Surface functionalized Philippine natural zeolite for arsenic adsorption in an aqueous solution

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This study shows the effectiveness of the natural zeolite and its surface modified form in adsorbing arsenic from deep well water sources and irrigated waters in some rural areas in the Philippines. It aims to compare the arsenic adsorption efficiency between, pre-conditioned sodium modified natural [Na-Philippine natural zeolites (PNZ)] and surface-modified Na-PNZ (SM-PNZ) with varying concentrations of 100% and 330% of the external cation exchange capacity (ECEC) of the PNZ. Characterization of the adsorbents were conducted such as X-ray diffraction (XRD) (mineralogy using X-ray diffraction), XRF (chemical composition using X-ray fluorescence), Fourier-transform Infrared for functionalization test and wettability tests (contact angle and water penetration tests). Arsenic adsorption studies were conducted using the Atomic absorption spectroscopy to determine the arsenic uptake of the adsorbents at varying contact times. The results proved that the adsorbent modified with surfactant, cetyltrimethylammonium bromide, at 100% ECEC has the highest arsenic uptake compared with Na-PNZ.