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.