Metanización y mineralización del 2-clorofenol en condiciones metanogénicas
The aim of this study is to contribute to the knowledge about 2-Chlorophenol degradation under methanogenic conditions. This work was divided in two parts. The first part was focused on evaluating the effect of the acclimatization, addition of electron donors and the atmosphere during mineralization...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis de maestría |
| Estado: | Versión publicada |
| Fecha de publicación: | 2008 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:vq27zn66b |
| Acceso en línea: | https://doi.org/10.24275/uami.vq27zn66b |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Phenols info:eu-repo/classification/LEM/Clorofenoles info:eu-repo/classification/LEM/Biomineralization info:eu-repo/classification/LEM/Mineralización info:eu-repo/classification/cti/6 |
| Sumario: | The aim of this study is to contribute to the knowledge about 2-Chlorophenol degradation under methanogenic conditions. This work was divided in two parts. The first part was focused on evaluating the effect of the acclimatization, addition of electron donors and the atmosphere during mineralization and methanization of 2-CP. Acetate and phenol were used as electron donors in stoichiometric relation with 2-CP. Nitrogen, carbon dioxide and helium were the atmosphere assessed; 50 and 80 days were the acclimatization times. In all cases the concentration of 2-CP used was 50 mg/L. The second part evaluated the effect of several oxygen concentrations (0.5 – 2 mg O2/L) and the acclimatization (50 days) during 2-CP mineralization and methanization. All the assays were performed in batch cultures using 60 mL serological bottles and adding as inoculum methanogenic sludge in steady state obtained from an UASB reactor. In all the experiments phenol was found as intermediary due to reductive dechlorination of 2-CP. Likewise, methane and carbon dioxide were detected indicating mineralization and methanization of 2-CP. In the first part, no effect of sludge acclimatization was observed on 2-CP consumption efficiency (84%) or production yield (0.7± 0.12). However, the lag phase was reduced in 62.5% if compared with the control. Likewise, the 2-CP specific consumption rate (qs) of the control was 0.0014 ± 0.0005 mg C/g VSS*d, this value was increased in 57% and 114% for acclimatization times of 50 and 80 days respectively, In reference to electron donors, it was observed that acetate consumption was independent of 2-CP consumption. No significant variation in yield products, consumption efficiencies and specific rates were observed if compared to the control assay without acetate. In contrast, no lag phase was observed when phenol was used resulting in an increase in the specific consumption rate (0.003 to 0.0044 ± 0.0005 mg C consumed / g VSS * d). Results concerning to atmospheres showed that carbon dioxide reduce consumption efficiency probably by a change in the metabolic pathway is given. The change is originated due to the production of other intermediaries; nitrogen and helium don not influence the 2-CP consumption because we had not observed difference among the consumption profiles. In the second part, no effect of oxygen on consumption efficiencies (92%) and specific consumption rates (0.0015 ± 0.0003 mg C/ VSS*d) was observed. At the highest concentration of oxygen assayed, methane and phenol production (YMETANO/S) decreased in 50% and 42% respectively while the yield of carbon dioxide (YCO2) increased compared to the methanogenic control without oxygen. The material balance suggested formation of an intermediary within an alternating metabolic pathway. Consumption period was diminished in 50% and the specific consumption rate increased in 73% when acclimatization sludge for 2-CP and oxygen was used. |
|---|