水葫芦生物炭联合高碘酸盐高效去除水中磺胺嘧啶

Efficient removal of sulfadiazine by water hyacinth(Eichhornia crassipes)biochar combined with periodate in water

以入侵植物水葫芦为原料,制备了水葫芦生物炭(EBC),发现EBC能够高效活化高碘酸盐(PI),促进磺胺嘧啶(SD)的降解,且效能优于喜旱莲子草BC和加拿大一枝黄花BC.相较于其他热解温度,500℃条件下制备的EBC(EBC500)可更好地活化PI,在较低剂量的PI(0.15mmol/L)条件下,20min内可将SD完全去除.随着EBC500和PI投加量的提升,SD的去除速率不断提高.猝灭实验和电子顺磁共振分析表明,碘自由基(⋅IO_(3),⋅IO_(4))、超氧自由基(O_(2)^(•−))、单线态氧(1 O_(2))是EBC500/PI体系降解SD的主要活性物种.同时,在EBC500和PI投加量分别为0.15g/L和0.15mmol/L的条件下,SD能够在较宽泛的初始pH值范围内(5~9)被完全去除.Cl^(−)、SO_(4)^(2−)和NO_(3)^(−)对SD的降解没有显著影响,但HCO_(3)^(−)和腐殖酸会抑制SD的去除.EBC500/PI体系可较好地应用于实际水体中SD的去除,对于其他典型磺胺类抗生素的降解也有良好的应用潜能,且EBC500具有良好的重复使用性.此外,根据6种中间产物,提出了SD的降解途径.通过生态毒性分析和植物种子萌发实验证明,EBC500/PI体系可显著降低SD溶液的生物毒性,说明该体系具有广阔的应用前景.

Water hyacinth biochar(EBC),derived from the invasive plant water hyacinth,exhibited remarkable capabilities in activating periodate(PI)and facilitating the degradation of sulfadiazine(SD).Notably,EBC outperformed Alligator weed BC and Canadian goldenrod BC in this regard.Among various pyrolysis temperatures,EBC prepared at 500(EBC500)demonstrated℃superior PI activation,effectively removing SD within a mere 20 minutes using a lower PI dose(0.15mmol/L).As the dosage of EBC500 and PI increased,the removal rate of SD also increased accordingly.Comprehensive analyses,including bursting experiments and electron paramagnetic resonance analysis,revealed that iodine radicals(⋅IO_(3),⋅IO_(4)),superoxide radicals(O_(2)^(•−)),and singlet oxygen(1 O_(2))served as the primary reactive species responsible for the degradation of SD in the EBC500/PI system.Meanwhile,under the conditions of EBC500 and PI dosages of 0.15g/L and 0.15mmol/L,respectively,SD can be completely removed across a wide range of initial pH values(5~9).Coexisting substances such as common anions(including Cl^(−),SO_(4)^(2−),and NO_(3)^(−))had minimal impact on the degradation of SD in the EBC500/PI system.However,HCO_(3)−and HA exhibited inhibitory effects on the removal of SD.Moreover,the EBC500/PI system demonstrates robust applicability for the degradation of SD in natural water matrixes,and good application potential for degradation of other typical sulfonamide antibiotics as well.Additionally,EBC500 demonstrated favorable reusability.Based on the identification of six intermediates,potential degradation pathways of SD were proposed.Ecotoxicity analysis and plant seed germination tests confirmed that the treatment with the EBC500/PI system significantly reduced the biological toxicity of SD,underscoring its promising application prospects.