摘要：

以淤泥为原料制备免烧材料，选择淤泥/水泥质量比、激发剂投加质量分数、硅酸钠投加质量分数和养护时间4个影响因素，采用Box-Behnken（BB）响应面法对制备条件进行优化，确定最优制备条件。通过等温吸附、吸附动力学模型和颗粒内扩散模型评价吸附性能，结合表征手段探究对磷酸盐的吸附机理。结果表明，免烧材料最优制备条件：淤泥/水泥质量比为2.48、激发剂投加质量分数为12.95%、硅酸钠投加质量分数为1.4%、养护时间为13 d，破损率预测值仅为2.32%，磷吸附量预测值为0.582 mg/g，吸附过程符合Langmuir模型、准二级反应动力学模型和颗粒内扩散模型。免烧材料通过化学沉淀、配体交换等方式吸附磷酸盐。免烧材料环境风险性低，经济效益高。

关键词: 淤泥, 免烧材料, 响应面法, 磷, 吸附机理

Abstract:

The non-sintered materials were prepared using sludge as raw materials, and four influencing factors were selected, including the mass ratio of silt/cement, the amount of activator, the amount of sodium silicate and the curing time, to determine the optimal preparation conditions by the Box-Behnken(BB) response surface method. The adsorption performance was evaluated by isothermal adsorption, adsorption kinetics and intragranular diffusion model, and the adsorption mechanism of phosphate was explored by characterization methods. The results showed that the optimal preparation conditions of the non-sintered materials were as follows:the mass ratio of silt/cement was 2.48, the amount of activator was 12.95%, the amount of sodium silicate was 1.4%, the curing time was 13 days, the predicted value of the breakage rate was only 2.32%, and the predicted value of phosphorus adsorption capacity was 0.582 mg/g. The adsorption process was in line with the Langmuir model, the quasi-second-order kinetic model and the intragranular diffusion model. The non-sintered materials adsorbed phosphorus by chemical precipitation and ligand exchange, with low environmental risk and high economic benefit.

Key words: sludge, non-sintered material, response surface methodology, phosphorus, adsorption mechanism

中图分类号: 

• X705