Gamma - Radiolytic desulphurisation of some high-sulphur Indian coals catalytically accelerated by MnO2

γ-Radiolysis of acidic aqueous coal slurries is a novel and effective method for the simultaneous oxidative desulphurisation and demineralisation of high-sulphur coals. This method is capable to selectively remove the inorganic and organic forms of sulphur simultaneously through the in situ-generated H2O2 and other radiolytic products. In effect, there is neither any appreciable degradation of coal matrix nor any loss in the caking property and volatile matter content of the coals after the removal of sulphur. However, significant removals of sulphur and mineral matter are effected at rather high γ -dose (175X104 Gy or so). Therefore, for the process to be economically viable and commercially adaptable, the applied γ -dose needs to be somehow substantially brought down, at which the same level of desulphurisation could be achieved. Catalytically, accelerating the radiolysis process is one such possibility to effect the desulphurization step at a low γ -dose. Reported in this paper are the results of investigations on the desulphurisation and demineralization of high-sulphur (sulphur content in the range 3–5.5%) Churphy, Chalang and Bapung coals of Meghalaya by γ -radiolytic process catalysed by MnO2. The maximum removal of total sulphur (15.6%, 30.0% and 29.8%) at 30 X 104 Gy in the presence of MnO2 and the simultaneous removal of mineral matter (20.0% and 18.5% from Churphy and Chalang coals at 30 X 104 Gy and 12.0% from Bapung coal at 45 X 104 Gy. are at par with removals at 175 X 104 Gy without MnO2, which has been attributed to MnO2 catalytically accelerating the radiolytic process via the formation of highly reactive MnO under the action of γ -rays. All the other features of non-catalysed radiolytic desulphurisation such as stabilisation of the slurry and coal not becoming radioactive during irradiation, increase in the heating value, improvement in the caking property

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Not AvailableRainfall variability and water scarcity continue to hamper the food and income security of smallholder farming systems in poverty-affected regions. Innovations in soil and water management, especially in the drylands, are critical for meeting food security and water productivity targets of Agenda 2030. This study analyzes how rainfed agriculture can be intensified with marginal impact on the landscape water balance. The impact of rainwater harvesting structures on landscape hydrology and associated agricultural services was analyzed in the semi-arid Jhansi district of Bundelkhand region in central India. The Parasai-Sindh pilot watershed was subjected to a 5-year (2012–2016) monitoring of rainfed system improvements in water availability and crop intensification due to surface water storage (haveli system), check dams, and field infiltration structures. Hydrological processes were monitored intensively to analyze the landscape’s water balance components. Rainwater harvesting (RWH) structures altered the landscape’s hydrology, limiting average surface runoff from 250 mm/year to 150 mm/year over the study period. Groundwater levels increased by 2–5 m (m), alleviating water scarcity issues of the communities in recurring dry years. Nearly 20% of fallow lands were brought under cultivation. Crop yields increased by 10–70% and average household income increased from US$960/year to US$ 2700/year compared to that in the non-intervention landscape. The combined soil–water–vegetation efforts strengthened water resilience and environmental systems in agricultural landscape.Not Availabl