Increasing global population and decreasing arable land pose tremendous pressures to agricultural production. The application of conventional chemical fertilizers improves agricultural production, but causes serious environmental problems and significant economic burdens. Biochar gains increasing interest as a soil amendment. Recently, more and more attentions have been paid to biochar-based slow-release of fertilizers (SRFs) due to the unique properties of biochar. This review summarizes recent advances in the development, synthesis, application, and tentative mechanism of biochar-based SRFs. The development mainly undergoes three stages: (i) soil amendment using biochar, (ii) interactions between nutrients and biochar, and (iii) biochar-based SRFs. Various methods are proposed to improve the fertilizer efficiency of biochar, majorly including in-situ pyrolysis, co-pyrolysis, impregnation, encapsulation, and granulation. Considering the distinct features of different methods, the integrated methods are promising for fabricating effective biochar-based SRFs. The in-depth understanding of the mechanism of nutrient loading and slow release is discussed based on current knowledge. Additionally, the perspectives and challenges of the potential application of biochar-based SRFs are described. Knowledge surveyed from this review indicates that applying biochar-based SRFs is a viable way of promoting sustainable agriculture.

Increasing quantities of pharmaceutical pollutants have been found in aquatic ecosystems. The treatment of pharmaceutical pollutants has been a major task that people have been committed to in recent years. The removal of pharmaceutical pollutants can be achieved by adsorption and advanced oxidation processes (AOPs). Compared with other carbon materials, biochar has a strong adsorption capacity and persulfate activation ability, and more importantly, biochar is cheap and easy to obtain; thus, it has higher economic benefits. This study firstly reviews the application of biochar in the removal of drugs (tetracycline (TC), sulfamethoxazole (SMX), acetaminophen (ACT), cephalexin (CPX), levofloxacin (LEV), etc.) through adsorption and persulfate-based AOPs. In addition, we summarize the adsorption mechanism of biochar for various pharmaceutical pollutants and the main attack sites on different pharmaceutical pollutants in persulfate-based AOPs catalyzed by biochar. Finally, the challenges and prospects of biochar with respect to the removal of pharmaceutical pollutants are put forward.