摘要：

采用镁盐改性和煅烧改性的方法制备改性凹凸棒土颗粒（Mg-TAP），利用正交试验确定了最优改性条件：MgCl₂质量分数为40%，煅烧温度500℃，颗粒粒径1.0~2.0 mm。通过XRF、XRD、FTIR等手段对制备的产品进行了表征，并结合等温吸附试验探讨了Mg-TAP对磷的吸附机理。结果表明，镁盐改性可以增加凹凸棒土晶体中碱金属离子含量，提高离子交换能力；高温煅烧可使凹凸棒土脱除部分结晶水，增加比表面积，并形成MgO和CaO等活性金属氧化物，其与水中磷酸根可形成MgHPO₄和Ca₃（PO₄）₂沉淀；Mg-TAP对磷的吸附为单分子层吸附，最大平衡吸附量为16.41 mg/g。

关键词: 镁盐改性, 煅烧改性, 凹凸棒土颗粒, 除磷, 吸附

Abstract:

The modified attapulgite particles(Mg-TAP) were prepared by magnesium salt modification and calcination modification. The optimum preparation conditions were determined by orthogonal experiments design, which were 40% of MgCl₂ mass fraction, 500℃ of calcination temperature, particle size ranging from 1.0 to 2.0 mm. The prepared materials were analyzed through XRF, XRD, FTIR etc. The adsorption mechanism of Mg-TAP for phosphate was studied by isothermal adsorption experiments. The results showed that modification with magnesium solution could increase the content of alkali metal ions in attapulgite crystals, and improve the capacity of ions exchange. High temperature calcination removed portion of crystal water from attapulgite, which resulted in an enhancement of specific surface area. Meanwhile, active metal oxides, such as MgO and CaO, were formed, and the precipitation of MgHPO₄ and Ca₃(PO₄)₂ was formed with phosphate in water. The adsorption of phosphate onto Mg-TAP was proposed as monolayer adsorption, and the maximum equilibrium adsorption amount was 16.41 mg/g.

Key words: magnesium modification, calcination modification, attapulgite particles, phosphorus removal, adsorption

中图分类号: 

• X703