Water elutriators

The pT-method can be used to assess the toxic potential of both treated and untreated wastewater, surface water (receiving streams), groundwater, pore water, elutriates and chemical extracts of sediments. This paper deals with wastewater, the application of the pT-method to sediments is described in Chapter 9 of this volume. The method can be applied universally and is user-friendly. Any number of aquatic... 

Two bioassays a) 7d chronic shrimp test (Mysidopsis bahia) b) 7d chronic fish test (Menidia beryllina) Waste-to-energy (WTE) ash concrete leachates Sea-water leaching with stabilized wastes sea-water elutriation with crushed wastes decantation and/or filtration... 

Chronic toxicity tests (typically 7-35 days of exposure) Water, pore water, elutriate Freshwater - water flea (C. dubia), fathead minnow (P. promelasy and rainbow trout (0. mykiss) Marine/estuarine - mysid shrimp (A. bahiay inland silverside (M. beryllinay and sheepshead minnow (C. variegatus)... 

Schulze Elutriator. The original type of water elutriator, it has since been improved by H. Harkort (Ber. Deut. Keram. Ges., 8, 6,1927). 

A number of high temperature processes for the production of titanium carbide from ores have been reported (28,29). The aim is to manufacture a titanium carbide that can subsequently be chlorinated to yield titanium tetrachloride. In one process, a titanium-bearing ore is mixed with an alkah-metal chloride and carbonaceous material and heated to 2000°C to yield, ultimately, a highly pure TiC (28). Production of titanium carbide from ores, eg, ilmenite [12168-52-4], EeTiO, and perovskite [12194-71 -7], CaTiO, has been described (30). A mixture of perovskite and carbon was heated in an arc furnace at ca 2100°C, ground, and then leached with water to decompose the calcium carbide to acetjdene. The TiC was then separated from the aqueous slurry by elutriation. Approximately 72% of the titanium was recovered as the purified product. In the case of ilmenite, it was necessary to reduce the ilmenite carbothermaHy in the presence of lime at ca 1260°C. Molten iron was separated and the remaining CaTiO was then processed as perovskite. 

Introduction of the flushing solution may occur within the vadose zone, the saturated zone, or both. Flushing solutions may consist of plain water, or surfactants, co-solvents, acids, bases, oxidants, chelants, and solvents. The infiltrating flushing solution percolates through the soil and soluble compounds present in the soil are dissolved. The elutriate is pumped from the bottom of the contaminated zone into a water treatment system to remove pollutants. The process is carried out until the residual concentrations of contaminants in the soil satisfy given limits. 

Contaminated soils are flooded with water or a water chemical mixture and the elutriated... 

A finely ground mixture of galena and limestone in the proportion of 1 to 4 by mass, is subjected to elutriation by a current of water flowing upwards at 5 mm/s. Assuming that the size distribution for each material is the same, and is as follows, estimate the percentage of galena in the material carried away and in the material left behind. The absolute viscosity of water is 1 mN s/m2 and Stokes equation should be used. 

The U.S. Bureau of Mines-Reno Research Center is conducting research on the chemical treatment of process waste waters by ion elutriation for removing low levels of anions from cyanide solutions. This research has been coordinated with other centers for developing a waste water treatment system. 

The boilers are of water-wall construction with the walls in the bed region lined with refractory to protect against erosion and abrasion damage. The heat released in the bed is removed from the flue gas by the exposed water walls and by convection pass tubing set in the gas path after the boiler. The coal boilers included multiclones to collect elutriated carbon and recycle it back to the boiler to increase combustion efiiciency. However, because biomass is more reactive, recycle is not required. 

Circulating Beds These fluidized beds operate at higher velocities, and virtually all the solids are elutriated from the furnace. The majority of the elutriated sohds, still at combustion temperature, are captured by reverse-flow cyclone(s) and recirculated to the foot of the combustor. The foot of the combustor is a potentially very erosive region, as it contains large particles not elutriated from the bed, and they are being fluidized at high velocity. Consequently the lower reaches of the combustor do not contain heat-transfer tubes and the water walls are protected with refractory. Some combustors have... 

Recent reports suggest that a significant portion of the dust measured by a vertical elutriator in a card room may be due to solids in humidifier water (23,25,43). Undoubtedly, much of the inorganic matter found in the model card room dusts arises from this source. 

Similar phenomena has been observed by others (43). Thus, much of the dust measured in total or elutriated s2unples of cotton dusts arises from the spray drying of the humidifier water. 

Dust Concentrations Measured in a Textile Mill with Vertical Elutriator Samplers as a Function of Variation in Water in Humidifier System. (25)... 

In the past few years the use of rotifers in ecotoxicological studies has substantially increased. The main endpoints used are mortality, reproduction, behavior, cellular biomarkers, mesocosms, and species diversity in natural populations [126]. Several workers have used Brachionus calyciflorus for various types of toxicity assessments. Thus, comprehensive evaluation of approximately 400 environmental samples for the toxicity assessment of solid waste elutriates, monitoring wells, effluents, sediment pore water, and sewage sludge was carried out by Persoone and Janssen [127]. The mortality of rotifers hatched from cysts is evaluated after 24 hours exposure. This microbiotest has been commercialized in a Rotoxkit F [128,129]. 

When the thirty-six hours were expired, the whole was allowed to cool, after which tire pots were removed and broken, and the vermilion which was ineruBted -within them, and chiefly in their upper parts, collected, ground with water between horizontal stones, then passed through sieves, and thereafter elutriated and. dried. The usual loss in converting the black sulphide by this process into vermilion, was nearly three per cent. 

Relaxation data for water in highly pure 70-/ diameter NaX crystals are shown in Figure 6, before and after elutriation with water to separate the desired size fraction. Note the maxima in the three sets of T2 data and the decrease on raising the temperature further. This effect is caused... 

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