Polyvinyl acetate processing wastewater treatment using combined Fenton's reagent and fungal consortium: Application of central composite design for conditions optimization.

The Fenton reaction as an oxidative degradation process was used for industrial chemical wastewater (ICW) pretreatment. The biodegradation of pretreated ICW was performed, in aqueous environment under aerobic condition, by a defined fungal consortium. The central composite design (CCD) was used to study the effect of nitrogen and phosphorus addition and the concentration of the pollution on the removal of polyvinyl alcohol (PVA) and organic compounds. The interaction between parameters was modeled using the response surface methodology (RSM). Results of optimization showed COD, PVA and color removal yields of 97.8%, 98.5% and 99.75%, respectively with a supplementof 1.4 gL-1 of (NH4)2SO4, 1.2 gL-1 of KH2PO4 and 75% of concentrated ICW. Enzymatic analysis proved that laccase and lignin peroxidase were involved in the biodegradation with 45 UIL-1 and 450 UIL-1, respectively. Furthermore, the analysis of metabolic products using Fourier transforms infrared spectroscopy (FTIR) and nuclear magnetic resonance (1HNMR) showed clearly the mineralization of organic compounds and the formation of formic acid and ethanol. Therefore, the effective treatment of ICW was achieved by developing an integrated chemical and biological process which met the requirement for a safety effluent respectful for environment without risks for public health.

Effect of enhancing nutrient balance in anaerobic digester feedstock by co-substrate addition on the microbial diversity and energy production from municipal sewage sludge.

Enhancement of methane production during anaerobic digestion of waste activated sludge (WAS) could improve the energy self sufficiency of the municipal wastewater treatment plants (WWTPs). Therefore, mixing WAS with organic wastes improved process performance and stability. In this work, the anaerobic co-digestion of WAS combined with the olive processing wastewater (OPW) was investigated and associated with the energetic benefits and microbial populations shifts. The bio-methane potential (BMP) of various WAS and OPW mixtures corresponding to increased phenols concentrations were tested. The anaerobic digestion of better proportions (90%/10% and 80%/20%) was performed in anaerobic sequencing batch reactors (ASBRs). The biodegradation of phenols at concentrations up to 0.76 g/L was confirmed by Sephadex gel filtration showing that ASBR, which is suspended growth reactor, can handle much higher concentration of toxic compounds. Microbial analysis showed that phenols induced significantly the archaea community dynamic, which showed highly richness and diversity in the well performed reactor. The dominant bacteria and archaea phylotypes were affiliated to Proteobacteria and Methanosarcinales, respectively. Therefore, OPW addition increased total energy production from 24.6 kWh/ton to 64.7 kWh/ton, which would provide 0.43 M€/year net benefits only from the electric power. In addition it brings a payback time on investment of 2 years for WWTPs modification, which was considered interesting.

Improvement of activated sludge resistance to shock loading by fungal enzyme addition during textile wastewater treatment.

The effects of the additions of the fungal enzymatic extract were investigated in relation to the treatment of real textile wastewater (RTW) by the activated sludge process (ASP). The used enzyme cocktail was produced by a new isolated fungal Chaetomium globosum IMA1. The system that was operated with enzyme addition showed a better chemical oxygen demand (COD) removal efficiency (95%) compared to the control system (75%). In addition, the improvement of color removal (OD620) efficiencies was around 15%, when the newly consortium fungal enzymes was added. As the organic loading rate (OLR) increased from 0.33 g to 0.66 g COD L-1 d-1, a decrease in the performance of the two reactors was observed by monitoring the quality of treated effluents. However, the ASP working with enzyme addition showed a strong resistance to shock loadings and restored after few days compared to the control system, which was strongly inhibited. In fact, the enzyme addition improved the sludge volume index (SVI) and the activity of microorganisms. A high activity of laccase (300 U.L-1) enzyme was observed throughout the decolorization process in the improved system.

Industrial textile effluent decolourization in stirred and static batch cultures of a new fungal strain Chaetomium globosum IMA1 KJ472923.

The treatment of an industrial textile effluent (ITE) was investigated by using a mono-culture of a novel fungal strain Chaetomium globosum IMA1. This filamentous fungus was selected based on its capacity for dye removal via the biodegradation mechanism. The respirometric analysis showed that C. globosum IMA1 was resistant to an indigo concentration up to 700 mg equivalent COD/L. The decolourization of the ITE by C. globosum was performed in static and stirred batch systems. The better lignin peroxidase (LiP), laccase and the manganese peroxidase (MnP) productions were 829.9 U/L, 83 U/L and 247.8 U/L, respectively since 3-5 days under a stirred condition. Therefore, the chemical oxygen demand (COD) and colors (OD620) removal yields reached 88.4% and 99.8%, respectively. Fourier transforms infrared spectroscopy (FTIR) analysis of the treated effluent showed that the decolourization was due to the degradation and the transformation of dye molecules. However, spectrophotometric examination showed that the complete dye removal was through fungal adsorption (8%), followed by degradation (92%).