Measurement of the sand physicochemical property
Sand pH was determined using a pH meter (PT-10, Sartorius, Göttingen,
Germany). Sand electrical conductivity (EC) was measured using a
conductivity meter (DDSJ-308A, Leici, Shanghai, China). The water
content (WC) was calculated based on the moisture difference value. The
contents of total carbon (TC), total nitrogen (TN), and total organic
carbon (TOC) were detected using an element analyzer (Elementar
Vario-EL, Germany). Concentrations of total phosphorus (P), vanadium
(V), yttrium (Y), zirconium (Zr), titanium (Ti), manganum (Mn), zinc
(Zn), chlorine (Cl) were measured using the wavelength dispersive X-ray
fluorescence spectrometer (AXIOS; PANalytical B.V., Netherlands) (Liu et
al., 2016; Liang et al., 2019). The content of Cl- was
measured by silver nitrate titration method. The contents of
Na+, Mg2+, Ca2+were determined by atomic absorption spectrophotometry.