4.7 Article

Variation of the hydraulic properties in sandy soils induced by the addition of graphene and classical soil improvers

期刊

JOURNAL OF HYDROLOGY
卷 612, 期 -, 页码 -

出版社

ELSEVIER
DOI: 10.1016/j.jhydrol.2022.128256

关键词

Column experiment; Solute transport; Soil improver; Breakthrough curve; Dispersivity

资金

  1. V:ALERE Program (VAnviteLli pEr la RicErca) of the University of Campania Luigi Vanvitelli

向作者/读者索取更多资源

This study monitored and modeled the changes in hydraulic parameters induced by the introduction of graphene in different types of soil. The results showed that graphene had minimal effects on hydraulic conductivity, porosity, and effective porosity, but it significantly increased specific retention and altered dispersivity. However, using electrical conductivity for model fitting produced unreliable results.
In this study, for the first time, the changes in relevant hydraulic parameters (e.g., hydraulic conductivity, effective porosity, and dispersivity) induced by the introduction of graphene in a calcareous sandy soil and a siliciclastic riverine soil were monitored and modelled via leaching column experiments. Column experiments were also run with traditional soil improvers (compost, biochar, and zeolite) to compare the changes induced by graphene versus well-studied soil improvers. Constant pressure head tests were used to calculate the hydraulic conductivity of each column, while leaching experiments were run to estimate porosity and specific retention, and for each treatment three replicates were done. Columns were then run in saturated conditions via a low flow peristaltic pump and monitored for electrical conductivity, temperature, and chloride. CXTFIT 2.0 was employed to inversely model the column experiments and retrieve parameters like effective porosity, longitudinal dispersivity, bulk thermal diffusivity, and thermal retardation factor. Results highlighted small changes of hydraulic conductivity, porosity, and effective porosity induced by graphene addition (as well as by the other soil improvers) for both soils. A marked increase (nearly 20 %) of specific retention values was instead recorded in the amended columns with respect to control ones. Chloride breakthrough curves modelling showed that graphene doubled dispersivity in the calcareous sandy soil (5.82 +/- 1.4 cm) compared to the control (2.6 +/- 0.29 cm), while it halved dispersivity in the siliciclastic riverine soil (0.31 +/- 0.05 cm) with respect to the control (0.65 +/- 0.06 cm). Thermal retardation factors were decreased by graphene by approximately 20 % for both soils. The model fitting via TDS (derived from the electrical conductivity monitoring) produced unreliable dispersivity values in most of the experiments due to the nonconservative nature of this parameter compared to chloride. The results highlight that graphene affected dispersivity but did not significantly alter other physical parameters relevant for solutes transport in sandy soils in comparison to classical improvers, thus future studies should focus on the graphene's effects on nutrients and agrochemicals leaching in unsaturated flow conditions.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据