酸化污泥膨润土的颗粒化制备

Preparation of Acidified Sludge-Bentonite Granules

以污泥为添加剂,研究了制备多孔污泥膨润土颗粒及其酸化的最佳条件.考察了焙烧温度与时间及配料比对颗粒孔隙的影响和酸种类、液固比、酸浓度、活化温度及活化时间对染料脱色效果的影响,并对颗粒的性能指标(比表面积、散失率、吸水率和形貌等)进行了表征.结果表明,酸化污泥膨润土颗粒的优化制备工艺条件为:污泥/膨润土最佳质量比1:3,焙烧温度700℃,焙烧时间7h,硫酸浓度6mol/L,液固比25mL/g,常温下酸活化4h.将其用于活性翠蓝染料的脱色,常温下反应2h的脱色率可达47%,效果明显优于不规则炭、柱状炭和酸化前颗粒.

Taking sludge as pore-forming agent, the optimized conditions for preparation and acidification of bentonite granules were investigated. The effects of calcination temperature, roasting time and sludge content on the porosity of granules were investigated to obtain porous samples with better mechanical strength, which were further treated with sulphuric acid activation. By altering acid type, acid concentration, ratio of liquid to solid, activation temperature and activation time, the acid activated bentonite granular adsorbent with better decoloration properties was obtained and characterized in specific surface area, lost ratio, water absorption and morphology. The results indicate that the optimal preparation conditions of porous bentonite granules are calcination temperature 700 ℃, calcination time 7 h, and mass ratio of sludge to bentonite 1：3. And the granules are acidized by the sulphuric acid of 6 mol/L to react for 4 h at ambient temperature and ratio of H2SO4 to granules 25 mL/g. The decoloration rate of Turquoise Blue by the prepared granules reaches 47% in 2 h, which is more excellent than that of other three granular adsorbents, irregular carbons, cylindrical carbons and raw material.