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In recent years, wide spread of antibiotic-resistant microorganisms and genes emerging globally, an eco-friendly method for efficient degradation of antibiotics from the polluted environment is essential. Intimately coupled photocatalysis and biodegradation (ICPB) using gC

Sn doped ZnO loaded cotton stalk activated carbon (Sn-ZnO/CSAC) was prepared by chemical precipitation method, and the products were characterized. The XRD resultants confirm that the presence of hexagonal wurtzite phase of the bare ZnO. Furthermore, particular particle size gradually decreases (21.49 nm) due to doping and loading. UV-Vis absorption intensity of doped/loaded sample was red-shifted and then PL intensity is reduced. The photocatalytic performances of bare, Sn-doped ZnO and Sn-ZnO/CSAC was estimated by photodegradation of brilliant green (BG) under sunlight. The photodegradation of BG dye in 120 min over Sn-doped ZnO/CSAC is nearly 96.52%, which is considerably improved than bare ZnO (72.60%), respectively.

The biological denitrification in the presence of gC

The issue of effluent, especially organic colorants from several manufacturing units overlays an immense delinquent of the current epoch owing to its effect on oncogenic health hazards. Thus, Rare Earth Metal dysprosium (Dy) doped Zinc Ferrite (ZnFe

The biological denitrification in the presence of gC3N4 doped TiO2 composite was investigated through series of batch experiment. gC3N4 doped TiO2 was synthesized and characterized by FT-IR, XRD, SEM-EDAX and the prepared composite used as electron donor for the enhancement biological denitrification. The role of extracellular polymeric substances in the biological nitrate reduction and electron transfer process has been elucidated. The XRD result confirms that TiO2 nanoparticle has 80% anatase and 20% rutile phase. The gC3N4 shows the diffraction peaks at 27.57°, corresponds to the diffraction planes of (002) the hexagonal graphitic carbon nitride. The SEM image of modified gC3N4/TiO2 nanocomposites showed agglomerated small spherical TiO2 nanoparticles attached on the surface of gC3N4. The highest level of nitrate removal was 90% (from 100 mg/L to 10 mg/L nitrate) in gC3N4/TiO2 nanocomposite in the 15% wt TiO2 doped gC3N4. The nitrate reduction in the biofilm with gC3N4 doped TiO2 composite have significantly enhanced the nitrate reduction than the control. Photoexcited electrons were generated from gC3N4 doped TiO2 photocatalyst act as excellent electron donor to the microbial communities. Extracellular polymeric substances acted as a passing media for microbial extracellular electron transfer and protective barrier for microbes. The electroactive microbes were harvested electrons from the gC3N4 doped TiO2 composite under irradiation and enhancing the biological nitrate reduction. Overall, the present study suggests that insight into the mechanism of photoexcited electron facilitated biological nitrate reduction and role of extracellular polymeric substances. The successful integration of gC3N4 doped TiO2 photocatalyst and biofilm is a promising technology for nitrate removal.

The present study reports the successful functionalization/magnetization of bio-polymer to produce chitosan-magnetic graphene oxide grafted polyaniline doped with cobalt oxide (ChMGOP-Co3O4). Analytical techniques furrier transform infra-red (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were used to confirm the formation of ChMGOP-Co3O4. The effects of several experimental factors (solution pH, adsorbent dosage and coexisting ions) on the uptake of As(V) ions using ChMGOP-Co3O4 were examined through batch experiments. As(V) removal process was validated by experimentally and theoretically investigating the adsorption capacity, rate, and thermal effects. Thermodynamic parameters such as free energy (ΔG°), entropy (ΔS°) and enthalpy (ΔH°) were also calculated and were used to explain the mechanism of adsorption. Based on the results, the sorbent showed a high adsorption capacities (90.91 mg/g) at favorable neutral pH and superior removal efficiencies as high as 89% within 50 min. In addition, the adsorption isotherm followed the Langmuir isotherm in compare to the Freundlich, due to its higher R2 value (0.992

In the present work, a green synthetic method for the preparation of extremely stable silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) using Sargassum ilicifolium has been demonstrated. Thus produced nanoparticles were characterized by UV-Visible (UV-Vis) spectroscopy, Fourier Transform InfraRed spectroscopy (FT-IR), Energy Dispersive X-ray spectroscopy (EDX), X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS) and Zeta potential analyses. The average size of Ag and Au NPs was 27.9 and 9.36 nm respectively from TEM, which was further substantiated by XRD data. Zeta potential values of -42.2 mV and -28.3 mV for Ag and Au NPs respectively suggested that the nanoparticles were negatively charged and highly stable. AgNPs showed desirable bactericidal activity towards Enterobacter species, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Proteus species. The photocatalytic behaviour of AgNPs was studied to degrade malachite green (MG) and methylene blue (MB) in aqueous medium. In MG, 82.9% degradation was achieved in 180 min of light exposure and the pseudo first order rate constant was 7.2 × 10

