Contribution of black carbon to nonlinearity of sorption and desorption of acetochlor on sediment

Abstract

In order to investigate the contribution of various black carbon (BC) contents to nonlinearity of sorption and desorption isotherms for acetochlor on sediment, equilibrium sorption and desorption isotherms were determined to measure sorption and desorption of acetochlor in sediment amended with various amounts of BC. In this paper, two types of BC referred to as BC400 and BC500 were prepared at 400°C and 500°C, respectively. Higher preparation temperature facilitated the formation of micropores on BC to enhance its sorption capacity. Increase of the BC content obviously increased the sorption amount and reduced the desorption amount for acetochlor. When the BC500 contents in total organic carbon (TOC) increased from 0 to 60%, Freundlich sorption coefficient (K_f) increased from 4.07 to 35.74, and desorption hysteresis became gradually obvious. When the content of BC in TOC was lower than 23%, the sorption isotherm had a significant linear correlation (p = 0.05). In case of desorption, a significant nonlinear change could be observed when the content of BC was up to 13%. Increase of BC content in the sediment would result in shifting the sorption-desorption isotherms from linearity to nonlinearity, which indicated that contribution of BC to nonlinear adsorption fraction became gradually remarkable.

Keywords

black carbon (BC) / sorption / desorption / sediment

References

[1] StamperD M, TrainaS J, TuovinenO H. Anaerobic transformation of alachlor, propachlor, and metolachlor with sulfide. J. Environ. Qual., 1997, 26: 488–494

[2] NamK, AlexanderM. Role of nanoporosity and hydrophobicity in sequestration and bioavailability: tests with model solids. Environ. Sci. Technol., 1998, 32: 71–74

[3] HuangW L, YuH, WeberJr. Hysteresis in the sorption and desorption of hydrophobic organic contaminants by soils and sediments. 1. A comparative analysis of experimental protocols. J. Contam. Hydrol., 1998, 31: 129–148(in Dutch)

[4] KanA T, FuG, HunterM, ChenW, WardC H, TomsonM B. Irreversible sorption of neutral hydrocarbons to sediments: experimental observations and model predictions. Environ. Sci. Technol., 1998, 32: 892–902

[5] HuangW L, PIngP A, YuZ Q, FuH M. Effects of organic matter heterogeneity on sorption and desorption of organic contaminants by soils and sediments. J. Appl. Geochem., 2003, 18: 955–972

[6] GoldbergE D. Black Carbon in the Environment: Properties and Distribution. New York: John Wiley, 1985

[7] SchmidtM W I, NoackA G. Black carbon in soils and sediments: Analysis, distribution, implication, and challenges. Global Biogeochem.Cycles, 2002, 14: 777–793

[8] BraidaW J, PignatelloJ J, LuY, RavikovitchP I, NeimarkA V, XingB. Sorption Hysteresis of Benzene in Charcoal Particles. Environ. Sci. Technol., 2003, 37: 409–417

[9] Accardi-DeyA, GschwendP M. Reinterpreting literature sorption data considering both absorption into organic carbon and adsorption onto black carbon. Environ. Sci. Technol., 2003, 37: 99–106

[10] CornelissenG, GustafsonÖ. Sorption of phenanthrene to environmental black carbon in sediment with and without organic matter and native sorbates. Environ. Sci. Technol., 2004, 38: 148–155(in Dutch)

[11] HuangW L, WeberW J Jr. A distributed reactivity model for sorption by soils and sediments. 10. Relationships between desorption, hysteresis, and the chemical characteristics of organic domains. Environ. Sci. Technol., 1997, 31: 2562–2569(in Dutch)

[12] CornelissenG, RigterinkH, TenH D E M, VrindB E A A, VanN P C M. A simple TENAX extraction method to determine the availability of sediment-sorbed organic compounds. Environ. Toxicol. Chem., 2001, 20: 706–711

[13] Allen-KingR M, GrathwohlP, BallW P. Ozone oxidation of compounds resistant to biological degradation. Water Res., 2002, 25: 985–993

[14] Accardi-DeyA, GschwendP M. Reinterpreting literature sorption data considering both absorption into organic carbon and adsorption onto black carbon. Environ. Sci. Technol., 2003, 37: 99–106

[15] MiddelburgJ J, NieuwenhuizeJ, Van BreugelP. Black carbon in marine sediments. Mar. Chem., 1999, 65: 245–252

[16] GustafssonÖ, GschwendP M. The flux of black carbon to surface sediments on the New England continetal shelf. Geochim. Cosmichim.Acta, 1998, 62: 465–472

Acknowledgements

This study was financially supported by the National Basic Research Program of China (Grant No. 2007CB407302).

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg