响应曲面法优化改性漂珠对水中三氯乙烯的吸附性能

本文对工业废弃物漂珠进行煅烧改性,制备易回收的吸附材料。以三氯乙烯作为目标污染物,研究改性漂珠吸附污染物的可行性和不同改性参数对去除污染物的影响。通过Box-Behnken设计-响应曲面法以煅烧温度、煅烧时间及粒径为影响因素,建立以三氯乙烯吸附量为响应值的预测模型,对改性漂珠进行XRD、SEM-EDS、BET等表征分析以探讨材料的吸附性能。结果表明,煅烧改性后的漂珠表面疏松多孔,比表面积增大2.4倍左右,影响改性漂珠吸附水中三氯乙烯的因素顺序依次为:煅烧时间＞煅烧温度＞粒径。模型优化的最优吸附条件为:粒径为0.25~0.38 mm,煅烧温度为640 ℃,煅烧时间为80 min,预测吸附最大值为1 326 μg/g,试验值为1 344 μg/g,两者仅相差1.4%。通过高温煅烧改性的漂珠具备更优良的吸附性能,是一种可大规模生产、以废治废、易回收的环保材料。

Adsorption Performance Optimization of Trichloroethylene in Water by Modified Cenospheres of Fly Ash Using Response Surface Methodology

The industrial waste cenospheres of fly ash (CFA) were calcined to prepare easily recoverable adsorbent materials. Using trichloroethylene (TCE) as the target pollutant, the feasibility of adsorption and the effects of different modification parameters on the removal of pollutant were investigated. Box-Behnken design (BBD) based on response surface methodology (RSM) was applied to demonstrate the effect of the interaction of calcination temperature, calcination time and particle size on the adsorption of TCE. X-ray diffraction (XRD), Scanning electron microscope and energy dispersive spectrometer (SEM-EDS), Brunner-Emmet-Teller (BET) were employed to explore the adsorption properties of materials. The results show that the surface of CFA after calcination modification is loose and porous, resulting in the increase of specific surface area by about 2.4 times. The order of factors affecting the adsorption of TCE by modified CFA is as follows: calcination time > calcination temperature > particle size. The optimum conditions are confirmed as follows: the particle size is 0.25~0.38 mm, the calcination temperature is 640 ℃ and the calcination time is 80 min. The adsorption value of CFA is 1 344 μg/g under the optimum conditions, with the difference of 1.4% compared with the predicted adsorption of 1 326 μg/g. CFA modified by high temperature calcination have better adsorption properties, which is a kind of environmental protection material that can be easy for mass production, waste utilization and recycled.