Control of ph in neutralization reactor of a waste water treatment system using identification reactor

Download
index.pdf
2005
Obut, Salih
Show full item record
252
views
1288
downloads
A typical wastewater effluent of a chemical process can contain several strong acids/bases, weak acids/bases as well as their salts. They must be neutralized before being discharged to the environment in order to protect aquatic life and human welfare. However, neutralization process is highly nonاlinear and has timeاvarying characteristics. Therefore, the control of pH is a challenging problem where advanced control strategies are often considered. In this study, the aim is to design a pH control system that will be capable of controlling the pH-value of a plant waste-water effluent stream having unknown acids with unknown concentrations using an onاline identification procedure. A Model Predictive Controller, MPC, and a Fuzzy Logic Controller, FLC, are designed and used in a laboratory scale pH neutralization system. The characteristic of the upstream flow is obtained by a small identification reactor which has ten times faster dynamics and which is working parallel to actual neutralization tank. In the control strategy, steadyاstate titration curve of the process stream is obtained using the data collected in terms of pH value from the response of the identification reactor to a pulse input in base flow rate and using the simulated response of the identification reactor for the same input. After obtaining the steadyاstate titration curve, it is used in the design of a ProportionalاIntegral, PI, and of an Adaptive Model Predictive Controller, AMPC. On the other hand, identification reactor is not used in the FLC scheme. The performances of the designed controllers are tested mainly for disturbance rejection, setاpoint tracking and robustness issues theoretically and experimentally. The superiority of the FLC is verified.
Chemical engineering.
http://etd.lib.metu.edu.tr/upload/2/12606395/index.pdf
https://hdl.handle.net/11511/15487
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Dissolution of colemanite and crystallization of gypsum during boric acid production in a batch reactor
Erdoğdu, Anıl; Eroğlu, İnci; Department of Chemical Engineering (2004)
One of the most commonly used boron compounds, boric acid, is produced by dissolving colemanite (2CaO₉3B2O3₉5H2O) in aqueous sulfuric acid whereby gypsum (CaSO4₉2H2O) is formed as a byproduct and must be separated from the main product. This process consists of two steps, dissolution of colemanite and formation of gypsum. The amount of boric acid formed depends on the first step, dissolution of colemanite. In the latter step, gypsum crystals are formed and stay in the reaction mixture to grow up to a size l...
Biological hydrogen production on acetate in continuous panel photobioreactors using rhodobacter capsulatus
Androga, Dominic Deo; Eroğlu, İnci; Department of Chemical Engineering (2009)
Photobiological hydrogen production from organic acids occurs in the presence of light and under anaerobic conditions. Stable and optimized operation of the photobioreactors is the most challenging task in the photofermentation process. The main aim of this study was to achieve in long term, a stable and high hydrogen production on acetate, using the photosynthetic bacteria Rhodobacter capsulatus in continuous panel photobioreactors. Rhodobacter capsulatus (DSM 1710), heat adapted Rhodobacter capsulatus (DS...
Characterization of zeolite membranes by gas permeation
Soydaş, Belma; Kalıpçılar, Halil; Department of Chemical Engineering (2009)
Zeolite membranes are attractive materials to separate gas and liquid mixtures. MFI is a widely studied zeolite type due to its ease of preparation and comparable pore size with the molecular size of many substances. In this study MFI type membranes were synthesized over porous α-Al2O3 supports and characterized with XRD, SEM and gas permeation measurements. In the first part of this study the effect of soda concentration of the synthesis solution on the membrane morphology and crystal orientation was inves...
Ion exchangers in the recovery of tartaric acid from aqueous solutions
Başaran, Tolga Yener; Öztin, Osman Cevdet; Department of Chemical Engineering (2006)
Tartaric acid is a dicarboxylic acid naturally present in grapes, and has many application areas with its salts. It can be produced synthetically, manufactured as a by-product in wine industry, or can be recovered by electrodialysis and solvent extraction methods. Since, ion exchange is one of the oldest processing techniques for the recovery and purification of valuable materials, it can be applied to obtain this valuable organic acid. In this study it is aimed to investigate the effects of resin basicity,...
Utilization of fly ash from fluidized bed combustion of a Turkish lignite in production of blended cements
Kürkçü, Mehmet; Selçuk, Nevin; Department of Chemical Engineering (2006)
Fly ashes generated from fluidized bed combustion of low calorific value, high ash content Turkish lignites are characterized by high content of acidic oxides, such as SiO2, Al2O3 and Fe2O3, varying in the range 50-70%. However, there exists no study for the investigation of the possibility of using these ashes as concrete admixture. Therefore, in this study, characterization of fly ashes from fluidized bed combustion of a Turkish lignite and evaluation of these fly ashes as a substitute for Portland cement...
Citation Formats
S. Obut, “Control of ph in neutralization reactor of a waste water treatment system using identification reactor,” M.S. - Master of Science, Middle East Technical University, 2005.
METU IIS - Integrated Information Service open@metu.edu.tr