Adsorptive Removal of Manganese from Manganese Slag Aqueous Solutions Using Biochars Loaded with Organic Acid-Fe

摘要

Manganese adsorptive removal is an important treatment process in constructed wetlands to deal with considerable amounts of tailing wastewater, many materials have been proposed for its removal. This work is aimed to examining the potential of biochars sorbent materials for removing Mn ions from manganese slag aqueous solutions by modified biochars. The biochars with different organic acid-Fe ratios were prepared; factors on Mn adsorption including mixing ratio, Fe adsorption rate, and the BET surface of the modified biochars were discussed and the sorption efficiency of Mn was investigated through column adsorption experiments. According to our study, it's clearly that loaded organic acid biochar with greater Fe content removed higher percent of Mn from the aqueous solution. Contents of Fe_2O_3(30-103%), Fe_3O_4 (65-106%) and CaCO_3 (4-80%) increased after loaded with organic acid-Fe in the biochars. With the increasing Fe content (2.58-5.07%) in biochar, the BET surface area of the Citric Acid-Fe biochar composites decreased from 81 m~2/g to 35 m~2/g, while the EDTA-Fe biochar composites decreased from 96 m~2/g to 22 m~2/g. The fixed loaded Fe biochars mixtures had a reduction of 4.02% to 32.01% in Mn sorption contrasting with raw biochar. The modified biochars could be used to remove the Mn ions in the tailing wastewater.