Reuse of Spent Zeolite Sorbents for Surface Runoff Treatment as Part of Artificial Soils

Abstract

Phytotesting in open field proved the effectiveness of introducing clinoptilolite rocks (CP-rocks) into soils from FOPS® filters after surface wastewater treatment on the roots development and drought resistance of plants. It is revealed that spent CP-rocks accumulate heavy metals (HMs) during water treatment, however, their concentrations do not exceed the MAC of these HMs in soils and wastewater sludge used in agriculture. It is discovered that plant roots to a large extent utilize not only the elements of the exchange complex of CP-rocks (K+, Ca2+, Mg2+), but also framework-forming elements (Al, Si). It is shown that Fe and Mn of CP-rocks poorly processed by plants, which results in their local accumulations in soils and creates conditions for hardpan formation along them. Surface wastewater treatment materials based on FOPS® filters are proposed to be used for the localization of HMs from soils, as well as for the reclamation of municipal solid waste landfills and reforestation.