Estudo dos parâmetros de extração de fenol de efluentes aquosos por um tensoativo não iônico
Environmental sustainability has become one of the topics of greatest interest in industry, mainly due to effluent generation. Phenols are found in many industries effluents, these industries might be refineries, coal processing, pharmaceutical, plastics, paints and paper and pulp industries. Bec...
সংরক্ষণ করুন:
| প্রধান লেখক: | |
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| অন্যান্য লেখক: | |
| বিন্যাস: | Dissertação |
| ভাষা: | por |
| প্রকাশিত: |
Universidade Federal do Rio Grande do Norte
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| বিষয়গুলি: | |
| অনলাইন ব্যবহার করুন: | https://repositorio.ufrn.br/jspui/handle/123456789/15829 |
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| সংক্ষিপ্ত: | Environmental sustainability has become one of the topics of greatest interest in
industry, mainly due to effluent generation. Phenols are found in many industries effluents,
these industries might be refineries, coal processing, pharmaceutical, plastics, paints and
paper and pulp industries. Because phenolic compounds are toxic to humans and aquatic
organisms, Federal Resolution CONAMA No. 430 of 13.05.2011 limits the maximum
content of phenols, in 0.5 mg.L-1, for release in freshwater bodies. In the effluents treatment,
the liquid-liquid extraction process is the most economical for the phenol recovery, because
consumes little energy, but in most cases implements an organic solvent, and the use of it can
cause some environmental problems due to the high toxicity of this compound. Because of
this, exists a need for new methodologies, which aims to replace these solvents for
biodegradable ones. Some literature studies demonstrate the feasibility of phenolic
compounds removing from aqueous effluents, by biodegradable solvents. In this extraction
kind called "Cloud Point Extraction" is used a nonionic surfactant as extracting agent of
phenolic compounds. In order to optimize the phenol extraction process, this paper studies the
mathematical modeling and optimization of extraction parameters and investigates the effect
of the independent variables in the process. A 32 full factorial design has been done with
operating temperature and surfactant concentration as independent variables and, parameters
extraction: Volumetric fraction of coacervate phase, surfactant and residual concentration of
phenol in dilute phase after separation phase and phenol extraction efficiency, as dependent
variables. To achieve the objectives presented before, the work was carried out in five steps:
(i) selection of some literature data, (ii) use of Box-Behnken model to find out mathematical
models that describes the process of phenol extraction, (iii) Data analysis were performed
using STATISTICA 7.0 and the analysis of variance was used to assess the model
significance and prediction (iv) models optimization using the response surface method (v)
Mathematical models validation using additional measures, from samples different from the
ones used to construct the model. The results showed that the mathematical models found are
able to calculate the effect of the surfactant concentration and the operating temperature in
each extraction parameter studied, respecting the boundaries used. The models optimization
allowed the achievement of consistent and applicable results in a simple and quick way
leading to high efficiency in process operation. |
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