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A chemical factory near Ranipet town in Vellore district, in the state of Tamil Nadu, India produced chromium-based inorganic chemicals. The factory area in granite gnessic terrain receives an average annual rainfall of 1,000 mm. About 1.5 lakh tons of solid wastes rich in hexavalent chromium (Cr 6? ), spreading over an area of 14,000 m 2 (about 3.5 acres), having about 4 m thickness, is accumulated in an open yard within the factory premises. The soil and groundwater in and around the factory area are contaminated with Cr 6? leached from dump site. Cr 6? is carcinogenic in nature and when leached in water can lead to respiratory disorders. Resistivity surveys comprising vertical electrical sounding, multielectrode resistivity imaging, drilling of bore wells, chemical analysis of soil, formation and groundwater samples and bore hole tracer studies were carried out within the factory and adjoining areas to decipher subsurface geology, hydraulic behavior of dyke as natural barrier and lateral and vertical extent of pollution zone in and around the chromium dump site. The data obtained were integrated and interpreted for understanding the pollution migration and its impact on environment. Remedial measures are suggested for containing the contamination.

In the present study, microstructure, mechanical properties and wear behaviour of AA6082 alloy reinforced with Yttrium oxide (Y 2 O 3 ) and graphite (Gr) surface hybrid composites produced via friction stir processing have been investigated. Vol.% of Y 2 O 3 particles was varied (2, 4 and 6 vol.%) while the graphite content was kept at as 4 vol.%. Microstructure of synthesized composites revealed uniform distribution of Y 2 O 3 +Gr particles accompanied by a significant reduction in grain size. Microhardness of the composites was found to be 40% higher than the matrix alloy and tensile strength of the composites increased with increase in vol.% of Y 2 O 3 with a marginal decrease in ductility. Wear test results along with SEM micrographs of worn out surface of composites and matrix alloy were compared and correlated with their hardness. Hybrid composites showed better wear resistance.

In this work, Abrasive Water Jet Machining (AWJM) on aluminum based hybrid composite with Silicon Carbide (SiC) and Boron Carbide (B4C) reinforcement particles are investigated. Two different abrasive grain sizes of 80 mesh and 120 mesh are selected to carry out the experiments. The cutting parameters namely pressure, standoff distance (SOD) and traverse speed are assessed in terms of the kerf angle, Material Removal Rate (MRR) and Surface Roughness (Ra). The result shows that the coarse abrasive particle has a favorable effect on the MRR, while the fine grained abrasive particle produced minimum kerf angle and good surface finish.

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