磁性硅藻土的磷释放条件及再生能力研究

Phosphorus Release Condition and Regenerability of Magnetic Diatomite

针对天然硅藻土吸附容量小、吸附后固液分离难且鲜有再生循环使用的问题,文章采用共沉淀法制备磁性硅藻土吸附剂。考察了溶液pH、反应时间、温度及固液比对吸附饱和的磁性硅藻土的释磷条件的影响,并在最佳吸附和最佳磷释放条件下研究了磁性硅藻土的再生能力。结果表明:当再生时间为90 min,pH为13,再生温度为75℃时,磷释放率达到最大;再生固液比对磷释放无明显影响,可实现再生液的减量化使用;吸附剂经3次吸附再生后对磷的吸附能力仍保持在80%以上,表明磁性硅藻土具有较好的稳定性和再生能力。

Magnetic diatomite was prepared by co-precipitation method to overcome the undesirable technical issues of diatomite,such as low adsorption capacity,difficult solid-liquid separation and few recycling using. The release conditions of phosphorus on exhausted magnetic diatomite were investigated by changing p H value,time,temperature and solid-liquid rate. The regenerability of magnetic diatomite was researched simultaneously under the best phosphorus release and best phosphorus adsorption conditions. The result showed that the phosphorus release rate increased to the largest when the time was 90 min,p H 13 and temperature 75 ℃. And there is no significantly influence of regeneration solid-liquid ratio on phosphorus release,which could realize reduction using regenerative liquid. The exhausted magnetic diatomite was amenable to efficient regeneration for repeated use and more than 80% of the adsorption capacity retained after 3-cycle adsorption-regeneration cycles.