In the present work, a visible light driven AgVO

Pb(II) is a heavy metal that is a prominent contaminant in water contamination. Among the different pollution removal strategies, adsorption was determined to be the most effective. The adsorbent and its type determine the adsorption process's efficiency. As part of this effort, a magnetic reduced graphene oxide-based inverse spinel nickel ferrite (rGNF) nanocomposite for Pb(II) removal is synthesized, and the optimal values of the independent process variables (like initial concentration, pH, residence time, temperature, and adsorbent dosage) to achieve maximum removal efficiency are investigated using conventional response surface methodology (RSM) and artificial neural networks (ANN). The results indicate that the initial concentration, adsorbent dose, residence time, pH, and process temperature are set to 15 mg/L, 0.55 g/L, 100 min, 5, and 30 °C, respectively, the maximum removal efficiency (99.8%) can be obtained. Using the interactive effects of process variables findings, the adsorption surface mechanism was examined in relation to process factors. A data-driven quadratic equation is derived based on the ANOVA, and its predictions are compared with ANN predictions to evaluate the predictive capabilities of both approaches. The R2 values of RSM and ANN predictions are 0.979 and 0.991 respectively and confirm the superiority of the ANN approach.

The issue of effluent, especially organic colorants from several manufacturing units overlays an immense delinquent of the current epoch owing to its effect on oncogenic health hazards. Thus, Rare Earth Metal dysprosium (Dy) doped Zinc Ferrite (ZnFe2O4) were as-synthesized by a facile co-precipitation technique as an effectual nano photocatalyst intended to the amputation of these noxious dyes. The structural, functional, optical, magnetic, and degradation properties of this RE (Dy3+) doped ions were investigated using various characterizations, such as crystallite size (D) and several parameters (cation distribution, oxygen positional parameters, and bond length) were determined using XRD (X-ray diffraction) and it was found that as the dy3+ ion concentration increases the speck size decreased and the grain size remained within nano regime, which intern affects the surface area. From BET analysis it was found that on increasing the doping concentration, the surface area increases which pave a substantial role in the photo-Fenton activity. By using FT-IR (Fourier-transform infrared spectroscopy) various functional parameters (elastic, interionic bonds, ion distribution, etc.) were determined. Raman spectra had no extra peak formation which is seen to have pure phase formation of the as-synthesized samples. HR-TEM (High-Resolution Transmission Electron Microscopy analysis were done to determine the nature of the sample, the as-synthesized magnetic samples exhibit a polycrystalline formation with cubical agglomeration. The magnetic property was very significant for x = 0.10 concentration. As-synthesized (Fe0.9064Zn0.0936) [Fe1.0936Dy0.1Zn0.8064] O4) exhibits a momentous photo – Fenton activity against MB (Methylene blue), its removal efficiency was found to be 97.3% after 45 min. Also, this spinel ferrite acts as a magnetic recyclable catalyst even after 5 cycles with an insignificant lessening of elements and photo-Fenton activity.

In the present work, a visible light driven AgVO3/BiOI nanocomposite photocatalyst with different wt % (1, 2, 3) of AgVO3 was fabricated by using facile hydrothermal method. Further, the nanocomposite was characterized by FT-IR, XRD, SEM, TEM, EDS, UV–vis DRS, photoluminescence and photoelectrochemical studies. The structural characterization showed nanorods on nanosheet surface. Among different AgVO3 loaded samples, the photocatalytic efficiency of 1 wt % AgVO3/BiOI nanocomposite was found to be comparatively higher than the pure BiOI and AgVO3. The photodegradation rate constant values of pure BiOI, AgVO3 and 1, 2, 3 wt % AgVO3/BiOI nanocomposites are 0.006, 0.0033, 0.0255, 0.01575, 0.0116 min−1 respectively. This enhanced photocatalytic activity was due to the increasing visible light absorption ability and efficient separation of the charge carriers. Thereby, the 1 wt % AgVO3/BiOI nanocomposite photocatalyst exhibited increased photodegradation activity, photostability and recyclability characteristics. The radical trapping experiment confirmed the role of OH and h+ in the photocatalytic degradation of RhB. Based on this, the probable mechanism of degradation of RhB under visible light irradiation has also been proposed. Hence, we believe it could be a promising material that can be employed for the photodegradation of organic pollutants present in wastewater.