Functionalization of kaolinite for removal of phosphate from urban sewage

• Published in: MethodsX 2021-01, Vol.8, p.101423-101423, Article 101423
• Main Authors: Carbinatti, Camilla, da Conceição, Fabiano Tomazini, Moruzzi, Rodrigo Braga, Menegário, Amauri Antônio
• Format: Article
• Language: English
• Subjects: Clay minerals; Functionalization of kaolinite for removal of phosphate from urban sewage; Method; Mineral precipitation; Phosphate removal; Surface functionalization
• ISSN: 2215-0161; 2215-0161
• DOI: 10.1016/j.mex.2021.101423

The PO43− widespread in urban sewages promotes eutrophication of water sources, with harmful effects to natural life and endanger human health. The removal of PO43− from urban sewage requires treatment at tertiary level, with high costs and low efficiency in most cases. Thus, a functionalization method for surface modification of kaolinite was proposed to improve the removal of PO43− from urban sewage. The kaolinite commercial did not remove PO43- from aqueous solution. However, the functionalized kaolinite (FK) was efficient, with a maximum removal capacity of 8.4 ± 0.1 mg PO43−/L, within less than 1 min of reaction. The removal of PO43- is associated with precipitation of pyromorphite, a mineral with low solubility (Ksp < 10−79,6). Finally, real urban sewage samples (raw and treated) were also tested for removal of PO43- using FK, confirming its effectiveness. The central aspects of this development are:•Functionalized kaolinite (FK), with Pb(II), for removal of PO43− from urban sewage was studied.•The FK was efficient for removal of up to 8.4 mg PO43−/L from aqueous solution, within a short reaction time.•The precipitation of pyromorphite was the mechanism responsible for removal of PO43- and FK efficiency have been confirmed for real urban sewage samples. [Display omitted]