Environmental Technology & Innovation最新文献

Despite increasing debates about their potential side effects on human health, data concerning the risks and the impacts associated with pesticides remains scarce. Analytical tools allowing the measurement of most pesticides and/or their metabolites to which the population can be exposed are also of need. In the present study, the limits of detection (LODs) of 3 different screening procedures based on either Low-Resolution and High-Resolution Mass Spectrometry (LR-MS and HR-MS) for the determination of pesticides in serum (among which carbamates, dithiocarbamates, neonicotinoids, organochlorines, organophosphates and pyrethroids) were explored. For HR-MS, a quadrupole time-of-flight was used in positive and negative electrospray ionization modes and data were obtained from either a targeted scheduled MSMS acquisition (HR-MSMS) or a data-independent acquisition (HR-DIA). For LR-MS, a triple quadrupole was used and data were acquired with a classical multiple-reaction monitoring (MRM) mode. Depending on the approach, the LOD values varied from 0.05 to 10 ng/mL. For the lowest concentrations, the proportion of molecules detected was systematically greater for the LR-MS approach, while those of HR-MSMS were better than those of HR-DIA. These differences in the LOD values were confirmed in a sample of 174 serums in which LR-MRM detected 89 compounds while HR-MSMS and HR-DIA detected 79 and 75 compounds, respectively. Nevertheless, for environmental and occupational purposes, HRMS approach could probably be efficient to detect most of pesticides and their metabolites in human serum and could be suitable for human biomonitoring studies or fundamental research exploring the impact of exposure to pesticides on human health.

A novel polyfunctional group-modified poly(hydroxyethyl methacrylate) polymer, termed PFG-PHEMA, was synthesized for adsorption of Cu²⁺ and Cd²⁺. Material characterization confirmed that the surface functional groups facilitated efficient adsorption of these ions. pH optimization experiments demonstrated that the adsorption capacities of Cu²⁺ and Cd²⁺, reaching 162.2 and 150.3 mg·L⁻¹ respectively, were maximized at a pH of 5, with an initial heavy metal concentration of 200 mg·L⁻¹. Kinetic and isotherm studies indicated that the adsorption process conformed to a monolayer, homogeneous, and chemisorption model, achieving equilibrium within 60 min. The maximum adsorption capacities were determined to be 500 mg·g⁻¹ for Cu²⁺ and 384.6 mg·g⁻¹ for Cd²⁺. Competitive adsorption experiments showed that PFG-PHEMA exhibited superior selectivity for Cu²⁺ over other metal ions. This selectivity was corroborated by X-ray photoelectron spectroscopy (XPS) analysis, which identified the sulfhydryl group as the crucial functional moiety responsible for Cu²⁺ selectivity. Furthermore, the presence of low concentrations of fulvic acid (FA) enhanced adsorption via ternary complex formation, whereas higher concentrations impeded adsorption by forming FA-metal complexes that competed with the polymer. Overall, the strategic incorporation of multiple functional groups into PFG-PHEMA conferred a high adsorption capacity for Cu²⁺ and Cd²⁺. The analysis further indicated that sulfhydryl groups exhibit high selectivity toward Cu²⁺, whereas amine and oxygen-containing groups preferentially bind to Cd²⁺, reinforcing the potential of PFG-PHEMA as a highly effective adsorbent for heavy metals.

The release of pollutants of emerging concerns like antibiotics in the environment is posing serious threats to ecosystems. The aim of this study was to remove four antibiotics from the aqueous phase using polymer-based adsorbent in its raw form for antibiotic removal coupled with a mechanistic understanding of the process. Polyethylene, post-cleaning, served as an adsorbent, characterized for surface area, pore size, and structure. Two-week batch experiments at 25°C and pH 7 were conducted at a laboratory scale. Polyethylene demonstrated over 90 % removal efficiencies for all the selected antibiotics. Data fitting into various models revealed Langmuir isotherm and Elovich kinetic model governed the adsorption. Antibiotics, excluding ciprofloxacin, followed second-order kinetics; ciprofloxacin was governed by pseudo-first-order kinetics. Pseudo-second-order kinetics had R² values of 0.9855, 0.9746, and 0.9997 for ofloxacin, sulfamethoxazole, and oxytetracycline, respectively. Elovich had R² values over 0.90 for all the antibiotics, with the order of values as oxytetracycline>ofloxacin>sulfamethoxazole> ciprofloxacin. Langmuir Isotherm indicated the R² value of 0.9777, 0.9902, 0.9551, and 0.9959 for ofloxacin, ciprofloxacin, sulfamethoxazole, and oxytetracycline, respectively. Regeneration results exhibited that all antibiotics had greater than 80 % removal efficiencies in the first two cycles while the regeneration capacity of ciprofloxacin and sulfamethoxazole reduced to 75 % and 50 %, respectively at the fourth cycle. The effective removal of antibiotics indicates its usefulness and potential for widespread application compared to the costly and chemical-intensive adsorbents. These findings highlight the potential of selected adsorbents for real-time applications as the lab-scale studies mimicked the real environment by using a mixture of antibiotics.

