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- Adamsson, Marie, 1966, et al.
(författare)
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Toxicity Identification Evaluation of ammonia, nitrite and heavy metals at the Stensund Wastewater Aquaculture plant, Sweden.
- 1998
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Ingår i: Water Science and Technology. - 0273-1223. ; 38:3, s. 151-157
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Tidskriftsartikel (refereegranskat)abstract
- The Stensund Wastewater Aquaculture plant was built in 1989. The plant is contained in a greenhouse because of its northern location with a temperate climate; The plant receives wastewater from 40 persons and has a residence time of 30 days. The purification concept is to use a constructed aquatic food chain (algae, zooplankton and fish) combined with hydroponic culture of higher plants to further deplete the nutrients in the wastewater. However, the production of algae and zooplankton has not been working as expected from pilot studies. The purpose of this investigation was to study if toxic chemicals were limiting the production of zooplankton (Daphnia magna) in the aquaculture treatment system. Grab samples were taken at six sites and tested for acute toxicity to Daphnia magna and analyzed for BOD, COD, ammonium-, nitrite-, nitrate- and total nitrogen, total phosphorus and heavy metals (Cd, Ci, Cu, Ni, Pb, Zn). Toxicity to D. magna was also determined after addition of EDTA, sodium thiosulphate and pH adjustment of the,water to 6, 7 and 8, in order to assess if heavy metals and/or pH-dependent toxicants were present Potential toxicants, with concentrations high enough to intoxicate Daphnia magna, were Cu, ammonia and nitrite. Subsequent improvement of nitrification reduced the ammonia and nitrite concentrations as well as the toxicity. Furthermore, the improved production of algae and Daphnia at the Stensund Wastewater Aquaculture plant verified that the primary cause of toxicity was ammonia. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.
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- Adamsson, Marie, 1966, et al.
(författare)
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Toxicity of human urine and its main nitrogen excretory and degradation products to Daphnia magna
- 1996
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Ingår i: Environmental Research Forum. - 1421-0274. ; 5-6, s. 137-144
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Tidskriftsartikel (refereegranskat)abstract
- The discovery of nitrogen as a major cause of eutrophication, especially in the marine environment, has intensified the research on nitrogen removal from sewage water. About eighty percent of the nitrogen in domestic sewage water originates from human urine. One alternative for nitrogen reduction technology in sewage treatment, is to separate the urine from fecal matter, and use the urine as a fertilizer, either in agriculture or in aquaculture. In temperate regions urine has to be stored during the winter season. The objectives of this study were to determine the toxicity to Daphnia magna of human urine, its major nitrogen excretory products (urea, uric acid, ammonia and creatinine) and their degradation products (nitrite and nitrate) and to determine how storage affects the chemical composition of these nitrogen compounds in urine and the resulting effect on urine toxicity to D.magna. The 48-h EC50 for D.magna of fresh morning urine from ten persons ranged from 2.8 to 12.5 percent by volume (mean +/- SD: 5.4 +/- 2.9). The 48h EC50s (expressed as mM of nitrogen) for the nitrogen compounds were 679 for urea, 78 for nitrate, 49 for creatinine, 2.4 for uric acid, 1.5 for ammonia and 0.6 for nitrite, at pH between 8.2-8.5. The toxicity of urine increased approximately five rimes during storage in 32 days at 20 degrees C. The major cause of this increase was conversion of urea to ammonia, which was accompanied by an increase in pH from 5.7 to 9.7, making the ammonia even more toxic. Therefore, the use of human urine as a fertilizer in aquaculture and probably also in agriculture must consider the potential toxicity of ammonia.
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| 4. |
- Andreasson, Maria, et al.
(författare)
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TOXICITY OF BILE FROM FISH EXPOSED TO PCP-SPIKED SEDIMENT
- 1994
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Ingår i: AQUATIC TOXICOLOGY. - 0166-445X. ; 30:2, s. 171-182
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Tidskriftsartikel (refereegranskat)abstract
- : In order to evaluate if toxicity of the bile may be used to establish lethal and sublethal exposure of fish to pollutants, rainbow trout (Oncorhynchus mykiss) were exposed to PCP-spiked sediment (4, 8, 16, 32 and 64 mg PCP/kg w.w.) for 1 or 2 days, sacrificed and their bile tested for toxicity to Daphnia magna. Exposure was monitored daily by Daphnia toxicity tests of sediment and water. The 24-h EC50s, expressed as mg PCP/kg sediment w.w., were 20 +/- 6.4 for sediment and 9.6 +/- 5.1 for water phase tests, respectively. The corresponding 24-h LC50 value for sediment to rainbow trout was ca 16 mg/kg w.w. Bile toxicity was tested directly and after hydrolysis by acid and by beta-glucuronidase. Bile and bile extract of surviving trout exposed to the median lethal concentration of sediment (16 mg PCP/kg w.w.) were 10 times more toxic than control fish. Hydrolyzed bile extract of fish exposed to 4 mg PCP/kg w.w. was 10-50 times more toxic than that of control fish. Thus, toxicity tests of extracts of hydrolyzed bile were more sensitive than toxicity tests based on water and sediment. Therefore, at least for chemicals which accumulate in the bile, toxicity tests of the bile may be used to establish sublethal exposure in fish.
