Enhanced removal of Fe,Cu,Ni,Pb,and Zn from acid mine drainage using food waste compost and its mechanisms  

作　　者：Wei Liu Savana Rast Xuming Wang SinLin Lan Emmanuel Yaw Owusu-Fordjour Xinbo Yang 

机构地区：[1]Department of Material Science and Engineering,University of Utah,Salt Lake City,UT 84112,USA [2]Department of Chemistry,University of Utah,Salt Lake City,UT 84112,USA

出　　处：《Green and Smart Mining Engineering》2024年第4期375-386,共12页绿色与智能矿业工程(英文)

基　　金：U.S.Department of Interior’s Office of Surface Mining Reclamation and Enforcement Mine Drainage Technology Initiative under the Award Number S23AC00049-00.

摘　　要：Heavy metals(HMs)in acid mine drainage(AMD)pose serious threats to aquatic life and soil.Biosorbents are promising materials to remove HMs from wastewater.Herein,food waste compost was used as a low-cost and sustainable biosorbent to remove Fe^(3+),Cu^(2+),Ni^(2+),Pb^(2+),and Zn^(2+)from an AMD and other model solutions with an initial pH of∼2.24.Batch adsorption tests were conducted to systematically investigate the influences of initial pH,compost dose,the presence of Fe^(3+)and SO_(4)^(2−)ions,and the pH-induced Fe precipitates on the removal performance.The involved removal mechanisms were explored by conducting stepwise precipitation tests,sequential extraction tests,and Fourier transform infrared spectroscopy(FTIR)characterization.It was found that the addition of the compost removed over 90%of Zn,Ni,Cu,and Pb at pH 5.80,5.50,4.50,and 3.00,respectively.At low compost doses,the presence of Fe^(3+)and SO_(4)^(2−)ions hindered the removal since the competition effect of Fe^(3+)ion and lower absorbability of metal-sulfate complexes,respectively.Sequential extraction tests revealed that higher fractions of Fe,Cu,and Pb were strongly immobilized through complexation and precipitation relative to Ni and Zn.Additionally,the pH-induced Fe precipitates did not favor the removal of the HMs,probably due to the adsorption of organic components released from the compost.This study suggests that compost has the potential to remove HMs from acidic wastewater without pre-neutralization.

关 键 词：Acid mine drainage Heavy metals Food waste compost ADSORPTION Sequential extraction 

分 类 号：O64[理学—物理化学]