Development of Formulated Reference Sediments for Freshwater and Estuarine Sediment Testing

Abstract

Sediments collected at various field locations may have chemical and physical constituents that influence test results and may contain organisms that cannot be readily removed. Thus, reference sediments are needed that can be formulated to match diverse freshwater and estuarine sediments encountered in comprehensive testing programs. This research evaluated formulated reference sediments in terms of (a) their ability to match field-collected sediments both chemically and physically; (b) their suitability as habitat (survival and reproduction) for typical invertebrate toxicity testing species (Hyalella azteca Saussure, Chironomus tentans Fabricius, and Daphnia magna Straus) during chronic exposures; and (c) their suitability as a substrate for HyalelIa azteca, Chironomus tentans, Daphnia magna, Ceriodaphnia dubia Richard, and Pimephales promelas Rafinesque in 14-d whole-sediment exposures. Formulated reference sediments were prepared to match naturally occurring sediments with respect to particle-size distribution, organic matter, organic carbon, pH, solids, CEC, but not redox potential. After preparation, a conditioning period of at least 7 d was required for pH stabilization of formulated reference sediments. In culture experiments, formulated reference sediment was suitable for Hyalella azteca, Chironomus tentans, and Daphnia magna survival and reproduction for 56,40, and 28 d, respectively. Hyalella azteca, Chironomus tentans, Daphnia magna, Ceriodaphnia dubia and Pirnephalesprornelas survival was 288% in 14-d exposures to formulated reference sediment. Formulated reference sediments may reduce some unexplained physical, chemical, or biological "toxicity" of field-collected sediments (e.g., organic matter) that may influence toxicity testing results. I

Use of a Deuterated Internal Standard with Pyrolysis-GC/MS Dimeric Marker Analysis to Quantify Tire Tread Particles in the Environment

“…Briefly, 2-mm sheets of specially prepared passenger tire tread (SBR) and truck tire tread (NR/BR) cured formulations (Bridgestone Corporation, Tokyo, Japan) were cut and cryogenically ground in a Pulva Corporation Model A2 Sizer (Saxonburg, PA, USA). Artificial soil similar to that used in ecotoxicity testing was prepared at Akron Rubber Development Laboratory (Akron, OH, USA) [45,46,47]. The soil recipe consists of quartz (78%), Sphagnum peat moss (2%), and kaolin clay (20%).…”

Use of artificial sediment to assess toxicity of chromium on Chironomus xanthus, Danio rerio and Poecilia reticulata

“…There are many advantages of using artificial sediment, among them: (i) the possibility of exercising rigorous control, with well-known characteristics and properties (size and proportion of particles, chemically specific surfaces), to assess and predict how natural sediments will react to contact with various types of pollutants; (ii) the absence of native microfauna and contaminants, to enable good reproducibility; (iii) the possibility of supporting the survival and growth of various organisms (plants and animals); (iv) the possibility of comparison with the results of other laboratory tests as well as field tests with natural sediments; (v) the ability to be stored without great difficulties (Suedel and Rodgers, 1994); and (vi) the ability to provide information on the behavior of substances individually or in complex mixtures in function of the substrate composition.…”

A laboratory‐formulated sediment incorporating synthetic acid‐volatile sulfide

“…The overlying water was renewed on days 3, 13, and 15. Time to equilibrium was estimated by sampling test water from each concentration and analyzing for conductivity daily and for iron and metal concentrations on selected days (3,13,15, and 24 d after preparation). One formulation was used immediately in toxicity tests, and the other formulation was used on day 24, prior to equilibrium being reached.…”

“…Chem. 15,1996 A.M. Gonzalez dentized Range test modules in the SAS statistical software package [20].…”

“…Unfortunately, there is still no agreement on an appropriate, consistent formulation for a LFS. Current research on developing LFS tends to focus on bulk sediment properties, such as particle-size distribution (i.e., sand/silt/clay ratios), moisture content, pH, and organic carbon content [14,15]. These parameters are important from biological and ecological perspectives because the LFS must be amenable to organism survival.…”