The increasing occurrence of pharmaceutical residues in freshwater ecosystems has emerged as an environmental concern owing to their persistence and potential adverse effects on non-target organisms, including aquatic plants. However, the physiological mechanisms underlying tolerance to pharmaceutical stress and the associated phytoremediation potential of aquatic ferns remain largely unexplored. Therefore, the study evaluated the responses of Azolla pinnata exposed to environmentally relevant concentrations of atorvastatin (0.5–10 µg L⁻¹) using chlorophyll a fluorescence (OJIP) analysis, biochemical assays, and spectrophotometric assessment of contaminant removal. Atorvastatin exposure induced an initial disruption of photosystem II photochemistry, reflected by reduced photochemical efficiency, restricted electron transport, increased energy dissipation, and partial inactivation of reaction centers. Prolonged exposure revealed a concentration-dependent physiological acclimation, with higher atorvastatin concentrations exhibiting partial restoration of photosynthetic performance accompanied by enhanced antioxidant activity and osmolyte accumulation, indicating activation of photoprotective and oxidative stress mitigation mechanisms. Spectrophotometric analysis revealed a substantial decline in atorvastatin concentration in the treatment medium, and the detection of atorvastatin in exposed plant tissues confirmed active uptake and accumulation by A. pinnata, thereby supporting its phytoremediation potential. These findings demonstrate that coordinated regulation of photosynthetic and antioxidant processes enables A. pinnata to tolerate environmentally relevant atorvastatin exposure while simultaneously facilitating contaminant removal. The study provides mechanistic evidence for pharmaceutical stress adaptation in an aquatic fern and highlights A. pinnata as a promising nature-based candidate for the remediation of atorvastatin-contaminated freshwater ecosystems. Azolla pinnata exhibits efficient phytoremediation of atorvastatin while undergoing concentration-dependent physiological stress. Atorvastatin induces dose-dependent toxicity, impairing PSII photochemistry and electron transport dynamics. A biphasic response reflects initial photoinhibition followed by adaptive recovery, enhancing both stress tolerance and remediation efficiency. Antioxidant activation (SOD, CAT) and proline accumulation mitigate oxidative damage and support sustained phytoremediation performance.
This study investigates the adsorption performance of cadmium sulfide (CdS)-filled chitosan (CS) biocomposite microspheres. Two different types of dyes were used as model dyes, such as cationic (Malachite green (MG)) and anionic (Congo red (CR)). The characterization was conducted using FTIR-ATR, SEM, XRD, zeta potential, and pHpzc analyzes. To identify the ideal conditions for the adsorption process, several experimental variables including pH, concentration, contact time, and temperature were examined. The ideal parameters were found to be pH 6 for CR dye and pH 7 for MG dye, 90 min of contact time for both dyes, 120 rpm stirring speed, and 0.045 g for CR dye and 0.125 g for MG dye. The non-linear Langmuir, Freundlich, D-R, and Temkin isotherm models were all fitted with adsorption data. The best fit of the adsorption process to the non-linear Langmuir isotherm model was demonstrated by the high correlation coefficient and low error functions. From the non-linear Langmuir model, the q_m value of CS-CdS-30 composite microspheres was calculated as 74.80 mg/g for CR dye and 30.85 mg/g for MG dye at 298 K. Furthermore, the CR and MG kinetics were characterized by the non-linear pseudo-second-order process. By conducting the adsorption process at various temperatures, thermodynamic characteristics were examined, and it was discovered that the adsorption process was spontaneous ( G^o = -29.66 kJ/mol for CR dye and G^o = -24.51 kJ/mol for MG dye at 298 K) and endothermic ( H^o = +17.36 kJ/mol for CR dye and H^o = +29.79 kJ/mol for MG dye). The prepared composite microspheres can be effectively used for up to five cycles. The removal of CR and MG dyes onto CS-CdS-30 composite microspheres was examined. The removal of CR and MG dyes follows the pseudo-second-order kinetic model. The qm values of CS-CdS-30 composite microspheres reached up to 74.80 mg/g for CR and 30.85 mg/g for MG at 298 K. CS-CdS-30 composite microspheres is natural, effective, and sustainable adsorbent.
Dual-modified activated carbon-based composite hydrogels, prepared in both integrated and encapsulated configurations, were synthesized using activated carbon modified with HCl and NaOH/FeCl₃ (molar ratio 3:1; Fe loading: 22.3 ± 0.14 mg/g dry, 77.2
Ecosystem Services (ESs) serve as critical indicators for quantifying the benefits humans derive from ecosystem structures, processes, and functions. Integrating multi-source remote sensing and statistical data from 1995 to 2020, this study systematically evaluated the spatiotemporal evolution and trade-off mechanisms of soil carbon storage (SCS), water conservation (WC), soil conservation (SC), food provision (FP) and energy provision (EP) by using the InVEST model and correlation analysis in Huainan mining area, China. The results indicate distinct drivers of land transition across zones: the mining core is governed by subsidence and restoration policies, whereas non-mining areas are primarily driven by urbanization. Land reclamation and wetland creation significantly enhanced regional regulating services. Negative correlations between EP and both SC and SCS confirmed the subsidence-induced physical soil instability and the physical stress exerted on surface carbon pools. While agricultural output remained relatively resilient to mining disturbances, the sector underwent a structural transition driven by the expansion of subsidence water bodies—an expansion achieved at the expense of native terrestrial carbon pools. Furthermore, ecological recovery exhibited a significant temporal lag, with SCS showing marked increases only years after restoration. Accordingly, this study proposes differentiated spatial governance strategies, providing a scientific reference for ecological management and planning in resource-based cities across East China.
The valorization of wet organic residues into solid biofuels represents an important strategy for advancing sustainable waste management. This study evaluates the hydrothermal carbonization (HTC) of blended food waste and rice husk with the aim of enhancing hydrochar fuel characteristics and energy recovery efficiency. A Box–Behnken response surface design was employed to examine the effects of rice husk proportion (0–100
