YAN Yun¹，YU Xiaoyan¹，LIU Hong²，CAO Rui¹，JIN Biqiang²，LI Song³

(1.Department of Resources and Environment of Xichang College, Sichuan Xichang 615013,China;
2.Department of Science of Xichang College， Sichuan Xichang 615013,China;
3. School of Chemistry & Chemical Engineering, Mianyang Normal University, Sichuan Mianyang 621000 ,China )

Abstract: A biochar was made from houttuynia cordata by calcining at high temperature and treating with HNO3. Under The optimum pyrolysis temperature of houttuynia cordata, 476℃, was determined by a differential heat-thermogravimetric analyzer (SHMADZU DTG-60) with air as the carry gas. The XRD analyses showed that the biochar was mainly composed of semi-crystalline turbine layer carbons and some minerals; the Fourier transform infrared spectroscopy (FTIR) analyses showed that stretching vibrations C═C and O─H in aromatic and pyridine rings were quite strong, standing of the possible active adsorption sites. The designed adsorption experiments showed that, when pH = 1, adsorption time was 120 min and sorbent dosage was 0.3 g, the Cr (VI) removal rate was the best (99.2%). It was found that the adsorption of Cr (VI) on the houttuynia cordata biochar followed the Langmuir adsorption model better than the Freundlich adsorption model, and that the adsorption was a spontaneous process.

Key words: houttuynia cordata, biochar; chromium (VI); adsorption; kinetics

EARTH AND ENVIRONMENT Vol.46, No.4, Tot No.324, 2018, Page 396-402