Naphthol Blue Black Research Articles

Photovoltaic Performance of Naphthol Blue Black Complexes and their Band Gap Energy

Along with the depletion of petroleum-based fuels, the development of renewable energy resources is a must. One of them is through DSSC (Dye Sensitized Solar Cells) technology, which has a dye sensitizer and semiconductor as the main components. The aim of this research is to investigating the photovoltaic performance of complexes series from metals (Mn(II); Fe(II); Co(II) and Ni(II)) and naphthol blue-black (NB) as a ligand. This investigation also successfully revealed factors that are highly influencing photovoltaic efficiency, namely the band-gap energy and the conductance of metal-NB complexes. The Fe(II)-NB complex has performed the highest photovoltaic activity as a result of the d-d electron transition and MLCT (Metal to Ligand Change Transfer) character which are covered by vivid color from the ligand. The bonding between metal and ligand was shown at a wavenumber of 316.33 cm-1 for M-N bonding and 486.06 cm-1 for M-O bonding. Fe(II)-NB complex had the narrowest band gap energy which is 5.86 eV and had the highest value of conductance and the highest efficiency, namely 0.0925%. This experiment successfully demonstrates that the narrower the energy gap of a molecule, the ability to transfer electrons is faster. Thus, the efficiency of the solar cell becomes higher. This investigation has proven that the narrow band gap makes the electron transfer becomes easier.

Hydrothermal synthesis of cadmium sulfide decorated reduced graphene oxide photocatalyst for the degradation of photostable naphthol blue black dye

Photocatalysis is being used for the mineralization of recalcitrant organic pollutants in water that cannot be treated with conventional methods. Cadmium sulfide decorated reduced graphene oxide (rGO-CdS) nanocomposite photocatalyst was synthesized by hydrothermal method and evaluated for the removal of a photostable textile azo dye, naphthol blue black (NBB) under ultraviolet light (UV-A, 365 nm). The rGO-CdS combination was opted for due to utilizing the narrow band gap (Eg = ~2.4 eV) of CdS and robust rGO support, capable of attracting organic pollutants to surface, bear, and protect CdS from photocorrosion. The formation of rGO-CdS was proved from the findings of physiochemical characterization UV–visible-, X-ray diffraction photoelectron, Raman, energy dispersive X-ray-spectroscopic, and scanning, transmission electron, and atomic force microscopic studies. The spherical CdS was decorated on the random shaped rGO sheets. Eg of CdS and rGO-CdS were 2.42 and 2.39 eV, respectively. After 2 h of light exposure, 2 g/L of rGO-CdS mineralized 95 % of NBB (2 × 10−4 mol/L). After 5 cycles, 80 % of photocatalytic efficiency was retained. In gas chromatography-mass spectrometry studies, 8 fragments of NBB were found after 1 h and confirmed that the degradation was mediated by photocatalytic dilapidation. The optimum pH for NBB degradation was 9. The rGO-CdS was found to be a potentially stable and reusable photocatalyst for environmental applications.

Photocatalytic Degradation of Tartrazine and Naphthol Blue Black Binary Mixture with the TiO2 Nanosphere under Visible Light: Box-Behnken Experimental Design Optimization and Salt Effect

In this study, TiO2 nanospheres (TiO2-NS) were synthesized by the solvothermal method. Firstly, the synthesized nanomaterial was characterized by X-ray diffraction (XRD), Fourier Transformed Infrared (FTIR), scanning electron microscopy (SEM) and UV-Vis Diffuse Reflectance Spectroscopy (DRS). To study the photocatalytic degradation of Tartrazine (TTZ) and Naphthol Blue Black (NBB) in a binary mixture, the influence of some key parameters such as pH, pollutant concentration and catalyst dose was taken into account under visible and UV light. The results show a 100% degradation efficiency for TTZ after 150 min of UV irradiation and 57% under visible irradiation at 180 min. The kinetic study showed a good pseudo-first-order fit to the Langmuir–Hinshelwood model. Furthermore, in order to get closer to the real conditions of textile wastewater, the influence of the presence of salt on TiO2-NS’s photocatalytic performance was explored by employing NaCl as an inorganic ion. The optimum conditions provided by the Response Surface Methodology (RSM) were low concentrations of TTZ (2 ppm) and NBB (2.33 ppm) and negligible salt (NaCl) interference. The percentage of photodegradation was high at low pollutant and NaCl concentrations. However, this yield became very low as NaCl concentrations increased. The photocatalytic treatment leads to 31% and 53% of mineralization yield after 1 and 3 h of visible light irradiation. The synthesis of TiO2-NS provides new insights that will help to develop an efficient photocatalysts for the remediation of contaminated water.

