Modified paddy husk carbon with linked fibrils of FeHO2 using aluminium as the surface regulator for enhanced As (III) removal in fixed bed system

Abstract

Abstract The As (III) uptake capacity of Fe-impregnated AC greatly depends on the availability of active surface sites of iron oxide. In this context, utilizing aluminium as a surface regulator, we proposed a process to attach linked fibrils of FeHO2 to develop an adsorbent with enhanced As (III) adsorption capacity. The procedure was based on the hydrothermal process using paddy husk-based activated carbon, and both Iron and aluminium ions in the test hydrolysis solution. The exhaust time was observed to rise with increasing dose, falling flow rate, and influent concentration. The CCD optimization result showed that the FeAlPBC was an efficient and cost-effective adsorbent with a maximum response of 1681 min when the independent parameters were retained at 15.0 g FeAlPBC dose, 500 μg/L influent concentrations, 2.0 mL/min flow rate, and a desirability value of 0.986. The experimental results and Thomas and advection-diffusion models were in good agreement. The FeAlPBC samples can be recycled for four cycles with little to no reduction in adsorption capacity. Also, the TCLP test demonstrated that the used FeAlPBC were inert and could be put into landfills without risk. In conclusion, FeAlPBC is a strong contender for removing As (III) from potable water and has a wide range of potential future applications.