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This study characterises the sewage sludge from 26 sewage treatment plants in India, which demonstrates the nutrient potential and highlights the associated challenges in using the sludge. The dry sludge had 2.35%–4.2% N, 2.46–3.2% phosphorus (P2O5) and 0.83%–1.24% potassium oxide (K2O), whereas sludge ash contains ~13.6% and 2.7%, P2O5 and K2O, respectively. Total nutrient potential from the sludge of the existing sewage treatment facility was 97.5 × 103 tonne/year, which is equivalent to 0.92% urea or 0.19% NPK used presently as conventional fertilisers in India. However, pre‐treatment may be required for this sludge before using it in agricultural fields as heavy metals, such as Zn, Cu, Ni, Cd, and Cr, were found higher than the compost standards. This study would be useful for the researchers and policymakers globally and would motivate them to make policies and deploy suitable technologies towards the nutrient utilisation from sewage sludge. [ABSTRACT FROM AUTHOR]

Dumping of municipal solid waste into uncontrolled dumpsites is the most common method of waste disposal in most cities of India. These dumpsites are posing a serious challenge to environmental quality and sustainable development. Mumbai, which generates over 9000 t of municipal solid waste daily, also disposes of most of its waste in open dumps. It is important to analyse the impact of municipal solid waste disposal today and what would be the impact under integrated waste management schemes. In this study, life cycle assessment methodology was used to determine the impact of municipal solid waste management under different scenarios. Six different scenarios were developed as alternatives to the current practice of open dumping and partially bioreactor landfilling. The scenarios include landfill with biogas collection, incineration and different combinations of recycling, landfill, composting, anaerobic digestion and incineration. Global warming, acidification, eutrophication and human toxicity were assessed as environmental impact categories. The sensitivity analysis shows that if the recycling rate is increased from 10% to 90%, the environmental impacts as compared with present scenario would reduce from 998.43 kg CO2 eq t-1 of municipal solid waste, 0.124 kg SO2 eq t-1, 0.46 kg PO4-3 eq t-1, 0.44 kg 1,4-DB eq t-1 to 892.34 kg CO2 eq t-1, 0.121 kg SO2 eq t-1, 0.36 kg PO4-3 eq t-1, 0.40 kg 1,4-DB eq t-1, respectively. An integrated municipal solid waste management approach with a mix of recycling, composting, anaerobic digestion and landfill had the lowest overall environmental impact. The technologies, such as incineration, would reduce the global warming emission because of the highest avoided emissions, however, human toxicity would increase. [ABSTRACT FROM AUTHOR]

The Indian power sector relies heavily on coal power plants for electricity generation as 59% of the total installed capacity is from coal power plants. Considerable research has been done in developed countries to analyze the suitability of CO2 capture technologies for coal power plants, but not in India. This work analyzes the suitability of various CO2 capture technologies for Indian coal power plants on the basis of different parameters: energy penalty, cost of CO2 capture, efficiency, and age and size of the power plant. An Integrated Environmental Control Model (IECM) was used to simulate the power plants, and to calculate the energy penalty and cost of capture. All existing 517 units of 115 coal power plants in India, along with one Integrated Gasification Combined Cycle (IGCC) plant and one ultra-supercritical plant were analyzed for CO2 capture suitability. Results show that the total installed capacity of Indian coal power plants would reduce to somewhere between 66 896 and 105 991 MW, depending on the CO2 capture technology applied, from and existing 126 320 MW. The average efficiency of Indian coal power plants would reduce from the current 29% to 24.4%, 20.7%, and 15.4% if we retrofit the plants with amine-, ammonia-, and membrane-based capture systems, respectively. Cost of CO2 capture for these three technologies would be $42.3, $75.2, and $81.9 per tonne of CO2, respectively. The CO2 capture technologies would be better off on coal power plants which are less than 20 years old, as the energy penalty would be less. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]