Photocatalytic degradation of naphthol blue black dye using undoped and Al-doped cobalt ferrite nanoparticles

The current study aims to evaluate the effectiveness of undoped (CoFe2O4) and aluminium-doped cobalt spinel ferrite (CoFe1.1Al0.9O4) nanoparticles as photocatalysts in the process of photocatalytic degradation of organic naphthol blue black (NBB) dye. In the sol-gel auto combustion method, a combination of metal nitrates, citric acid, sodium hydroxide, and liquid ammonia was utilized as the raw chemical ingredients for synthesizing nanoparticles of CoFe2-xAlxO4 (x = 0.0, 0.3, 0.6, 0.9, 1.2, 1.5) spinel ferrites. The nanoparticles were subjected to various characterization techniques including thermal analysis (TGA/DTA), X-ray diffraction (XRD) analysis, field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and UV–visible spectroscopy for comprehensive analysis. The XRD analysis confirmed the presence of a spinel cubic structure in the synthesized spinel ferrite nanoparticles. The interplanar distance (d) and crystalline size (D) were determined using Bragg's equation and Scherrer's relationship, respectively. The morphological characteristics and elemental composition of the spinel ferrites were confirmed through FE-SEM and EDS. Furthermore, the UV spectrum of the synthesized photocatalyst was investigated to compare the energy band gap between undoped and Al-doped cobalt spinel ferrites. The analysis of photoluminescence (PL) spectra was conducted to investigate the dynamics of charge carriers, focusing on their transfer, relocation, and recombination processes. The surface area of the synthesized photocatalyst ranged from 3.525 to 16.113 m2/g. Photocatalytic degradation of naphthol blue black (NBB) dye was carried out under visible light exposure utilizing both cobalt spinel ferrite nanoparticles without doping and those doped with aluminium. Several factors, including pH level, H2O2 concentration, amount of photocatalyst (spinel ferrite) and initial dye concentration, were considered through the photocatalytic degradation of NBB dye. The highest percentage degradation (%) of NBB dye was determined at pH 11. For NBB dye with an initial concentration of 20 ppm, the maximum degradation was achieved using 200 mg of spinel ferrite nanoparticles per 100 mL dye solution under visible light irradiation for 40 min.

Green Synthesis of Mixed ZnO-SnO2 Nanoparticles for Solar-Assisted Degradation of Synthetic Dyes

In this work, ZnO, SnO2, and their mixed ZnO-SnO2(25%) nanoparticles (NPs) were successfully green synthesized in a straightforward manner with a low-cost and environmentally friendly approach using a banana peel extract. The synthesized nanophotocatalysts were characterized using various techniques including FTIR, XRD, UV-Vis, TEM, SEM, BET, PL, EDS, and TGA. The characterization results showed that the ZnO and SnO2 powders were crystallized in a hexagonal wurtzite and rutile-type tetragonal structures, respectively, and their mixed ZnO-SnO2(25%) NPs contain both structures. Also, it was found that the addition of SnO2 into the ZnO structure reduces the PL intensity of the latter, confirming better separation of electron/hole pairs. The average particle size of a ZnO-SnO2(25%) NP photocatalyst was found to be 7.23 nm. The cationic dyes methylene blue (MB) and crystal violet (CV) as well as the anionic dyes naphthol blue black (NBB) and Coomassie brilliant blue R 250 (CBB) were employed as model dyes to assess the dye removal efficiencies of the biosynthesized nanophotocatalysts under sunlight. In all cases, the mixed ZnO-SnO2(25%) NP photocatalyst showed much better photocatalytic activity than individual photocatalysts. The degradation percent of dyes using ZnO-SnO2(25%) NPs ranged between 92.2% and 98%. The efficient photocatalytic activity of ZnO-SnO2(25%) NPs is attributed to the effective charge separation and reduced electron/hole recombination rate. The kinetic study results conformed to a pseudo first-order reaction rationalized in terms of the Langmuir–Hinshelwood model. Furthermore, the results showed that the ZnO-SnO2(25%) NP photocatalyst is highly stable and could be recycled several times without a noticeable reduction in its catalytic activity towards dye removal.

