Abstract:
Soil composition varies considerably in nature, so it is vital to investigate the mechanism of the effect of various soil parameters on biochar sorption capacity. In this study, two biochars (W4 and W7) were derived from wheat straw at temperatures of 400 and 700 °C and were incubated with three different soils. Changes in biochar surface features by aging in the soils and the consequent impact on phenanthrene sorption were examined. The results showed that the effect of adding biochar on phenanthrene sorption capacity (Koc) varied by soil. When biochar was freshly mixed with soil, the Koc value in soil with higher clay content was more dramatically altered by biochar, which is due to clay particles adhering to the biochar surface. Moreover, the Koc value was significantly decreased by the addition of W4 but increased by the addition of W7 in general. After aging, most of the Koc value decreased. The greatest decrease in Koc value was observed in biochar and soil composed with the highest clay content for W4 (24-63%), as well as soil composed with the highest organic matter content for W7 (46-64%). This is because the surface polarity and micropores of biochar dropped the most rapidly in these mixes, resulting in a significant decrease in hydrophobic and pore-filling properties. The results revealed that the impact of biochar-soil interactions on phenanthrene sorption is related to not only biochar properties but also soil clay particles, soil organic matter content and pH. The findings of the study can be utilized to assess the efficacy of biochar application in soil remediation for various features.
摘要:
土壤成分在自然界中变化很大,因此,研究各种土壤参数对生物炭吸附能力的影响机制至关重要。在这项研究中,两种生物炭(W4和W7)是在400和700°C的温度下从小麦秸秆中提取的,并与三种不同的土壤一起孵育。研究了土壤老化引起的生物炭表面特征的变化以及对菲吸附的影响。结果表明,添加生物炭对菲吸附能力(Koc)的影响因土壤而异。当生物炭与土壤新鲜混合时,生物炭对粘土含量较高的土壤中的Koc值的影响更大,这是由于粘土颗粒粘附在生物炭表面。此外,Koc值通过添加W4而显著降低,但总体上通过添加W7而增加。老化后,大部分Koc值下降。在生物炭和W4粘土含量最高的土壤中观察到Koc值的最大下降(24-63%),以及W7有机质含量最高的土壤(46-64%)。这是因为生物炭的表面极性和微孔在这些混合物中下降最快,导致疏水性和孔隙填充性能显着下降。结果表明,生物炭-土壤相互作用对菲吸附的影响不仅与生物炭性质有关,而且与土壤黏土颗粒有关。土壤有机质含量和pH值。该研究的结果可用于评估生物炭在土壤修复中各种特征的应用效果。