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Heavy metal ions in water can affect human health. Taking Pb2+ for an example, it can lead to kidney failure and tumor infection. Polyvinylidene fluoride (PVDF) has been widely used as filter membranes in wastewater treatment. This paper uses citric acid (CA) as the connecting arm to graft carboxymethyl chitosan (CMCS) onto PVDF and prepare a novel granular molecular sieve‐supported PVDF derivative (s‐PVDF‐CA‐CMCS). The structure was characterized and the adsorption capacity for heavy metal ions was investigated. The results indicate that s‐PVDF‐CA‐CMCS has good adsorption performance for aqueous heavy metal ions, especially for Pb2+, with a removal rate of 99.39 % and an adsorption capacity of 198.41 μg/g. The adsorption data fits the pseudo‐second‐order kinetic model (R2=0.9992), and the removal rate of Pb2+ was 78.48 % after 5 cycles of adsorptions, indicating that s‐PVDF‐CA‐CMCS may be potential applications for removing heavy metal ions in water treatment. [ABSTRACT FROM AUTHOR]

Incorporation of nanoparticles into a three-dimensional porous framework to enhance adsorption capacity and recyclability of nanomaterial is of great significance for water contamination removal. Herein, a functionalized cellulose/MXene composite aerogel is prepared by the oxidative self-polymerization of dopamine hydrochloride and freeze-drying, which exhibits an excellent adsorption performance for methylene blue (MB). Characterization results show the successful combination of PDA and Ti3C2Tx into the cellulose aerogel with merits of light weight, high structural stability and high porosity. The adsorption process is understood more deeply through the adsorption kinetics. The Langmuir isotherm model was used to better fit the adsorption process, and the maximum adsorption capacity for MB reaches 168.93 mg g−1. Such a superior adsorption ability for MB is maintained in salt-containing water, or even a little higher when the concentration of NaCl is above 3%, recommending the functionalized cellulose/MXene composite aerogel for efficient removal of dyes in high-salt water environment. [ABSTRACT FROM AUTHOR]

High-yield selective adsorbents and suitable modification methods are both significant for the efficient treatment of U-contaminated wastewater. In this work, a rich-mesoporous aluminum phosphate adsorbent (APO-10) was synthesized by simply increasing the mass of reactants under a fixed solvent volume. After increasing the mass of reactants ten times, APO-10 has the added defect level, the increased specific surface area, and mesoporous structure, and the increased number and enhanced adsorption ability of adsorption active sites (phosphorus-oxygen groups) on the surface, resulting in an enhanced adsorption performance of U(VI) in various environmental conditions. Its ultrahigh adsorption capacity calculated by the Langmuir model can reach 826.44 mg g−1 at pH = 5.5 and T = 298 K. Its crystal structure did not change after adsorption and remained at 584.40 mg g−1 after 6 cycles. Additionally, APO-10 shows an excellent uranium-selectivity over 68% from a mixed aqueous solution and has excellent applicability in the acidic and alkaline environment based on dynamic adsorption and desorption column experiments. This study not only provides a high-yield efficient selective adsorbent (APO-10) with excellent anti-radiation structure stability for the treatment of radioactive contamination but also provides a feasible modification method by simply increasing the mass of reactants. [Display omitted] • A high-yield adsorbent (APO-10) was synthesized by increasing the raw materials. • The physicochemical properties of the adsorbent changed after added raw materials. • The increased adsorption capacity of APO-10 for U(VI) reaches 826.44 mg g−1. • APO-10 shows the enhanced uranium-selectivity from a mixed aqueous solution. • APO-10 has excellent structural stability and enhanced recycling performance. [ABSTRACT FROM AUTHOR]

The effective removal of phosphorus (P) has been a recent hot topic due to water eutrophication hazards and zero-liquid discharge (ZLD) regulations. In this study, MgO-loaded bentonite (Bt) was immobilized by sodium alginate (SA), and then freeze-dried to form beads (SA-MgO@Bt). For comparison, SA-immobilized pure Bt was freeze-dried to form another kind of bead (SA-Bt), and SA-immobilized Bt with MgO loading was oven-dried to form a third type of bead (OSA-MgO@Bt). The specific surface area (SSA) of SA-MgO@Bt was measured to be 59.5 m2/g, 2.2 and 1.4 times that of SA-Bt and OSA-MgO@Bt. The total pore volume of SA-MgO@Bt was also verified to be much higher than that of the other two beads. Overall, SA-MgO@Bt exhibited a maximum adsorption capacity of 70.5 mg/g, a high removal efficiency above 91% in a wide pH range from 3 to 10, and a high selectivity for phosphate from high-salinity water, surpassing those of SA-Bt and OSA-MgO@Bt, and related adsorbents reported in literature. For the fixed-bed column experiments with a water flow rate of 1.0 mL/min, the phosphate concentration could still be reduced from 50 mg/L to 0.5 mg/L even after 8 h. Based on the dynamics, isotherms, and microstructural analysis, the ligand exchange and Mg–P complexation formation, in addition to the electrostatic attraction mode, were also proposed to contribute to the adsorption performance of SA-MgO@Bt. Finally, the pot experiments also validated the feasibility of the as-obtained phosphate-adsorbed SA-MgO@Bt beads as a slow-release-fertilizer for the growth of mint, providing new possibilities of P resource utilization. [Display omitted] •Novel porous MgO-loaded bentonite beads were synthesized for phosphate removal. •SA-MgO@Bt showed a high adsorption selectivity to phosphate in aqueous solution. •Fixed-bed column experiments also validated the high performance of SA-MgO@Bt. •High porosity and MgO active sites contributed to the enhanced adsorption capacity. •Pot experiments showed that P loaded SA-MgO@Bt can be used as fertilizer. [ABSTRACT FROM AUTHOR]

The development of an effective phosphate removal strategy is still considered to be an important challenge in the field of wastewater remediation. In this study, novel alginate immobilized Zr-bentonite hydrogel beads were synthesized assisted by Zr-modification and Na 2 CO 3 + HCl pore forming (abbreviated as NH-SA-ZrBT), that led to an enhancement in the specific surface area and porosity. The novel NH-SA-ZrBT adsorbent exhibited a high stability and adsorption selectivity for phosphate from complex water environments with various competitive anions, NaCl salinity and humic acid. The isotherm was fitted well by both Langmuir and Freundlich models, suggesting that the adsorption process was the chemisorption and the hydrogel beads could function through a variety of mechanisms. The maximum adsorption capacity of NH-SA-ZrBT for phosphate was calculated to be 63.61 mg/g at 25 °C by Langmuir model and had a high retention of 92.2% after five adsorption-desorption cycles. The kinetic data were better fitted by the pseudo-second model. Considering the zeta potential and XPS data before and after the phosphate adsorption, the adsorption mechanism was proposed to be a combination of electrostatic attraction, ligand exchange and inner sphere complexation. The present study demonstrates a new strategy for the fabrication of stable, separable and low-cost bentonite-containing hydrogel beads for phosphate removal from complex wastewater. Unlabelled Image • Alginate immobilized ZrBT beads were synthesized by a facile crosslinking method. • Zr modification and pore forming treatment enhanced the porosity and adsorption. • Selectivity remained high even with competitive ions, high salinity and humic acid. • Electrostatic interaction, ligand exchange and complexation dominate the adsorption. [ABSTRACT FROM AUTHOR]