טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentTalia Rothschild
SubjectAnaerobic Digestion of Aromatic Hydrocarbons in
Petrochemical Industry Effluents
DepartmentDepartment of Quality Assurance and Reliability
Supervisors Professor Emeritus Shelef Gedaliahu
Dr. Kimchie Shlomo
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Abstract

This research deals with the investigation of a biological treatment process for the wastewater of a petrochemical industry plant which considers the addition of a new process line for the production of Trimellitic Anhydride (TMA).

This research investigates the anaerobic degradation kinetics of TMA in the environment of petrochemical industry wastewater, using the sludge from a UASB (Upflow Anaerobic Sludge Blanket) type reactor as an inoculum. The 400 m3 UASB reactor, operating in GADIV petrochemical plant, had been used for this purpose. GADIV's wastewater contains mostly Phthalic acid and Benzoic acid and in the future they may also contain TMA from a new process line.

The influence of future addition of TMA to the plant's wastewater on the COD degradation in the reactor, as well as TMA's own biodegradability, were investigated.

The experimental bio-reactors in the present research consist of two simulation systems: an array of 12 anaerobic batch reactors and one continuous pilot plant (100 Liter working volume) reactor of a UASB type.

The experiments in the anaerobic batch reactors system tested the reaction order of the COD degradation in the wastewater of a petrochemical plant and of the major aromatic compounds found in this wastewater: Phthalic acid, Benzoic acid and TMA. For the degradation kinetics of the three aromatic compounds a first order reaction was found.

The anaerobic batch reactors system also tested the influence of the contaminants Phthalic acid and Benzoic acid on the COD degradation rate and on the rate of TMA degradation in the presence of each contaminant. It was found that:

The COD degradation rate constant in UASB reactor treating petrochemical industry wastewater is: 0.365-0.487 day-1

The COD degradation rate constant in UASB reactor containing TMA and treating petrochemical industry wastewater is:

0.194-0.318 day-1.

The COD degradation rate constant in a UASB reactor treating TMA, as a sole carbon source, in water is: 0.078 - 0.102 day-1

The present research shows that anaerobic treatment in a UASB reactor provides a solution to petrochemical industry wastewater which were investigated in this research and specifically for the TMA which may be added to these wastewater. The addition of the new stream containing TMA to the plant's wastewater gives a solution by anaerobic treatment of the combined streams, which is better than the option of separate treatment of each stream.