WATER RESEARCH
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2020
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IF 9.13
Simiao Li,Xiuwei Ao,Chen Li,Zedong Lu,Wenfeng Cao,Fangfang Wu,Shuming Liu,Wenjun Sun
The UV/NH 2 Cl process is an emerging advanced oxidation process (AOP) that is greatly effective in degrading pharmaceuticals and personal care products (PPCPs). However, detailed information regarding the process is lacking. The degradation of ibuprofen (IBP, an electron-withdrawing PPCP) and naproxen (NPX, an electron-donating PPCP) in UV/NH 2 Cl and UV/NaClO processes was performed to investigate the applicability and security of the UV/NH 2 Cl process and compare with those of UV/NaClO. UV/NH 2 Cl was effective in degrading both IBP and NPX and the degradation followed pseudo-first order kinetics (k IBP = 0.0037 cm 2 /mJ and k NPX = 0.0044 cm 2 /mJ). This indicated the broad applicability of UV/NH 2 Cl to different kinds of PPCPs. Ranges of values of UV intensity (0.3–1.0 mW/cm 2 ) and pH (6.0–8.0) showed little effect on the degradation of PPCPs by UV/NH 2 Cl based on UV Dose but HCO 3 − (2–8 mM), natural organic matter (NOM, 2–8 mg/L), and the natural water matrixes were inhibitory. Increasing the dosage of NH 2 Cl from 0.15 mM to 0.75 mM, resulted in an even increase of k IBP ; however, k NPX increased slowly after 0.3 mM NH 2 Cl. Mechanism experiments involving nitrobenzene showed that •OH was the major radical involved in degrading IBP and NPX via UV/NH 2 Cl. The electron spin resonance spectroscopy and kinetic modeling results also indicated the larger amount of •OH and weaker reactive chlorine species (mainly ClO• and ClO 2 •) in UV/NH 2 Cl compared with UV/NaClO. Compared to UV/NaClO in synthetic and natural water, UV/NH 2 Cl was a more stable degrader with little pH- and substrate-dependence, while UV/NaClO preferred degrading the electron-donating PPCP and at low pH. The UV/NH 2 Cl produced less halogenated disinfection byproducts (DBPs) (even nitrogenous DBPs) and was less cytotoxic theoretically than UV/NaClO based on the DBPs included in this study. Thus UV/NH 2 Cl process may be an effective AOP for water treatment .
研究领域:
环境科学
·
水处理工程
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DOI
PubMed
高影响因子
Water Resources and Industry
·
2023
·
IF 5.1
Jiayu Zhang,Qiongfang Wang,Lei Dong,Pinhua Rao,Xin Zhang,Naiyun Gao,Xiaoying Yin
In this paper, UV/NH 2 Cl process was used to research the degradation of sulfathiazole (STZ) and the formation of disinfection by-products (DBPs) after disinfection were detected. UV and NH 2 Cl process showed a synergistic effect on the removal of STZ. Natural organic matter and CO 3 2− inhibited the STZ degradation, NO 3 − promoted the degradation of STZ, whereas NH 2 Cl concentration, HCO 3 − and Cl − had dual effects on the removal of STZ. The removal of STZ by UV/NH 2 Cl was slightly influenced by pH. The contribution of reactive chlorine species and reactive nitrogen species to STZ degradation was significantly higher than that of HO · . Possible STZ degradation pathways were presented by analyzing intermediate products. In addition, the pretreatment of UV/NH 2 Cl significantly reduced the formation of DBPs during NH 2 Cl or NaClO disinfection. In conclusion, UV/NH 2 Cl process is an effective water treatment technology and can be well applied for practical purposes.
研究领域:
环境科学
·
水处理技术
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2026
·Vol. 14
·期 5
·124863
·
IF 7.5
Bingliang Zhang,Cong Wang,Fuyao Tong,Meixue Chen,Xiaojuan Liu,Xifeng Shi
UV-based advanced oxidation processes (UV-AOPs) show great potential for municipal wastewater advanced treatment. Although chlor(am)ine-based UV-AOPs have been widely investigated, discrepancies in chlorinated byproduct (Cl-BP) formation and biotoxicity risks among UV/chlorine (UV/Cl 2 ), UV/chloramine (UV/NH 2 Cl), vacuum ultraviolet/ultraviolet/chlorine (VUV/UV/Cl 2 ), and VUV/UV/chloramine (VUV/UV/NH 2 Cl) processes for municipal secondary effluent treatment remain poorly understood. Herein, gas chromatography, Fourier transform ion cyclotron resonance mass spectrometry, and Vibrio fischeri were employed to reveal the formation characteristics of Cl-BPs and acute toxicity variations during these treatments. The results indicated that UV/Cl 2 process produced the highest levels of total organic chlorine (TOCl), known Cl-BPs, calculated cytotoxicity, and acute toxicity. In contrast, VUV/UV/NH 2 Cl treatment exhibited the lowest values for these parameters, with reductions of 61.3%, 96.3%, 99.7%, and 28.0% relative to UV/Cl 2 system. UV/Cl 2 treatment yielded the largest number of unknown Cl-BPs with high saturation, while VUV/UV/NH 2 Cl process generated the fewest Cl-BPs, consisting of more unsaturated CHONCl compounds. Mass difference analysis revealed that Cl 2 -based AOPs had the most precursors and precursor-product pairs, with oxygenation, chlorine substitution and addition as the principal reactions, whereas NH 2 Cl-based ones were dominated by nitrogen-related reactions. Considering Cl-BP and biotoxicity mitigation, VUV/UV/NH 2 Cl process emerges as the most promising technology for advanced treatment of municipal secondary effluent. Overall, this study provides fundamental insights and technological guidance for applying (VUV/)UV-AOPs to real municipal wastewater.
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高影响因子
Journal of Environmental Chemical Engineering
·
2026
·Vol. 14
·期 2
·121835
·
IF 7.5
Zongyu Yan,Mian Wu,Haoran Wang,Tong Xu,Shuaishuai Xin,Qianwen Wang,Guocheng Liu,Qinghua Yan,Yanlong Sun,Chengzhi Zhou,Ya-nan Zhang,Yanjun Xin
The widespread use of antiviral drugs (AVDs) has introduced novel challenges to water treatment processes in recent years. Therefore, it is urgently required to develop an efficient and sustainable technology for AVDs elimination. This study examines the effectiveness of UV-activated monochloramine (UV/NH 2 Cl) as a potent treatment modality for degrading AVDs. Results showed that the degradation rate constants ( k ) of ganciclovir, acyclovir, and stavudine were 0.381, 0.339, and 0.395 min −1 , respectively, under UV/NH 2 Cl conditions (NH 2 Cl/AVDs molar ratio = 40). Both •OH and reactive chlorine species are crucial for AVDs degradation. The degradation pathways of AVDs in the UV/NH 2 Cl system are primarily characterized by C-N bond cleavage, oxidation, hydroxylation, and chlorination. A comprehensive evaluation on the degradation kinetics of ten AVDs UV/NH 2 Cl revealed a correlation between the AVDs molecular structures and the degradation efficiency. The k of AVDs was positively correlated with the polarizability. This phenomenon can be attributed to the spatial electron distribution of AVDs with a high polarizability, which is more susceptible to alteration. Conversely, the k was inversely correlated with the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap, as a smaller HOMO-LUMO gap makes the AVDs more conducive to electron exchange and subsequent participation in redox reactions. This study confirms the efficient abatement performance of the UV/NH 2 Cl system for AVDs, and simultaneously provides critical technical references and novel theoretical insights for the AVDs removal in real water matrices.
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高影响因子
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