A new hydrothermal approach has been investigated for synthesis of alumina which has been utilized for decontamination of trivalent and hexavalent chromium (Cr) as well as microbes from water. The heat treatment of aluminum nitrate and sucrose forms single phase g-alumina compact of 318 m 2 /g surface area at 1100 °C. The carbon particles present in aluminum nitrate- sucrose system get oxidized as carbon dioxide. The removal efficiency of synthesized alumina has been compared with commercial alumina and studied as a function of pH, time and adsorbent dose. Interestingly, synthesized alumina have better removal efficiency than commercial one. The adsorption data was best fitted to Langmuir isotherm suggesting monolayer adsorption. The adsorption capacity of the proposed material was found to be 11.76 mg g -1 and 11.9 mg g -1 for Cr (III and VI) respectively, which is better than several inorganic materials reported. The proposed alumina also inhibits growth of several bacteria like Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Staphylococcus aureus, Streptococcus pyogene, Pseudomonas aeruginosa, Klebsiella pneumoniae, Serratia marcescens, Salmonella typhimurium and Proteus hauseri upto 98%. The adsorption experiments were carried out in triplicate to get reproducible results. All experimental data for Cr removal has been reported with 95% confidence level (K=2).