Tree-inspired polycaprolactone-mugwort adsorption membrane for Cu(II) removal from wastewater

Abstract

Recently, wastewater discharge has been increasing due to the increase in semiconductor production, and heavy metals in semiconductor wastewater can cause life-threatening effects on the brain, liver, and kidneys. In this study, we developed an eco-friendly polycaprolactone-mugwort (PCL-mugwort) adsorption membrane through electrospinning to remove various heavy metal ions contained in semiconductor wastewater. PCL is a representative biodegradable and biocompatible polymer, and mugwort is a natural material and rich in minerals, calcium, iron, and etc. The removal performance of the PCL-mugwort adsorption membranes for heavy metal ions was evaluated under static conditions with stirring and dynamic conditions with filtration. With 100 μM aqueous solution (5 mL) of copper ions, the 36 cm2 the PCL-mugwort adsorption membrane, with a mugwort content in the membrane: 0.13 mg/cm2, shows a high removal efficiency of 71.7 % within 6 h under a static condition and 65.4 % under a dynamic condition with a flow rate of 10 mL/h. The removal mechanism was analyzed using two- and three-parameter isotherms, indicating that the adsorption followed a multilayer process on a heterogeneous surface with adsorption sites having different energies. In addition, the PCL-mugwort adsorption membrane was scrolled to mimic the internal structure of a non-powered artificial tree with a capillary force to pump wastewater for simultaneous removal of heavy metal ions and evaporation of clean water.