几种吸附材料对磷吸附性能的对比研究

针对白洋淀府河水体磷污染问题,研究了天然沸石、硅藻土、粉煤灰、赤泥、铁铝泥五种材料对磷的吸附性能,并利用盐酸改性铁铝泥、铁盐改性粉煤灰和赤泥,对比研究了改性后材料对磷的吸附能力,探讨了水体pH值和其他离子对其吸附性能的影响。结果表明:沸石、硅藻土、粉煤灰、赤泥对磷的吸附符合一级动力学模型,而铁铝泥和改性后材料吸附磷符合准二级动力学模型;改性前后各材料吸附磷等温线均符合Langmuir方程。各材料吸附磷能力为:改性赤泥>改性粉煤灰>改性铁铝泥>铁铝泥>赤泥和粉煤灰>沸石>硅藻土,改性材料吸附磷能力明显提高。溶液pH值显著影响改性材料吸附磷效果,pH为7时吸附量最大;硫酸根和碳酸氢根离子抑制磷的吸附,氯离子和硝酸根离子没有明显影响。

CONTRASTIVE STUDY ON PHOSPHORUS ADSORPTION OF SEVERAL ADSORBENTS

The adsorption capacity of natural zeolite,fly ash,red mud,diatomaceous earth,iron-aluminum mud was researched and the phosphorus adsorption of the modified adsorbents(iron-aluminum mud modified with hydrochloric acid,fly ash and red mud modified with ferric chloride) were compared in this paper.The effects of pH and other ions in water on phosphorus adsorption by the modified adsorbents were investigated.The results indicate that phosphorus adsorption by natural zeolite,fly ash,red mud and diatomaceous earth can be simulated by the first kinetic models,while phosphorus adsorption by iron-aluminum mud and the modified adsorbents can be simulated by second order kinetic models.The phosphorus adsorption by adsorbents and the modified adsorbents can be better described with Langmuir adsorption isotherm.The order of the phosphorus adsorption is as follows: modified red mud> modified fly ash> modified iron-aluminum> iron-aluminum > red mud and fly ash > natural zeolite > diatomaceous earth.The adsorption capacity of the modified adsorbents is obviously improved.The optimal pH for phosphorus adsorption by the modified adsorbents is at pH of 7.HCO-3 and SO42-ions in water can significantly restrain phosphorus adsorption.