Soil application of biochars has been shown to effectively immobilize potentially toxic elements (PTEs). Soil water regime can also affect PTE availability. No previous studies have examined the interactive effect of biochars and soil water regime on Pb availability. Therefore, this study investigated the effect of high and low temperature (300 and 600 °C) biochars derived from cow manure (CB), municipal compost (MB) and licorice root pulp (LB) applied at 3 wt%, under two soil moisture regimes (field capacity (FC) and saturation (ST)) on Pb release kinetics and chemical fractions in a Pb-contaminated calcareous soil. Results showed that CB and MB treatments significantly enhanced Pb stabilization compared to LB, attributed to their favorable chemical properties (high P, ash, carbonate, oxidizable C content and high pH) which could promote Pb conversion into stable chemical fractions. Immobilization of Pb was enhanced under saturated conditions compared to FC by the treatments, which is attributed to increased soil pH, reduction of metal oxides and possible formation of sulfides. The most significantly effective treatments were the CB300, CB600 and MB600 treatments under ST, as indicated by significant decrease in soil Pb mobility factor from 29.1% (CL + FC) to 21.2–22.9%, and 11.7–16.3% increase in non-EDTA-extractable Pb. Results of this study demonstrate that combined application of high ash biochars and soil water saturation significantly enhances Pb immobilization in calcareous soil.

在土壤中施用生物炭已被证明可以有效地固定潜在的有毒元素（PTE）。土壤水分状况也会影响PTE的可用性。以前没有研究研究生物炭和土壤水分状况对铅有效性的交互作用。因此，本研究调查了在两种土壤湿度下，分别以3 wt％施用来自牛粪（CB），市政堆肥（MB）和甘草根浆（LB）的高温和低温（300和600°C）生物炭的效果。铅污染的石灰质土壤中，铅的释放机制（场容量（FC）和饱和度（ST））释放动力学和化学成分。结果表明，与LB相比，CB和MB处理显着增强了Pb的稳定性，这归因于其良好的化学性能（高P，灰分，碳酸盐，可氧化的C含量和高pH），可促进Pb转化为稳定的化学馏分。通过处理，与FC相比，在饱和条件下，Pb的固定化得到了增强，这归因于土壤pH升高，金属氧化物减少和可能形成硫化物。最有效的处理方法是ST下的CB300，CB600和MB600处理，这表明土壤铅迁移率从29.1％（CL + FC）显着降低至21.2-22.9％，非EDTA则增加11.7-16.3％可萃取的铅。这项研究的结果表明，高灰分生物炭和土壤水分饱和的联合应用显着增强了石灰性土壤中铅的固定化。这归因于土壤pH值升高，金属氧化物减少以及可能形成硫化物。最有效的处理方法是ST下的CB300，CB600和MB600处理，这表明土壤铅迁移率从29.1％（CL + FC）显着降低至21.2-22.9％，非EDTA则增加11.7-16.3％可萃取的铅。这项研究的结果表明，高灰分生物炭和土壤水分饱和的联合应用显着增强了石灰性土壤中铅的固定化。这归因于土壤pH值升高，金属氧化物减少以及可能形成硫化物。最有效的处理方法是ST下的CB300，CB600和MB600处理，这表明土壤铅迁移率从29.1％（CL + FC）显着降低至21.2-22.9％，非EDTA则增加11.7-16.3％可萃取的铅。这项研究的结果表明，高灰分生物炭和土壤水分饱和的联合应用显着增强了石灰性土壤中铅的固定化。非EDTA可萃取的Pb增加3％。这项研究的结果表明，高灰分生物炭和土壤水分饱和的联合应用显着增强了石灰性土壤中铅的固定化。非EDTA可萃取的Pb增加3％。这项研究的结果表明，高灰分生物炭和土壤水分饱和的联合应用显着增强了石灰性土壤中铅的固定化。