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Modeling phosphorus exchange between bottom sediment and water in tropical semiarid reservoirs.

Moura, Diana S.; Lima Neto, Iran E.; Clemente, Allan; Oliveira, Samylla; Pestana, Carlos J.; Aparecida de Melo, Maria; Capelo-Neto, José


Diana S. Moura

Iran E. Lima Neto

Allan Clemente

Samylla Oliveira

Carlos J. Pestana

Maria Aparecida de Melo

José Capelo-Neto


This study investigated phosphorus (P) dynamics in the sediment-water interface of three distinct reservoirs located in a tropical semiarid region. Sequential chemical fractioning of the P content in the sediment and controlled experiments of the sediment-water interface were performed to understand and model the effect of the different P fractions on the exchange dynamics under anoxic and oxic scenarios. The results revealed that the older the reservoir, the higher the amount of iron and aluminum-bound P in the sediment, and that this fraction was responsible for a 10-fold increase in P concentration in the water during anoxic conditions. After aeration, P in water decreased but did not return to its initial concentration. The most recently constructed reservoir showed the lowest P concentration in the sediment and dominance of the unavailable P fraction, resulting in no potential impact on water quality. Phosphorus release and precipitation rates were well described by zero- and first-order models, respectively. Reservoirs with high P availability in the sediment, not only released more phosphorus but also presented a lower precipitation rate, resulting in higher potential damage to water quality and making some in-lake treatment techniques ineffective.

Journal Article Type Article
Publication Date May 31, 2020
Journal Chemosphere
Print ISSN 0045-6535
Electronic ISSN 1879-1298
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 246
Article Number 125686
Institution Citation MOURA, D.S., LIMA NETO, I.E., CLEMENTE, A., OLIVEIRA, S., PESTANA, C.J., APARECIDA DE MELO, M. and CAPELO-NETO, J. 2019. Modeling phosphorus exchange between bottom sediment and water in tropical semiarid reservoirs. Chemosphere [online], In Press. Available from:
Keywords Bottom sediments; Eutrophication; Internal load; Mathematical modeling; Phosphorus availability