Journal of Ecology and Rural Environment ›› 2016, Vol. 32 ›› Issue (1): 168-172.doi: 10.11934/j.issn.1673-4831.2016.01.026

Previous Articles    

Effects of Rice-Straw-Derived Biochar on Adsorbing and Slow-Releasing of Metolachlor

GE Chao-chao, GUO Xuan, LI Jian-fa, LÜ Jin-hong, LIU Sen, XU Hai-xia   

  1. Department of Chemistry, Shaoxing College of Arts and Science, Shaoxing 312000, China
  • Received:2015-02-08 Online:2016-01-25 Published:2016-01-27

Abstract:

Aiming at controlling herbicide pollution of the environment, biochars were prepared out of rice straw through oxygen-limited pyrolysis at low temperatures(200 and 350℃), and their effects of adsorbing and slow-releasing herbicide metolachlor were investigated. Results show that the biochar prepared at temperature of 350℃(D350) was 23.2 m2·g-1 in specific surface area and hence much higher than rice straw in metolachlor sorption capacity, and close to the biochar prepared at temperature of 200℃(D200). But, biochar D350 showed a higher surface adsorption capacity to metolachlor and a higher desorption hysteresis index(5.35) than D200 did(2.07), indicating that granular preparation of biochar can be used as sustained releaser of metolachlor, with parameter nr of its in-water release kinetic model being close to that(0.50) of the Fickian diffusion model, and the time it took to release 50% of adsorbed metolachlor(t50) is positively related to the desorption hysteresis index.

Key words: biomass, sorption, herbicide, sustained release

CLC Number: