Bioremoval of an azo textile dye, Reactive Red 198, by Aspergillus flavus

Construction of a new membrane bed biofilm reactor and yttria-stabilized zirconia for removing heavy metal pollutants

The objective is to design a reactor with a composite new membrane bed biofilm reactor and yttria-stabilized zirconia. We constructed a valuable reactor using response surface methodology (RSM) for process optimization. The present system can remove heavy metal Pb from wastewater using a two-part biofilm reactor: the first reactor, which includes active sludge and media, was investigated; then, the second part, which includes membranes, was made. The amount of heavy metal removed from the effluent was measured at different pH and contact time. The results obtained from this study showed that the optimum conditions for obtaining the optimal removal efficiency separately, with a lead value of 40 mg L-1 for the MBBR reactor, had the highest removal value of 55% and for the membrane with an input lead value of 20 ppm at pH = 12 call time 30 minutes equal to 85%. All analyses in this article have been repeated numerous times to prove the repeatability.

Investigation of enzymes and solvents in the production process of 6-ammonium penicillanic acid (6-APA) in industry to reduce costs and improve production conditions

In this study, the optimization of the amount of enzyme consumed in the enzymatic phase of substitution of butanol solvent instead of methanol in the powder washing phase after filtration was investigated. To perform this study, different amounts of the enzyme penicillin G amidase (PGA) were tested in reactions with the same conditions. The highest efficiency was observed in the reaction that the ratio of penicillin powder to the amount of enzyme was 2:1. In this reaction, for every 100 g of penicillin consumed, 50 g of the PGA was used. Replacement of butanol instead of methanol after filtration, the powder obtained from this step was washed with butanol instead of methanol and the powder obtained from this step was examined after drying. The resulting solvent powder was very small and the drying speed of the powder increased compared to the time of methanol usage. Optimizing the amount of enzyme in this process due to the high cost of the enzyme made this reaction more economically viable at the end of this study. In this study, for the first time, butanol was used as a suitable substitute for methanol and the ratio of enzyme use to penicillin powder was optimized. This research deals with the future perspective in the field of research in this regard.

Decolorization of acid blue 29, disperse red 1 and congo red by different indigenous fungal strains

Azo dyes are toxic and recalcitrant environmental pollutants in wastewater and soil in many industrial sites in Asia and Arabic countries. The aim of this study was to find fungal species useful in wastewater treatment and soil remediation efforts. We assessed the ability of different indigenous Aspergillus strains (i.e. A. flavus, A. fumigatus, A. niger and A. terreus) to degrade the azo dyes Acid Blue 29 (AB29), Disperse Red 1 (DR1) and Congo Red (CR). The optimal conditions for dye decolorization by the above-mentioned strains appeared to be as follows: temperature range 30-35 °C, pH 7, glucose as the carbon source (10 g/L), ammonium sulphate as the nitrogen source (1.5 g/L) and 100 mg/L initial dye concentration. The Aspergillus strains decolorized all azo dyes more than 86%. The HPLC and GC-MS analyses confirmed that aniline (retention time 9.0 min), 3-nitroaniline (retention time 15.92 min), 4-nitroanline (retention time 17.81 min), N,N' diethyl-1,4-phenylendiamine (retention time 18.184 min), and benzidine (retention time 15.07 min) were formed as the intermediate metabolites of dye degradation. All Aspergillus strains decolorized 85% of the dyes in synthetic wastewater.

A kinetic study of textile dyeing wastewater degradation by Penicillium chrysogenum

The potential of Penicillium chrysogenum to decolorize azo dyes and a real industrial textile wastewater was studied. P. chrysogenum was able to decolorize and degrade three azo dyes (200 mg L(-1)), either independently or in a mixture of them, using glucose as a carbon source. A kinetic model for degradation was developed and it allowed predicting the degradation kinetics of the mixture of the three azo dyes. In addition, P. chrysogenum was able to decolorize real industrial wastewater. The kinetic model proposed was also able to predict the decolorization of the real wastewater. The calibration of the proposed model makes it a useful tool for future wastewater facilities' design and for practical applications.

Novel fungal consortium for bioremediation of metals and dyes from mixed waste stream

The present study is targeted towards development of a three member fungal consortium for effective removal of metals [Cr(6+) and Cu(2+)] and dyes [AB and PO] from mixed waste streams. Initial studies using individual fungal strain showed that Aspergillus lentulus was best for Cu(2+) and AB removal, Aspergillus terreus for Cr(6+) removal whereas, Rhizopus oryzae was best for PO removal. Based on the complementary pollutant affinities and positive interactions, a consortium comprising all three strains was developed. Consortium removed 100% Cr(6+) and 81.60% Cu(2+) from metal mixture which was significantly higher than that achieved individually by A. lentulus (Cr(6+): 83.11%; Cu(2+): 67.32%), A. terreus (Cr(6+): 95.57%; Cu(2+): 65.77%) or R. oryzae (Cr(6+): 25.34%; Cu(2+): 30.20%). Further, 98.0% AB and 100.0% PO was removed after 48 h by the consortia. Unlike individual strains, consortium's performance was unaltered irrespective of the complexity of metal-dye mixtures, thereby establishing its superiority.