净水除磷基质的综合筛选与长效建模预测

Comprehensive screening and prediction of effective and lasting water purification and phosphorus removal substrates

为筛选效果好且长效的除磷基质,选取电气石陶粒、赤泥陶粒、凹凸棒石、硅胶、海绵铁、活性炭、火山岩、沸石8种基质进行磷静态吸附试验,优选3种基质进行单基质柱状除磷渗流试验和微观结构表征,获取基质的除磷特征,并依据渗流试验数据建模预测长效除磷效果。结果表明:8种基质对磷的吸附能力差异较大,其中电气石陶粒、赤泥陶粒、沸石吸附能力较好;渗流试验中,电气石陶粒在111 d后对磷的去除率仍维持在67%,赤泥陶粒则降至37%;不同基质出水总磷浓度随时间呈现不同变化规律,其统计模型预测性较好,经建模预测得出,电气石陶粒在第160天左右对磷的去除率降至50%,第300天左右达到吸附饱和,赤泥陶粒则在第150天左右达到吸附饱和。基质微观结构(比表面积、表面特征)及化学元素组成等对除磷效果有明显影响。

In order to select effective and lasting phosphorus removal substrates,eight kinds of substrates,including tourmaline ceramsite,red mud ceramsite,attapulgite,silica gel,sponge iron,activated carbon,volcanic rock and zeolite,were taken for phosphorus static adsorption experiments.Three substrates were selected for singlesubstrate columnar phosphorus removal percolation experiment and microstructure characterization,to obtain the phosphorus removal characteristics of each substrate,and to predict their long-term phosphorus removal effect by modeling based on percolation experimental data.The investigation results showed that the adsorption capacities of the eight substrates for phosphorus were quite different,the top three of which were tourmaline ceramsite,red clay ceramsite,and zeolite in order.In the seepage experiment,the phosphorus removal rate of tourmaline ceramsite remained at 67%after 111 days,while that of red mud ceramsite dropped to 37%.The total phosphorus concentration of effluent from different substrates presented differently over time,and the pertinent statistical models showed good predictability.It was predicted by the models that the phosphorus removal rate of tourmaline ceramsite would drop to 50%in about 160 days,and the adsorption saturation would be reached in about 300 days.In comparison,the red mud ceramsite would be saturated on adsorption in about 150 days.The microstructure of the substrates,including their specific surface area and surface characteristics,and their chemical element composition had a significant effect on the removal rate.