Green Synthesis, Characterization, and Photocatalytic Activity of Zinc Oxide Nanoparticles on Photodegradation of Naphthol Blue Black Dye

Zinc oxide (ZnO) nanoparticles have been successfully synthesized using water extract of red dragon fruit (Hylocereus polyrhizus) stem with zinc acetate dihydrate as a precursor of ZnO. Chemical compounds contained in the red dragon fruit stem extract, such as phenolics, terpenoids, and steroids, acted as reducing agents, stabilizers, and capping agents. The phase structure, crystallite size, functional groups, shape, and morphology of ZnO nanoparticles were determined by X-ray diffraction (XRD), Fourier Transform infrared (FT-IR) Spectroscopy, and Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX). The XRD pattern confirmed the crystallinity of synthesized zinc oxide was in the zincite (ZnO) phase with an average crystallite size of 79.09 nm. Spectroscopy FTIR analysis showed that the synthesized ZnO nanoparticles had characteristics similar to the ZnO standard/commercial. SEM-EDX analysis revealed that the synthesized ZnO nanoparticles were spherical, evenly distributed, and homogeneous particle size. The photocatalytic activity of synthesized ZnO nanoparticles was evaluated on the photodegradation of naphthol blue black (NBB) dye. The results showed that the synthesized ZnO nanoparticles have high photocatalytic activity that can degrade NBB dye up to 98.82%. This high photocatalytic activity was obtained at operating parameter conditions with the initial pH of NBB at 2, the dosage of ZnO nanoparticles at 250 mg, and the initial dye concentration at 10 ppm.

Preparation of Magnetic Activated Carbons from Cassava Peel using H3PO4 and KOH Activation by Microwave Heating for Naphthol Blue-Black Adsorption

To address the separation problems and produce the reusable adsorbent, cassava peel magnetic activated carbon (MAC) prepared via microwave-assisted activation has been proposed to replace activated carbon (AC) for naphthol blue-black removal. To create MACs, ACs were embedded with nano-sized magnetite particles using co-precipitation methods. In this sense, 2 different activating agents (i.e., H3PO4 and KOH) have been used. H3PO4 activation provides a larger pore size and more functional groups, while KOH activation provides a larger surface area and higher porosity. The increase of H3PO4 concentration from 40 to 60 % leads to an increase in porosity as well as an increase in the weight ratio of KOH to char from 1 to 3. Impregnation magnetite to the ACs reduces surface area from 457.76 to 337.94 m2 g-1 for KOH activation, and from 360.65 to 232.74 m2 g-1 for H3PO4 activation, decreasing adsorption capacity from 97.5 to 97 % for KOH activation and from 99 to 98 % for H3PO4 activation. However, the adsorbent is easy to separate under the magnetic influence. The adsorption data of MAC by H3PO4 activation show suitability with the Redlich-Peterson isotherm model, suggesting that naphthol blue-black removal is not ideal monolayer adsorption, but a combination of physisorption and chemisorption processes that exhibit heterogeneity of naphthol blue-black adsorption on the surface of adsorbent. Meanwhile, for MAC by KOH activation, the Langmuir isotherm is more suitable. HIGHLIGHTS Cassava peel was used in the preparation of magnetic activated carbon The effect of microwave-assisted H3PO4 and KOH activation was discussed Prediction of isotherm models was proposed and compared GRAPHICAL ABSTRACT

