研究了水热改性颗粒钢渣对低浓度含磷废水的除磷效能及影响因素。结果表明,与普通钢渣相比,改性钢渣的除磷能力显著提高,且适宜的废水pH值范围更广;当初始磷浓度为10mg/L、改性钢渣投量为20g/L时,反应2h后即可使磷浓度降到0.1mg/L以下。改性前钢渣主要通过离子交换吸附作用除磷,改性后钢渣则主要通过化学沉淀作用除磷。XRD表征结果显示,普通钢渣表面的矿物活性在水热及激发剂的条件下被活化,并生成利于磷酸盐在其表面富集沉淀的水化硅酸钙和氢氧化钙;改性钢渣除磷反应的产物主要为非单一晶形或无晶形的磷酸钙沉淀。
Abstract: The efficiency and influence factors of phosphorus removal from low-concentration phosphorus-containing wastewater by hydrothermally modified granular steel slag were evaluated. The results show that the modified steel slag is more efficient than raw steel slag in phosphorus removal, and the suitable pH range of wastewater is wider. When the initial phosphorus concentration is 10 mg/L and the modified steel slag dosage is 20 g/L, the phosphorus concentration can be decreased to less than 0. 1 mg/L after 2 h. The mechanism of phosphorus removal by raw steel slag is mainly through ion exchange adsorption, which is different from that of modified steel slag with chemical precipitation. The results of XRD show that the activity of the minerals on the surface of raw steel slag can be activated by activators under hydrothermal condition, the calcium silicate hydrate and calcium hydroxide are the main hydrated products which can promote the phosphate to precipitate on the steel slag. The reaction products from phosphorus removal by modified steel slag are amorphous calcium phosphate or mixtures of non-single crystal calcium phosphates.