Wastewater Treatment from Lead and Strontium by Potassium Polytitanates: Kinetic Analysis and Adsorption Mechanism

Processes

Alexander Gorokhovsky¹  Igor Burmistrov¹  Sergey Altukhov¹  Alexey Shevelev¹  Maria Vikulova¹  Anna Ermolenko¹  Tatyana Blagova¹  Anna Godymchuk²  PeterOgbuna Offor³ 

[1] Department of Chemistry and Technology of Materials, Yuri Gagarin State Technical University of Saratov, 77 Polytecnicheskaya Street, 410054 Saratov, Russia;Department of Materials Science, National Research Tomsk Polytechnic University, 30 Lenina Avenue, 634050 Tomsk, Russia;Metallurgical and Materials Engineering Department, University of Nigeria, Nsukka 410001, Nigeria;

关键词: sorption;    heavy metals;    radioactive metals;    potassium titanate;    ion exchange;   

DOI  :  10.3390/pr8020217

来源: DOAJ

【 摘 要 】

The reduction of heavy and radioactive metal pollution of industrial wastewater remains a vital challenge. Due to layered structure and developed surface, potassium polytitanate had potential in becoming an effective sorbent for metal extraction from wastewater in the presented paper. On the basis of the different sorption models, this paper studied the mechanism of Pb²⁺ and Sr²⁺ cation extraction from aqueous solution by non-crystalline potassium polytitanate produced by molten salt synthesis. The ion exchange during metal extraction from model solutions was proven by kinetic analysis of ion concentration change, electronic microscopy, and X-ray fluorescence analysis of sorbent before and after sorption, as well as by theoretical modeling of potassium, lead, and strontium polytitanates. The sorption was limited by the inner diffusion in the potassium polytitanate (PPT) interlayer space, as was shown using the Boyd diffusion model. The sorption processes can be described by Ho and McKay’s pseudo-second-order model compared to the Lagergren pseudo-first-order model according to kinetic analysis. It was found that the ultimate sorption capacity of synthesized sorbent reached about 714.3 and 344.8 (ions mg/sorbent grams) for Pb²⁺ and Sr²⁺ ions, respectively, which was up to four times higher than sorption capacity of the well-known analogues. Therefore, the presented study showed that potassium polytitanate can be considered as a promising product for industry-scaled wastewater purification in practice.

【 授权许可】

Unknown