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A comparison of instrumental dewatering methods for the separation and concentration of suspended sediment for subsequent trace element analysis
Author(s) -
Horowitz A. J.,
Elrick K. A.,
Hooper R. C.
Publication year - 1989
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.3360030206
Subject(s) - dewatering , filtration (mathematics) , sediment , suspended solids , effluent , environmental science , trace element , volumetric flow rate , cross flow filtration , hydrology (agriculture) , soil science , environmental engineering , geology , chemistry , geotechnical engineering , wastewater , mechanics , mathematics , paleontology , biochemistry , statistics , physics , membrane , geochemistry
A comparison involving both field and laboratory trials was performed to evaluate the utility of two continuous‐flow centrifuges and a tangential‐flow filtration system for dewatering suspended sediments for subsequent trace element analysis. Although recovery efficiencies for the various devices differ, the analytical results from the separated suspended sediments indicate that any of the tested units can be used effectively and precisely for dewatering. Further, the three devices appear to concentrate and dewater suspended sediments in such a manner as to be equivalent to that which could be obtained by in‐line filtration. Only the tangential‐flow filtration system appears capable of providing both a dewatered sediment sample and a potentially usable effluent, which can be analysed for dissolved trace elements. The continuous‐flow centrifuges can process whole water at an influent feed rate of 41 per minute; however, when suspended sediment concentrations are low (<30mg −1 ), when small volumes of whole water are to be processed (30 to 401), or when suspended sediment mean grain size is very fine (<10 μm), influent feed rates of 21 per minute may be more efficient. Tangential‐flow filtration can be used to process samples at the rate of 11 per minute.