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Present work proposes on the synthesis of nano calcium oxide derived from waste cockle shell (Anadara granosa) and applied as heterogenous catalyst in biodiesel production via transesterification reaction under reaction parameter 15:1 methanol to oil ratio, 5 wt.% catalyst and 3 hour reation time and constant temperature at 65 ± 2 °C. The waste cockle shell was prepared in nano size via ball mill technique which was run for 36 hours at 350 rpm speed and then calcined at 900 °C for 2 hours to decompose calcium carbonate, CaCO₃ into nano calcium oxide, n-CaO. The catalyst was characterized by particle size analyzer, Transmission Electron Microscopy, Field Emission Scanning Electron Microscope, Surface Area Analyser, X-Ray Diffractometer, Fourier transform infrared, Hammet indicator and benzoic acid titration. Particle size of n-CaO catalyst was found within the range of  29 nm to 67.5 nm. Specific surface area of synthesised n-CaO is 8.41 m²/g with basicity strength of 0.055 mmol/g.  Methyl ester conversion of palm oil with n-CaO as a catalyst was 88.87 wt.%

Chlorination is a common disinfection method for tap and swimming pool water as it is the most effective and low-cost method compared with others. The purpose of the study was to assess cancer risk of THMs exposure in tap and swimming pool water in Kuantan hotels. Temperature and pH were analyzed as an in-situ measurement while the rest of the parameters were analyzed in the laboratory. The concentration of four forms of THMs in tap and swimming pool water analyzed from Hotel X are 1.23ug/L and 1.35ug/L for CHCl3 respectively and none for the CHCl2Br, CHClBr2 and CHBr3. The concentration of four forms of THMs in tap and swimming pool water at Hotel Y are 1.25ug/L and 1.18ug/L respectively for CHCl3 and none for the CHCl2Br, CHClBr2 and CHBr3. The cancer risk from exposure to THMs at Hotel X are 1.6 x 10- 5 for tap water, 1.9 x 10-5 for swimming pool water and 2.0 x 10-4 for both tap and swimming pool water while cancer risk from exposure to THMs at Hotel Y are 1.7 x 10-5 for tap water, 1.6 x 10-5 for swimming pool water and 1.19 x 10-4 for both tap and swimming pool water.Thus, it shows that, it is in range of acceptable risk.