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Department of Health Services— Title 22 Toxicity Screen Test 2 <br /> information. <br /> Low pressure air is supplied to the laboratory for the purpose of slowly bubbling air into the <br /> exposure tanks to maintain an acceptable dissolved oxygen concentration. Filtered air is supplied via a <br /> Sutor-bilt oil-less blower that provides up to 340 1/min at 0.35 kg/cm2. The blower is equipped with a <br /> pressure equalizing expansion chamber and an adjustable pressure relief valve to maintain a constant <br /> delivery pressure and volume. Air is delivered to the laboratory through PVC piping with numerous <br /> Individual flow,yalves. Individual aquaria receive air through commercial plastic aquarium air tubing and <br /> a 3 mrnl inside diameter by 30 cm long soft glass tube which reaches the bottom of the test container.Air <br /> is bubbled into the aquaria at a rate of approximately 30 mi /min following the guidelines of Kopperdahl <br /> (1976) and Peltier and Weber(1985). <br /> Test Containers <br /> The toxicity tests are conducted in 5-gallon glass aquaria, approximately 26 cm high, 21 cm <br /> wide, and 41 cm long. For the definitive test, the aquaria contain a total of 10 liters of waste material <br /> and/or dilution softwater which provides a water depth within the test aquaria of approximately 14 cm. <br /> Test containers are cleaned thoroughly with Liqui-Nox brand commercial glassware detergent <br /> and warm tap water, rinsed five times with warm tap water, rinsed with reagent grade acetone, rinsed <br /> five times with deionized water, rinsed with 5% HCI, and then rinsed three times with delonized water. <br /> Determination of Water Quality Parameters <br /> Water quality measurements are taken and recorded for pH, dissolved oxygen and temperature <br /> after dosage of the appropriate concentration of waste sample to the test aquaria, and at 24, 48, 72, and <br /> 96 .hours subsequent to initiation of the toxicity test exposures. The following instrumentation and <br /> methods are utilized to determine water quality parameters for each of the test and control aquaria.Total <br /> alkalinity and hardness, both expressed as mg/I CaCQ , are determined from sub-samples of dilution <br /> water and the 750 mg/l concentration obtained immediately prior to initiation and at the completion of <br /> toxicity testing. <br /> A Horiba U-10 Water Quality Checker is utilized for determining the pH of the exposure <br /> solutions. After stabilization of the reading, the pH is recorded on the static toxicity test worksheet to the <br /> nearest 0.1 pH unit. <br /> Dissolved oxygen concentrations (mg/1) are determined by gently swirling the Horiba U-10 Water <br /> Quality Checker in the aquarium to be monitored. Dissolved oxygen concentrations are recorded on the <br /> static toxicity test worksheet to the nearest 0.1 mg/l, only after stabilization of the reading. <br /> Exposure temperature is determined by the Horiba U-10 Water Quality Checker calibrated by a <br /> mercury bulb thermometer graduated to 0.1°C with calibration traceable to the National Institute of <br /> Standards and Technology (NIST). <br /> Alkalinity values are calculated by potentiometric titration to a pre-selected pH of 4.6 utilizing <br /> Method 2320B, Standard Methods(181h Edition). <br /> Hardness values are calculated by EDTA titration utilizing Method 2340C, Standard Methods <br /> (18'" Edition). <br /> MBC Applied Environmental Sciences,3000 Redhill Avenue, Costa Mesa, California 92626 <br />