Flow-through tests

Tidewater silverside, Menidia peninsula Flow-through test 0.7 11... 

California grunion, Leuresthes tenuis Flow-through test 1.1 11... 

Atlantic silverside, Menidia menidia Flow-through test 1.4 11... 

Gillia altilis 300 LC50 (96 h) in flow-through test 19... 

The layflat-LDPE tubing used for making SPMDs was 2.6 cm wide and had a wall thickness of about 75 pm. The A of the 0.5 mL triolein SPMDs used in these flow-through tests was about 200 cm with an AV (lipid -I- membrane) ratio of about 80 cm The A of the 1 mL triolein SPMDs used in the static exposures was about 360 cm (i.e., = 72 cm ). The surface area of the 1 mL lipid... 

LC50 (14-d) for fathead minnows 2.25 mg/L (flow through test, Gledhill et ah, 1980). 

Similar Pu-rich regions were identified by SEM of solids remaining from an acidic (pH = 4) flowthrough test (Fig. 10). Observation of similar Pu-rich precipitates in the acid flow through tests supports the contention that the Pu enrichment is not an artifact of the starting material. 

In keeping with the general theme of this book, our task is somewhat more difficult inasmuch as we routinely must deal with the effects of water on systems. The tests described in ASTM 3527D are designed to describe the qualities of hydrophobic materials. More often than not, the products that are the subjects of this book will be in moist environments. In many cases, the products will be immersed in water. While the dry tests provide some guidance, it is clear that tensile, compressive, and water flow-through tests are needed to determine and describe the in-service properties of the materials. 

In flow-through tests, the treated water is continually replaced either by a constant flow or by additions of small volumes of treated water at 1-10 minute intervals. Various delivery systems have been designed to either supply measured amounts of newly mixed test concentrations or to add premixed solutions to the test chambers. Depending on the physical characteristics of the chemicals involved and the reliability or accuracy of the delivery systems, there is ample opportunity with this method for something to go wrong in the delivery of the test chemical. However, because the water is constantly replaced and the organisms can be fed, it is possible in tests conducted in flow-through systems, to expose test... 

Test Apparatus. A flow-through test vessel was constructed to allow the testing of any l/4-in.-OD pH electrode at temperatures up to 300°C and pressures up to 300 bars. The system is illustrated schematically in Figure 4. 

Butte, W., Willing, A., Zanke, G.P. (1987) Bioaccumulation of phenols in zebrafish determined by a dynamic flow through test. In QSAR in Environmental Toxicology II. Kaiser, K.L.E., pp. 43-53, Editor, D. Reidel Publishing Company, Dordrecht, The Netherlands. 

Simple Tube Furnace Flow-Through Test.468... 

I) It is noted that only steady-state BCF values from flow-through tests with fish for which the lipid content is known, were taken from the hteratuxe. 

The log Kqw value was calculated by Andreas Kaune on the basis of the measured log value of 5.28 for l,2,3,4,7,7-hexachloro-2,5-norbornadiene. BCFw value in fathead minnows (0.12 g body weight, 4% lipid) was measured in a 30-day flow-through test by Spehar et al. [231]. 

Flow-through test and kinetic approach (H. Kuhlmann, G. Rimkus and W. Butte (1999) unpublished). 

Spehar et al. [231] investigated the bioconcentration potential of hexachloro-norbornadiene and heptachloronorbornene using 30-day flow-through test with early juvenile fathead minnows Pimephales promelas) with a body weight of 0.12 g and 4% lipid content. The measured mean concentrations of hexa-chloronorbornadiene (HCND) in water was 20.0 3.9 pg and the water concentration of heptachloronorbornene (HepCNB) was 25.9 3.4 pg b. The bioconcentration factors on a wet weight basis after 30 days in this fish species were 6,400 and 11,200, respectively. The bio concentration factors on a lipid basis (BCFl) of HCND and HepCNB after 30 days were 160,000 and 280,000, respectively (see Table 13). 

However, in 1985 Oliver and Niimi [251] investigated the bio concentration of hexabromobenzene (HBB) and other highly lipophilic organic chemicals in a flow-through test in rainbow trout Oncorhynchus mykiss). After 96 days, they found a bio concentration factor (BCF ) on a wet weight basis of 1400 (lipid = 7.6%) and a BCFl value of 18,000. But these authors stated also that no steady-state after 96 days was reached. However, the metabolism of HBB was not investigated. Nevertheless, these experiments by Oliver and Niimi [251] have clearly shown that hexabromobenzene can be taken up from water by fish and is bio concentrated to a relatively high amount. However, the BCFl value of HBB is lower than predicted from its Kqw value. 

Butte et al. [253] investigated in a flow-through test system the bioconcentration of hexabromobenzene (HBB) beside other chemicals in zebrafish... 

The bioaccumulation factors were determined by Oliver and Niimi [251] in rainbow trout using a flow-through test. 

Bioconcentration test with carp (3.4% lipid), flow-through tests for 10 weeks. MX concentration in water 1) 1 pg l h 2) MX concentration in water 10 pg 1 [340]. 

Recently, van den Heuvel et al. [378 a] studied the bioconcentration of [ H]avermectin Bj in an 28-d uptake flow-through test with bluegill sunfish Lepomis macrochirus). Avermectin Bj (see Fig. 16), the major component of abamectin, possesses a molecular mass of 872. The molecular dimensions are 17.0 X 18.7 X 18.4 A and were determined by Nachbar (cited in [378]) by finding the smallest parallelepiped whose faces were centered on the inertial axes of the molecule and would enclose the van der Waals surface of the molecule. A van der Waals radius of 1.2 A for hydrogen was used and the atomic coordin-... 

The species in Table 3 were selected based on several criteria, primarily ease of culture, commercial availability, and size. The test species are acclimated for a specific period of time prior to testing to eliminate diseased organisms. Generally, a minimum of 10 animals are exposed in static and static-renewal tests and 20 in a flow-through test for each test concentration and control. The recommended loading... 

Technically, the best method to ensure precise exposure and water quality is the use of a flow-through test methodology. A continuous-flow methodology usually involves the application of peristaltic pumps, flow meters, and mixing chambers to ensure an accurate concentration. Continuous flow methods are rarely used. The usual method is an intermittent flow using a proportional diluter (Figure 3.10) to mix the stock solution with diluent to obtain the desired test solutions. 

All other species 96 h in static tests, at least 96 h in renewal and flow-through test Physical and Chemical Parameters Water temperature (°Q Freshwater... 

DO concentration 60-100% for static test during first 48 h 40-100% for static test after 48 h 60-100% for renewal and flow-through tests (all times) ... 

---