Bolster Carl H
Food Animal Environmental System Research Unit, US Department of Agriculture - Agricultural Research Service, Bowling Green, KY, 42104, United States.
Chemosphere. 2023 Dec;345:140523. doi: 10.1016/j.chemosphere.2023.140523. Epub 2023 Oct 23.
Biochar has been investigated as a potential soil amendment for increasing P sorption to soils. Several studies of shown that coating biochar with Fe oxides can increase the amount of P sorbed to the biochar, yet little is known about the kinetics of P sorption to soils amended with Fe-coated biochar. In this study, the kinetics of P sorption are measured in four soils with contrasting surface properties and textures. In addition, a wood-based biochar, both unmodified (BC) and modified by chemical precipitation of Fe oxides (BC), was added to these four soils at a rate of 5% (w/w). P sorption to each soil with and without the unmodified or Fe-coated biochar was measured at incubation times ranging from 1 to 314 h. The data were fit using five different kinetic models to determine if the addition of the BC or BC significantly affected the amount of P sorption and the kinetic behavior of P sorption to the biochar-amended soils. Results showed that amending with BC had minimal impact on P sorption to the four soils, whereas the impact of the BC on P sorption varied depending on soil. In the low P sorbing soil, the BC nearly doubled the amount of P sorbed whereas in the high P sorbing soil, addition of the BC resulted in less-than-expected increases in P sorption. For each biochar and soil treatment, the same kinetic model provided the best fit to the observed sorption over time. In two soils, the kinetic model parameters were significantly different following the addition of the BC whereas the model parameters for all four soils were significantly different following addition of BC. This study provides new insights into P sorption kinetics to biochar-amended soils.
生物炭已被作为一种潜在的土壤改良剂进行研究，用于增加土壤对磷的吸附。多项研究表明，用铁氧化物包覆生物炭可增加生物炭对磷的吸附量，但对于用铁包覆生物炭改良的土壤中磷吸附动力学却知之甚少。在本研究中，测定了四种具有不同表面性质和质地的土壤中磷的吸附动力学。此外，将一种未改性的（BC）和通过铁氧化物化学沉淀改性的（BC）木质生物炭以5%（w/w）的比例添加到这四种土壤中。在1至314小时的培养时间内，测定了添加或未添加未改性或铁包覆生物炭的每种土壤对磷的吸附情况。使用五种不同的动力学模型对数据进行拟合，以确定添加BC或BC是否显著影响磷的吸附量以及磷在生物炭改良土壤上的吸附动力学行为。结果表明，添加BC对四种土壤中磷的吸附影响最小，而BC对磷吸附的影响因土壤而异。在低磷吸附土壤中，BC使吸附的磷量几乎增加了一倍，而在高磷吸附土壤中，添加BC导致磷吸附量的增加低于预期。对于每种生物炭和土壤处理，相同的动力学模型对随时间观察到的吸附情况拟合最佳。在两种土壤中，添加BC后动力学模型参数有显著差异，而在所有四种土壤中添加BC后模型参数均有显著差异。本研究为生物炭改良土壤中磷的吸附动力学提供了新的见解。
