硫酸活化市政污泥对氨氮的吸附研究

Adsorption of Ammonium by Activated Municipal Sludge with Sulphuric Acid

采用污水厂剩余污泥作为原料,以硫酸作为活化剂制备吸附剂,并将其应用到含氨氮废水处理中。进而系统地研究了溶液初始p H值、氨氮初始浓度、吸附时间等因素对硫酸活化市政污泥吸附氨氮的影响。结果表明,在吸附剂投加量为2 g/L、p H值为7.5、温度为303 K条件下,硫酸活化市政污泥对氨氮的吸附效果最佳。吸附动力学和热力学研究结果表明,吸附剂对氨氮的吸附过程可用准二级动力学模型(R2=0.998 6)来描述,且均符合Langmuir等温吸附模型、Freundlich等温吸附模型和Temkin等温吸附模型。由Langmuir等温吸附模型计算得到活化市政污泥对氨氮的最大吸附容量为44.84 mg/g。颗粒内扩散速率也是其吸附反应的限制因素,但不是唯一限制因素。该研究表明硫酸活化剩余污泥可以作为处理含氨氮废水的材料。

Excess sewage sludge activated by H2SOg solution was used to prepare adsorbent and applied for the treatment of wastewater containing ammonium. The influences of ammonium concentra- tion, pH and adsorption time on ammonium adsorption using the activated sludge were investigated. The adsorption capacity of the adsorbent for ammonium was the best at dosage of 2 g/L, pH 7.5 and tempera- ture of 303 K. Adsorption kinetics and thermodynamic studies showed that the adsorption process of am- monium onto the adsorbent could be fitted with pseudo-second-order kinetic model （R2 = 0.998 6）. Iso- therms studies showed that the adsorption process of ammonium onto the adsorbent can be fitted with Langmuir model, Freundlich model and Temkin model. The maximum adsorption capacity of activated sludge was calculated as 44.84 mg/g by Langmuir model. The intraparticle diffusion rate was the limiting factor in the adsorption process, but was not the only one. This study indicated that the excess sewage sludge activated by H2SO4, solution could be used as adsorbent for treating wastewater containing ammoni- um.