O/N/P-doped biochar induced to enhance adsorption of sulfonamide with coexisting Cu2+/Cr (VI) by air pre-oxidation

The aim of this work to study the effectiveness of newly synthesized O/N/P-doped biochar for the removal of antibiotics with coexisting heavy metals. This study developed a low-dose additive agent with air pre-oxidation (APO) to obtain O/N/P-doped biochar (ONPBC) at 650/350 degrees C pyrolysis temperature with adsorption amount of 76.99 mg.g(-1) (ONPBC650) and 62.33 mg.g(-1) (ONPBC350) for sulfapyridine (SPY), comparing to pristine bio-char 9.25 mg.g(-1) (BC650) and 11.60 mg.g(-1) (BC350), indicating the adsorption capacity of biochar has been greatly improved after modification. The main sorption mechanisms were elucidated for ONPBC650 (surface physical sorption) and ONPBC350 (H-bonding). The coexisting Cu2+/Cr (VI) showed different inhibition effects on the adsorption of SPY by ONPBC650/350. Considering a trade-off between high adsorption capacity and low inhibition effect of coexisting heavy metals, economic low-temperature O/N/P-doped biochar such as ONPBC350 could be a preferred adsorbent for the removal of sulfonamide or similar organic pollutants from contaminated water.

Automated summary

This study aims to investigate the removal of antibiotics and heavy metals using newly synthesized O/N/P-doped biochar, which significantly enhances the adsorption capacity after modification and demonstrates different inhibition effects on coexisting heavy metals. Economic low-temperature O/N/P-doped biochar is proposed as a preferred adsorbent for removing organic pollutants from contaminated water, striking a balance between high adsorption capacity and low inhibition effects.