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<p>The paper reports the development of ZnO-MgAl layered double hydroxides as an adsorbent-photo catalyst to remove the dye pollutants from aqueous solution and the experiments of a photocatalytic study were designed and modeled by response surface methodology (RSM) and artificial neural network (ANN). The co-precipitation and urea methods were used to synthesize the ZnO-MgAl layered double hydroxides and FT-IR, XRD and SEM analysis were done for characterization of the catalyst.The performance of the ANN model was determined and showed the efficiency of the model in comparison to the RSM method to predict the percentage of dye removal accurately with a determination coefficient (R²) of 0.968. The optimized conditions were obtained as follows: 600 ^oC, 120 min, 0.05 g and 20 ppm for the calcination temperature, irradiation time, catalyst amount and dye pollutant concentration, respectively. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 22nd January 2016; Revised: 14th March 2016; Accepted:15th March 2016</em></p><p><strong>How to Cite:</strong> Hosseini, S.A., Akbari, M. (2016). ZnO/Mg-Al Layered Double Hydroxides as a Photocatalytic Bleaching of Methylene Orange - A Black Box Modeling by Artificial Neural Network. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (3): 299-315 (doi: 10.9767/bcrec.11.3.570.299-315)</p><p><strong>Permalink/DOI:</strong> <a href="http://doi.org/10.9767/bcrec.11.3.570.299-315">http://doi.org/10.9767/bcrec.11.3.570.299-315</a></p>

This research investigates the effect of enzymatic treatment of two different regenerated cellulosic fibers (Lyocell and viscose) on their ability of bacteria sorption from an aqueous suspension. The sorption of Escherichia coli (E. coli, Gram negative) and Staphylococcus aureus (S. aureus, Gram positive) cells by treated Lyocell and viscose fabrics were determined by measuring the optical density (OD) of the remaining bacteria suspension after removal of the fabric samples using spectrometry. Fourier transform infrared spectroscopy and scanning electron microscopy (SEM) were utilized to investigate structural and morphological changes of the enzyme treated samples. The result showed that the moisture content and crystallinity of both viscose and Lyocell samples increased after enzymatic treatment. Comparing the results of OD measurements indicated that enzymatic treatment of cellulosic samples significantly increased the bacteria absorption properties compared to those untreated samples. However, treated samples showed different ranges of sorption ability with different kinds of bacteria. The maximum bacteria sorption of 38% and 37% of E. coli bacteria from an aqueous suspension was found for the treated viscose and Lyocell samples compared with only 20% and 10% of the untreated viscose and Lyocell samples, respectively. It was also found that S. aureus sorption of cellulose-treated viscose and Lyocell fabrics from a bacterial suspension could significantly improve up to 33% compared with only 5% of untreated samples. Furthermore, SEM micrographs confirmed that bacterial sorption of the cellulose-treated samples were effectively improved in terms of their uniform sorption on the fibers surface.