Biochar offers a potential sustainable pathway for recovering phosphorus from wastewater to agriculture. Magnesium-modified biochar has demonstrated an enhanced phosphate adsorption capacity and excellent bioavailability. This study aims to identify the life cycle environmental hotspots in phosphorus recovery from wastewater using magnesium-modified biochars derived from bamboo, corn, and wood and compared them with common phosphate fertilizers. The results show that the biomass supply stage and the modification stage are the main environmental hotspots in most impact categories. As the phosphorus load of wastewater decreases, the phosphorus recovery stage could become the hotspot. Although phosphate-loaded magnesium-modified biochars in the base case do not have a better overall environmental performance than most phosphate fertilizers (especially those without nitrogen), they have significantly lower mineral resource scarcity and ecotoxicity. The sensitivity analysis suggests that the results are sensitive to the background inventory selected. The analysis indicates that the biochar yield, the phosphate adsorption capacity of the biochars, the source of modification chemical, and the source of biomass feedstock are key areas for technological and inventory improvement. In the future, a comprehensive field application inventory and a diverse set of background inventory are needed to better assess this sorption-based phosphorus recovery pathway.

中文翻译：

---

确定使用改性生物炭从废水中回收磷的生命周期环境热点


生物炭为从废水中回收磷到农业提供了一种潜在的可持续途径。镁改性生物炭已显示出增强的磷酸盐吸附能力和出色的生物利用度。本研究旨在确定使用竹子、玉米和木材衍生的镁改性生物炭从废水中回收磷的生命周期环境热点，并将其与普通磷肥进行比较。结果表明：生物质供应阶段和改性阶段是大多数影响类别中的主要环境热点;随着废水含磷量的降低，磷回收阶段可能成为热点。尽管在基本情况下，载磷酸盐的镁改性生物炭的整体环境性能并不优于大多数磷肥（尤其是那些没有氮的磷肥），但它们的矿产资源稀缺性和生态毒性显著降低。敏感度分析表明，结果对所选的后台清单敏感。分析表明，生物炭产量、生物炭的磷酸盐吸附能力、改性化学品的来源以及生物质原料的来源是技术和库存改进的关键领域。未来，需要全面的现场应用清单和多样化的背景清单，以更好地评估这种基于吸附的磷回收途径。