In this study, adsorption capacities of uremic toxins over Faujasite (HFAU) and Beta (HBEA) have been evaluated by varying the composition of solvent by using water, physiological, and sodium chloride solutions. HFAU was found to be more efficient in adsorption of these molecules. The adsorption results over HFAU were compared in various conditions to understand the adsorption mechanism. Thus, the adsorption mechanism was confirmed also by Fourier transform infrared and X-ray diffraction analysis, and it is found to be through the interaction of creatinine by hydrogen bonding on two types of sites on zeolites. Pseudo-second-order equation described well the adsorption kinetics data. Equilibrium isotherms were determined by Fowler–Guggenheim model. Finally, hydrophobic HFAU zeolite seems to be an efficient adsorbent; it is able to be easily regenerated under air, through retention of these initial adsorption properties.

Activated carbon derived from pine cones waste was prepared by carbonization at 450°C, activated by different activating agents: ZnCl ₂, H ₂ SO ₄ and NaOH, and then pyrolyzed at 600°C. Adsorption of Cr VI and other heavy metals (Mn II, Fe II, Cu II) on activated carbons was investigated to evaluate the adsorption properties. Special attention was paid to the effects of carbon surface functionalities that were analyzed by FT-IR and zeta potential study. Moreover, XRD study of activated carbon was also carried out. Results had shown that activated carbon by NaOH was the best adsorbent for removal of chromium VI from wastewater. The solid-solution interaction was determined by analyzing the adsorption isotherms at room temperature at different pH. When pH is above 4, the removal fraction of Cr (VI) ions decreased with the increase of pH. The removal fraction of Cr (VI) ions decreased below pH 4. The preferable removal of Cu (II) over Mn(II) and Fe (II) could be due to its lower affinity to solvent.Pseudo-second order equation provided the better correlation for the adsorption kinetics data. Equilibrium isotherms were determined by Fowler-Guggenheim model.

Industrial wastewater discharge, tainted with hazardous substances, including dyes like methylene blue (MB) from the textile sector, further emphasizes the need for water treatment to produce safe drinking water. This study explores the potential of olive mill solid waste, an abundant and cost-effective agricultural waste in Mediterranean regions, to yield high-quality activated carbon (AC) with zinc chloride activation for MB adsorption. The activation process, carried out at a modest temperature of 500 °C without the need for an inert atmosphere, resulted in AC with remarkable characteristics, boasting a substantial surface area of 1184 cm²·g⁻¹ and a total pore volume of 0.824 cm³·g⁻¹. Extensive characterization of the AC was carried out through a large range of surface techniques. The pH of the solution had minimal influence on MB adsorption, the maximum removal was 95%, which was under slightly acidic pH conditions (5.8), and the adsorbent dose was 0.4 g·L⁻¹ for a 50 mg·L⁻¹ MB concentration. Equilibrium data pertaining to MB adsorption were subjected to fitting with different models, namely Langmuir, Freundlich, and Temkin. Notably, the Langmuir model exhibited the best fit, revealing a maximum monolayer adsorption capacity of 500 mg·g⁻¹ at 25 °C, and the adsorption kinetics closely followed a pseudo-second-order model.

Activated Montmorillonite (AM) reveals as a low-cost and efficient adsorbent for the adsorption of nicotine and pyridine from aqueous solutions. In this study, the influence of several operation conditions (initial compounds concentration, volumetric flow rate, and height of bed) on the shape of breakthrough curves and the mass transfer resistance was evaluated. Adsorption experiments were developed in order to determine the adsorption isotherm of the system, then the adsorption of pyridine and nicotine onto activated Montmorillonite in single and binary system has been studied using fixed bed reactor. In continuous adsorption, Results show that the maximum nicotine uptake 110 mg/g of AM was achieved through electrostatic attraction and hydrogen bond at a pH = 6.3, a flow rate of 1 ml/min and a height of bed equal to 12 mm. In binary mixtures, zeolites adsorption is governed primarily by the size of pollutants present in water. Thus, the bigger compound (in this case, Nicotine), was adsorbed more easily than the pyridine present in the mixture. Experimental data were fitted according to Fowler Guggenheim for the isotherms and Wolborska model for the breakthroughs. AM was regenerated by ethanol and the results show that about 94% of the adsorption capacity is maintained after three times of cyclic adsorption-desorption process.

Assessment of Chemical and Microbiological Drinking Water of Beirut and Mount Lebanon

The aim of this study is to develop a short cost-effective methodology for tracing the temporal and spatial anthropogenic inputs of micropollutants into ecosystems. The method involves a precise identification of the sampling sites based on various constraints: (1) one sampling site at each location to reduce the cost and the sampling time, (2) the sites are at sufficient mixing length from the release of micropollutants, and (3) they are identified with the aim to conduct mass balances. The methodology is applied to the identification, the quantification, and the distribution and transport of 21 emerging micropollutants in the Meurthe and Moselle river systems in the vicinity of the city of Nancy in France. The validity and reliability of the methodology is verified by using a mass-balance method at the confluence of the two rivers, where the mass fluxes upstream and downstream of the confluence compare well for nearly all the micropollutants. The methodology is employed to reveal mass fluxes of micropollutants discharged from the WWTP into the river water and point out the high efficiency of the drinking water treatment plant. The approach provides new insight into the identification of the sources of micropollutants in the rivers and the effects of hydrological and anthropogenic factors. The spatial anthropogenic inputs of micropollutants are highlighted in particular situations where discrepancies in the mass balance take place.