碱液润胀微晶纤维素吸附酸性矿山废水中的Cr(VI)

Alkali-Swelled Microcrystalline Cellulose Adsorbs Cr(VI) in Acid Mine Wastewater

摘要: 含Cr(VI)等金属离子在内的酸性矿山废水，如果不经过处理会对环境产生严重的危害。微晶纤维素(MCC)是纤维素经过稀酸水解至极限聚合物而成的，与一般的纤维素相比，它粒径更小，结晶度更高，孔隙率与内表面积更大，表现出更强的反应性能。因此，实验以MCC为原料，通过氢氧化钠溶液润胀，考察碱改后的MCC除去水中六价铬的能力。结果表明：氢氧化钠质量浓度(W/W)为10%时，吸附剂用量为1 g时，吸附时间为9 h，pH为2时，碱改MCC吸附Cr(VI)的效率最高。在不控制pH值的Cr(VI)离子水溶液中，碱改MCC与MMC吸附Cr(VI)离子的等温线符合Freundlish方程。当Cr(VI)离子浓度为1 mg/L时，其吸附量分别为45.13和24.50 µg/g。

Abstract: Acid mine wastewater containing metal ions such as Cr(VI) will cause serious harm to the envi-ronment if it is not treated. Microcrystalline cellulose (MCC) is a cellulose that is hydrolyzed to a limiting polymer by dilute acid. Compared with general cellulose, it has smaller particle size, higher crystallinity, greater porosity, internal surface area, and a stronger reaction performance. Therefore, the experiment used MCC as a raw material, and was swollen by a sodium hydroxide solution to examine the ability of the alkali-modified MCC to remove hexavalent chromium from water. The results show that when the concentration of sodium hydroxide (W/W) is 10%, the adsorption time is 9 h when the amount of adsorbent is 1 g, and the adsorption efficiency of Cr(VI) is the highest when alkali is changed to MCC. In the Cr(VI) ion aqueous solution without controlling the pH value, the isotherm of the alkali-modified MCC and MMC adsorbing Cr(VI) ions conform to the Freundlish equation. When the Cr(VI) ion concentration is 1 mg/L, the adsorption amounts are 45.13 and 24.50 μg/g, respectively.