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The existence of organic pollutants in water discharges has made wastewater treatment extremely difficult. This is mainly due to the release of various hazardous substances into waterways, which cause significant damage to humans and the aquatic ecosystem. This paper discusses the biosynthesis process of pure ZnO and Ag co-doped ZnO (1%Ag_ZnO and 2%Ag_ZnO). Highly pure nanoparticles (NPs) were obtained by simple and ecological route, through employment of Zn-nitrate as host and Ag-nitrate as dopant and phytochemicals of Zizyphus lotus fruit as reduction agent. The Ag_ZnO NPs were prepared in a one pot synthetic mode (1 and 2% Ag). The obtained samples were characterized by XRD analysis and FTIR spectroscopy which revealed the hexagonal Wurtzite structure of crystals with an average crystallite diameter varying from 16 to 29 nm. The elimination capability of NPs was investigated through the photo-degradation of tartrazine (TR) under solar light irradiation. The operating parameters namely the catalyst dose, initial TR concentration (Co) have been optimized for the TR degradation as function of time. The dye TR was more effectively removed by doped ZnO NPs under solar irradiation. The best performance was obtained with 2%Ag/ZnO, due mainly to the radicals O2·− and ·OH. Results indicated also that the TR removal rate increases with the increase in catalyst load and the decreased in the initial TR concentration. [ABSTRACT FROM AUTHOR]

The widespread occurrence of drugs in the aquatic environment has raised concerns over the last decades about the mechanisms to be used to remove these emerging contaminants because of their harmful effects on the water quality and human health. This current research was aimed to explore the preparation of an activated carbon from kernel oil treatment residues of Argania Spinosa for the removal of amoxicillin (AMX) from water. The conditions for synthesizing the activated carbon (AC-RS) were used: an impregnation weight ratio of char to KOH 1:1 at activation temperature of 800 °C for 1 h of activation time, which gave a BET surface area and total pore volume of 1618 m2 g−1 and 0.763 cm3 g−1, respectively. The effect of AMX/AC-RS interactions as well as the operating conditions (time, solution pH, initial concentration, and temperature) on the adsorption capacity was also studied. The adsorption of AMX onto AC-RS, with maximum adsorption capacity of 303.03 mg g−1, is much higher compared to several adsorbents reported in the literature. The high amount of AMX absorbed by AC-RS at pH 6 mainly results from the adsorption sites involved in the electrostatic attraction force, π-π hydrophobic interaction, and hydrogen bonding. The regeneration study ascertained the fact that AC-RS was reusable even after four consecutive cycles and the efficiency remains higher than 70%. Therefore, the optimized batch parameters were employed for the AMX removal in real wastewater, a percentage of 77.2% was obtained. [ABSTRACT FROM AUTHOR]

In this study, response surface methodology (RSM) was used to evaluate the experimental parameter's effect in the competitive adsorption capacity of Ni(II) and Cu(II) ions using activated carbon prepared from sewage sludge. The metal removal efficiency was optimized toward various parameters using central composite design (CCD) under RSM. The model's predictions are in good agreement with experimental results (R2 = 0.986, 0.974 and Adj-R2 = 0.960, 0.950 for Ni(II) and Cu(II) ions, respectively). ANOVA results showed that the process was mainly influenced by the Ni(II) concentration and adsorbent dose, whereas the other factors showed lower effects. The optimum Ni(II) concentration, Cu(II) concentration, adsorbent dose, contact time and temperature were found to be 40 mg/L, 40 mg/L, 4 g/L, 100 min and 30 °C. Under optimal conditions, maximum adsorption capacity of both metals (7.48 and 4.04 mg/g, respectively for Ni(II) and Cu(II) ions) was obtained. [ABSTRACT FROM AUTHOR]