Feasibility of using nanoscale zero-valent iron and persulfate to degrade sulfamethazine in aqueous solutions
Feasibility of using nanoscale zero-valent iron and persulfate to degrade sulfamethazine in aqueous solutions
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DOI：
10.1016/j.seppur.2017.10.073
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发表时间：
2018-04
影响因子：
8.6
通讯作者：
Chia-Chang Lin;Yuxiang Chen
中科院分区：
文献类型：
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作者：
Chia-Chang Lin;Yuxiang Chen
本研究考察了纳米零价铁和过硫酸盐(nZVI/PS)工艺对水溶液中磺胺二甲嘧啶(SMT)的降解效果。NZVI是使用带有叶片填料的旋转填充床形成的。降解SMT的nZVI/PS过程中产生的主要自由基是SO4自由基点−。NZVI可以逐渐释放Fe2+，进而激活PS形成SO4自由基点−，从而提高了SMT的降解效率。研究了PS/nZVI摩尔比、SMT初始浓度和无机阴离子种类对SMT降解效率的影响。当PS浓度分别为0.5、1和2mmoL/L时，选择PS/nZVI摩尔比为1/0.5时，nZVI用量减少，降解效率随初始 浓度的增加而降低。高浓度的无机阴离子(SO42-−、HCO3-−、NO3-−和Cl-−)对SMT的降解有抑制作用，其抑制作用顺序为SO42-−>；HCO3-−>；NO3-−>；Cl-−。使用形成的nZVI对SMT的降解效率显著高于使用从CentroN生物化学技术公司购买的商业nZVI。当NZVI投加量为56 mg/L、PS浓度为2 /L、SMT初始浓度为10 mg/L时，在无无机阴离子的条件下，5 m in的降解率可达93%。因此，nZVI/PS工艺对水溶液中SMT的降解是非常有效的。
This study investigates the effectiveness of the nanoscale zero-valent iron and persulfate (nZVI/PS) process in degrading sulfamethazine (SMT) in aqueous solutions. nZVI was formed using a rotating packed bed with blade packings. The dominant generated free radical in the nZVI/PS process for degrading SMT was SO4radical dot−. nZVI can gradually release Fe2+, which subsequently activates PS to form SO4radical dot−, increasing the efficiency of degradation of SMT by this process. The effects of the PS/nZVI molar ratio, initial SMT concentration, and species of inorganic anions on the efficiency of degradation of SMT were also studied. A PS/nZVI molar ratio of 1/0.5 in the nZVI/PS process was chosen to reduce the required nZVI dosage at PS concentrations of 0.5, 1, and 2 mmol/L. The efficiency of degradation of SMT declined as the initial SMT concentration was increased. Inorganic anions (SO42−, HCO3−, NO3−, and Cl−ions) at high concentrations inhibited the degradation of SMT and their suppressive effects followed the order SO42−> HCO3−> NO3−> Cl−. The efficiency of degradation of SMT using the formed nZVI significantly exceeded that using commercial nZVI that was purchased from Centron Biochemistry Technology. At an nZVI dosage of 56 mg/L, a PS concentration of 2 mmol/L, and an initial SMT concentration of 10 mg/L, the efficiency of degradation of SMT was 93% after 5 min in the absence of inorganic anions. Therefore, the nZVI/PS process is highly effective in degrading SMT in aqueous solutions.