Fabrication of environmentally-friendly composited sponges for efficient removal of fluoroquinolones antibiotics from water*

In this study, two environmentally-friendly macroscopically formal (PVF) composited sponges (PL and PLS) functionalized with lignin and lignosulfonate, respectively, were fabricated by a one-step mechanical foaming method. PLS, obtained with the fed mass ratio of 0.3:1 lignosulfonate to PVF in the preparation process, possessed a large specific surface area of approximately 22.396 m2/g, a three-dimensional skeleton structure with a skeletal density of 3.236 g/cm3, and 0.338 mmol/g of acidic oxygen-containing groups. Thus, it showed a high adsorption capacity of 0.16-0.24 mmol/g in removing seven antibiotics, of the popular fluoroquinolones (FQs) family from water. The contributions of hydrogen bonding, electrostatic attraction (EA) and 7C-7C electron donor-acceptor interaction to the adsorption of FQs onto the PL and PLS sponges were analyzed systematically by investigating the pH dependence of the adsorption capacity, and the changes in adsorption of two sub structural analogs of FQs as molecular probes, and by performing theoretical calculations. The EA between the acidic oxygen-containing groups on the sponges and the amino groups of FQs played a dominant role in adsorption in near neutral conditions, leading to a superior adsorption performance for PLS. Overall, the composited sponges have the advantages of simple production, environmental-friendliness, convenient recycle, and low cost, which renders them potentially viable in treating real wastewater containing FQs.

Automated summary

In this study, two environmentally-friendly macroscopically formal (PVF) composited sponges (PL and PLS) functionalized with lignin and lignosulfonate, respectively, were fabricated by a one-step mechanical foaming method. PLS showed a high adsorption capacity for removing seven antibiotics from water, attributed to its large specific surface area and the dominant role of electrostatic attraction in near neutral conditions. These composited sponges have the advantages of simple production, environmental-friendliness, convenient recycle, and low cost, making them potentially viable in treating real wastewater.