H_2O_2/NaOH改性玉米秸秆制备石油吸附剂的实验研究

Modification of Corn Stalk by H_2O_2/NaOH for Producing Oil Adsorbent

本文采用H2O2/NaOH对玉米秸秆(RCS)进行改性来制备可吸附石油的生物质吸附剂(HNCS)。通过模拟实验,比较了不同改性时间的HNCS吸油量,发现改性14h的吸油量最大,达14.08g·g-1,而改性前RCS仅为4.33g·g-1,改性使得吸油量提高了325%,且吸油速率更快。通过扫描电子显微镜(SEM)、比表面积/孔隙度分析仪和傅里叶红外光谱仪(FT-IR),对改性前后样品结构进行表征,同时采用洗涤剂法和硫酸法对纤维素、半纤维素、木质素含量进行测定,结果发现:改性后的HNCS表面更加粗糙,且出现大量的吸附孔隙,比表面积为7.14m·2g-1,表面亲水性官能团减少,纤维素含量增加而木质素含量减少。这说明吸油量和吸油速率受到吸附剂表面官能团、比表面积和孔隙/间隙的影响。

Oceans or inland fresh water disasters resulting from oil spills have created a great need to find more efficient materials for oil spill cleanup. Mechanical recovery by the help of oil adsorbents is one of the most important methods in oil spill cleanup. Most biomass adsorbents, however, end up in landfills or in incineration after a single use. In this study, H2O2/NaOH was used to modify raw corn stalk（RCS） to obtain biomass oil adsorbent（HNCS）. After 14-hour modification, the maximum sorption capacity of HNCS reached 14.08 g·g-1, which increased by 325% compared with RCS（4.33 g·g-1）. The oil adsorption rate also increased rapidly. The structure of RCS and HNCS was further characterized by Scanning Electron Microscope（SEM）, BET surface area analyzer and Fourier Transform Infrared Spectroscopy（FT-IR）. The amount of cellulose, hemicellulose and lignin were measured using Van-Soest Method and Sulfuric Acid Method. The results showed that the surface roughness of HNCS increased and a large number of adsorption pores appeared; the specific surface area of HNCS reached 7.14 m2·g-1 and hydrophilic functional groups were reduced; the cellulose content was increased with the decrease in lignin content. Functional groups, surface area and pore of adsorbent were the main factors that influence the oil sorption capacity and oil absorption rate. The results indicated that use of the HNCS as oil adsorbent was quite feasible.