CLASSIFICA O DOS LODOS FORMADOS DURANTE O PROCESSO DE COAGULA O/FLOCULA O DA áGUA COM OS COAGULANTES PAC E MORINGA OLEIFERA

The drinking-water treatment plants, generally, generates waste in some stages of the treatment,mainly in the settling vessel (sludge). This sludge is formed during the coagulation/flocculation stage, withaid of chemical coagulants (PAC – Poly Aluminium Chloride) or natural (Moringa oleifera) that currentlyare being intensively researched. According to ABNT NBR 10004 this sludge is classified as “solid waste”and therefore must be previously classified in order to be disposed of adequately. The classification of thesludge formed in coagulation/flocculation process, using PAC and Moringa as coagulant, is investigated.This was done according to the set of regulations ABNT NBR 10004 (“Solid Waste - Classification”),ABNT NBR 10005 (“Procedures for obtaining leached extract of solid waste”) and ABNT NBR 10006(2004) (“Procedures for obtaining soluble extract of solid waste”) based on metals analysis of sludge leachedand solubilized extract. The sludge leaching and solubilization tests indicate that PAC and Moringa sludgeare classified as Class II A, non-hazardous and non-inert waste. Even with the use of a natural coagulant, thesludge can have a high concentration of heavy metals in its composition, as these are, probably, from rawwater used in the treatment. Therefore, the sludge must be disposed adequately, as not to cause damage tothe environment and humans.