Assessing the influence of biochars on the hydraulic properties of a loamy sand soil

Abstract

A laboratory analysis is presented in this study that evaluates the impact of three different biochars, derived from biowastes of sludge (SDB), manure (MDB) and spent coffee grounds (SCGDB), on the physical properties of a loamy sand soil. Column experiments are conducted to measure the hydraulic conductivity and water content of these biochars when mixed with soil at a fixed concentration (5% with respect to (w.r.t) reference soil) under saturated conditions. The results show a substantial increase of the hydraulic conductivity for the biochars derived from SCGDB and SDB, whereas no changes were observed for MDB. The saturated water content is increased with the addition of SCGDB and trivial changes are observed for the remaining treatments. Numerical computations using HYDRUS-1D are conducted for a hypothetical scenario, revealing the different impact that each biochar has on the reference soil.