Abstract：
Due to the natural biochar aging, the improvement of soil quality and immobilization of soil pollutants achieved by biochar may change; understanding the dynamic evolution of the in situ performance of biochar in these roles is essential to discuss the long-term sustainability of biochar remediation. Therefore, in this study, combined biochar from co-pyrolysis of pig manure and invasive Japanese knotweed - P1J1, as well as pure pig manure - PM - and pure Japanese knotweed - JK - derived biochar were applied to investigate their remediation performance in a high As- and Pb-polluted soil with prolonged incubation periods (up to 360 days). Biochar application, especially P1J1 and PM, initially promoted soil pH, dissolved organic carbon, and EC, but the improvements were not constant through time. The JK-treated soil exhibited the highest increase of soil organic matter (OM), followed by P1J1 and then PM, and OM did not change with aging. Biochar, especially P1J1, was a comprehensive nutrient source of Ca, K, Mg, and P to improve soil fertility. However, while soluble cationic Ca, K, and Mg increased with time, anionic P decreased over time, indicating that continuous P availability might not be guaranteed with the aging process. The total microorganism content declined with time; adding biochars slowed down this tendency, which was more remarkable at the later incubation stage. Biochar significantly impeded soil Pb mobility but mobilized soil As, especially in PM- and P1J1-treated soils. However, mobilized As gradually re-fixed in the long run; meanwhile, the excellent Pb immobilization achieved by biochars was slightly reduced with time. The findings of this study offer fresh insights into the alterations in metal(loid)s mobility over an extended duration, suggesting that the potential mobilization risk of As is reduced while Pb mobility slightly increases over time.
摘要：
由于天然生物炭的老化,通过生物炭实现的土壤质量的改善和土壤污染物的固定可能会发生变化;了解生物炭在这些作用下的原位性能的动态演变对于讨论生物炭修复的长期可持续性至关重要。因此,在这项研究中，来自猪粪和入侵日本虎杖-P1J1共热解的组合生物炭，以及纯猪粪-PM-和纯日本虎杖-JK-衍生的生物炭，用于研究它们在高As和Pb污染的土壤中的修复性能。生物炭的应用，尤其是P1J1和PM，最初提高土壤pH值，溶解的有机碳，和EC，但是随着时间的推移，改善并不恒定。JK处理的土壤表现出最高的土壤有机质（OM）增加，其次是P1J1，然后是PM，OM不随老化而改变。生物炭,特别是P1J1，是Ca的综合营养源，K,Mg,和P来提高土壤肥力。然而,而可溶性阳离子Ca，K,Mg随时间增加,阴离子P随时间减少，表明老化过程可能无法保证连续的P可用性。总微生物含量随时间下降；添加生物炭减缓了这一趋势，这在孵化后期更为显著。生物炭显着阻碍了土壤Pb的迁移，但动员了土壤As，特别是在PM和P1J1处理的土壤中。然而,动员起来，从长远来看逐渐重新固定；同时，随着时间的推移，生物炭获得的优异的Pb固定化效果略有降低。这项研究的结果为金属（loid）在延长的时间内的流动性变化提供了新的见解，表明As的潜在动员风险降低，而Pb的迁移率随时间略有增加。
