TUTCRIS - Tampereen teknillinen yliopisto


Biovalorisation of liquid and gaseous effluents of oil refinery and petrochemical industry



KustantajaTampere University
TilaJulkaistu - 12 joulukuuta 2019
OKM-julkaisutyyppiG5 Artikkeliväitöskirja


NimiTampere University Dissertations


Liquid effluents of oil refinery contain toxic selenium oxyanions and phenol, while gaseous effluents contain toxic CO/syngas. To remove the phenol and simultaneously reduce the selenite oxyanions, a fungal-bacterial co-culture of Phanerochaete chrysosporium and Delftia lacustris was developed. Two modes of co-cultures of the fungus and the bacterium were developed. The first being a freely growing bacterium and fungus (suspended growth co-culture), the second being the growth of the bacterial biomass encircling the fungal biomass
(attached growth co-culture). Both types of fungal-bacterial co-cultures were incubated with varying concentrations of phenols with a fixed selenite concentration (10 mg/L). The suspended growth co-culture could degrade up to 800 mg/L of phenol and simultaneously reduce 10 mg/L of selenite with production of nano Se(0) having a minimum diameter of 3.58
nanometer. The attached growth co-culture could completely degrade 50 mg/L of phenol and simultaneously reduce selenite to nano Se(0) having a minimum diameter of 58.5 nm.

In order to valorize the CO/syngas by bioconversion techniques an anaerobic methanogenic sludge was acclimatized to use CO as sole carbon substrate for a period of 46 days in a continuous stirred stank reactor, supplied with CO at 10 ml/min. 6.18 g/L acetic acid, 1.18 g/L butyric acid, and 0.423 g/L hexanoic acid were the highest concentrations of metabolites produced. Later, acids were metabolized at lower pH, producing alcohols at concentrations of
11.1 g/L ethanol, 1.8 g/L butanol and 1.46 g/L hexanol, confirming the successful enrichment strategy. The next experiment focused on the absence of trace element tungsten, and consecutively selenium on the previously CO acclimatized sludge under the same operating conditions. An in-situ synthesized co-polymeric gel of N-ter-butyl-acrylamide and acrylic acid was used to recover ethanol, propanol and butanol from a synthetic fermentation broth. The scope of repeated use of the gel for the alcohol recovery was investigated and every time
approximately 98% alcohol was recovered.

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