Skip to main content
SpringerLink
Log in

Light-induced variation in environmentally persistent free radicals and the generation of reactive radical species in humic substances

  • Research Article
  • Published:
Frontiers of Environmental Science & Engineering Aims and scope Submit manuscript

Abstract

Environmentally persistent free radicals (EPFRs) in humic substances play an essential role in soil geochemical processes. Light is known to induce EPFRs formation for dissolved organic matter in aquatic environments; however, the impacts of light irradiation on the variation of EPFRs in soil humic substances remain unclear. In this study, humic acid, fulvic acid, and humin were extracted from peat soil and then in situ irradiated using simulated sunlight. Electron paramagnetic resonance spectroscopy results showed that with the increasing irradiation time, the spin densities and g-factors of humic substances rapidly increased during the initial 20 min and then gradually reached a plateau. After irradiation for 2h, the maximum spin density levels were up to 1.63 × 1017, 2.06 × 1017, and 1.77 × 1017 spins/g for the humic acid, fulvic acid, and humin, respectively. And the superoxide radicals increased to 1.05 × 1014–1.46 × 1014 spins/g while the alkyl radicals increased to 0.47 × 1014–1.76 × 1014 spins/g. The light-induced EPFRs were relatively unstable and readily returned back to their original state under dark and oxic conditions. Significant positive correlations were observed between the concentrations of EPFRs and reactive radical species (R2= 0.65–0.98, p < 0.05), which suggested that the newly produced EPFRs contributed to the formation of reactive radical species. Our findings indicate that under the irradiation humic substances are likely to be more toxic and reactive in soil due to the formation of EPFRs.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Allard B, Borén H, Pettersson C, Zhang G (1994). Degradation of humic substances by UV irradiation. Environment International, 20(1): 97–101

    Article  CAS  Google Scholar 

  • Amir S, Jouraiphy A, Meddich A, El Gharous M E, Winterton P, Hafidi M (2010). Structural study of humic acids during composting of activated sludge-green waste: Elemental analysis, FTIR and 13C NMR. Journal of Hazardous Materials, 177(1–3): 524–529

    Article  CAS  Google Scholar 

  • Campos-Martin J M, Blanco-Brieva G, Fierro J L G (2006). Hydrogen peroxide synthesis: An outlook beyond the anthraquinone process. Angewandte Chemie International Edition, 45(42): 6962–6984

    Article  CAS  Google Scholar 

  • Cerqueira S D A, Romao L P C, Lucas S C O, Fraga L E, Simoes M L, Hammer P, Lead J R, Mangoni A P, Mangrich A S (2012). Spectroscopic characterization of the reduction and removal of chromium(VI) by tropical peat and humin. Fuel, 91(1): 141–146

    Article  CAS  Google Scholar 

  • Chamulitrat W, Hughes M F, Eling T E, Mason R P (1991). Superoxide and peroxyl radical generation from the reduction of polyunsaturated fatty acid hydroperoxides by soybean lipoxygenase. Archives of Biochemistry and Biophysics, 290(1): 153–159

    Article  CAS  Google Scholar 

  • Chen Y, Liu L, Su J, Liang J F, Wu B, Zuo J L, Zuo Y G (2017). Role of humic substances in the photodegradation of naproxen under simulated sunlight. Chemosphere, 187: 261–267

    Article  CAS  Google Scholar 

  • Deng Y Z, Peng S P, Liu H D, Li S D, Chen Y F (2019). Mechanism of dichloromethane disproportionation over mesoporous TiO2 under low temperature. Frontiers of Environmental Science & Engineering, 13(2): 21

    Article  CAS  Google Scholar 

  • Feng X, Hua Y, Zhang C, Kong X, Li X, Chen Y (2020). Effect of soaking conditions on the formation of lipid derived free radicals in soymilk. Food Chemistry, 315(15): 126237

    Article  CAS  Google Scholar 

  • Gehling W, Khachatryan L, Dellinger B (2014). Hydroxyl radical generation from environmentally persistent free radicals (EPFRs) in PM2.5. Environmental Science & Technology, 48(8): 4266–4272

    Article  CAS  Google Scholar 

  • Gohre K, Scholl R, Miller G C (1986). Singlet oxygen reactions on irradiated soil surfaces. Environmental Science & Technology, 20(9): 934–938

