Removal of hydroxychloroquine from an aqueous solution using living microalgae: Effect of operating parameters on removal efficiency and mechanisms.

Wastewater contaminated with hydroxychloroquine (HCQ) poses a serious threat to the environment and human life. This study aimed to evaluate the ability of living microalgae to remove HCQ from an aqueous solution. Batch mode experiments were conducted under different conditions to investigate the effect of operating parameters on HCQ removal efficiency and mechanisms. Equilibrium, kinetic and thermodynamic study was also carried out to better describe the interactions between HCQ and microalgae. The maximum HCQ removal was 92.10 ± 1.25% obtained under optimal pH of 9.9 ± 0.1, a contact time of 45 min, a stirring speed of 300 rpm, an initial HCQ concentration of 20 mg/L, and a microalgae dose of 100 mg/L. The Langmuir isotherm and the pseudo-second-order kinetic model were best suited for the biosorption experiments, and the maximum biosorption capacity was 339.02 mg/g. The thermodynamic study showed that the biosorption process was exothermic and spontaneous. Experiments on real wastewater showed that the HCQ removal was not significantly affected by the presence of other contaminants in the water. PRACTITIONER POINTS: The best HCQ removal was 92.10 ± 1.25% obtained under optimal conditions. The Langmuir isotherm and the pseudo-second-order kinetic model were best suited for the biosorption experiments. The maximum biosorption capacity was 339.02 mg/g. The thermodynamic study showed that the biosorption process was exothermic and spontaneous. The microalgae studied can be successfully used in HCQ removal from water.

Effect of COVID-19 on the Generation of Waste in Marrakech, Morocco.

BACKGROUND: The production of solid waste continues to increase as the population and standard of living increases. In addition, changes in living conditions can induce significant variation in the quantitative and qualitative characteristics of waste. OBJECTIVES: The aim of the present study was to examine the impact of the lockdown period on the generation of solid waste produced in the city of Marrakech. METHODS: The tonnage of household waste, construction and demolition waste and green waste was collected from the landfill and an analysis was made during the lockdown period in 2020 in comparison with the same period in 2019. RESULTS: The analysis of solid waste tonnage in 2019 and 2020 showed that the lockdown had a significant impact on the various wastes; with a 27.61% decrease for household waste, 6.27% decrease in the case of green waste, and 57.40% decrease for construction and demolition waste. DISCUSSION: The degree to which the tonnage of household waste decreased depended on the standard of living in each district which was defined by housing type. The tonnage of construction and demolition waste was influenced by the halt in construction activity in the city. CONCLUSIONS: The results of the present study showed that the tonnage of household waste and demolition and construction waste decreased during the lockdown period. COMPETING INTERESTS: The authors declare no competing financial interests.