A novel process for dehydration of antibiotics fermentation residues

Abstract

Wet antibiotics fermentation residues (AFRs) are rich in water and organic matters. AFRs can cause environmental pollution via secondary fermentation, which also makes them inconvenient to be stored, transported and disposed. A novel dehydration process of wet AFRs was developed by applying inorganic salts as dehydration agent (DA), in which colloidal water in wet AFRs was transferred into the hydrate of DA and formed solid AFRs–DA mixture at room temperature. When Na2SO4 was used as the optimal DA, differential thermal gravity (DTG) analysis demonstrated that the temperature of complete dewatering of AFRs–DA mixture decreased from 162.7 to 98.5°C compared with wet AFRs, and the dewatering energy consumption decreased by 26.58%. The suitable mass ratio of Na2SO4 and AFRs was in the range of 1.2–2.0. During the process of incineration at 750°C, the organic matters in the AFRs–DA mixture were completely converted into small molecules, for example, H2O and CO2, and the harmless disposal of AFRs was realized. Meanwhile, DA changed from hydrate to anhydrous form, from which DA can be recycled. The dewatering reaction time decreased by 61.8% with the recycled Na2SO4 at least five recycles. This study provides a promising energy saving approach for wet AFRs disposal. © 2018 American Institute of Chemical Engineers Environ Prog, 37: 1901–1907, 2018