Fluidized-bed denitrification for mine waters. Part I: Low pH and temperature operation
| Autor: | Gang Zou, Jaakko A. Puhakka, Giovanni Esposito, Stefano Papirio, Minna Peltola, Anna Ylinen |
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| Přispěvatelé: | Papirio, Stefano, Ylinen, A., Zou, G., Peltola, M., Esposito, G., Puhakka, J. A. |
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Environmental Engineering
Denitrification Iron Inorganic chemistry chemistry.chemical_element Bioengineering Nitrate Microbiology Mining Comamonadaceae Denitrifying bacteria chemistry.chemical_compound Bioreactors Actinomycetales Bioreactor Acid mine water Copper Fluidized-bed reactor Environmental Chemistry Humans Ferrous Compounds Ethanol Nitrates Chemistry Temperature Biodegradation Hydrogen-Ion Concentration Pollution Kinetics Biodegradation Environmental Fluidized bed Batch Cell Culture Techniques Environmental chemistry Oxidation-Reduction Water Pollutants Chemical |
| Popis: | Mining often leads to nitrate and metal contamination of groundwater and water bodies. Denitrification of acidic water was investigated in two up-flow fluidized-bed reactors (FBR) and using batch assays. Bacterial communities were enriched on ethanol plus nitrate in the FBRs. Initially, the effects of temperature, low-pH and ethanol/nitrate on denitrification were revealed. Batch assays showed that pH 4.8 was inhibitory to denitrification, whereas FBR characteristics permitted denitrification even at feed pH of 2.5 and at 7–8 °C. Nitrate and ethanol were removed and the feed pH was neutralized, provided that ethanol was supplied in excess to nitrate. Subsequently, Fe(II) and Cu impact on denitrification was investigated within batch tests at pH 7. Iron supplementation up to 100 mg/L resulted in iron oxidation and soluble concentrations ranging from 0.4 to 1.6 mg/L that stimulated denitrification. On the contrary, 0.7 mg/L of soluble Cu significantly slowed denitrification down resulting in about 45 % of inhibition in the first 8 h. Polymerase chain reaction—denaturant gradient gel electrophoresis demonstrated the co-existence of different denitrifying microbial consortia in FBRs. Dechloromonas denitrificans and Hydrogenophaga caeni were present in both FBRs and mainly responsible for nitrate reduction. |
| Databáze: | OpenAIRE |
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