垃圾焚烧飞灰制备水处理填料

摘要以垃圾焚烧飞灰、页岩和稻壳为原料,经造粒、烘干、焙烧等工艺,制备水处理填料(以下简称填料),并通过单因素实验研究了不同条件下填料的性能。结果表明,填料的最佳制备条件为垃圾焚烧飞灰添加量(以质量分数计,下同)77.5%,页岩添加量15.0%,稻壳添加量7.5%,焙烧温度1 080℃,焙烧时间10min。在此条件下,填料的堆积密度为0.587 6g/cm^3,吸水率为23.67%,破碎率与磨损率之和为1.32%,比表面积为2.472m^2/g。经检测,填料的重金属浸出值远低于《危险废物鉴别标准浸出毒性鉴别》(GB 5085.3—2007)限值。通过扫描电子显微镜(SEM)对填料的表面及内部结构进行观测,发现制备的填料表面较为粗糙,内部孔隙发达。将填料应用于模拟废水处理中,COD和氨氮去除率分别达87%和56%。

Preparation of water treatment fillers using municipal solid waste incineration fly ash

Municipal solid waste incineration(MSWI)fly ash,shale and rice husk were used as raw materials for preparing water treatment fillers by granulating,drying and sintering process.Performance of filler was tested under different conditions by single factor experiment.The best conditions for preparation of the fillers were obtained as follows:MSWI fly ash dosage(measured as mass fraction,the same below)was 77.5%,shale dosage was 15.0%,rice husk dosage was 7.5%,and sintering at 1 080℃for 10 min.In this condition,the bulk density was 0.587 6 g/cm^3,the water absorption rate was 23.67%,the sum of failure rate and wear rate was 1.32%,and the specific surface area was 2.472 m^2/g.The leaching concentrations of heavy metals were much lower than the regulated limit value in“Identification standard for hazardous waste-identification for extraction toxicity”(GB 5085.3-2007).The microstructures and characters of the fillers were observed with scanning electron microscope,and it was found that the surface of the filler made in the optimum conditions was coarse and the inner space was porous.When the filler was used in the treatment of simulated wastewater,the removal rates of COD and ammonia nitrogen were 87%and 56%,respectively.