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Oxidation‐Reduction Potential as a Control Variable for the Anaerobic Stage during Anaerobic‐Aerobic p ‐Nitrophenol Degradation
Author(s) -
Buitrón Germán,
Betancur Manuel J.,
Moreno Gloria,
Moreno Jaime A.
Publication year - 2003
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp0340842
Subject(s) - anaerobic exercise , reduction potential , chemistry , pulp and paper industry , degradation (telecommunications) , effluent , anaerobic respiration , bioreactor , biodegradation , environmental science , environmental engineering , computer science , biology , inorganic chemistry , organic chemistry , physiology , engineering , telecommunications
Abstract Combined anaerobic‐aerobic processes are a viable alternative for the treatment of xenobiotic compounds that are difficult to treat by traditional processes. The variable nature of the sequencing batch reactors, SBR, systems allows manipulation of the selective pressure on the microorganisms. Then, the activity of the community can be dynamically adjusted to meet changing effluents conditions. To improve the response of the SBR to changing influent conditions, several efforts have been made to automate and control the duration of the sequential phases of the SBR. The objective of this work is to present and discuss the feasibility of the use of the oxidation‐reduction potential, ORP, as a control variable for the determination of the anaerobic phase length in an anaerobic‐aerobic SBR used to degrade p ‐nitrophenol, PNP. The control of the anaerobic phase of the anaerobic‐aerobic reactor was achieved with software developed at the Institute of Engineering‐UNAM. During the anaerobic stage, the PNP is reduced to p ‐aminophenol, PAP. As a consequence of the compound transformation, there is a change in the oxidation‐reduction potential of the culture medium. This change was used to indicate the minimal concentration of PNP and, as a consequence, the maximal PAP concentration. The feasibility of the algorithm for using the variations in the ORP to determine on‐line the length of the anaerobic stage in an anaerobic‐aerobic process was demonstrated in our laboratory.