天然黄铁矿的除磷性能

Removal efficiency of phosphorus by pyrite

除磷是控制水体富营养化的重要手段。为了考察黄铁矿的除磷特征,采用序批实验,分别研究了反应时间、初始磷浓度和干扰离子(NH+4、NO-3和SO2-4)对黄铁矿除磷的影响。动力学表明,黄铁矿的除磷过程符合伪二级动力学模型。pH=6.5时,磷的平衡去除量为6.82 mg/kg。Langmuir方程能较好描述黄铁矿除磷的吸附等温过程,其磷的饱和吸附量为11.01 mg/kg。NH+4、NO-3和SO2-4对黄铁矿除磷基本没有影响。磷的去除主要是通过铁磷沉淀和铁氧化物及氢氧化物的吸附,去除的磷主要以可被生物利用的Fe、Al-P形态存在。黄铁矿的这些除磷性能和机制对选取黄铁矿作为人工湿地填料实现同步脱氮除磷具有重要指导作用。

Phosphorus removal is important for the control of eutrophication. Batch experiments were car- ried out to investigate the characteristics of phosphorus removal by pyrite. The effects of contact time, initial phos- phate concentration and interfering ions（ NH4 , NO3- and SO24- ） on the phosphorus removal were investigated. Ki- netic data correlated well with the pseudo-second-order kinetic model. The equilibrium removal capacity was 6.82 mg/kg at pH of 6.5. The adsorption data could be better fitted by the isotherm models of Langmuir,the maximal adsorptive capacity reached 11. 01 mg/kg. NH4＋ ,NO3- and SO24- had no significant effect on phosphorus remov- al. The phosphorus removal was mainly achieved by iron-phosphate precipitation and iron oxides and hydroxide adsorption, the removed phosphorus mainly existed in Fe, A1-P,which could be utilized by biology. These per- formance and mechanism of phosphorus removal by pyrite have an important guiding function, in the selection of pyrite as constructed wetland substrate and achieve synchro-nization removal of nitrogen and phosphorus.