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| 5. |
- Andreasson, Maria, et al.
(författare)
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TOXICITY OF BILE FROM FISH EXPOSED TO PENTACHLOROPHENOL-SPIKED SEDIMENT
- 1995
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Ingår i: MARINE ENVIRONMENTAL RESEARCH. ; 39:1-4, s. 335-339
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Tidskriftsartikel (refereegranskat)abstract
- Many pollutants are concentrated in sediments as well as in the bile of fish. In order to evaluate if toxicity of fish bile can be used to determine lethal and sublethal exposure to pollutants, rainbow trout (Oncorhynchus mykiss) were exposed to pentachlorophenol- (PCP) spiked sediment. PCP was added to a natural fresh water sediment at concentrations of 4, 8, 16, 32 and 64 mg PCP/kg wet weight (w/w) and equilibrated with water at 10% sediment in water. Trout were exposed for 1 or 2 clays, sacrificed and their bile was tested for toxicity to Daphnia magna. Exposure was monitored daily by toxicity tests of sediment and water using D. magna. Twenty-four hour EC50s, expressed as mg PCP/kg sediment w/w (mean +/- SD, N = 5), were 20 +/- 6.4 for sediment and 9.6 +/- 5.1 for water phase tests, respectively. The corresponding sediment 24-h LC50 for rainbow trout was ca 16 mg/kg w/w. Toxicity of bile was tested directly and after extraction with acetone-hexane (1:3, v/v). Prior to extraction, subsamples of bile were hydrolyzed by acid (pH 3.5 at 70 degrees C for 3 h) and beta-glucuronidase (pH 5.0 at 40 degrees C for 3 h). Bile and bile extract toxicity in surviving trouts exposed to the median lethal sediment concentration (16 mg PCP/kg w/w) was > 10 x more toxic than bile from control fish, and hydrolyzed bile extract from fish exposed to 4 mg PCP/kg sediment was 10-50 x more toxic than from control fish. Thus, toxicity tests with extracts of hydrolyzed bile were more sensitive than toxicity tests with water and sediment. Therefore, at least for chemicals readily excreted through the bile, toxicity tests may be used to quantify sublethal exposure in fish.
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| 10. |
- Berglind, Rune, 1952, et al.
(författare)
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THE EFFECTS OF LEAD ON DELTA-AMINOLEVULINIC-ACID DEHYDRATASE ACTIVITY, GROWTH, HEMOGLOBIN CONTENT, AND REPRODUCTION IN DAPHNIA-MAGNA
- 1985
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Ingår i: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY. - 0147-6513. ; 9:2, s. 216-229
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Tidskriftsartikel (refereegranskat)abstract
- The effects of continuous exposure to lead for various periods and recovery in clean water on δ-aminolevulinic acid dehydratase (ALA-D) activity, hemoglobin content, growth, and reproduction were studied in Daphnia magna. Steady-state inhibition of ALA-D activity was reached within 2 days in 16, 64, and 256 μg Pb liter−1, but restoration in clean water was prolonged in relation to previous exposure. In spite of the inhibition of ALA-D activity hemoglobin content increased after 2 days in 16 and 24 μg Pb liter−1. Furthermore, hemoglobin content in previously exposed animals increased during recovery in clean water. Maximum hemoglobin content (2.9 times control value) was found after 2 days recovery of animals exposed to 64 μg Pb liter−1. These findings suggest that some enzyme(s) other than ALA-D in the biosynthetic pathway of hemoglobin formation is (are) more sensitive to lead. Growth, in contrast to reproduction, was stimulated by low concentrations of lead (<64 μg Pb liter−1), although in 256 μg Pb liter−1 growth was also significantly impaired. After 19 days the 16 and 50% reproductive impairment concentrations were ⩽1 and 10 μg Pb liter−1, respectively.
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