VUV/UV/NaClO及UV/NaClO去除百里香酚:降解机制及水质影响因素
Degradation of thymol by VUV/UV/NaClO and UV/NaClO processes:Degradation mechanism and water quality affecting factors
袁雨瑾 1肖习羽 2李青松 1李玉瑛 3吴俊文 4戴惠林1
作者信息
- 1. 厦门理工学院 水资源环境研究所,福建 厦门 361024
- 2. 厦门理工学院 水资源环境研究所,福建 厦门 361024;汕头大学 海洋灾害预警与防护广东省重点实验室,广东 汕头 515063
- 3. 五邑大学 生物科技与大健康学院,广东 江门 529020
- 4. 汕头大学 海洋灾害预警与防护广东省重点实验室,广东 汕头 515063
- 折叠
摘要
采用VUV/UV/NaClO及UV/NaClO工艺去除百里香酚(Tml),对比考察pH、CO32-、NO3-和腐殖酸(HA)等因素对Tml去除的影响,鉴定识别Tml的降解产物并推测了降解途径,探究VUV/UV/NaClO工艺中反应溶液的急性毒性变化,通过反应溶液组分毒性鉴定评估结合 ECOSAR 软件模拟识别了毒性较大的产物.结果表明,UV/NaClO 和VUV/UV/NaClO工艺中Tml的去除拟一级反应动力学常数kobs均随着pH的增大先减少后增加,且均在pH为 7 时达到最小,分别为 0.1836 min-1 和 0.5547 min-1;CO32-的存在有利于Tml的去除,在VUV/UV/NaClO工艺中,低浓度NO3-对Tml的去除有轻微抑制作用,高浓度则反之;而在 UV/NaClO工艺中,NO3-的存在有利于Tml的去除;HA对Tml的去除有抑制作用.相同条件下不同水质因素对VUV/UV/NaClO工艺的促进或抑制更为显著,约为UV/NaClO工艺的 1.05～3.57 倍.VUV/UV/NaClO工艺中Tml主要发生了自由基的取代、加成和氧化分解反应,生成了氯代、醌和醛类中间产物.VUV/UV/NaClO处理后的溶液毒性呈先上升后下降再上升的趋势,生成的丙酸乙烯基酯和戊醛类等小分子有机物导致了反应后期反应溶液急性毒性增加.
Abstract
VUV/UV/NaClO and UV/NaClO processes were employed to degrade thymol(Tml)in aqueous solution.Effects of pH,CO32-,NO3-and humic acid(HA)on Tml removal were comparatively studied.The degradation products were identified and a possible degradation pathway was proposed.Meanwhile,the alteration of acute toxicity during VUV/UV/NaClO process was investigated,and the most toxic by-products were identified by toxicity assessment and ECOSAR software simulation.The results show that the pseudo first-order kinetic constants(kobs)for Tml removal decreased firstly and then increased with increasing pH in both UV/NaClO and VUV/UV/NaClO processes,and the minimum values were 0.1836 and 0.5547 min-1 at pH=7,respectively.The presence of CO32-favors Tml degradation,while low concentration of NO3-demonstrates a slightly inhibiting effect but high concentration shows the opposite.HA has an inhibiting effect on the degradation of Tml.The impact of water quality on Tml degradation was more obvious during VUV/UV/NaClO process,in which kobs was about 1.05～3.57 times of that of the UV/NaClO process.Tml in the VUV/UV/NaClO process mainly showed radical substitution,addition and oxidative decomposition reactions,and chlorinated,quinone and aldehyde intermediates were generated.The acute toxicity of the VUV/UV/NaClO process treated solution had an increase-decrease-increase profile.The increase of acute toxicity in the later stage may be due to the generation of small-molecule organic compounds such as vinyl propionate and glutaraldehyde.
关键词
VUV/UV/NaClO/UV/NaClO/百里香酚(Tml)/水质/自由基Key words
VUV/UV/NaClO/UV/NaClO/thymol/water quality/radical引用本文复制引用
基金项目
国家自然科学基金(51878582)
国家自然科学基金(42076038)
福建省科技计划引导性资助项目(2021Y0041)
出版年
2024
国家科技期刊平台
NSTL
万方数据