给水污泥对水中磷的吸附性能

Phosphorus adsorption performance of water-supply sludge

以给水污泥为磷的吸附材料,采用静态吸附和动态吸附方法对比研究了干、湿状态下给水污泥对磷的吸附特性。静态吸附实验结果表明,给水污泥对磷的吸附过程以化学吸附为主,满足Freundlich等温吸附方程式。在300 K条件下,原始状态的湿污泥相比烘干后的污泥能更快地达到磷吸附平衡,且具有更高的理论饱和吸附量,分别为3.487mg·g^(-1)(相当于11.710mg·g^(-1),以干污泥计)和9.832mg·g^(-1)。长期动态吸附实验结果表明,原始状态的给水污泥对磷的实际饱和吸附量为3.065 mg·g^(-1),接近理论饱和吸附量。因此,原始状态的给水污泥可直接用作除磷材料,无需预先烘干处理。

Water-supply sludge was used as an adsorbent for phosphorus. The adsorption characteristics of phosphorus in dry and wet water-supply sludge were compared through static and dynamic adsorption methods. Results of static adsorption showed that the adsorption process was mainly governed by chemical adsorption, which can be well fitted by Freundlich equation. Under the temperature of 300 K, faster equilibrium of phosphorus with higher saturated adsorption capacity was observed in wet sludge as compared to that of dry sludge. The adsorption capacities were 3.487 mg.g-1 （equal to 11.710 mg-g-1 of the dry sludge） and 9.832 mg.g-1 for wet and dry sludge, respectively. It was revealed that the saturated adsorption capacity of the sludge was 3.065 mg.g-1 in the long-term dynamic adsorption experiments, close to the theoretical value in the static experiments. Therefore, original water-supply sludge can be directly used as the phosphorus adsorbent even without the drying process.