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Internal phosphorus load in a Mexican reservoir: Forecast and validation
Author(s) -
Hansen Anne M.,
MárquezPacheco Henri
Publication year - 2015
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.3102
Subject(s) - phosphorus , environmental science , sediment , precipitation , water column , intense pulsed light , environmental chemistry , chemistry , hydrology (agriculture) , geology , meteorology , geomorphology , physics , oceanography , geotechnical engineering , organic chemistry , optics
To determine the internal phosphorus load (IPL) as a function of redox potential (Eh) in a Mexican reservoir, the results from a phosphorus (P) release experiment were extrapolated to temporal and spatial variations of Eh in sediments, and an IPL‐Eh of 24.2 ± 2.5 t/yr was obtained. This result is compared with the P mass balance (MB) in the reservoir, where the IPL‐MB is determined as the difference between P inputs to the reservoir and the outputs. Inputs of P are the sum of the external P load from the hydrological basin, the IPL, and P in atmospheric precipitation; outputs of P are the sum of sedimented P, and the removal of P in water and biomass, and the resulting IPL‐MB, is 26.4 ± 4.9 t/yr. In addition, P concentrations in sediment cores (SCs) are analyzed, and the historical release of P from sediments determined, resulting in an IPL‐SC of 23.5 ± 1.4 t/yr. The different IPL results are similar, as average values are within the standard deviation of IPL‐MB. It is concluded that analysis of the variations in Eh in sediments allows determination of the reservoir's IPL. Six‐weekly IPL‐Eh and IPL‐MB values are analyzed, and it can be seen that IPL occurs mainly during the period from May to August, when the water column is thermally stratified. Environ Toxicol Chem 2015;34:2583–2589. © 2015 SETAC