Tracing the spatial propagation of river inlet water into an agricultural polder area using anthropogenic gadolinium
Rozemeijer, J. ; Siderius, C. ; Verheul, M. ; Pomarius, H. - \ 2012
Hydrology and Earth System Sciences 16 (2012)8. - ISSN 1027-5606 - p. 2405 - 2415.
watervoorziening - rivierwater - watertekort - zoet water - waterkwaliteit - landbouwgrond - tracer technieken - zeldzame aardelementen - nutriëntenstromen - water supply - river water - water deficit - fresh water - water quality - agricultural land - tracer techniques - rare earth elements - nutrient flows - quality - impact - irrigation - hydrology - nitrogen
Diverting river water into agricultural areas or nature reserves is a frequently applied management strategy to prevent fresh water shortage. However, the river water might have negative consequences for chemical and ecological water quality in the receiving water bodies. This study aimed to obtain a spatial image of the diverted river water propagation into a hydrologically complex polder area, the polder Quarles van Ufford in The Netherlands. We used anthropogenic gadolinium (Gd-anomaly) as a tracer for river water that was diverted into the polder. A clear reduction in the river water contribution was found between very dry conditions on 5 August 2010 and very wet conditions on 22 October. Despite the large river water impact on 5 August, the diverted river water did not propagate up into the small agricultural headwater ditches. Gadolinium proved to be an effective tracer for diverted river water in a polder system. We applied our results to upgrade the interpretation of water quality monitoring data and to validate an integrated nutrient transport model
Effects of lanthanum and lanthanum-modified clay on growth, survival and reproduction of Daphnia magna
Lürling, M.F.L.L.W. ; Tolman, Y. - \ 2010
Water Research 44 (2010)1. - ISSN 0043-1354 - p. 309 - 319.
waterkwaliteit - meren - klei - eutrofiëring - daphnia magna - lanthaan - zeldzame aardelementen - fosfor - aquatische ecologie - waterzuivering - water quality - lakes - clay - eutrophication - daphnia magna - lanthanum - rare earth elements - phosphorus - aquatic ecology - water treatment - phosphorus binding clay - rare-earth-elements - microcystis-aeruginosa - cyanobacterial toxins - suspended clay - waters - blooms - phosphate
The novel lanthanum-modified clay water treatment technology (Phoslock) seems very promising in remediation of eutrophied waters. Phoslock is highly efficient in stripping dissolved phosphorous from the water column and in intercepting phosphorous released from the sediments. The active phosphorous-sorbent in Phoslock is the Rare Earth Element lanthanum. The purpose of this study was: 1) to establish a dose response relationship between Phoslock and the growth of Daphnia magna, 2) to determine the amount of lanthanum released from Phoslock, and 3) to test the effects of lanthanum on life-history characteristics of D. magna in artificial P-free and P-containing medium.
The novel lanthanum-modified clay water treatment technology (Phoslock (R)) seems very promising in remediation of eutrophied waters. Phoslock (R) is highly efficient in stripping dissolved phosphorous from the water column and in intercepting phosphorous released from the sediments. The active phosphorous-sorbent in Phoslock (R) is the Rare Earth Element lanthanum. A leachate experiment revealed that lanthanum could be released from the clay, but only in minute quantities of 0.13-2.13 mu g l(-1) for a worst-case Phoslock (R) dosage of 250 mg l(-1). A life-history experiment with the zooplankton grazer Daphnia magna revealed that lanthanum, up to the 1000 mu g l(-1) tested, had no toxic effect on the animals, but only in medium without phosphorous. In the presence of phosphorous, rhabdophane (LaPO4 center dot nH(2)O) formation resulted in significant precipitation of the food algae and consequently affected life-history traits. With increasing amounts of lanthanum, in the presence of phosphate, animals remained smaller, matured later, and reproduced less, resulting in lower population growth rates. Growth rates were not affected at 33 mu g La l(-1), but were 6% and 7% lower at 100 and 330 mu g l(-1), respectively, and 20% lower at 1000 mu g l(-1). A juvenile growth assay with Phoslock (R) tested in the range 0-5000 mg l(-1), yielded EC50 (NOEC) values of 871 (100) and 1557 (500) mg Phoslock (R) l(-1) for weight and length based growth rates, respectively. The results of this study show that no major detrimental effects on Daphnia are to be expected from Phoslock (R) or its active ingredient lanthanum when applied in eutrophication control. (C) 2009 Elsevier Ltd. All rights reserved.
Distribution, speciation and bioavailability of Lanthanides in the Rhine-Meuse estuary, The Netherlands
Moermond, C.T.A. ; Tijink, J. ; Wezel, A.P. van; Koelmans, A.A. - \ 2001
Environmental Toxicology and Chemistry 20 (2001)9. - ISSN 0730-7268 - p. 1916 - 1926.
rivieren - estuaria - zeldzame aardelementen - biologische beschikbaarheid - chemische speciatie - distributie - nederland - rijn - maas - aquatische ecosystemen - rivers - estuaries - rare earth elements - bioavailability - chemical speciation - distribution - netherlands - river rhine - river meuse - aquatic ecosystems
Changing environmental conditions may influence the fate and bioavailability of lanthanides (part of the rare earth elements [Ln]) in estuaries. The aim of this study was to quantify the variation in estuarine lanthanide solid/water distribution, speciation, and bioaccumulation. The latter was studied in the amphipod Corophium volutator under field and laboratory conditions. Calculations with the chemical equilibrium model MINEQL indicate that dissolved lanthanides are complexed mainly to carbonates and dissolved organic matter. In the water phase, the relative abundance of the free ion, LnCO3, and humic complexes decreases from lanthanum to lutetium, whereas the relative abundance of Ln(CO3)2 increases. Cerium and europium anomalies were found in the water. Europium anomalies were also found in some biota. The biota sediment accumulation factors (BSAFs) decreased across the series from lanthanum to lutetium. Regression analysis revealed that alkalinity correlated negatively with lanthanide uptake. This suggests that increasing complexation reduced bioavailability under the prevailing conditions. The BSAFs did not depend on salinity or pH, which may simplify sediment-quality criteria for fresh versus saline waters. Field BSAFs were significantly lower than laboratory values for the same sediments, which is explained by adaptation of the organisms to lanthanides.