Although the effectiveness of zero-valent iron (ZVI) and zero-valent manganese (ZVMn) in heavy metal removal is well-established, their combined synergistic potential for antimony (Sb) remediation from wastewater has remained largely unexplored. Addressing this gap, this study introduced a magnetic zero-valent iron-manganese bimetallic material (ZVIM), synthesized via the borohydride reduction method, to investigate its capabilities and underlying mechanisms for Sb reduction and adsorption. The ZVIM, characterized by a high specific surface area of 220 m²/g, exhibited a high adsorption capacity (614.6 mg/g for Sb(III) and 241.7 mg/g for Sb(V)), facilitating over 96.7 % removal for both Sb(III) and Sb(V). The adsorption conformed to the pseudo-second-order kinetic model, and the isotherm data aligned with the Freundlich model, indicative of a heterogeneous adsorption process. The removal of Sb(III) predominantly occurred via surface complexation and electrostatic adsorption to the positively charged ZVIM surface, accompanied by a partial oxidation of Sb(III) to Sb(V). In contrast, the elimination of Sb(V) was primarily facilitated through surface complexation mechanism, encompassing both reduction and electrostatic adsorption. The outcomes of this study shed light on the intricate interactions between Sb species and the ZVIM, revealing the material as a promising candidate for the efficacious removal of Sb from wastewater.

Although clay dispersion is one of the few techniques currently used in the field to control cyanobacterial harmful algal blooms (CyanoHABs), low flocculation efficiency and resuspension of flocculated algal cells are its main drawbacks. This study simulated the "flocculatio-lysis-degradation-nutrient regulation" model of biocontrol technique to develop a modified clay (ECRE-CS-PFS-CPL) using polyferric sulfate (PFS), chitosan (CS) and Eichhornia crassipes root extracts (ECRE) to modify the clinoptilolite (CPL). The results revealed that ECRE-CS-PFS-CPL introduced functional groups, specifically aldehyde group —CHO and amide group —CO-NH—, leading to an enhanced void structure. At 0.2 g/L concentration, ECRE-CS-PFS-CPL demonstrated a removal efficiency of 98.02 % within 30 min. ECRE-CS-PFS-CPL exhibited a positive charge in nature water, leveraging charge neutralisation to expedite the flocculation of M. aeruginosa cells. The combination of coated CS and algal cells resulted in the formation of large, dense flocs through net sweeping and bridging, which was 58.28 times larger than control. Subsequently, the loaded ECRE inhibited the algal cells via allelopathy. The inhibition activated the antioxidant system of M. aeruginosa, with significant increases in catalase (CAT) and superoxide dismutase (SOD) activities. Photosynthetic pigments (Chl-a), photosynthetic efficiency (Fv/Fm) and maximum relative photosynthetic electron transfer rate (ETRmax) were markedly reduced, indicating the damage to photosynthetic system. Furthermore, Chl-a remained consistently low during extended monitoring, registering at 4.98 % of control after 40 days. ECRE-CS-PFS-CPL effectively reduced microcystins by 81.48 % and phosphate levels in algal cultures by 91.92 % compared to control. Consequently, ECRE-CS-PFS-CPL offers an efficient, environmentally safe and sustainable solution for CyanoHABs control.

Addressing the urgent need for sustainable solutions in waste management, this study focuses on the pivotal task of recycling heavy metals from electroplating sludge (ES), a critical issue both environmentally and economically. The research introduces a novel leaching process utilizing pickling liquor as a reagent to extract valuable metals from the sludge. Key parameters such as agitation speed, solid to liquid ratio (S/L), temperature, and duration were examined to optimize the leaching rate. Results revealed impressive extraction rates, with 92.33 % Cr, 89.49 % Cu, and 89.59 % Ni extracted within 120 min from S/L 10 g/L, at 300 rpm, and 25 °C. However, it was noted that increasing temperature negatively impacted the leaching rate and led to the formation of undesirable compounds. X-ray diffraction (XRD) analysis identified gypsum and potassium jarosite as predominant compounds formed on the leaching residues at different temperatures of 25 °C and 45 °C. Field emission scanning electron microscopy (FE-SEM) illustrated significant morphological changes in the residues, indicating the influence of temperature on compound formation. Additionally, environmental risk assessment of the residues was conducted using synthetic precipitation leaching procedure (SPLP) and toxicology characteristic leaching procedure (TCLP) methods. In conclusion, this research underscores the promising potential of the developed leaching process using pickling liquor to reclaim valuable metals from ES. By optimizing parameters and assessing environmental risks, this study contributes to advancing environmentally sound practices in industrial waste management.