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To alleviate the adverse effects of pesticide residues on the environment, development of a more safe, economical, and reliable usage approach of pesticides is critically urgent. In the present study, a novel pesticide carrier LA-NSM (lauric acid-modified Nitraria seed meal) with controlled release property was prepared through grafting esterification of lauric acid onto Nitraria seed meal substrates. The structure of the obtained samples was characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and contact angle measurements. The results indicated that LA-NSM products had a well-defined hydrophobic surface and irregular holes for efficient loading of pesticide molecules. Deltamethrin (DEL), a representative insoluble pyrethroid insecticide in water, was deliberately selected as the index pesticide to evaluate the loading and releasing efficiency of LA-NSM. The loading capacity of LA-NSM for DEL can reach about 1068 mg/g. pH, humidity of soil, and temperature had a significant influence on controlled release performance of LA-NSM@DEL. Moreover, the releasing kinetics of LA-NSM@DEL composites could be fitted well with the Higuchi model. Overall, the highly hydrophobic property, excellent loading, and controlled release ability of LA-NSM made it a promising candidate in agricultural applications. [ABSTRACT FROM AUTHOR]
Glucose carbon microspheres have been widely used for wastewater treatment as adsorbent owing to their strong adsorption capacity, but for large-scale applications, the glucose carbon microspheres are inconvenient to be recycled from aqueous suspension due to their good suspendability. Moreover, the primitive nature of small particle size, large specific surface area and high surface energy of glucose carbon microspheres make them prone to aggregate and thus, disperse no-effectively for the other extended application. To solve this dilemma, polyester (PET) fibers decorated with glucose carbon microspheres (GC@PFs) were herein fabricated by one-step hydrothermal carbonization with acrylic acid as a coupling agent. The products were characterized by Fourier Transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Boehm titration, X-ray diffraction (XRD), Thermo-gravimetric Analysis (TG), Scanning Electron Microscope (SEM) and zeta potential respectively. The experimental results showed that a large amount of glucose carbon microspheres were evenly dispersed on the surface of carboxyl activated polyester fibers with uniform particle diameter, and the composite fibers showed desirable adsorption ability of cationic dyes for its more negative zeta potential. The dye adsorption isotherm follows Langmuir model and pseudo-second-order kinetic model better. Remarkably, the adsorbent has an excellent recyclability for maintaining a high removal rate (>85%) to dye even after 10 cycles.<br>• Glucose carbon microspheres were evenly distributed on the PET fibers surface that solved the problem of easy aggregation. • The polyester fibers were firstly decorated with glucose carbon microspheres through one-step hydrothermal carbonization. • Acrylic acid maintained the integrity of PET fabric and introduced a quite number of carboxyl groups on the PET surface. • The surface decorated composite material possessed good adsorption property and easy recovery performance. • The glucose carbon microspheres decorated polyester fibers showed a highly selective adsorption for the cationic dyes.