In the current work, neodymium oxide (Nd2O3) nanoparticles were synthesized and characterized by means of X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The major aim/investigation of this research was to fit/model and optimize the removal of Acid Blue 92 (AB92) dye from synthetic effluents (aqueous solutions) using the adsorption process based on neodymium oxide (Nd2O3) nanoparticles. To optimize the adsorption conditions, central composite design (CCD) based on response surface methodology (RSM) was applied. The effects of pH (3–9), adsorbent dosage (0.1–1 g/L), initial concentration of AB92 (100–300 mg/L), and contact time (10–100 min) on the adsorption process were investigated. Apart from equilibrium and kinetic experiments, thermodynamic evaluation of the adsorption process was also undertaken. The adsorption process was found to have the best fitting to Langmuir isotherm model and pseudo-second-order kinetic equation. Also, the process was found to be spontaneous and favorable with increased temperature. The optimal conditions found were: pH = 3.15, AB92 concentration equal to 138.5 mg/L, dosage of nanoadsorbent equal to 0.83 g/L, and 50 min as contact time, which resulted in 90.70% AB92 removal. High values for the coefficient of determination, R2 (0.9596) and adjusted R2 (0.9220) indicated that the removal of AB92 dye using adsorption can be explained and modeled by RSM. The Fisher’s F-value (25.4683) denotes that the developed model was significant for AB92 adsorption at a 95% confidence level.

Polyoxometalates (POMs), eco‐friendly solid acids, are polyatomic anions containing transition metal (group 5 or group 6) oxyanions linked together through shared oxygen atoms. First, the structure, classification, synthesis, non‐photocatalytic applications, and their photocatalytic properties and applications are presented. POMs are very interesting due to their unique and remarkable characteristics. One of the most attractive characteristics of POMs is their activity as an electron relay, that is, they can undergo stepwise multi‐electron redox reactions while their construction remains intact. Based on this characteristic, POMs have been widely used as photooxidation catalysts for organic and inorganic contaminants removal. According to the literature, POMs are useful homogeneous photocatalysts for the mineralization of dyes, phenol and its derivatives, chloroacetic acids, and pesticides and wood pulp bleaching. Applications of POMs have been limited because of their high solubility in water. Immobilization and solidification of POMs using different methods and various supports for making them reusable are studied in this review. Varieties of composites of POMs are synthesized to make them photorespond to the visible light region.

A considerable increase in the penetration of distributed generation (DG) to the distribution networks leads to a higher possibility of malfunction of present protection schemes of these systems. One of the major problems caused by higher levels of DG penetration is the reduction of the relay reach or relay access. This problem relatively relieves using adaptive overcurrent protection techniques but in certain conditions, the minimum relay access reduces to less than 20 percent of line length, in the presence of DGs and adaptive current protection cannot be used. In this paper a combined adaptive protection method is presented, which applies overcurrent and undervoltage protection simultaneously. Function of the protection system improves because of different action areas of these two types of protection. The feasibility of the proposed method authenticated through simulation.

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