    Article  CAS  Google Scholar 

  • Jia H Z, Nulaji G, Gao H W, Wang F, Zhu Y Q, Wang C Y (2016). Formation and stabilization of environmentally persistent free radicals induced by the interaction of anthracene with Fe(III)-modified clays. Environmental Science & Technology, 50(12): 6310–6319

    Article  CAS  Google Scholar 

  • Jia H Z, Zhao S, Shi Y F, Zhu L Y, Wang C Y, Sharma V K (2018). Transformation of polycyclic aromatic hydrocarbons and formation of environmentally persistent free radicals on modified montmorillonite: The role of surface metal ions and polycyclic aromatic hydrocarbon molecular properties. Environmental Science & Technology, 52(10): 5725–5733

    Article  CAS  Google Scholar 

  • Khachatryan L, McFerrin C A, Hall R W, Dellinger B (2014). Environmentally persistent free radicals (EPFRs). 3. Free versus bound hydroxyl radicals in EPFR aqueous solutions. Environmental Science & Technology, 48(16): 9220–9226

    Article  CAS  Google Scholar 

  • Li Y, Niu J, Shang E, Crittenden J C (2015). Synergistic photogeneration of reactive oxygen species by dissolved organic matter and C60 in aqueous phase. Environmental Science & Technology, 49(2): 965–973

    Article  CAS  Google Scholar 

  • Li Y, Niu J, Shang E, Crittenden J C (2016). Influence of dissolved organic matter on photogenerated reactive oxygen species and metal-oxide nanoparticle toxicity. Water Research, 98: 9–18

    Article  CAS  Google Scholar 

  • Li H, Pan B, Liao S H, Zhang D, Xing B S (2014). Formation of environmentally persistent free radicals as the mechanism for reduced catechol degradation on hematite-silica surface under UV irradiation. Environmental Pollution, 188(5): 153–158

    Article  CAS  Google Scholar 

  • Monteil-Rivera F, Brouwer E B, Masset S, Deslandes Y, Dumonceau J (2000). Combination of X-ray photoelectron and solid-state 13C nuclear magnetic resonance spectroscopy in the structural characterisation of humic acids. Analytica Chimica Acta, 424(2): 243–255

    Article  CAS  Google Scholar 

  • Novotny E H, Martin-Neto L (2002). Effects of humidity and metal ions on the free radicals analysis of peat humus. Geoderma, 106(3–4): 305–317

    Article  CAS  Google Scholar 

  • Oniki T, Takahama U (1994). Effects of reaction-time, chemical-reduction, and oxidation on ESR in aqueous-solutions of humic acids. Soil Science, 158(3): 204–210

    Article  CAS  Google Scholar 

  • Page S E, Kling G W, Sander M, Harrold K H, Logan J R, McNeill K, Cory R M (2013). Dark formation of hydroxyl radical in arctic soil and surface waters. Environmental Science & Technology, 47(22): 12860–12867

    Article  CAS  Google Scholar 

  • Page S E, Sander M, Arnold W A, McNeill K (2012). Hydroxyl radical formation upon oxidation of reduced humic acids by oxygen in the dark. Environmental Science & Technology, 46(3): 1590–1597

    Article  CAS  Google Scholar 

  • Radovic L R (2009). Surface chemical and electrochemical properties of carbons. In: Béguin F, Frąckowiak E, eds. Carbon Materials for Electrochemical Energy Storage Systems. London: CRC Press, 163–211

    Google Scholar 

  • Scott D T, McKnight D M, Blunt-Harris E L, Kolesar S E, Lovley D R (1998). Quinone moieties act as electron acceptors in the reduction of humic substances by humics-reducing microorganisms. Environmental Science & Technology, 32(19): 2984–2989

    Article  CAS  Google Scholar 

  • Sharpless C M, Aeschbacher M, Page S E, Wenk J, Sander M, McNeill K (2014). Photooxidation-induced changes in optical, electrochemical, and photochemical properties of humic substances. Environmental Science & Technology, 48(5): 2688–2696

    Article  CAS  Google Scholar 

  • Sposito G, Martin-Neto L, Yang A (1996). Atrazine complexation by soil humic acids. Journal of Environmental Quality, 25(6): 1203–1209

    Article  CAS  Google Scholar 

  • Tollin G, Steelink C (1966). Biological polymers related to catechol: electron paramagnetic resonance and infrared studies of melanin, tannin, lignin, humic acid and hydroxyquinones. Biochimica et Biophysica Acta- Biomembranes, 112(2): 377–379

