铝改性蒸压加气混凝土材料及其除磷效果

Effect of phosphorus removal by aluminum modified autoclaved aerated concrete

为进一步提高蒸压加气混凝土材料这一建材碎料的除磷效果,采用浸渍-焙烧法制备了铝改性蒸压加气混凝土碎料除磷材料(Al-MAAC),考察了Al-MAAC的最佳制备条件以及反应时间、进水磷浓度和投加量等对除磷效果的影响。研究结果表明:最佳制备条件为1 g蒸压加气混凝土粉末材料,10 mL、0.2 mol·L^-1氯化铝溶液,混合改性0.5 h;当投加量为0.5 g·L^-1、时间为1.5 h时,低浓度含磷废水(总磷≤1 mg·L^-1)中磷的去除率可达到96.1%。综合上述结果,铝改性蒸压加气混凝土的除磷机理为材料与废水中的PO^3-4-P反应,生成以羟基磷灰石为主的钙磷-磷铝共沉淀物,从而达到除磷目的。因此,铝改性蒸压加气混凝土可作为用于深度除磷的一种价廉易得的新型材料。

In order to further improve the phosphorus removal effect of autoclaved aerated concrete,aluminum modified autoclaved aerated concrete(Al-MAAC)was prepared by impregnation-roasting method.The effects of the optimum preparation conditions,reaction time,phosphorus concentration in influent and dosage on phosphorus removal were studied.The results showed that the optimium preparation conditions were following:1 g autoclair aerated concrete powder material was mixed with 10 mL aluminum chloride solution of 0.2 mol·L-1 for 0.5 h.When the dosage was 0.5 g·L-1 and the reaction time was 1.5 h,the phosphorus removal rate of low concentration phosphorus-contained wastewater(total phosphorus≤1 mg·L-1)could reach 96.1%.Based on the above results,the dephosphorization mechanism of aluminum modified autoclaved aerated concrete was that the material could react with PO^3-4-P in the wastewater and produce calcium phosphate-phosphate-aluminum coprecipitate mainly composed of hydroxyapatite,thus the goal of dephosphorization was achieved.Therefore,aluminum modified autoclaved aerated concrete can be used as a new adsorbent for deep phosphorus removal.