Figure 6: Comparison of metal and nutrient status of amended and
routinely made Jaivik Prom
For Jaivik Prom, the heavy metal concentrations for the amended product
are well within permissible limits for the amended product except for
the Cadmium concentrations. The nutrient concentration is higher for
Zinc, Boron, Manganese, and Sodium in the amended product. The other
nutrients are lesser as compared to routine products but the inherent
levels in the modified product are good enough to be used for plant
growth promotion.
Conclusion
With increasing volumes of sludge, there is a dire need for sludge
management. While direct land disposal takes place in underdeveloped
countries, it is not a viable option as it leads to accumulation of
toxins like aromatic hydrocarbons, heavy metals in the soil contaminates
groundwater as well as nearby surface water due to seepage problems.
Landfilling has also been found to be a potential source of greenhouse
gases and leads to global warming. The other technologies like
incineration, pyrolysis, metal and phosphorous extraction, use for fuel
also exist associated with their costs and energy expenses. In this
study we have proposed a unique solution for the sludge for Jagjeetpur
STP in haridwar whereby it can be usefully converted to agrcicultural
inputs after treatment. Analysis of the data obtained directly from the
plant, commissioned under Namami Gange Program showed the stability in
its performance from the timeline of solid particles produced in the
centrifuge outlets and MLSS data. Three products were made from the STP
sludge compost instead of using the routinely made compost from farmyard
manure. Detailed analysis of STP sludge compost showed the presence of
plant nutrients which can be used for the purpose of growth promotion.
Upon fortification of the sludge with other ingredients to make products
for specific purposes it was seen that the concentration of heavy metals
in the modified product was well within limits for the a barring few
exceptions. the physicochemical parameters were also within the
prescribed specification of tye FCO, 1985. The nutrient concentrations
were also in the desirable range and hence can be used as a good organic
fertilizer. The mixing of different ingredients for the three products
respectively and appropriate fortification resulted in bringing the
undesirable parameters within specified limits with an increase in the
desirable nutrient concentrations. Further amendments with more
experimental data will further improve the quality of the products for
obtaining better results. This can be a sustainable solution for sludge
management with minimal input of energy. Moreover, sale of these reputed
products can bring revenue for the company and gains for the farmers.
Thus, it is a true situation of conversion of waste to value added
products.