Application of the general rate law model to the sonolytic degradation of nonvolatile organic pollutants in aqueous media

The pseudo-first and pseudo-second order equations have been the most commonly used models to characterize the sonolytic disappearance kinetics of nonvolatile pollutants in aqueous media. In this work, the general rate law model, i.e., pseudo-nth order kinetics equation, was applied for the first time to the sono-decomposition of different nonvolatile organic pollutants, naphthol blue black (NBB), furosemide (FSM), 4-isopropylphenol (4-IPP), and rhodamine B (RhB), in water. It was shown that the general rate law for a chemical reaction would apply to the kinetics of sonochemical decomposition. It is not feasible to set the order of ultrasonic pollutant degradation kinetics to pseudo-first or pseudo-second, as is typically used in numerous studies. The sonochemical oxidation reaction has a fractional order, the order is often non-integer, which frequently indicates a complex sonolytic decomposition reaction mechanism. The degradation mechanism of NBB and RhB does not change with the initial substrate concentration. They are ultrasonically degraded by hydroxyl radicals both in the bulk liquid solution and at the liquid/bubble interfacial layer. The destruction mechanism of FSM and 4-IPP changes as the initial contaminant concentration changes. At low initial substrate concentrations, these pollutants are oxidized mainly by reaction with hydroxyl radicals in the bulk liquid solution and at the interfacial shell of the cavitation bubbles. At high initial substrate concentrations, FSM and 4-IPP are degraded by thermal destruction in the liquid/bubble interfacial layer and by •OH radicals both in the bulk liquid solution and at the liquid/bubble interfacial layer. Additionally, the pseudo-nth order model predicts very well the sonolytic degradation at various sonication frequencies and intensities. The general rate law expression should be used to assess the real kinetics order of the sonolytic destruction process without any predetermined assumptions or constraints.

Adsorption of Anionic and Cationic Dyes on Activated Carbon Prepared from Oak Cupules: Kinetics and Thermodynamics Studies.

In this study, activated carbon produced from oak cupules (ACOC) was prepared using chemical activation with H3PO4. ACOC is subsequently used as an adsorbent to facilitate the removal of an acidic dye, naphthol blue black (NBB), and basic dye crystal violet (CV) from aqueous solutions. The ACOC was characterized by FTIR spectroscopy, XRD, and SEM. The adsorption isotherm data fits well with the Langmuir model for NBB and CV. The kinetic models of adsorption of NBB and CV by ACOC were pseudo-first order and pseudo-second order, respectively. Thermodynamic parameters were evaluated and indicated that the adsorption of both dyes onto ACOC was endothermic and spontaneous. The adsorption capacity of ACOC reached 208 mg g-1 for NBB and 658 mg g-1 for CV. ACOC was shown to be a promising adsorbent for the removal of NBB and CV from aqueous solutions.

Outstanding performance of electro-Fenton/ultra-violet/ultra-sound assisted-persulfate process for the complete degradation of hazardous pollutants in contaminated water

This work focuses on the degradation of the hazardous azo dye Naphthol Blue Black (NBB) utilizing an innovative approach combining electro-Fenton (EF), ultra-violet (UV), and ultra-sound (US) processes while varying the operating parameters (concentration of iron and dye, pH, current intensity). Under the optimum experimental conditions, an excellent degradation efficiency of the NBB dye is achieved after 60 min, i.e., 98%, 95%, and 65% for EF, UV, and US processes, respectively. The addition of persulfate significantly improves the efficiency and accelerates the kinetics of the NBB degradation. Combining all processes assisted with persulfate achieved 99% NBB degradation within a very short contact time of 2 min and 98% reduction in COD after 55 min. The as-obtained outstanding performance associated with the synergistic effects of EF/US/UV alongside the addition of persulfate can be adopted to degrade other hazardous substances.

