Synthesis and Characterization of Poly(o-chloroaniline)/TiO2 Nanocomposites for Photocatalytic Degradation of Direct Yellow 50 Dye in Textile Wastewater

<p>The nanocomposites of poly(o-chloroaniline) with titanium dioxide have been prepared via chemical oxidative polymerization technique using o-chloroaniline monomer and titanium dioxide nanoparticles for photocatalytic application. The different composites were prepared by varying the load percentage of titanium oxide nanoparticles (TiO2 NPs) in polyorthochloroaniline (POCA) matrix. The synthesized composite materials were characterized by Scanning electron microscopy (SEM), X-Rays diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) techniques. The POCA/TiO2 nanocomposites were further applied to evaluate the photocatalytic degradation potential towards direct yellow 50 (DY50) dye in an aqueous medium under ultraviolet radiations.</p>

Thiolation of Myco-Synthesized Fe3O4-NPs: A Novel Promising Tool for Penicillium expansium Laccase Immobilization to Decolorize Textile Dyes and as an Application for Anticancer Agent

Environmental pollution due to the continuous uncontrolled discharge of toxic dyes into the water bodies provides insight into the need to eliminate pollutants prior to discharge is significantly needed. Recently, the combination of conventional chemotherapeutic agents and nanoparticles has attracted considerable attention. Herein, the magnetic nanoparticles (Fe3O4-NPs) were synthesized using metabolites of Aspergillus niger. Further, the surfaces of Fe3O4-NPs were functionalized using 3-mercaptoproionic acid as confirmed by XRD, TEM, and SEM analyses. A purified P. expansum laccase was immobilized onto Fe3O4/3-MPA-SH and then the developed immobilized laccase (Fe3O4/3-MPA-S-S-laccase) was applied to achieve redox-mediated degradation of different dyes. The Fe3O4/3-MPA-S-S-laccase exhibited notably improved stability toward pH, temperature, organic solvents, and storage periods. The Fe3O4/3-MPA-S-S-laccase exhibited appropriate operational stability while retaining 84.34% of its initial activity after 10 cycles. The catalytic affinity (Kcat/Km) of the immobilized biocatalyst was increased above 10-fold. The experimental data showed remarkable improvement in the dyes’ decolorization using the immobilized biocatalyst in the presence of a redox mediator in seven successive cycles. Thus, the prepared novel nanocomposite-laccase can be applied as an alternative promising strategy for bioremediation of textile wastewater. The cytotoxic level of carboplatin and Fe3O4-NPs singly or in combination on various cell lines was concentration-dependent.

Cost Estimations of Water Pollution for the Adoption of Suitable Water Treatment Technology

This study analyzed the cost implications of using suitable technologies and the cost of inaction when addressing water pollution. This was achieved by developing three main models for the costs (model one) and benefits (model two and model three). The first model accounts for the operational costs of adopting suitable technologies, namely the use of diatomaceous earth for textile wastewater treatment. The second model analyzed the cost of inaction through analyzing the cost of treatment for water pollution-related diseases for the affected population. The occurrence and cost of treatment for three diseases, namely diarrhea, amoebiasis and bacterial infection, were used as indicators of water pollution in the area. The third model included the contingent valuation method (CVM) data on the willingness to pay for environmental restoration of the surveyed population. The benefit–cost ratio (BCR) of the resulting data from the three models were used to highlight the economic viability of the proposed project. A BCR of (0.67) for the cost of the proposed project versus the benefits of the project on human health using data from one hospital was obtained. There is a high possibility that the real BCR would increase if more data from other hospitals or other diseases were included. The results imply that the use of D.E can be considered a good candidate for treating wastewater. To thoroughly discuss the BCR of treating wastewater from one factory, the BCR of the proposed restoration project along River Sosiani, and the value of using DE as suitable technology, more studies are needed to evaluate the unaccounted costs and benefits for accurate economic estimations of the proposed project. The outcome of the study is a framework of numbers and figures that can be presented to decision makers and policy makers as critical information when making decisions.