垃圾焚烧炉渣与污泥合成填料对污水中磷的去除研究

Wastewater P Removing Effect of Composite Filter Filling Consisting of Slag of Garbage Incinerator and Residual Sludge From Wastewater Treatment Plant

垃圾焚烧炉渣和污水厂污泥合成填料是经济有效且磷聚高效的吸附剂,该技术为垃圾焚烧炉渣和污泥提供新的利用方向。采用Langmuir吸附等温方程模拟吸附剂的磷聚性能优于Freundlich模型,利用其计算所得4∶1和1∶1两种比例合成的填料对磷的最大吸附量分别为27 300和13 750 mg·kg-1,是沸石填料最大吸附量的54.6和27.5倍。合成填料磷解吸率明显低于沸石,且随着溶液磷初始浓度的升高,合成填料的磷解吸率保持稳定。pH值对合成填料吸附磷的影响小,表明合成填料适应污水的pH值范围广;浸出试验显示合成填料重金属浸出率低,环境安全性能优良。综上所述,垃圾焚烧炉渣和污水厂剩余污泥合成的填料吸附剂吸附磷能力强,饱和吸附量大,解吸率低,是一种较为理想的磷聚填料。

Composite of slag from garbage incinerators and residual sludge from wastewater treatment plants is proved to be a cost-effective adsorbent high in P adsorption capacity.This technology has opened up a field for recycling of the slag and sludge.Compared with the Freundlich model,the Langmuir model could better simulate phosphorus adsorption capacity of the adsorbent.Calculation using the Langmuir model shows that maximum phosphorus adsorption capacity of the adsorbent varied with ratio of its composition.It was 27 300 and 13 750 mg · kg-1,54.6 and 27.5 times greater than that of zeolite,respectively,when its composition ratio was 4 ∶ 1 and 1 ∶ 1.The composite adsorbent was significantly lower than zeolite in P desorption rate.Neither initial P concentration nor pH in the solution had much effect on P desorption rate of the composite adsorbent,indicating that the composite adsorbent is applicable to solutions wide in pH range.Extraction tests show that the adsorbent is low in heavy metal extraction rate,safe to the environment and good in performance.To sum up,the composite adsorbent composed of slag from garbage incinerators and sludge from wastewater treatment plants is both high in P adsorption capacity and saturated adsorption,but low in desorption rate.It is,therefore,an ideal phosphate adsorbing filling.