Co-Precipitation Synthesis of Clay-Magnetite Nanocomposite for Adsorptive Removal of Synthetic Dye in Wastewater of Benang Bintik Batik

Clay is a natural material that has been widely applied as a low-cost adsorbent for removing various contaminants from wastewater. To improve its characteristics and activity, natural clay from Central Kalimantan was activated by acid and calcination treatments, then synthesized with magnetite (Fe3O4) in nanocomposite by co-precipitation method. The obtained nanocomposite was further characterized by Fourier transform infrared spectroscopy, X-ray diffraction, nitrogen adsorption, vibrating sample magnetometry, and transmission electron microscopy methods. The results showed that co-precipitation method has been successfully produced clay-magnetite nanocomposite from activated clay with specific surface area, saturation magnetization, and particle size were 37.458 m2/g, 24.910 emu/g, and 50 nm, respectively. The obtained natural clay, activated clay, and clay-magnetite nanocomposite were then evaluated for adsorptive removal of naphthol blue black (NBB) synthetic dye from wastewater generated by an industry of Benang Bintik batik in Central Kalimantan using a batch system. The results showed that optimum pH for adsorptive removal process from these adsorbents were 2, while the optimum contact times of natural clay, activated clay, and clay-magnetite nanocomposite were 90, 60, and 60 minutes, respectively. The clay-magnetite nanocomposite also showed a much better removal efficiency (99.58%) than activated clay (86.28%) and natural clay (68.27%). The utilization of clay-magnetite nanocomposite as adsorbent not only can increase its removal efficiency against NBB dye, but also can facilitate the separation of the adsorbent solid phase from wastewater using an external magnetic field after the adsorptive removal process.

Synthesis and characterization of CdO-SnO2 NPs with excellent performance for Naphthol Blue Black (NBB) dye photodegradation and multi-application study

Precipitation and sonication techniques have been used to successfully synthesise CdO-SnO2 nanocomposite material. It was characterised using high-resolution scanning electron microscopy (HR-SEM) with elementary dispersive X-rays (EDX), high-speed transmission electron microscopy (HR-TEM), XRD analysis, photoluminescence spectroscopy (PL), UV–Vis DRS and BET. Using simulated UV irradiation at 365 nm, the prepared nanocomposites were also tested for their ability to degrade naphthol blue black (NBB) in water. Chemical oxygen demand measurements confirm dye mineralization. The higher activity of CdO-SnO2 nanocomposite material is attributed to a realisable mechanism. This nanocomposite material was found to be durable and reusable as a result of the reaction. Compared to SnO2 nanocomposite material, CdO-SnO2 nanocomposite material showed the highest antibacterial activity and electrochemical activity.

Optimization of the operating parameters and their effects on the degradation of Naphthol Blue Black by the Fenton process

The objective of this work was to model and optimize the degradation of black azo dye Naphthol Blue Black (NBB) by the Fenton process (advanced oxidation) using a minimum of experiments. A Plackett-Burman screening design was first applied to determine the main factors influencing the process. The dye discoloration efficiency gave a yield approximately equal to 97% in the best conditions of several operating parameters used. The variance analysis (ANOVA) showed the effects of all different factors and deduced the most important ones. Subsequently, a second quadratic design of experiments central composite type (CCD) was applied using the response surface methodology (RSM) to optimize the most important parameters deduced by the first design cited above, in order to obtain the best performance of the discoloration of NBB with this process. So from the contour plots and the response surfaces, the discoloration yield enhanced to the maximum and the optimization plot given by the Mnitab software, showed the following optimized parameters [NBB]=37.5 mg/L, [H2O2]=66.5 mg/L, [Iron]=3.5 mg/L and pH=3.4 for a yield of 100% with a desirability of 1.0000. At last, to confirm that the discoloration was due to the degradation of the dye, the chemical oxygen demand (COD) was studied and in the optimized conditions, the degradation reached 94.78% after 120 min of treatment. The kinetics of the dye degradation showed by the COD abatement was relatively slow compared to the kinetics of the dye discoloration.

