Water and sediment ecotoxicity studies in Temuco and Rapel River Basin, Chile
ABSTRACT Five samples were collected from the Rapel River Basin near the city of Rancagua and three from the city of Temuco. Three of the samples were collected from raw drinking water supplies. The following bioassays were performed on some or all of the samples: Microtox; Microtox solid phase test; SOS-Chromotest with and without S9; Toxi-Chromotest; Sediment-Chromotest; Panagrellus redivivus percent survival and percent maturation; submitochondrial reverse electron transfer and forward electron transfer tests; Daphnia magna 24 h acute toxicity; ECHA biocide monitor, and the competitive immunoassay tests for benomyl, metolachlor, atrazine, and triazines. All the sampling sites were positive for the presence of genotoxicants requiring S9 activation while three sites also indicated the presence of direct-acting genotoxicants/mutagens (−S9). Also, all the sites were positive for the presence of pesticides. In some samples there was 100% inhibition of P. redivivus maturation. Details and discussion on the implication of the results are presented. © 1996 by John Wiley & Sons, Inc.
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ABSTRACT: Two different forest industry wastewater sludges were composted in piles. The piles were founded with leachate collection systems. The aim was to study the progress of the composting process, the amount and quality of leachates as well as the toxicity of the sludges and leachates. The sludges consisted of mixtures of primary and biosludge. The piles were monitored for eight months by physical measurements, chemical analyses and toxicity tests. The leachates were collected for six months. The lignin concentrations and the amount of mycelium were measured from the sludges and from the soil. Test plots and control plots were established to a field with different amounts of composted sludge in order to study the applicability of the sludges in agriculture. The results showed that both sludges were amenable to composting. The original sludges were toxic but the toxicity decreased during composting and all the sludges were proved to be non- toxic at the end of composting. The leachates were determined non-toxic and the heavy metal concentrations were low in both sludges and leachates. The sludges proved to be suitable for use as soil improver in agricultural plant production. Keywords Agricultural use; composting; pulp and paper industry; toxicity; wastewater sludges01/2000;
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ABSTRACT: Heterogeneous oily waste from an old dumping site was composted in three windrows constructed from different proportions of waste, sewage sludge, and bark. The objectives of this pilot study were to examine the usefulness of composting as a treatment method for this particular waste and to study decontamination in the composting process by using a battery of toxicity tests. Five samples from the windrow having intermediate oil concentrations were tested with toxicity tests based on microbes (Pseudomonas putida growth inhibition test, ToxiChromotest, MetPLATE, and three different modifications of a luminescent bacterial test), enzyme inhibition (reverse electron transport), plants (duckweed growth inhibition and red clover seed germination), and soil animals (Folsomia candida, Enchytraeus albidus, and Enchytraeus sp.). The luminescent bacterial tests were used as prescreening tests. Chemical analyses of samples were carried out simultaneously. Both toxicity and oil concentration, including those of polyaromatic hydrocarbons (PAHs), were reduced during composting and soil quality improved significantly. The total oil hydrocarbon concentration decreased from 90,000 to 19,000 mg/kg, measured with the IR method, in 4 months, and from 86,000 to 1400 mg/kg, measured with GC method. The concentration of PAHs decreased from 135 to 23.5 mg/kg. During the fourth month of composting (stabilization stage), the proportion of the heaviest oil fractions (asphaltenes) became dominant. Toxicity varied between different samples and between different bioassays; however, the first sample was significantly more toxic than the others, and most of the tests revealed a decrease in toxicity during the composting process.Ecotoxicology and Environmental Safety 11/2000; 47(2):156-66. · 2.48 Impact Factor