Arsenic, chromium and mercury removal using mussel shell ash or a sludge/ashes waste mixture

作者：Seco Reigosa Natalia; Pena Rodriguez Susana; Carlos Novoa Munoz Juan; Arias Estevez Manuel; Fernandez Sanjurjo Maria J; Alvarez Rodriguez Esperanza; Nunez Delgado Avelino^*

来源：Environmental Science and Pollution Research, 2013, 20(4): 2670-2678.

DOI：10.1007/s11356-012-1192-6

• Ash from shell calcination
• Calcined mussel shell
• Heavy metals adsorption
• Sewage sludge
• Waste recycling
• Waste mixture
• Wood ash

Different batches of valued mussel shell and waste mussel shell ash are characterised. Shell ash has pH %26gt; 12 and high electrical conductivities (between 16.01 and 27.27 dS m(-1)), while calcined shell shows pH values up to 10.7 and electrical conductivities between 1.19 and 3.55 dS m(-1). X-ray fluorescence, nitric acid digestion and water extractions show higher concentrations in shell ash for most parameters. Calcite is the dominant crystalline compound in this ash (95.6 %), followed by aragonite. Adsorption/desorption trials were performed for mussel shell ash and for a waste mixture including shell ash, sewage sludge and wood ash, showing the following percentage adsorptions: Hg(II) %26gt; 94 %, As(V) %26gt; 96 % and Cr(VI) between 11 and 30 % for shell ash; Hg(II) %26gt; 98 %, As(V) %26gt; 88 % and Cr(VI) between 30 and 88 % for the waste mixture. Hg and As desorption was %26lt; 5 % for both shell ash and the waste mixture, while Cr desorption was between 92 and 45 % for shell ash, and between 19 and 0 % for the mixture. In view of that, mussel shell ash and the mixture including shell ash, sewage sludge and wood ash could be useful for Hg(II) and As(V) removal.

• 出版日期2013-4