Galvano-Fenton Engineering Solution with Spontaneous Catalyst's Generation from Waste: Experimental Efficiency, Parametric Analysis and Modeling Interpretation Applied to a Clean Technology for Dyes Degradation in Water.

In this paper, the degradation of the diazo dye naphthol blue black (NBB) using the Galvano-Fenton process is studied experimentally and numerically. The simulations are carried out based on the anodic, cathodic, and 34 elementary reactions evolving in the electrolyte, in addition to the oxidative attack of NBB by at a constant rate of during the initiation stage of the chain reactions. The selection of the operating conditions including the pH of the electrolyte, the stirring speed, and the electrodes disposition is performed by assessing the kinetics of NBB degradation; these parameters are set to 3, 350 rpm and a parallel disposition with a 3 cm inter-electrode distance, respectively. The kinetics of in the electrolyte were monitored using the principles of Fricke dosimetry and simulated numerically. The model showed more than a 96% correlation with the experimental results in both the blank test and the presence of the dye. The effects of and concentrations on the degradation of the dye were examined jointly with the evolution of the simulated , , and concentrations in the electrolyte. The model demonstrated a good correlation with the experimental results in terms of the initial degradation rates, with correlation coefficients exceeding 98%.

Dye-sensitized solar cells with napthol blue black as dye sensitizer

Nowadays, fossil fuel supply is decreasing over time. Thus, people are required to look for alternative energy sources that are renewable and environmentally friendly. Dye-Sensitized Solar Cells (DSSC) is one of the promising sources to overcome those problems. In this research, a DSSC with naphthol blue-black (NBB) as dye sensitizer has been developed. In order to improve the performance of the DSSC, NBB was modified by inserting Fe to form Fe-NBB complex compound. Fe-NBB showed light harvesting characteristic through MLCT phenomenon (Metal to Ligand Charge Transfer) at 273 nm and metal-ligand bonding at 486.06 cm−1 and 316.33 cm−1. NBB and its derivatives (Fe-NBB) were applied as dye sensitizer in the DSSC. The obtained open circuit voltage, short circuit current, and efficiency for NBB were 0.218 V, 0.096 mA/cm2 and 0.0083 %, respectively. While, Fe-NBB were 0.363 V, 0.567 mA/cm2 and 0.0925%.

Immobilization of copper oxide nanoparticles onto chitosan biopolymer: Application to the oxidative degradation of Naphthol blue black

In this study, copper oxide nanoparticles, prepared using pistacia vera hull extract, were immobilized onto chitosan. FT-IR spectrum of copper oxide-chitosan exhibited chemical shifting of the main peaks of the biopolymer indicating that hydroxyl and amino groups were reacted with copper oxide nanoparticles. SEM features showed spherical surface and physical stability of the composite. The shifting of the burning temperature in DTA from 278.5 °C to 212.6 °C in the composite proved the interaction between chitosan and copper oxide nanoparticles. The composite was applied for the oxidative degradation of naphthol blue black in the presence of H2O2. The change of copper oxide nanoparticles loading, time, dye concentration, temperature, and oxidant dose were studied. The degradation yield reached 86 % (C0 = 30 mg/L, T=20 °C, H2O2 = 8 mL/L). The activation energy (Ea), entropy (ΔS*) and enthalpy (ΔH*) were equal to 45.558 KJ. mol−1, −116.203 J mol−1 K−1 and 42.986 kJ mol−1, respectively.

