TOXICITY IDENTIFICATION OF POULTRY LITTER AQUEOUS LEACHATE

Poultry litter is a mixture of excreta, feed, feathers, and bedding ma terial. Poultry litter is useful as a fertilizer due to the presence o f nitrogen phosphorus, and potassium. Litter is commonly used for grow ing corn, soybeans, potatoes, tomatoes, leafy vegetables, and cover cr ops. The aqueous leachate of poultry Litter has been shown to exhibit toxicity to a variety of indicator organisms. The objective of this re search was to identify classes of toxicants in the litter aqueous leac hate. The aqueous extract of poultry Litter was subjected to toxicity identification tests approved by the United States Environmental Prote ction Agency that use Ceriodaphnia dubia as the test organism. Tests p erformed included pH adjustment, filtration, aeration, C-18 solid-phas e extraction, EDTA addition, sodium thiosulfate addition, and extracti on through zeolite. Zeolite extraction, filtration at low pH, and aera tion at low pH reduced overall toxicity by 68, 20, and 22%, respective ly. The major sources of toxicity appear to be ammonia and anionic org anic compounds. Toxicity was apparently not due to the presence of hea vy metals or oxidants.