Dissolved humic substances supplied as potential enhancers of Cu, Cd, and Pb adsorption by two different mangrove sediments
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The external supply of humic substances has been recently suggested for the remediation of metal-polluted sediments; however, little is known about how to supply them and their effects on metal mobility. The study sought to investigate the sediment—metals—humic substance interaction in mangrove forest sediments. We aimed to evaluate the sediment adsorption potential in the case of large and rapid metal loads, as recently occurred in the Doce River (Brazil).
Materials and methods
In each mangrove forest sampling point of the Benevente River (RB) and Vitoria bay (MO), sediments were collected randomly along the river banks at a depth of 0–10 cm. Samples were characterized in terms of pH, CEC, organic carbon, texture, specific surface area, and elemental composition. The heavy metal content was measured by mass absorption spectrophotometry. Humic substances were extracted from the sediments according to the International Humic Substances Society (IHSS) method, avoiding separation of fulvic and humic acids. Original sediments were supplemented with humic substances and six Cu, Cd, or Pb concentrations. Freundlich and Langmuir equations were employed to create adsorption isotherms.
Results and discussion
The two sediments are significantly different, specifically with regard to organic carbon and Fe content, texture, and specific surface area. External humic substances increased the Cu adsorption capacity in both sediments but without an important change in Cu adsorption dynamics. Humic substances slightly increased the sediment adsorption capacity of Pb in RB sediment while they decreased in MO sediment, characterized by lower specific surface area, probably due to coverage of the active adsorption sites. Cd isotherms showed that the different characteristics of sediments alone do not affect Cd adsorption, but coupled with humic substances; Cd affinity for the soil surface increased five times in RB sediments confirming sediment-metal-humic substance interactions.
Humic substances affect soil metal retention mainly by altering the ion affinity for sediment surface, leading to contrasting results. The Fe concentration could be important depending on specific surface area and humic substance percentage, due to its capacity to form spheroids linked to molecules of humic substances on the clay surface. Several works have been carried out on this research area, but due to the many variables and different metal ions, we recommend further studies.
KeywordsHeavy metals Isotherms Mangroves Organic matter
The authors thank Dr. Evan Visser for the English revision.
The FAPES (Fundação de Amparo a Pesquisa do Espirito Santo/Espirito Santo State Foundation for Support to Research) has provided funds for M. Pittarello (process 69729913/2015), P. Carletti was financially supported by the University of Padova DOR1883089/18, and F. F. Sodré thanks the CNPq (480410/2012-7).
- Alam AKMR, Hossain ABME, Hoque S, Chowdhury DA (2018) Heavy metals in wetland soil of greater Dhaka district, Bangladesh. Pollution 4:129–141Google Scholar
- Borja A, Basset A, Bricker S, Dauvin J, Elliot M, Harrison T, Marques JC, Weisberg S, West R (2012) Classifying ecological quality and integrity of estuaries. In: Wolanski E, McLusky D (eds) Treatise on estuarine and coastal science. Academic Press, Waltham, pp 125–162Google Scholar
- Craig PJ, Jenkins RO (2004) Organometallic compounds in the environment: an overview. In: Hirner AV, Emons H (eds) Organic metal and metalloid species in the environment. Springer, Berlin, pp 1–15Google Scholar
- De Sà A, Abreu AS, Moura I, Machado AV (2017) Polymeric materials for metal sorption from hydric resources. In: Grumezescu MA (ed) Water purification. Academic Press, London, pp 289–322Google Scholar
- Donagema GK, de Campos DVB, Calderano SB, Teixeira WG, Viana GHN (2011) Manual de métodos de análise de solo. Empresa Brasileira de Pesquisa Agropecuária, Rio de JaneiroGoogle Scholar
- FAO (2007) The world’s mangroves 1980–2005. A thematic study prepared in the framework of the global forest resources assessment 2005 FAO Forestry Paper 153. Food and Agriculture Organization, RomeGoogle Scholar
- Förstner U (1989) Contaminated sediments: lecture notes in earth sciences, Vol. 21. Springer, BerlinGoogle Scholar
- Ladonin DV, Plyaskina OV (2004) Mechanisms of Cu (II), Zn (II), Pb (II) sorption by soddy-podzolic soil. Eur Soil Sci 37:460–468Google Scholar
- MacFarlane GR, Koller CE, Blomberg SP (2007) Accumulation and partitioning of heavy metals in mangroves: a synthesis of field-based studies. Chem 69:1454–1464Google Scholar
- Nardi S, Carletti P, Pizzeghello D, Muscolo A (2009) Biological activities of humic substances. In: Huang PM, Senesi N (eds) Biophysico-chemical processes in environmental systems. John Wiley & Sons, Hoboken, pp 305–339Google Scholar
- Noel V, Juillot F, Morin G, Marchand C, Ona-Nguema G, Viollier E, Prevot F, Dublet G, Maillot F, Delbe L, Marakovic G, Bargar JR, Brown GE Jr (2017) Oxidation of Ni-rich mangrove sediments after isolation from the sea (Dumbea Bay, New Caledonia): Fe and Ni behavior and environmental implications. ACS Earth and Space Chemistry 1:455–464. https://doi.org/10.1021/acsearthspacechem.7b00005 CrossRefGoogle Scholar
- Pons LJ, Breemen N, Van Driessen PM (1982) Physiography of coastal sediments and development of potential soil acidity. In: Kittrick JA, Fanning DS, Hossner LR (eds) Acid sulfate weathering. Soil Sci Soc Am, Madison, pp 1–18Google Scholar
- Rovai AS (2012) Restauração de manguezais no Brasil: retrospectiva e perspectivas. Dissertation, Universidade Federal de Santa Catarina, BrazilGoogle Scholar
- Sposito G (2008) The chemistry of soils. Oxford University Press, New YorkGoogle Scholar
- Stumm W (1992) Chemistry of the solid water interface—processes at the mineral-water and particle-water- interface in natural systems. Wiley, ChichesterGoogle Scholar
- Swift SS (1996) Soil characterization, part 3, chapter 35. In: Methods of soils analysis. Soil science society of america and american society of agronomy, MadisonGoogle Scholar
- Wijaya AR, Ohde S, Shinjo R, Ganmanee M, Cohen MD (2016) Geochemical fractions and modeling adsorption of heavy metals into contaminated river sediments in Japan and Thailand determined by sequential leaching technique using ICP-MS. Arab J Chem. https://doi.org/10.1016/j.arabic.2016.10.015