混凝沉淀法处理锑离子的影响因素及动力学研究

Influential factors and kinetics of antinomy ion treatment by ways of flocculation and precipitation

研究了聚合硫酸铁(PFS)对含锑(Sb)废水的处理效果,探讨了pH值、初始质量浓度、沉淀时间、石灰乳投加量及温度对PFS处理含锑废水的影响。结果表明,pH值对锑离子的去除有重要影响,碱性条件有利于锑离子的去除,当pH=9时,去除率达到96.81%。在PFS和石灰乳投加量一定的情况下,去除率随着初始质量浓度的升高而下降。沉淀时间对锑离子的去除有一定影响,随着时间的延长,去除率增大,当沉淀时间为90min时,水中锑离子基本沉降完全。石灰由于质优价廉,常被用来调节废水pH值,但大量石灰加入水中会引起沉渣过多,使得二次处理困难,因此选择用NaOH和HCl调节废水pH值,并定量投加石灰的方法处理废水。对初始质量浓度为5.0 mg/L的含锑废水,PFS和石灰乳投加量均为500.0 mg/L时去除率可达98.0%。温度对PFS处理含锑废水的效果影响不大,随着废水初始质量浓度的升高,温度的影响逐渐显著,温度升高导致去除率增大。PFS去除锑离子的过程符合二级线性动力学方程。

The present paper is to introduce our treating results over the influential factors and kinetics of antinomy ion by ways of flocculation and precipitation.For our research purpose,we have made analysis and discussion over the poly ferric sulphate effects on the antimonial sewage.In addition,we have also done tests of the effects of the pH value,the initial concentration,the setting time,the dosage of lime milk and temperature on the removing rate.The results of our research indicate that pH value has a significant effect on removing the antimony ions in addition to the favorable effect of the alkaline condition on the treatment.We have found that the removal rate can be made as high as 96.81% in the high pH region（pH 9.0）.However,the removing rate proves to decrease with the increase of the initial concentration on the condition that the dosage of PFS and the lime milk remain unchanged.Besides,the setting time tends to have a particular effect on the removal efficiency of the antimony ions,with the prolonging of the setting time.Moreover,when the antinomy ions tend to settle down almost totally when the setting time comes up to 90 minutes.Lime is also known to be easy to accommodate to the pH value of the sewage due to its superior quality and expensive price,though too much lime may lead to over sediment,thus making the secondary processing difficult.Such a situation can be avoided by adding NaOH and HCl so as to control the pH value of sewage first,followed by adding quantificational lime to it.As for the initial concentration of sewage with the antimony ions of 5 mg/L,it would be possible to make the removal rate as high as 98.00% on the condition that the dosage of lime milk and PFS went up to 500 mg/L respectively.Though it is possible to find a slight fluctuation of the removal rate along with the changes of temperature at low initial concentrations,the removal rate tends to rise with the increase of temperature at high initial concentrations.Moreover,in the course of such applications,it is also possible to prove the influence of poly ferric sulphate on the antimonial sewage in conformity with the secondary dynamics equation.Thus,PFS has been found to be a kind of highly efficient material with low secondary contamination for disposing the antimonial sewage,which will be highly promising for future application.