多介质地下渗滤系统基质对氨氮和磷吸附特性研究

Isothermal Absorption Properties of Ammonium-nitrogen and Phosphorus on the Matrix in Multi-Media Subsurface Wastewater Infiltration System(SWIS)

为增强地下渗滤系统对氨氮和磷的去除效果,延长系统的服务年限,通过吸附等温实验,研究传统基质煤渣和新型基质膨润土对氨氮和磷的吸附特性。结果表明,氨氮和总磷的吸附等温曲线符合Freundlich和Langmuir方程。新型基质膨润土的吸附性能强于煤渣的吸附性能,其中两种基质对氨氮的饱和吸附量:膨润土(1335.09 mg/kg)>煤渣+膨润土(1120.38 mg/kg)>煤渣(736.30 mg/kg),对磷的饱和吸附量为:煤渣+膨润土(1120.38 mg/kg)>膨润土(391.87 mg/kg)>煤渣(350.47 mg/kg)。相比未添加膨润土地下渗滤,添加膨润土地下渗滤的服务年限可提高2.8倍,表明添加膨润土可以提高污染物的去除率和系统服务年限,并且煤渣和膨润土之间的吸附作用可以相互影响,对磷吸附具有相互促进作用。

To enhance the removal rate of the ammonium-nitrogen and phosphorus and extend the server time of subsurface wastewater infiltration system （SWlS）, the experiment of adsorption isotherm was carried out to study the adsorption characteristic of the traditional matrix （coal cinder） and the new matrix （bentonite）. The results showed that the adsorption isotherm of ammonium-nitrogen and phosphorus fit the Freundlich and Langmuir equations. The adsorption properties of bentionite were stronger than the coal cinder, and the NH4＋-N saturated adsorption capacity of two matrixes were that： bentonite （1335.09 mg/kg）〉coal cinder＊bentonite （1120.38 mg/kg）〉coal cinder （736.30 mg/kg）, the TP saturated adsorption capacity of two matrixes were that： coal cinder＋bentonite （1454.80 mg/kg）〉bentonite（bentonite （391.87 mg/kg）〉coal cinder（350.47 mg/kg）. Compared with the SWIS without bentonite, the server time of SWIS adding bentonite was increased by 2.8 times. The results prove that adding the bentonite can improve the removal rate of pollutants and extend the server time of the SWIS, the adsorption properties of matrixes can influence mutually and has synergistic effect.