High-permeability graphene oxide and poly(vinyl pyrrolidone) blended poly(vinylidene fluoride) membranes: Roles of additives and their cumulative effects

We prepared poly (vinylidene fluoride) (PVDF) based membranes via the phase inversion method to investigate the individual and simultaneous effects of graphene oxide (GO) and poly (vinyl pyrrolidone) (PVP) additives. It was demonstrated that the noticeable contribution of GO was to lower membrane surface charge. The principal role of PVP was to enhance membrane porosity, α-to-β phase transformation and mechanical strength. PVP also assisted GO distribution in the membrane matrix owing to their hydrogen-bonding interactions. GO-PVP-PVDF membrane showed cumulative effects in membrane physicochemical properties. In both pure water and naphthol blue black (NBB) dye solutions at pHs 4–10, the filtrate permeance increased from the pure PVDF to GO-PVDF, PVP-PVDF and GO-PVP-PVDF membranes. Therein, GO and PVP introduction provided permeance increases by one order of magnitude. All the membranes exhibited high dye rejections of ≥80.0% due to the Donnan exclusion mechanism. The membranes showed negligible dye adsorption. The stable filtration performance was demonstrated over 24-h multi-cycle filtration. The GO-PVP-PVDF membrane achieved outstanding high permeance (953–1350 L m−2 h−1 MPa−1) and excellent dye removal efficiencies (83.2–87.5%), which opened an avenue for application of this PVDF composite membrane to actual dye wastewater treatment.

Electrochemical oxidation of Naphthol Blue Black with different supporting electrolytes using a BDD /carbon felt cell

The electrochemical oxidation of Naphthol Blue Black (NBB) solution by means of anodic oxidation with electro-generated H2O2 (AO-H2O2) and Electro-Fenton (EF) was studied, using boron doped diamond (BDD)/ carbon felt (CF) cell. The experiments were carried out in NaCl and Na2SO4 as supporting electrolytes with initial concentration of 0.1 mM of NBB. The studied parameters were pH, applied current, concentration of Fenton catalyst, concentration of supporting electrolytes, and Cl-/SO42- mixture. The degradation of NBB was almost total when NaCl was used compared to Na2SO4, thanks to the electro-generated active chlorine (HClO/ClO-). The higher degradation is found with EF compared to AO-H2O2 process, the kinetic of degradation of NBB always follows a pseudo first-order reaction. The optimum conditions for the mineralization of NBB (i.e., 0.1 mM NBB, 50 mM Na2SO4 at pH 3.0, 0.1 mM Fe2+, and a current of 300 mA) were determined. These conditions yielded a total color removal in less than 10 min and 98% of total organic carbon (TOC) removal at 120 min electrolysis time. The biochemical oxygen demand/ Chemical oxygen demand (BOD/COD) ratio was decreased from 0.5 to 0.3, during the same timescales. Whereas, the mineralization current efficiency (MCE%) dropped from 21.5% to 0.05% in the electrolysis time range from 15-120 min suggesting the concomitant parasitic reactions. The evolution of nitrite NO2-, nitrate NO3-, ammonium NH4+, and sulfate SO42- concentrations were also followed as the end-products during the electrolysis.

Extraction-spectrophotometric determination of an ACE inhibitor with naphthol blue-black in formulations

Extraction-spectrophotometric determination of an ACE inhibitor with naphthol blue-black in formulations

Nanostructured Cellulose-Based Sorbent Materials for Water Decontamination from Organic Dyes.

Nanostructured materials have been recently proposed in the field of environmental remediation. The use of nanomaterials as building blocks for the design of nano-porous micro-dimensional systems is particularly promising since it can overcome the (eco-)toxicological risks associated with the use of nano-sized technologies. Following this approach, we report here the application of a nanostructured cellulose-based material as sorbent for effective removal of organic dyes from water. It consists of a micro- and nano-porous sponge-like system derived by thermal cross-linking among (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized cellulose nanofibers (TOCNF), branched polyethylenimine 25 kDa (bPEI), and citric acid (CA). The sorbent efficiency was tested for four different organic dyes commonly used for fabric printing (Naphthol Blue Black, Orange II Sodium Salt, Brilliant Blue R, Cibacron Brilliant Yellow), by conducting both thermodynamic and kinetic studies. The material performance was compared with that of an activated carbon, commonly used for this application, in order to highlight the potentialities and limits of this biomass-based new material. The possibility of regeneration and reuse of the sorbent was also investigated.