Study of the Composition of Fractions of Manipueira: Solid and Liquid Residues Filtered on 0.45 µm Membrane and Qualitative Paper

Abstract

Cassava, is an important crop in the national agricultural and economic scenario. Its processing generates waste, such as manipueira, which has several applications but can cause environmental impact when improperly disposed of. This work aimed to evaluate the physicochemical characteristics of manipueira in different fractions (suspended solid, filtered at 0.45 μm, and in a common filter). The fractions were characterized physicochemically (pH and conductivity) and chemically using the following techniques: i) total organic carbon (TOC), ii) elemental analysis (CNHS), iii) MP-AES and infrared atomic emission spectrometry iv) SCP and AGNES. The resulting TOC values reflect a potential for the application of the material as a biofertilizer. The pH of manipueira is outside the standard established by Brazilian legislation. The metals Ba, Cd, Ni and Pb, and Zn, from the filtrate at 0.45 μm, are within the maximum limits established by CONAMA 430/2011resolution, while Cr, in the two filtrates, and Zn from the filtrate of the common filter, is above the maximum limits. Using SCP and AGNES it was possible to determine the presence of Pb in the solid residue as well as in the samples filtered at 0.45 μm, indicating the necessity of adequate treatment of the effluent before discard.