    Article  CAS  Google Scholar 

  • Tong H J, Arangio A M, Lakey P S J, Berkemeier T, Liu F, Kampf C J, Brune W H, Poschl U, Shiraiwa M (2016). Hydroxyl radicals from secondary organic aerosol decomposition in water. Atmospheric Chemistry and Physics, 16(3): 1761–1771

    Article  CAS  Google Scholar 

  • Vejerano E P, Rao G, Khachatryan L, Cormier S A, Lomnicki S (2018). Environmentally persistent free radicals: Insights on a new class of pollutants. Environmental Science & Technology, 52(5): 2468–2481

    Article  CAS  Google Scholar 

  • Wan D, Sharma V K, Liu L, Zuo Y G, Chen Y (2019). Mechanistic insight into the effect of metal ions on photogeneration of reactive species from dissolved organic matter. Environmental Science & Technology, 53(10): 5778–5786

    Article  CAS  Google Scholar 

  • Wang X L, Guo X Y, Yang Y, Tao S, Xing B S (2011). Sorption mechanisms of phenanthrene, lindane, and atrazine with various humic acid fractions from a single soil sample. Environmental Science & Technology, 45(6): 2124–2130

    Article  CAS  Google Scholar 

  • Watanabe A, McPhail D B, Maie N, Kawasaki S, Anderson H A, Cheshire M V (2005). Electron spin resonance characteristics of humic acids from a wide range of soil types. Organic Geochemistry, 36(7): 981–990

    Article  CAS  Google Scholar 

  • Wen B, Zhang J J, Zhang S Z, Shan X Q, Khan S U, Xing B S (2007). Phenanthrene sorption to soil humic acid and different humin fractions. Environmental Science & Technology, 41(9): 3165–3171

    Article  CAS  Google Scholar 

  • Zhang K K, Sun P, Zhang Y R (2019). Decontamination of Cr(VI) facilitated formation of persistent free radicals on rice husk derived biochar. Frontiers of Environmental Science & Engineering, 13(2): 85–93

    Article  CAS  Google Scholar 

  • Zhao S, Gao P, Miao D, Wu L, Qian Y, Chen S, Sharma V K, Jia H Z (2019). Formation and evolution of solvent-extracted and nonextractable environmentally persistent free radicals in fly ash of municipal solid waste incinerators. Environmental Science & Technology, 53(17): 10120–10130

    Article  CAS  Google Scholar 

  • Zhu K, Jia H, Wang F, Zhu Y, Wang C, Ma C (2017). Efficient removal of Pb(II) from aqueous solution by modified montmorillonite/carbon composite: Equilibrium, kinetics and thermodynamics. Journal of Chemical & Engineering Data, 62(1): 333–340

    Article  CAS  Google Scholar 

  • Zhu K, Jia H, Zhao S, Xia T, Guo X, Wang T, Zhu L (2019). Formation of environmentally persistent free radicals on microplastics under light irradiation. Environmental Science & Technology, 53(14): 8177–8186

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant No. 41877126), National Key R&D Program of China (Grant No. 2018YFC1802004), China Postdoctoral Science Foundation funded project (No. 2019M650278), Shaanxi Key R&D Program of China (No. 2019ZDLNY01-02-01), and Shaanxi Science Fund for Distinguished Young Scholars (Grant No. 2019JC-18).

Author information

Authors and Affiliations

  1. College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China

    Yafang Shi, Yunchao Dai, Ziwen Liu, Xiaofeng Nie, Song Zhao, Chi Zhang & Hanzhong Jia

  2. Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, 712100, China

    Hanzhong Jia

Authors
  1. Yafang Shi
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yunchao Dai
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Ziwen Liu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Xiaofeng Nie
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Song Zhao
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Chi Zhang
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Hanzhong Jia
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Hanzhong Jia.

Additional information

Highlights

• Light irradiation increased the concentration of free radicals on HS.

• The increased spin densities on HS readily returned back to the original value.

• The “unstable” free radicals induced the formation of reactive radical species.

• Reactive radicals’ concentration correlated strongly with EPFRs’ concentration.

Electronic supplementary material

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Shi, Y., Dai, Y., Liu, Z. et al. Light-induced variation in environmentally persistent free radicals and the generation of reactive radical species in humic substances. Front. Environ. Sci. Eng. 14, 106 (2020). https://doi.org/10.1007/s11783-020-1285-2

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s11783-020-1285-2

Keywords

Search

Navigation