Optimization of hexavalent chromium ion adsorption using natural silica modified with DMA (Dimethylamine) by batch method

Abstract

Heavy metals are the most dangerous source of pollution for environmental systems because they have non-biodegradable, toxic, and even carcinogenic properties even in low concentrations (ppm). Usually metals are insoluble, precipitated, dissolved, absorbed, inorganic, reduced, oxidized, and free of metals. One of the heavy metals that can cause negative effects on humans and living things is chromium ion. One way to overcome chromium metal in waste is to absorb it with DMA modified silica adsorbent. The adsorption of chromium (VI) from aqueous solutions was examined at various pH, contact times, and initial Cr (VI) concentrations. Langmuir adsorption isotherm yields a regression coefficient R2 = 0.9807. In the initial conditions Cr (VI) 100 mg L-1, pH 2.0 with stirring for 90 minutes, the maximum adsorption capacity of Cr (VI) was 1,024 mg g-1. In this study, researchers used natural silica modified with dimethylamine as an adsorbent for the adsorption of Cr (VI) ion, GPTMS (glycidoxypropyltrimethoxilane) as an intermediate or bridge connecting silica with DMA (modifying compound).