Used coffee/PCL composite filter for Cu(II) removal from wastewater

A coffee ground composite membrane for copper adsorption was prepared using used coffee grounds and polycaprolactone, a biodegradable polymer. The prepared sample shows a removal efficiency of 90 % or more in 4 h at a concentration of 100 mu M (= 13.45 ppm), which satisfies the drinking water acceptance criteria of 1.5 mg L-1 set by the World Health Organization. The functional groups of the coffee composite filter were analyzed with Xray photoelectron spectroscopy, and the surface of the filter membrane was analyzed using scanning electron microscope. UV-vis spectrophotometry confirmed the adsorption capacity and amount of Cu(II) adsorption of the filter or coffee grounds, and Langmuir, Freundlich, Redlich-Peterson, and Fritz-Schlunder isotherms were used to investigate the removal mechanism. The kinetic studies were also performed to clearly demonstrate the adsorption process.

Automated summary

A coffee ground composite membrane for copper adsorption was prepared and demonstrated high removal efficiency of over 90% in a short period of time, satisfying the drinking water acceptance criteria. The analysis of structure and properties indicated good adsorption capacity of the composite membrane. The results of this study are of great significance for the development of new environmentally friendly adsorption materials.