Facile and innovative application of surfactant-modified-zeolite from Austrian fly ash for glyphosate removal from water solution

This study highlights a pioneering approach in the development of an efficient, affordable, and economically feasible adsorbent specifically tailored for the removal of glyphosate (Gly) from contaminated water. To accomplish this objective, a low-cost and pure NaA Zeolite (NaAZ) was synthesized with 93% crystallinity from Austrian fly ash (AFA) as a precursor for the first-time. Taguchi design was employed to optimize critical parameters such as the SiO2/Al2O3 ratio, alkalinity concentration, time, and temperature. The cation exchange capacity (CEC) and external cation exchange capacity (ECEC) are determined as critical factors for the modification process. Subsequently, the pure NaAZ was modified with hexadecyl trimethyl ammonium chloride (HDTMAC), a cationic surfactant. The utilization of surfactant-modified zeolite (SMZ) for Gly removal demonstrates its innovative application in this field, highlighting its enhanced adsorption capacity and optimized surface properties. The AFA, NaAZ, and SMZ were characterized using analytical techniques including XRD, XRF, FTIR-ATR, SEM, TGA, BET, CHNSO analyzer and ICP-OES. The adsorbent exhibited effective Gly removal through its pH-dependent charge properties (pH 2-10), with an optimized pH 6 facilitating a significant electrostatic interaction between the adsorbent and Gly. SMZ demonstrated remarkable adsorption capacity and removal efficacy, surpassing most reported adsorbents with values of 769.23 mg/g and 98.92% respectively. Our study demonstrates the significant advantage of the SMZ, with a low leaching concentration of only 6 ppm after 60 days, ensuring environmental safety, long-term stability, and public health considerations. The kinetics of the adsorption process was well described by the pseudo-second order and the Freundlich isotherm. Pore diffusion and H-bonding were postulated to be involved in physisorption, whereas electrophilic interactions led to chemisorption type of adsorption. Consequently, SMZ provides a practical significance, broad applicability and promising solution for Gly removal, facilitating sustainable water treatment.

Zeolite H-Beta as a Dispersive Solid-Phase Extraction Sorbent for the Determination of Eight Neonicotinoid Insecticides Using Ultra-High-Performance Liquid Chromatography—Tandem Mass Spectrometry

In this study, a dispersive solid-phase extraction (DSPE) pretreatment procedure using zeolite H-Beta as a sorbent was exploited for the determination of eight neonicotinoids in bottled water and honey products based on ultra-high-performance liquid chromatography–tandem mass spectrometry analysis. The zeolite H-Beta was demonstrated to be a suitable sorbent for neonicotinoid insecticides, even after 10 recycles of reuse. The method performance was evaluated by the linearity (R2 ≥ 0.998), recovery (71–108%), precision (0.1–7.8%), limit of detection (0.05–0.1 ng/mL) and limit of quantification (0.1–0.2 ng/mL), which suggested excellent stability and high sensitivity with the use of the DSPE procedure. The method was further successfully applied in the test of neonicotinoid insecticides in 34 samples. Zeolite H-Beta shows promise as an efficient and practical material for monitoring neonicotinoid insecticides in bottled water and multiplex honey matrices.

Synthesis and Modification of Clinoptilolite

Clinoptilolite is a natural mineral with exceptional physical characteristics resulting from its special crystal structure, mainstreamed into a large zeolite group called heulandites. An overall view of the research related to the synthesis, modification and application of synthetic clinoptilolite is presented. A single phase of clinoptilolite can be hydrothermally synthesized for 1–10 days in an autoclave from various silica, alumina, and alkali sources with initial Si/Al ratio from 3.0 to 5.0 at a temperature range from 120 to 195 °C. Crystallization rate and crystallinity of clinoptilolite can be improved by seeding. The modification of clinoptilolite has received noticeable attention from the research community, since modified forms have specific properties and therefore their area of application has been broadening. This paper provides a review of the use of organic compounds such as quarter alkyl ammonium, polymer, amine and inorganic species used in the modification process, discusses the processes and mechanisms of clinoptilolite modification, and identifies research gaps and new perspectives.