Specifically Designed Magnetic Biochar From Waste Wood for Arsenic Removal
Abstract Arsenic is a kind of metal elements, widely distributed in nature. Many technologies, including adsorption, ion exchange, membrane separation and extraction, have been developed to treat arsenic-containing wastewater due to a series of drinking water safety problems caused by arsenic pollution. Biochar has some advantages of big surface area, low cost and so on. Therefore, waste wood was used as biochar, FeCl3·6H2O and KMnO4 were also used to promote the performance of arsenic removal. The results of XRD, BET, EA and VSM analysis show that modified biochar has major elements of Fe, Mn with KMnO4. The modified biochar (Fe1Mn1C1) has higher magnetism of 40 emu g-1. Through adsorption performance assessment, the best ratio of Fe/C is 1:1 and the adsorption efficiency and capacity of Fe1C1 is 61.6% and 0.681 mg g-1, respectively. Then, the best ratio of Mn, Fe and C is 4:1:1 with highest adsorption efficiency of 80.8% and capacity of 0.724 mg g-1. The best dosage of Fe1C1 and Fe1Mn2C1 is the same as 1 g L-1. It shows better adsorption capacity under higher pH with pristine biochar (PB) and Fe1C1 while under lower pH with Fe1Mn2C1. The adsorption patterns of PB and Fe1Mn2C1 fit Langmuir well. In contrast, adsorption pattern of Fe1C1 fits Freundlich well. In addition, three types of biochars all fit the pseudo second order adsorption kinetics.