Materials Letters | 2019
Bioinspired paddy-soil-like superior purification materials for sewage treatment
Abstract
Abstract Inspired by the integrated adsorption/degradation purification performances of paddy soil, a biomimetic paddy-soil-like superior purification material has been hydrothermally synthesized from natural zeolites. The formations of tobermorite and hydroxyapatite benefited the flexural strength up to 12\u202fMPa and adsorptive properties to contaminants. In sewage treatment experiments, the zeolite-based materials achieved the limited removal rates of 34.6% (from 364 to 238\u202fmg/L) and 26.3% (from 46.6 to 34.3\u202fmg/L) respectively for COD and NH4+ due to saturation adsorption. After bioburden, the removal rate of COD and NH4+ increased significantly to 93.4% (from 364 to 24\u202fmg/L) and 81.1% (from 46.6 to 8.8\u202fmg/L), reflecting the integrated function of adsorption and further degradation. The variations of NO3−/NO2− showed that various microorganisms within the matrix did contribute to the continuous and efficient purification performance.