响应曲面法优化污泥/粉煤灰复合陶粒滤料的制备

Optimization of preparation of sludge/fly ash composite ceramsite filler materials by response surface methodology

以污泥、粉煤灰和废玻璃为原料,辅以硅酸钠作为黏结剂,烧制复合陶粒滤料。在单因素实验基础上,利用Box-Behnken响应曲面法优化,考察了预热温度、烧结温度、烧结时间等因素及其相互作用对复合陶粒滤料性能的影响。研究结果表明,响应曲面建立的数学模型拟合度较高,预热温度、烧结温度和烧结时间3个因素之间的交互作用对复合陶粒滤料吸水率均有显著影响,烧结时间是最主要的因素。在污泥、粉煤灰、废玻璃的质量比为4∶3∶3,辅以3%(以质量分数计)硅酸钠黏结剂,预热温度为500℃,预热时间为20 min,烧结温度为1133℃,烧结时间为23 min条件下,可制备出满足CJ/T 299—2008《水处理用人工陶粒滤料》要求的陶粒滤料。与其他陶粒对比,污泥/粉煤灰复合陶粒滤料具有低表观密度和高吸水率等优点,适宜作为水处理滤料及人工湿地填料。

The ceramsite filter media was fired by sludge,fly ash and waste glass as raw materials and supplemented with sodium silicate as binder.Based on single-factor experiment,the effect of preheating temperature,sintering temperature,sintering time and their interaction on the performance of composite ceramsite filter materials were investigated by using optimization with Box-Behnken response surface method.The results showed that the mathematical model established by the response surface had a high degree of fit.The interaction among the three factors of preheating temperature,sintering temperature and sintering time had significant effect on the water absorption rate.Sintering time was the most important affecting factor.Under the condition that the mass ratio of sludge,fly ash and waste glass was 4∶3∶3,supplemented by 3%(by mass fraction)binder,the preheating temperature was 500℃,the preheating time was 20 min,the sintering temperature was1133℃,and the sintering time was 23 min,the ceramsite filter material that met the requirements of CJ/T 299—2008“artificial ceramsite filter material for water treatment”could be prepared.Compared with other ceramsite,sludge or fly ash composite ceramsite filter material had the advantages of low density and high-water absorption rate,which was suitable for water treatment filter material and artificial wetland filler.