Degradation of ciprofloxacin and sulfamethoxazole by ferrous-activated persulfate: Implications for remediation of groundwater contaminated by antibiotics

Efficient degradation of sulfamethoxazole by the Fe(II)/HSO5− process enhanced by hydroxylamine: Efficiency and mechanism

“…The incomplete degradation of SMX in the HA/Fe(II)/PMS process might be due to the depletion of PMS (Zou et al, 2013). It should be pointed out that the HA/Fe(II)/PMS process exhibited an equivalent or even higher degradation efficiency of SMX, compared to reported catalytic PS oxidation processes (Table S1), e.g., Fe(II)/PS (Ji et al, 2014), thermo/PS (Ji et al, 2015), and Fe 0 /PS (Ghauch et al, 2013). …”

“…S5. Among these products, only P-98 and P-270 had been detected in Fe(II)/PS process (Ji et al, 2014).…”

“…Previous researches indicated the degradation products and pathways for same targets (e.g., SMX) were different in various SO4 •--based on oxidation processes (Ahmed et al, 2012;Ayoub and Ghauch, 2014;Gao et al, 2015;Ghauch et al, 2013;Ji et al, 2015). Qi et al (2014) reported the nitro derivative of SMX as an intermediate in microwave-activated persulfate process, but the same product were not found in ferrous-activated persulfate process (Ji et al, 2014). However, the lack of that information in the HA/Fe(II)/PMS process necessitates the study about degradation pathways and mechanism of antibiotics in the system.…”

“…Recently, increasing attention has been paid to the catalytic peroxymonosulfate (HSO5 -, PMS) oxidation based on sulfate radicals (SO4 •-) due to its high efficiency of selection and degradation for some refractory organic contaminants (Neta et al, 1988). Having a comparable oxidizing ability of HO • (E 0 = 1.9-2.7V) (Buxton et al, 1988), SO4 •-with E 0 of 2.5-3.1V (Neta et al, 1988) presents a powerful oxidation capacity of antibiotics (Ahmed et al, 2012), e.g., destruction of antibiotics in pure water, underground water, domestic wastewater, and swine wastewater (Ahmed et al, 2012;Ahmed et al, 2014;Ben et al, 2009;Ji et al, 2014). However, little information is currently available with regard to the remediation of antibiotics in pharmaceutical wastewater based on SO4 •-oxidation.…”

“…Activated approaches of PMS or persulfate (PS) by such as photons (Ahmed et al, 2014;Kim H.Y. et al, 2015), heat (Ji et al, 2015;Qi et al, 2014), organic compound (Lei et al, 2015;Zhou et al, 2015), metal-based catalyst (Ayoub and Ghauch, 2014;Ghauch et al, 2013), transition metals (Ji et al, 2014) have been used to produce more SO4 •-to eliminate organic contaminants. Among these activated methods, ferrous iron (Fe(II)) has the superiority of low cost, high activity, and environmental-friendly nature.…”