零价钴活化过一硫酸盐降解罗丹明B废水

Degradation of Rhodamine B in Wastewater by Zero-valent Cobalt Activated Peroxymonosulfate

该文采用零价钴(ZVCo)活化过一硫酸盐(PMS)降解罗丹明B(RhB)废水,考察了初始p H、ZVCo投加量、PMS用量、常见无机阴离子(如Cl^(-)、SO_(4)(2-)、NO_(3)^(-)、HCO_(3)^(-))和天然有机物(NOM)对ZVCo/PMS反应体系的影响;探究了RhB在该体系中的降解机理。实验结果表明,pH为7时,Rh B的降解效率最高,在6 min内其降解效率可达98.5%。Cl^(-)的存在对Rh B的降解有轻微的抑制作用;HCO_(3)^(-)和NOM能够较大限度地抑制Rh B的去除;SO_(4)(2-)和NO_(3)^(-)几乎无影响。自由基淬灭实验表明羟基自由基(HO·)和硫酸根自由基(SO_(4)·-)均参与了Rh B的降解过程,且SO_(4)·-是该体系中起主要作用的自由基。ZVCo具有良好的稳定性,材料经重复使用4次后对Rh B的降解效率仍高达98.4%。

This paper is intended to introduce a method of using zero-valent cobalt(ZVCo)activated peroxymonosulfate(PMS)to degrade rhodamine B(Rh B)in wastewater.Thereby a laboratory experiment was conducted for investigating the effects of parameters of initial p H,ZVCo dosages,PMS,and common inorganic anions(Cl^(-),SO_(4)(2-),NO_(3)^(-)and HCO_(3)^(-),and natural organic matter(NOM))on the ZVCo/PMS process,and the mechanism of Rh B degradation during ZVCo/PMS process was explored.The experiment showed that the degradation efficiency of Rh B attained the top value at p H 7,up to as high as98.5%within 6 min;it was found the presence of Cl^(-)could slightly inhibit the degradation of Rh B,while an obvious inhibition occurred with the addition of HCO_(3)^(-)and NOM;and SO_(4)(2-)and NO_(3)^(-)almost did not affect degradation of Rh B.Besides,the radical quenching testing suggested that both hydroxyl radical(HO·)and sulfate radical(SO_(4)·-)were involved in the degradation of Rh B and SO_(4)·-was the dominant reactive species in this system.ZVCo has an excellent feature of stability and reusability,and the degradation efficiency of Rh B by ZVCo/PMS could be maintained at 98.4%for four times.