New use for biochar derived from bovine manure for tetracycline removal

This study investigated the physicochemical properties of bovine manure biochar (BC) obtained at different temperature of 500 degrees C (BC-500) and 700 degrees C (BC-700). The effects of the contact time, temperature, pH, background electrolyte, and regenerated adsorbent on the adsorption of tetracycline (TC) by BC-500 and BC-700 were determined. The TC removal rates were 95.31% by BC-500 after 12 h and 99.70% by BC-700 after 4 h. The maximum adsorption capacities of BC-500 and BC-700 were 5.38 mg/g and 5.82 mg/g, respectively. The adsorption of TC by BC-500 and BC-700 was characterized better by pseudo-second order kinetics. The adsorption kinetics of BC-500 and BC-700 were fitted well by the pseudo-second order kinetic model. Regeneration experiments showed that BC-500 and BC-700 still delivered satisfactory removal efficiencies even after three cycles, 52.95% and 77.20%, respectively. The main mechanisms responsible for the adsorption of TC by BC were determined as hydrophobic interactions and pi-pi electron donor acceptor interactions. This new type of inexpensive and readily available adsorbent may provide an effective solution for the removal of TC from wastewater in the future.

Automated summary

The study investigated the physicochemical properties of bovine manure biochar obtained at different temperatures and their adsorption of tetracycline. The results showed that both BC-500 and BC-700 had high TC removal rates, with different maximum adsorption capacities, and were well described by pseudo-second order kinetics. Even after multiple cycles, the biochar still maintained satisfactory removal efficiencies, mainly through hydrophobic interactions and pi-pi electron donor acceptor interactions.