Spout Fluidized Bed Assisted Preparation of Poly(tannic acid)-Coated Urea Fertilizer

Yu Wang; Heling Guo; Xiaolin Wang; Zhiyuan Ma; Xie Li; Rui Li; Qian Li; Rongjie Wang; Xin Jia

doi:10.1021/acsomega.9b03310

Spout Fluidized Bed Assisted Preparation of Poly(tannic acid)-Coated Urea Fertilizer

ACS Omega. 2020 Jan 9;5(2):1127-1133. doi: 10.1021/acsomega.9b03310. eCollection 2020 Jan 21.

Authors

Yu Wang¹, Heling Guo¹, Xiaolin Wang¹, Zhiyuan Ma², Xie Li¹, Rui Li¹, Qian Li¹, Rongjie Wang¹, Xin Jia¹

Affiliations

¹ School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Key Laboratory of Materials-Oriented Chemical Engineering of Xinjiang Uygur Autonomous Region, Engineering Research Center of Materials-Oriented Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832003, People's Republic of China.
² State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China.

Abstract

Slow-release fertilizers (SRFs) have been widely used to reduce environment pollution derived from excessive nutrients. Coated fertilizers have been designed and prepared using various materials. However, development of new green coating materials and simple process is still a huge challenge. In this study, tannic acid (TA), a natural polyphenol, was used to prepare poly(tannic acid) (PTA)-coated fertilizers with urea prills as the core, and the technology of the coating process in a spout fluidized bed was developed. PTA coating could be formed rapidly by the fast oxidation of TA by an oxidation solution containing CuSO₄ and H₂O₂. The coated urea release behavior was systematically studied in water and soil. In both water and soil, the release rate of nitrogen from coated urea is much slower than that from raw urea. Raw urea was completely dissolved within 30 min, while 27% of urea was released from coated urea. The pot experiments indicated that coated urea has a positive effect on the plant growth as well. Our results provide an effective method to prepare environment-friendly SRFs, indicating a promising application in sustainable agriculture.