成型表面改性生物质环境材料制备及其吸附水中多环芳烃的研究

Research on Preparation of the Surface Modified-shaped Environmental Biomaterials and Adsorption on Aqueous PAHs

700℃热解炭化大豆秸秆8h,经H3PO4溶液表面改性处理后,采用成型工艺技术制得成型表面改性生物质环境材料。测定了所制备的表面改性秸秆生物质环境材料的比表面积、表面形态及其对亚甲基蓝的吸附性能;以单一多环芳烃(PAHs)菲和复合PAHs萘、菲、苊为目标污染物,研究了生物质环境材料对水中有机污染物的吸附性能。结果表明,成型工艺制备的生物质活性炭的比表面积为320～359m2/g,孔隙高度发达。SEM结果显示,成型压力、热处理温度和热处理时间明显影响所制得材料的表面形态。成型工艺对亚甲基蓝吸附值影响顺序为热处理温度>成型压力>胶粘剂比例>热处理时间;成型生物质环境材料的最佳制备条件为:粘结剂比例15%、成型压力65MPa、热处理温度260℃、热处理时间90min。按此条件制得的生物质环境材料对亚甲基蓝的吸附值达135mg/g。成型工艺制备的秸秆生物质环境材料对水中菲的去除率均超过98%,与商品活性炭对菲的去除率相当;其对复合污染下3种PAHs的去除率为菲>萘>苊,对于同一PAHs,不同生物质环境材料的吸附能力存在差异。

The soybean stalk were pyrolyzed at 700℃ in muffle, and then surface modified by H3PO4 the obtained biomass carbons were pressed to obtain the columns of stalk biomass environmental biomaterials by molding technics. The BET specific surface, surface form, and the adsorption capacity of columns of shaped environmental biornaterials on methylene blue were determined, respectively. In order to prepare the economical and highly effective adsorption materials and evaluate their adsorption capacity, the absorption efficiencies of environmental biornaterials on single phenanthrene and mixed naphthalene, phenanthrene with acenaphthene were further studied. The results show that the BET specific surfaces obtained by shaped environmental biomaterials is 320-359m2/g, with good pore space structures; molding pressure, heat treatment temperature and heat treatment time have a clear affect on the surface forms of the shaped environmental biomaterials. The factors that influences adsorption of the methylene blue follows an descending order： heat treatment temperature 〉 molding pressure 〉 ratio of binder 〉 heat treatment time. The optimum condition obtained the shaped environmental biomaterials is binder： 15 %, molding pressure： 65 MPa, heat treatment temperature： 260℃, and heat treatment time： 90rnin, respectively. The adsorption values of the methylene blue on shaped activated carbon prepared by these conditions arrived at 135rng/g. The environmental biomaterials from soybean stalk can effectively remove the PAHs from water, and removal efficiencies on phenanthrene arrive at 98%, which is close to commercial activated carbons（CAC）. For the shaped activated carbons based on different treatments, there is an obvious discrepancy in PAHs absorption.