@article{fdi:010077100,
  title = {{P}hosphorus adsorption/desorption processes in the tropical {S}aigon {R}iver estuary ({S}outhern {V}ietnam) impacted by a megacity},
  author = {{N}guyen, {T}. {T}. {N}. and {N}emery, {J}. and {G}ratiot, {N}icolas and {G}arnier, {J}. and {S}trady, {E}milie and {T}ran, {V}. {Q}. and {N}guyen, {A}. {T}. and {N}guyen, {T}. {N}. {T}. and {G}olliet, {C}laire and {A}ime, {J}oanne},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {S}aigon {R}iver flows through one of the most rapidly growing megacities of {S}outheast {A}sia, {H}o {C}hi {M}inh {C}ity ({HCMC}, > 8.4 million inhabitants). {T}his tidal river is characterized by a tropical monsoon climate, alternating a wet and a dry season. {I}n the last few decades, increased economic and urban developments of {HCMC} have led to harmful impacts on the water quality of this tidal river, with severe eutrophication events. {T}his situation results from the conjunction of contrasting hydrological seasons and the lack of upgraded sanitation infrastructures: indeed, less than 10% of the domestic wastewater is collected and treated before being discharged directly into urban canals or rivers. {T}his study focuses on {P} dynamics because this is considered the key nutrient factor controlling freshwater eutrophication. {B}ased on field measurements and original laboratory experiments, we assessed the {P} levels in the river water and sediments, and investigated {P} adsorption/desorption capacity onto suspended sediment ({SS}) within the salinity gradient observed. {F}ield surveys showed a clear impact of the {HCMC} megacity on the total {P} content in {SS}, which increased threefold at {HCMC} {C}enter, as compared with the upstream values (0.3-0.8 g{P} kg(-1)). {D}ownstream, in the mixed estuarine area, the {T}otal {P} was lower than 0.5 g{P} kg(-1). {L}aboratory experiments were carried out to characterize the influence of {SS} concentrations ({SS} = [0.25-0.9] g {L}-1 ), salinity ({S} = [2.6-9.3]) and turbulence ({G} = [22-44] s(-1)) on the sorption capacity of {P} onto sediment. {T}he size of sediment particles and their propensity to flocculate were also originally measured with a recently developed instrument: the {S}ystem for the {C}haracterization of {A}ggregates and {F}locs ({SCAF} ({R})). {U}nder the experimental conditions considered, {SS} concentrations had the greatest effect on the adsorption of {P} onto sediment, e.g., {P} adsorption capacity increased when {SS} concentrations rose. {I}n contrast, salinity and turbulence had a smaller effect on the adsorption properties of sediments. {A}mong these observed variables, the {SS} concentration was shown to be the main driver for adsorption capacity of {P} onto {SS} within the salinity gradient. {W}e discuss the implication of these findings on understanding {P} dynamics within a highly urbanized, tropical estuary.},
  keywords = {{S}ediment ; {T}ropical region ; {P}hosphorus dynamics ; {E}utrophication ; {F}locculation ; {VIET} {NAM} ; {SAIGON} {COURS} {D}'{EAU} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{E}stuarine {C}oastal and {S}helf {S}cience},
  volume = {227},
  numero = {},
  pages = {art. 106321 [13 p.]},
  ISSN = {0272-7714},
  year = {2019},
  DOI = {10.1016/j.ecss.2019.106321},
  URL = {https://www.documentation.ird.fr/hor/fdi:010077100},
}