Physicochemical and Toxicological Assay of Leachate from Malt Spent Rootlets Biochar.

The aim of this study was to characterize the leachate derived from biochar produced from malt spent rootlets (MSR) and to evaluate the required washing level in order to provide water free from inorganic substances. MSR biochar was placed in a column and subjected to six serial washes with distilled water, and the leachate was analysed for main anions and heavy metals. The 1st wash aliquot contained increased levels of mainly phosphates (980 mg/L) and chlorides (760 mg/L), and lower levels of nitrates, sulfates, fluoride and bromide, which were decreased over washes.