Preparation and evaluation of Ni-loaded activated carbon for enrichment of arsenic for analytical and environmental purposes

• The 10% Ni–AC possesses great adsorption capacity and selectivity for As(V).
• XPS data proved the presence of NiO and Ni(OH)2 on the Ni-loaded AC surface.
• The main As adsorption mechanism on Ni–AC is the surface complexation.
• SEM–EDX study confirmed the homogenous arsenic distribution on the 10C surface.
• Carbon slurry sampling GFAAS for As determination in food samples is proposed.

A new adsorbent based on thermal modification of activated carbon impregnated by nickel(II) nitrate was prepared and utilized for arsenic enrichment from aqueous solution. Various ratios of the impregnating agent to carbon mass were analyzed for the evaluation of arsenic adsorption capacity and selectivity. The properties of As(V) ions affecting the adsorption process on the prepared activated carbon were studied. The carbon impregnated with 10% Ni(NO3)2 and thermally treated at 250 °C exhibited the highest adsorption capacity and selectivity towards arsenic ions. The physical and chemical properties of the Ni-loaded activated carbon were investigated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). These studies confirmed that the surface reactions of nickel oxides or hydroxides with arsenate ions enhanced the arsenic adsorption on the Ni-loaded activated carbon. Enrichment of arsenic from environmental samples onto the studied adsorbent was tested and successfully applied for As determination using the carbon slurry sampling technique for graphite furnace atomic absorption spectrometry determination (GFAAS) using the standard calibration method.

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