SynopsisA toxicity procedure has been developed and proposed for use in establishing acceptable initial loading rates and detoxification potentials for hazardous industrial waste when combined with soil. The procedure involves conducting toxicity screening and toxicity reduction experiments using selected waste-soil combinations. These experiments employ a bacterial bioluminescence assay (Microtox TM) to determine acute toxicity of organic contaminants contained in the water soluble fraction (WSF) of waste-soil mixtures. Toxicity screening test results are used to establish a range of loading rates acceptable for use in subsequent waste-soil treatability studies. Toxicity reduction experimental results are used to determine soil detoxification potentials over time for soluble toxic organics contained in the waste-soil loading combination selected. A major factor in determining acceptability of any test procedure is whether or not different investigators can achieve reproducible and comparable results. This paper describes the proposed procedure and reports results from toxicity experiments conducted concurrently by two laboratories using aliquots from the same soil and waste samples. Comparability of results was reported to be a function of the similarity ofwaste sample aliquots used in the toxicity experiments. Toxicity screening results for uniform technical grade creosote aliquots were highly comparable between the two laboratories, while results for highly variable creosote wood preserving waste (WPC) aliquots were much less comparable. Toxicity reduction experimental results for the WPC waste also indicated significant variation between laboratories for initial (Day 0) samples; however, the same patterns of detoxification over time were observed by each laboratory with toxicity results a t the end of the experimental period (Day 42) being similar.
Can. Ent. 105: 299-310 (1973) Twenty species of ground beetles (Family Carabidae) and one species of carrion beetle (Family Silphidae) were collected in six stations east of a kraft paper mill in Thunder Bay, Ontario, from May to August, 1971. The beetle population decreased markedly towards the mill. There was no apparent statistical difference in size variation of specimens near the mill and those further away.
Open-faced and diffusion-barrier charcoal canisters were individually exposed to a fixed temperature, humidity, and radon concentration in a chamber for a period of 7 d. The radon progeny activity in the canister under study was measured every 3 h. A total of 15 runs were made for the open-faced canisters and nine runs for the barrier canisters with temperatures and absolute humidities ranging from 15-30 degrees C and 0-15 g m-3, respectively. In addition, several runs were made with the radon, temperature, and humidity changing during the 7 d. Results show that open-faced canisters adsorb radon up to 60% more efficiently at 15 degrees C than at 30 degrees C while the barrier canisters show little temperature dependence. The barrier canisters are much less sensitive to humidity effects than the open-faced canister. When used to measure the radon concentration in air, the open-faced canister integrates over a period of only approximately 48 h while the barrier canister integrates over a period of approximately 96 h. The short integration time and the interference of water adsorption by open-faced canisters indicate that the open-faced canisters should be used for exposure times of 48 h and no longer.
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