Meta-analysis reveals the effect of biochar on sulfonamides and tetracyclines in soil

Sulfonamides (SAs) and tetracyclines (TCs) are widely used as broad-spectrum antibiotics, raising global concern due to their potential to accumulate in soil and consequent impact on the ecosystem. Although biochar has the ability to reduce SAs and TCs in soil, the understanding of the factors affecting the efficacy of biochar remediation remains inadequate. Here, a meta-analysis was conducted to evaluate the effects of biochar on SAs and TCs concentrations, soil properties, and microbial diversity in soils contaminated with antibiotics. The incorporation of biochar resulted in a marked decrease in the concentrations of SAs and TCs in soil, by 55.8% and 20.9%, respectively. In biochar-amended soil, the soil properties were enhanced, with notable increases of 3.2% in pH and 36.5% in organic matter, respectively. This further enhanced soil microbial diversity, with notable increases observed in both the Chao index (19.8%) and the Shannon index (6.9%). Additionally, agricultural waste biochar pyrolyzed at 300-500 °C demonstrated superior efficiency in reducing SAs and TCs. Furthermore, the remediation efficiency increased with higher soil pH and longer application time. The results of this research provided strong evidence for the remediation of soil antibiotic contamination.