EFECTO DE LAS ZEOLITAS SOBRE CIERTAS PROPIEDADES DE UN SUELO ENMENDADO CON BIOSÓLIDOS

The application of biosolids as an organic amendment in degraded soils constitutes an alternative of disposal; however, they may contain varying concentrations of potentially toxic trace elements (PTE) that accumulate in soils and may alter microbial activity. Zeolites are minerals that have porous spaces and internal channels with a high cation-exchange capacity. The objective of this work was to determine the influence of the addition of zeolites on the microbial activity, pH, electrical conductivity (EC), oxidizable carbon and phosphorus availability (P) in a soil amended with biosolids. An incubation experiment was carried out at room temperature. The incorporation of zeolites did not significantly modify the microbial activity of the non-amended or biosolids amended soils. However, zeolites significantly increased the pH (by 2.89 and 1.18) and EC (by 4374 and 1459 µS/cm) in the non-amended or biosolids amended soils and produced a significant reduction in the concentration of extractable phosphorus. In view of the increase in pH and EC values observed, the proportion of biosolids and zeolites or the use of supplementary irrigation should be carefully evaluated when these amendments are incorporated together, to avoid soil salinization if the objective is to use them for soil restoration.