Determination of leachate toxicity through acute toxicity using Daphnia pulex and anaerobic toxicity assays
Autor: | Yazmín Stefhany Carabalí Rivera, Patricia Torres Lozada, Luz Edith Barba Ho |
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Jazyk: | angličtina |
Rok vydání: | 2017 |
Předmět: |
0301 basic medicine
toxicidad anaerobia 010501 environmental sciences Biology 01 natural sciences Daphnia pulex 03 medical and health sciences municipal landfill anaerobic toxicity Leachate 0105 earth and related environmental sciences leachate Waste management General Engineering Building and Construction biology.organism_classification Acute toxicity Anaerobic digestion 030104 developmental biology lixiviado lcsh:TA1-2040 62 Ingeniería y operaciones afines / Engineering Environmental chemistry Toxicity Anaerobic bacteria relleno sanitario municipal Ecotoxicity lcsh:Engineering (General). Civil engineering (General) Anaerobic exercise |
Zdroj: | Ingeniería e Investigación, Vol 37, Iss 1, Pp 16-24 (2017) Repositorio UN Universidad Nacional de Colombia instacron:Universidad Nacional de Colombia |
ISSN: | 2248-8723 0120-5609 |
Popis: | The municipal solid waste (MSW) of large cities, in particular in developing countries, is mainly disposed of in landfills (LFs), whose inadequate management generates the emission of greenhouse gases and the production of leachates with high concentrations of organic and inorganic matter and occasionally heavy metals. In this study, the toxicity of the leachates from an intermediate-age municipal landfill was evaluated by ecotoxicity and anaerobic digestion tests. The acute toxicity assays with Daphnia pulex presented a toxic unit (TU) value of 49.5%, which indicates that these leachates should not be directly discharged into water sources or percolate into the soil because they would affect the ecosystems served by these waters. According to statistical analyses, the leachate toxicity is mainly associated with the inorganic fraction, with chlorides, calcium hardness and calcium having the greatest influence on the toxicity. The anaerobic toxicity assays showed that in the exposure stage, the methanogenic activity exceeded that of the control, which suggests that the anaerobic bacteria easily adapted to the leachate. Therefore, this treatment could be an alternative to mitigate the toxicity of the studied leachates. The inhibition presented in the recovery stage, represented by a reduction of the methanogenic activity, could arise because the amount of supplied substrate was not enough to fulfill the carbon and nutrient requirements of the bacterial population present. The municipal solid waste (MSW) of large cities, in particular the ones of developing countries, is mainly disposed in landfills (LFs), whose inadequate management generates the emission of greenhouse gases and the production of leachates with high concentrations of organic and inorganic matter and, occasionally heavy metals. In this study, the toxicity of the leachates from an intermediate-age municipal landfill was evaluated by ecotoxicity and anaerobic toxicity tests. The acute toxicity assays with Daphnia pulex presented a toxic unit (TU) value of 49.5%, which indicates that these leachates should not be directly discharged into water sources or percolate into the soil because they would affect the ecosystems related to these waters. According to statistical analyses, the leachate toxicity is mainly associated with the inorganic fraction, having the chlorides, calcium hardness and, calcium as the greatest influences on the toxicity. The anaerobic toxicity test showed that in the exposure stage, the methanogenic activity exceeded the control one, which suggests that the anaerobic bacteria easily adapted to the leachate. Therefore, this treatment could be an alternative to mitigate the toxicity of the studied leachates. The inhibition presented in the recovery stage, represented by a reduction of the methanogenic activity, may be because the amount of supplied substrate was not enough to fulfill the carbon and nutrient requirements of the bacterial population present. |
Databáze: | OpenAIRE |
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