Sludge reclaimed from drinking water treatment plant was carbonized and chemically activated by K 2 CO 3 and CH 3 COOH. The proposal was to evaluate its adsorbent properties as a low-cost alternative material for metal ion remediation. Morphological, physicochemical, and chemical characteristics have been presented and comprehensively discussed. Main findings revealed a surface area rich in mesopores and loaded with weakly acidic functional groups, also presenting an eroded aspect. Carbonization of the sludge's organic content increased the concentration of nitrogenic and oxygenated functional surface groups. Chemical activation by K 2 CO 3 and CH 3 COOH increased adsorption and desorption capacity, pore volume, and pore size by two, three, and over tenfolds, respectively. Uptake of cations increased by 51% and, for anions, around 27%. Association of carbonization with sequenced activation processes converted drinking water treatment plant sludge into an excellent and promising alternative adsorbent material. and activation is available on the literature. Considering the lack of studies regarding the production of activated carbons from DWTP sludge, this study reports the conversion of this widely available feedstock through carbonization and chemical activation.Activated carbons (AC) are scientifically known for having high sorption capacity for different types of chemical species [28], a characteristic of an adsorbent material with large surface area, porous structure, and chemically active surface [29]. Additionally, the high concentration of metals in raw water treatment sludge and, consequently, in its char, may also improve ion-solution interaction. Activated carbons usually have their surface functional groups bonded to complex aromatic rings, behaving similarly to aromatic hydrocarbons [30]. As so, a thermochemical modification would then improve these characteristics in the AC's surface chemistry, as a function of the usage purpose. Overall, the chemical activation of carbonized materials'

Como pode ser observado, houve um incremento no conteúdo de oxigênio durante a estabilização e consequentemente uma diminuição relativa no conteúdo de carbono, que comprova a perda de massa durante o processo. Na carbonização houve um incremento significativo no conteúdo relativo de carbono. Se observa que o conteúdo de carbono é maior nas fibras aditivadas com lignina kraft.Durante a carbonização ocorre aromatização das unidades fenil propano e por isso o conteúdo de carbono aumenta. Já o contéudo de carbono das fibras aditivadas com álcool furfurílico foi