بحوث سكوبس — علياء كريم عبدالله عواد

In this research, a mesoporous rod-shaped ZnO/CuO/CeO2 n-p-n heterojunction has been designed via a two-step co-precipitation technique for photocatalytic applications. Characterization by powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FTIR), UV–Vis, and Scanning Electron Microscopy (SEM) techniques confirmed the formation of mesoporous rod-shaped ZnO/CuO/CeO2 n-p-n heterojunction having preferred interface developing between the ZnO, CuO, and CeO2 phases, thus extended the light-absorption window up to 800 nm. Under sunlight, the ability of a mesoporous ZnO/CuO/CeO2 n-p-n heterojunction to act as a photocatalyst was tested with methyl orange (MO) and crystal violet (CV) as target molecules. We found the degradation efficiencies of CV and MO dyes on mesoporous ZnO/CuO/CeO2 to be 96% and 88%, respectively, after 90 min of sunlight irradiation. The estimated rate constants (k, min−1) for deterioration of CV and MO under sunlight over ZnO/CuO/CeO2 composite were 0.039 and 0.022 min−1, respectively. We endorsed the greater photo-response, the well-aligned band-structure, and practical usage of the photo-induced carriers of the mesoporous photocatalyst to be the leading causes for the outstanding photocatalytic properties of ZnO/CuO/CeO2 n-p-n heterojunction. The ultimate oxidizing species that destroyed dyes were O2‾ and ·OH over ZnO/CuO/CeO2 photocatalyst under sunlight illumination. Besides, the recycling tests confirmed the high photostability of the ZnO/CuO/CeO2 photocatalyst. Hopefully, the mesoporous rod-shaped architecture of the n-p-n heterojunction with anticipated interface manufacturing will assist the photocatalyst strategy with better photocatalytic action under sunlight irradiation. © 2022 Elsevier Ltd and Techna Group S.r.l.

Cyanide is a toxic compound that is found in industrial wastewater, and it causes death for humans. Therefore, cyanide removal is essential to protect humans and the environment. The electrocoagulation method (ECM) was adopted in this study to remove cyanide from artificial wastewater samples. The ECM was adopted in this study because it is a cost-effective method with minimum use of chemicals, making it eco-friendly. The experiments were done in batch flow using iron electrodes (anode-cathode). The results show an increase in the current density from 2 to 10 mA.cm-2 increased the removal of cyanide by 48.8%. Similarly, the increase of the treatment time from 10 to 90 minutes increased the removal of cyanide by 71% at a current of 10 mA/cm-2. The summary of the results of this study showed that ECM is a good alternative for cyanide removal from wastewater. © Published under licence by IOP Publishing Ltd.

Due to the lack of fresh water, the purification of polluted water is of utmost importance and places a significant financial burden on countries. The effect of Myriophyllum spicatum and Lemna gibba on nitrate absorption in an area of the Tigris River has been investigated in the light of the low cost and ease of application of aquatic plants in purifying water pollution. Aquarium experiments were designed with three treatments, three replicates, and a closed flow. In the aquarium, the biological requirements for the growth of the studied plants were met. The residence time was determined to be 36 days, and nitrate changes were recorded every three days, 12 times. Except for periods 3 and 4, there were significant differences in the rate of nitrate absorption between the studied plants in all treatments (P < 0.05). At the end of the 12th period, M. spicatum and L. gibba had contaminant removal efficiency of 83.31% and 86.27%, respectively. L. gibba ability to utilize nitrate as a nutrient was demonstrated by its significantly increased dry weight at the end of the experiment (P < 0.05). In the current study, the significant difference between the average levels of nitrate in the samples and the control sample indicates the presence of a factor other than bacterial decomposition, namely the presence of plants. According to the findings, these macrophytes are viable for reducing nitrate and organic matter loads in polluted waters. Controlling these macrophytes, so that the nutrients in their tissues do not return to the environment during decomposition is necessary to improve water quality and maintain the achieved quality. © The Author(s).