantities of sludge. Overall this represents a management challenge of large proportions.

Research:  Currently at the GKVK-University of Agricultural Sciences – research work is going on to understand the nutrient value of this sludge. A Ph D student is pursuing her Doctorate and is experimenting on field trials using the sludge as manure. The initial test results show very good amounts of Potassium and Phosphates in the sludge.



Separately sludge is also being picked up from Ecosan toilets. These are source separating composting toilets which segregate urine and solids. The solids are covered with ash after every use and desiccated before application as a fertilizer on soils. Farmers of Kamasamudram and H.D.Kote have such toilets in their homes and are very happy with the fertilizer they get. In fact this compost is priced at Rs 10 a kg.


Sludge sells for upto Rs 10 a kg.

Similarly the landscape of rural India is dotted with pit toilets, more than 130 million of them at the last count. These too accumulate solid sludge and need to be emptied using mechanical systems. They are also found to be rich in Phosphates and Potassium.

All these various forms of sludge will be taken, tested applied on fields and crop productivity tested under expert supervision.

When research and application come together in a spirit of cooperation, it is possible to find solutions for India’s vast water, food and sanitation problems. At the base, this is a nutrient cycle at play. How we scientifically understand and manage it will show us the path to solutions. If every gram of sludge generated in our Sewage Treatment Plants become useful as manure it will partially solve India’s fertilizer needs and eliminate pollution. It will also increase productivity and richness of our soils as well as enhance the livelihood opportunities of farmers.

Recognizing and converting waste to a resource will help thousand of apartments and layouts, small and medium towns and even metropolis to manage their sewage efficiently for reuse and recycling. This would be water wisdom.


Innovation is alive and kicking in sanitation

June 8, 2013

It is not only Bill and Melinda who are funding innovation in the toilet business :).

When millions of people all across India start to build toilets in rural areas and in small towns they do not have a sewerage system to connect to. They usually build a single pit lined with concrete rings and connect the toilet to it. In India the toilets too are pour flush toilets and not the dry toilets prevalent across much of Africa.

Eventually these pits do fill up, depending on many factors such as the depth of the toilet pit , the number of users, their diet , the soils ability to infiltrate water etc etc.


The pan for an Indian toilet – this has a water seal too


A single pit toilet lined with pre-cast concrete rings

Eventually they will fill up


Jugaad to the rescue – These tablets if placed in a full pit will ‘burn’ it and reduce the filling making it possible to use the pit for more time


These are called ‘pit medicine’ in Kannada and are available across many small towns. Each set costs Rs 50 ( 1 US $) and is a single time use.


Taa-daah …Honey-sucker to the rescue. Will empty the pit toilet in minutes.

Now imagine a set of tablets which can also sterilize the pit content and kill all pathogens . The pit sludge can then be easily removed using the ‘Honey-sucker ‘ and spread out on the fields in the rural areas and in the small towns to act as fertilizer for the crops.

..and oh by the way , one of the fastest growing business around small towns and villages is in these pre-cast concrete ring making. All you need is an empty site , a steel mould for pouring the concrete , some cement and GI wires /streel rods and you are in business. As there is a huge government push for sanitation demand is picking up in villages for these rings for the toilet pit

The concrete ring makers

                            All over South India , in small towns and large villages, concrete    rings for pit toilets are being made

This is what we will be working at in the near future.


Trees of Bangalore – the Pongaemia (karanj- hongey)

January 2, 2013

The Pongaemia Pinnata is a lovely , hardy tree found all over Bangalore. It provides shade in summer . Its flowers and leaves are very rich soil fertilizers. The seeds are pressed for oil and have been traditionally used for lighting lamps. Now they are also used as a bio-diesel. The tree harbours many birds and insects and is fabled in the Tamil language especially.


Click here for another video ->     Pongaemia and livelihood


Ecosan-source separating composting toilet

January 25, 2008

An ecosan toilet is a source separating composting toilet and a black water saver. It also generates good nutrients for plant growth. It also does not pollute

our precious water resources. This is the way to go with sanitation