In a batch reactor, the EF advanced oxidation decolorization of aqueous solutions of methyl orange MO, a commercial azo reactive textile dye, was investigated in the presence of two different electrodes. The evaluation included various operational variables such as the I_C current intensity (60 mA, 80 mA, and 100 mA), initial concentration of pollutant MO (20 mg/L, 40 mg/L, and 60 mg/L), initial pH of solution (3, 5, and 7), temperature of solution (20 °C, 30 °C, and 50 °C), and initial concentration of catalyst [Fe²⁺] (0.1 mM, 0.2 mM, and 0.3 mM) on the discoloration rate. A Box-Behnken Design of Experiment (BBD) was used to optimize the parameters that directly affect the Electro-Fenton (EF) process. Under the optimal experimental conditions such as [Fe²⁺] = 0.232 mM, pH = 3, I_C = 80 mA, [MO] = 60 mg/L, and T = 30 ± 0.1 °C, the maximum discoloration rate achieved was 94.9%. The discoloration of the aqueous MO solution during the treatment time was confirmed by analysis of the UV-visible spectrum. After a review of the literature on organic pollutant degradation, the EF system provided here is shown to be one of the best in terms of discoloration rate when compared to other AOPs.

Iron-doped hydrochar can effectively remove the methyl orange dye (MO). In this study, iron-doped hydrochar (5% Fe@BC) was successfully synthesized through a two-step hydrothermal carbonization (HTC) process, using FeSO₄.7H₂O and sawdust. It was subsequently employed for MO removal. The characterization of the synthesized Fenton-like catalyst (5% Fe@BC) was conducted, using scanning electron microscopy, Fourier-transform infrared and X-ray diffraction techniques to confirm the presence of iron species. The effects of different operating parameters such as catalyst mass, H₂O₂ concentration, solution pH, organic pollutant concentration, and reaction temperature have been examined. The Box-Behnken design combined with three factors: catalyst mass X₁, temperature X₂, organic pollutant concentration X₃. The response surface methodology coupled with Box-Behnken Design was used to optimize the key variables and response. With this approach, an exhaustive assessment of the variables influencing the optimization process was performed. A significant quadratic model was generated through analysis of variance with a P-value of 0.0001 and an R² of 0.99. This confirms a strong relationship between the variables and the response, as well as a high level of model predictability. The optimum conditions were achieved with a catalyst mass of 0.5 g/L, a temperature of 35.5 °C, and an MO concentration of 50 mg/L. The result indicates that 93% of the discoloration efficiency was achieved within 60 min under the optimal conditions. Iron doping in the (5% Fe@BC) plays a crucial role in the degradation and removal of MO. Therefore, the 5% Fe@BC prepared from sawdust and iron salts (FeSO₄·7H₂O) through a two-step HTC process is an inexpensive and effective catalyst for removing organic pollutant from aqueous solutions, using heterogeneous Fenton-like process.

In this study, the effectiveness of using natural bio-coagulants and bio-flocculants to treat textile wastewater through the coagulation-flocculation method was examined. These bio-based agents have several advantages over chemical agents, including biodegradability, natural abundance, low...

This study is based on the use of a natural material in the adsorption process to remove organic pollutants. The objective is to assess its effectiveness in adsorbing the organic pollutant MB from an aqueous solution, while operating in an open system. The DP bioadsorbent was characterized using...

Similar to countries with arid and semi-arid climates, Morocco faces problems of degradation of the quality of its environment and more specifically the quality of groundwater. In this work, we approached the physico-chemical characterization of the raw effluents of three industrial units of the...

This study deals with the valorization of a biomaterial, almond shell, for the treatment of urban effluents of the city of Fez by a fixed bed column adsorption process. A parametric analysis of the process is carried out with conditions such as particle size, pH and height of the adsorbent bed to evaluate the optimal removal percent and obtain an optimal removal capacity of the adsorbent load. Characterization of the adsorbent prior to continuous adsorption was carried out by X-ray diffraction, Fourier-transform infrared spectrometry and scanning electron microscopy. The adsorption treatment seems to be influenced by certain parameters, such as the particle size of the biomaterial used, the height of the adsorption bed and the pH. The results suggest that this biomaterial can be used as a less expensive, available, biodegradable and very effective adsorbent to eliminate the load of urban waters on a small scale and why not on a large scale to replace chemicals in the treatment and to recover waste such as almond shell. The parameters measured reached maximum values varying between 82% for COD, 79% for EC and 71% for nitrite under well-defined operating conditions, with a particle size of 0.063 mm, a height column height of 7 cm and a pH of 6.5.