Removal of Organic Pollutants from Wastewater Using Wood Fly Ash as a Low-Cost Sorbent

摘要

In this study, untreated and treated wood fly ash (WA) was used as a low-cost sorbent in batch sorption tests to investigate the removal of organic pollutants from a real wastewater generated by cleaning/washing of machinery in a wood-laminate floor industry in Sweden. The experiments focused on the effect of the WA dosage and particle size on the removal efficiency for organic compounds. With a WA dosage of 160 g L~(-1) and a particle size less than 1 mm, the reductions of chemical oxygen demand (COD), biologic oxygen demand, and total organic carbon were 37 ± 0.4, 24 ± 0.4, and 30 ± 0.3%, respectively. Pre-treatment of WA with hot water improved the COD removal efficiency by absorption from 37 ± 0.4 to 42 ± 1.6% when the same dosage (160 g IT1) was applied. Sorption isotherm and sorption kinetics for COD using untreated WA can be explained by Freundlich isotherm and pseudo-second-order kinetic models. Intra-particle diffusion model indicates that pore diffusion is not the rate-limiting step for COD removal. Based on the experimental data, WA could be used as an alternative low-cost sorption media/filter for removal of organic compounds from real industrial wastewater.