Recently, arsenic-contaminated water has become a big concern. Therefore, the present study aimed to absorb arsenic from the aqueous solution using modified saxaul tree ash. Arsenic adsorption process was performed in vitro by investigating the effect of various parameters such as pH, contact time, arsenic concentrations, temperature and adsorbent dosage on the adsorption efficiency. Isotherms, kinetics and thermodynamic studies were also conducted to better understand the process of adsorption. Maximum level of arsenic adsorption was obtained at a pH of 7, adsorbent dosage of 1.5 g/L, contact time of 60 min, initial arsenic concentration of 250 µg/l and temperature of 323 K. The amount of adsorbed arsenic was increased with increasing initial concentration of arsenic and temperature. Freundlich adsorption isotherm clearly described the arsenic adsorption by modified saxaul ash. Based on the results obtained, it could be concluded that the modified saxaul ash can efficiently remove arsenic from its aqueous solutions.

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There are different ways for antibiotics to enter the aquatic environment, with wastewater treatment plants (WWTP) considered to be one of the main points of entrance. Even treated wastewater effluent can contain antibiotics, since WWTP cannot eliminate the presence of antibiotics. Therefore, adsorption can be a sustainable option, compared to other tertiary treatments. In this direction, a versatile synthesis of poly(styrene-block-acrylic acid) diblock copolymer/Fe3O4 magnetic nanocomposite (abbreviated as P(St-b-AAc)/Fe3O4)) was achieved for environmental applications, and particularly for the removal of antibiotic compounds. For this reason, the synthesis of the P(St-b-AAc) diblock copolymer was conducted with a reversible addition fragmentation transfer (RAFT) method. Monodisperse superparamagnetic nanocomposite with carboxylic acid groups of acrylic acid was adsorbed on the surface of Fe3O4 nanoparticles. The nanocomposites were characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) analysis. Then, the nanoparticles were applied to remove ciprofloxacin (antibiotic drug compound) from aqueous solutions. The effects of various parameters, such as initial drug concentration, solution pH, adsorbent dosage, and contact time on the process were extensively studied. Operational parameters and their efficacy in the removal of Ciprofloxacin were studied. Kinetic and adsorption isothermal studies were also carried out. The maximum removal efficiency of ciprofloxacin (97.5%) was found at an initial concentration of 5 mg/L, pH 7, adsorbent’s dosage 2 mg/L, contact time equal to 37.5 min. The initial concentration of antibiotic and the dose of the adsorbent presented the highest impact on efficiency. The adsorption of ciprofloxacin was better fitted to Langmuir isotherm (R2 = 0.9995), while the kinetics were better fitted to second-order kinetic equation (R2 = 0.9973).