In this study, an accurate method using high pressure liquid chromatography (HPLC) has been established for the simultaneous determination of chlorogenic acid (CA), vitexin-4′′-o-glucoside (VG), vitexin-2′′-o-rhamnoside (VR), orientoside (ORT), rutin (RT), vitexin (VIT) and hyperoside (HYP) from Crataegus pinnatifida leaves. The Box–Behnken design (BBD) combined with response surface methodology (RSM) was used to optimize the ultrasound-assisted extraction (UAE) method. Under optimized conditions (extraction temperature 41 °C, extraction time 31 min, ratio of liquid/solid 15 and ethanol concentration 39%), the yields of CA, VG, VR, ORT, RT, VIT and HYP were 0.46, 0.38, 4.37, 0.033, 0.036, 0.30 and 1.19, mg g⁻¹, respectively. Additionally, antioxidant activities of UAE extracts in DPPH radical scavenging (DPPH), ABTS radical scavenging (ABTS) and reducing power tests were determined as 0.69 mg mL⁻¹ (IC₅₀ value), 0.86 mM Trolox and 0.24 mg mL⁻¹ (IC₅₀ value), respectively. Compared with conventional maceration extraction (ME) and heat-refluxing extraction (HRE) methods, the UAE method showed remarkable advantages in terms of higher extraction yields and better antioxidant activities. Overall, the present results showed that UAE was an efficient and alternative method for the extraction of phenolic compounds from C. pinnatifida leaves and its extracts were potential antioxidant ingredients or additives for the food industry with potential preservation properties.

This study developed a new magnetic adsorbent from waste coconut shells using high-temperature carbonization, EDTA-2Na chelation, and Fe₃O₄ magnetic loading. Response surface methodology optimized the preparation conditions to a mass ratio of activated carbon: EDTA-2Na:Fe₃O₄ = 2:0.6:0.2. Characterization (SEM, XRD, FT-IR, and EDS) showed that EDTA-2Na increased the surface carboxyl and amino group density, while Fe₃O₄ loading (Fe concentration 6.83%) provided superior magnetic separation performance. The optimal adsorption conditions of Cu²⁺ by EDTA-2Na-Fe₃O₄-activated carbon composite material are as follows: when pH = 5.0 and the initial concentration is 180 mg/L, the equilibrium adsorption capacity reaches 174.96 mg/g, and the removal rate reaches 97.2%. The optimal adsorption conditions for Pb²⁺ are as follows: when pH = 6.0 and the initial concentration is 160 mg/L, the equilibrium adsorption capacity reaches 157.60 mg/g, and the removal rate reaches 98.5%. The optimal adsorption conditions for Cd²⁺ are pH = 8.0 and an initial concentration of 20 mg/L. The equilibrium adsorption capacity reaches 18.76 mg/g, and the removal rate reaches 93.8%. The adsorption followed the pseudo-second-order kinetics (R² > 0.95) and Langmuir/Freundlich isotherm models, indicating chemisorption dominance. Desorption experiments using 0.1 mol/L HCl and EDTA-2Na achieved efficient desorption (>85%), and the material retained over 80% of its adsorption capacity after five cycles. This cost-effective and sustainable adsorbent offers a promising solution for heavy metal wastewater treatment.

This study investigates the synthesis of SMS-Ti-Mn (SMS-Ti-Mn stands for spent mushroom substrate activated carbon-Ti-Mn) nanocomposites and their application in removing the heavy metal antimony from water. In the process of antimony mining and smelting, the concentration of antimony in the waste residue can still reach as high as 80.5 mg/L. In addition, the soil in the electronic waste dismantling area is severely contaminated with antimony. In short, antimony enters the environment in various ways from mining, smelting, and manufacturing to the final waste process and continuously migrates in different environmental media, increasing the environmental exposure risk of antimony pollution. Single-factor experiments and response surface methodology were employed to determine the optimal conditions, including the adsorption time, pH, and solid–liquid ratio. Material characterization was performed to understand the role of nano-metals, and adsorption kinetics were analyzed using the quasi-first-order kinetic model. The research results revealed that the optimal conditions for antimony removal were an adsorption time of 40 min, a pH of 4, and a solid–liquid ratio of 2:1 (mg/mL). Under these conditions, the nanocomposites showed an adsorption capacity of 10.502 mg/g, which was 5.8 times higher than that of iron coagulants, 11 times higher than that of manganese-modified activated carbon, and 1.7 times higher than that of iron–manganese sludge adsorbents. Characterization revealed enhanced functional groups (carbonyl, Ti=O, Mn=O), contributing to improved adsorption. Kinetic analysis indicated physical adsorption as the dominant mechanism, and the regression model accurately predicted the adsorption capacity. SMS-Ti-Mn nanocomposites offer a promising strategy for treating antimony-contaminated water, with strong potential for practical applications in water treatment. They can decompose naturally after use, reduce secondary pollution, and promote ecological balance. Secondly, agricultural waste treated with heavy metal removal can be used as a fertilizer and soil amendment to improve soil quality and promote sustainable agricultural development.