稀土浸矿氨氮废水的吹脱试验研究

针对稀土浸矿产生的高氨氮废水,采用吹脱法对其进行处理,通过单因素试验和正交试验对影响因素进行了研究。结果表明,各主要因素对吹脱效果的影响大小为p H吹脱温度气液比;最佳操作条件:p H=11,温度为40℃,气液比为5 555.6∶1,吹脱时间为100 min。吹脱出的NH_3用H_2SO_4吸收,形成(NH_4)_2SO_4溶液,可作为浸取剂返回生产中使用或者用于生产(NH_4)_2SO_4肥料,实现资源回收利用。该试验工艺可作为脱氮除磷二级生物处理或一级强化处理的预处理。

ExperimentaI research on the air stripping method for the treatment of ammonia nitrogen wastewater in Ieaching rare earth

Aiming at the highly concentrated ammonia nitrogen wastewater produced in rare earth leaching ,air stripping method has been used for its treatment. Through single-factor tests and orthogonal tests,the influential fac-tors of it are studied. The results show that the order of influence degrees of the main factors on the air stripping ef-fect is pH>stripping temperature>gas-liquid ratio. The optimum operation conditions are as follows:pH=11,tempe-rature 40℃,gas-liquid ratio 5 555.6∶1,and stripping time 100 min. The NH3 air stripped from the wastewater can be absorbed by sulfuric acid,forming(NH4)2SO4 solution, which can be used as leaching solvent to be used in produc-tion again,or to be used for ammonium sulfate fertilizer production,realizing the recovery and recycling of resources. This experimental process can be used in the pretreatment of denitrification and dephosphorization second-class bio-logical treatment or first-class enhanced treatment.