Removal of Quinolone Antibiotics from Wastewater by the Biochar-Based Sludge Adsorbent

Antibiotics have been detected in tiny environmental matrices all over the world, which caused a lot of concern. To solve this problem, biological treatment can be a low-cost and high-efficiency way. The use of biochar adsorbents made from the residual sludge of sewage for wastewater treatment can achieve pollutant removal while realizing pollutant reduction and reuse, which is of great significance for green development. In this study, a prepared biochar-based adsorbent (PBA) was modified and used for norfloxacin (NOR) removal. The composition of the adsorbent was characterized, and the influence of application factors on adsorption performance was investigated. After being modified and optimized, an overall removal efficiency of 84% was achieved for NOR in 4 h. The adsorption behavior was spontaneous and consistent with the Lagergren pseudo-second kinetic model and Langmuir model. The adsorption capacity of PBA reached 8.69 mg center dot L-1 for NOR. A total removal efficiency of 62% was obtained for five mixed quinolone antibiotics by PBA. The PBA could be well regenerated and reused five times. This study explored a new method of the bio-waste utilization of sewage sludge for antibiotic removal from wastewater.

Automated summary

Antibiotics have been detected in small environmental matrices worldwide, causing concern. The use of biochar adsorbents made from residual sewage sludge can remove pollutants and promote pollutant reduction and reuse, which is significant for green development. In this study, a modified biochar-based adsorbent (PBA) was used for the removal of norfloxacin (NOR) from wastewater with an overall removal efficiency of 84% achieved in 4 hours. The adsorption behavior followed the Lagergren pseudo-second kinetic model and Langmuir model, and the capacity of PBA for NOR reached 8.69 mg·L-1. A total removal efficiency of 62% was obtained for five mixed quinolone antibiotics using PBA, which could be regenerated and reused five times. This study presents a new method for utilizing sewage sludge as a bio-waste for antibiotic removal from wastewater.