CHARACTERIZATION OF SOIL ADDITIVE DERIVED FROM SEWAGE SLUDGE

Abstract

he aim of the present work is to characterize the soil additive derived from sewage sludge as potentially economically acceptable material for agricultural production as well as for soil and environment protection. The soil additive consisting of sewage sludge obtained from the wastewater treatment plant Pannon-Víz Zrt. (Győr, Hungary) and agricultural byproducts represented by wastes from grain mill industry and crushed corn cobs was prepared using the low-capacity granulator equipment constructed by Energy Agency Public Nonprofit Ltd. (Hungary). The characterization of sewage sludge as primary composite and prepared soil additive includes the determination of physico-chemical parameters such as pH determined in suspension with distilled water, 0.01 mol/dm³ CaCl₂ or 1 mol/dm³ KCl solutions, pHzpc predicted by potentiometric titration and ProtoFit software, water holding capacity (WHC), cationexchange capacity (CEC) and total organic carbon (TOC). The elemental analysis by X-ray fluorescence spectrometry revealed that sewage sludge as well as prepared soil additive contain significant amount of Zn and Cu as important microelements in plant nutrition. Also, it was found that prepared soil additive represents the considerable source of a significant proportion, strong bound and in this way gradually released microelements. Obtained results suggest on the application potential of prepared soil additive in agricultural production as well as in remediation and reclamation of contaminated or degraded soil.