硫氮共掺杂活性炭的制备及其对Cr(VI)吸附性能的研究

Preparation of Sulfur-Nitrogen Co-Doped Activated Carbon and Study on Its Adsorption Capacity for Cr(VI)

摘要: 在我国工业发展的过程中，铬占据了举足轻重的地位，但由于其毒性大、难降解的特点，导致产生大量含铬废水难以治理，严重威胁着人的生命健康。本文采用热解法，以活性炭(AC)为原料，硫脲为掺杂剂，得到硫氮共掺杂活性炭(N,S-AC)。通过X射线衍射，红外光谱，扫描电子显微镜技术研究，发现其是活性炭基础结构上镶接了-NH等还原官能团的颗粒结构。通过对比吸附剂用量、溶液pH和初始浓度，结果发现，其最大吸附容量可达92.40 mg/g，与理论值相近，而且符合Freundich等温吸附过程。推测吸附机理为Cr(VI)被快速还原为Cr(III)并络合的化学过程。

Abstract: In the process of industrial development in China, chromium has played a pivotal role, but due to its toxicity and being difficult to degrade, a large amount of chromium wastewater is produced, which seriously threatened human life health and property safety. In this paper, using activated carbon (AC) as raw material and thiourea as a dopant, sulfur nitrogen co-doped activated carbon (N,S-AC) was obtained by pyrolysis method. Through X-ray diffraction, infrared spectroscopy and scanning electron microscopy, it was found that the activated carbon was a particle structure embedded with reducing functional groups such as -NH. By comparing the amount of adsorbent, solution pH and initial concentration, it was found that the maximum adsorption capacity was 92.40 mg/g, which was close to the theoretical value. It also accords with Freundich isothermal adsorption process. The adsorption mechanism is assumed to be a chemical process of rapid reduction of Cr(VI) to Cr(III) and complexation.