Applicability of reused industrial dry sanding powder for adsorption of arsenic

Abstract

This study examined the potential reuse of powdered wastes (PW) generated during the sanding and sawing process in a local chemical company in Korea with the viewpoint of the recycling these wastes and minimizing the level of contamination. As the aluminium hydroxide inside the PW could be thermally converted to various types of aluminium oxides depending on the calcination temperature, the adsorptive properties could be changed and it may affect on adsorption ability. Calcination of the PW was performed for 3 h at 550 degrees C, 750 degrees C, and 950 degrees C. From the results, amorphous aluminium oxide was thermally generated by calcinating the PW at 550 degrees C and with further increase of temperature to 950 degrees C, the crystallinity of amorphous aluminium oxide was gradually increased. The physicochemical analysis of calcined powdered wastes (CPW) at various temperatures showed that more developed porosity was noted in the CPW as the calcinations temperature increased, whereas surface area was significantly decreased from 175.5 m2 g(-1) to 46.5 m2 g(-1). The removal efficiency of arsenate on the CPW decreased as the calcinations temperature increased from 550 degrees C to 950 degrees C. The CPW550 exhibited the highest adsorption capacities toward arsenate over pH range of 2-8 and showed a complete removal of the arsenate (10.0 mg L(-1)) within the first 10 min. Adsorption kinetic studies showed that the rate of arsenic adsorption on the CPW decreased with the increase of the calcination temperature. When the maximum adsorption capacity of arsenic onto the CPW was calculated by Langmuir equation, the CPW550 has the highest value as 43.9 mg g(-1).

Treatment of As(V) and As(III) by electrocoagulation using Al and Fe electrode

“…The Fe/acid/pH represents EC system with Fe electrode, acidic initial solution, and pH variation with reaction time, respectively. because the As(V) removal substitutes more OH position in Fe-hydroxide than that in Al-hydroxide.Available information(Goldberg & Johnston 2001;Meng et al 2002;Redman et al 2002;Yang et al 2007;Park et al 2008) indicate that As(V) can be effectively removed by Al and Fe salt coagulation and strongly bind to the surface of Al-or Fe-oxide with forming inner-sphere interface species. Additionally, the suitable removal pH for As(V) by Al or Fe salt coagulation range from 4-9.…”