The development of effective heavy metal adsorbents has always been the goal of environmentalists. Pectin/activated carbon microspheres (P/ACs) were prepared through simple gelation without chemical crosslinking and utilized for adsorption of Pb²⁺. Scanning electron microscopy (SEM) revealed that the addition of activated carbon increased the porosity of the microsphere. Texture profile analysis showed good mechanical strength of P/ACs compared with original pectin microspheres. Kinetic studies found that the adsorption process followed a pseudo-second-order model, and the adsorption rate was controlled by film diffusion. Adsorption isotherms were described well by a Langmuir isotherm model, and the maximum adsorption capacity was estimated to be 279.33 mg/g. The P/ACs with the highest activated carbon (P/AC_2:3) maintained a removal rate over 95.5% after 10 adsorption/desorption cycles. SEM-energy-dispersive X-ray spectrum and XPS analysis suggested a potential mechanism of adsorption are ion exchange between Pb²⁺ and Ca²⁺, electronic adsorption, formation of complexes, and physical adsorption of P/ACs. All the above results indicated the P/ACs may be a good candidate for the adsorption of Pb²⁺.

Traditional aerogels lack specific functional groups for the adsorption of Pb²⁺, which results in a low adsorption capacity and limits the application scope. Novel porous pectin-based aerogels (PPEAs) were prepared by incorporating polyethylenimine (PEI) using ethylene glycol diglycidyl ether (EGDE) as a cross-linker for the removal of Pb²⁺ from water. The cross-linking mechanism, morphology, mechanical strength, thermal stability, adsorption properties, and mechanism of the aerogels were investigated. The aerogels possessed several desirable features, such as a large maximum Pb²⁺ adsorption capacity (373.7 mg/g, tested at pH 5.0), ultralight (as low as 63.4 mg/cm³), high mechanical strength (stress above 0.24 MPa at 50% strain), and easy recyclability. Meanwhile, the equilibrium adsorption data was well described by the Langmuir–Freundlich (Sips) model and the kinetic adsorption process was well fitted using the pseudo-second-order model. The donor groups, such as -NH₂, and oxygen-containing functional groups were responsible for the Pb²⁺ adsorption, which was confirmed by the FTIR and XPS analysis. The excellent characteristics mean that PPEAs are highly effective adsorbents in the remediation of lead-containing wastewater.

Hyperlipidemia, characterized by an abnormal lipid metabolism, is related to multiple cardiovascular diseases that pose challenges to global public health. Macadamia oil (MO), rich in monounsaturated fatty acids (around 80%), is regarded as a functional oil used to regulate lipid accumulation. Nonetheless, the lipid-lowering mechanism of MO is still unknown. Therefore, the lipid-lowering effects of MO in high-fat diet (HFD)-induced hyperlipidemic mice were evaluated in this study. The results revealed that MO could effectively reduce body weight and the organ index and improve serum lipid levels by reducing total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels and elevating high-density lipoprotein cholesterol levels. Additionally, MO supplementation could improve abnormal liver function caused by hyperlipemia, characterized by decreased liver enzyme levels, including alanine aminotransferase and aspartate aminotransferase. Meanwhile, MO also exhibited an inhibitory effect on oxidative stress and lipid accumulation caused by an HFD. Moreover, findings from qRT-PCR and Western blotting analyses suggest that MO supplementation markedly prevented hyperlipidemia by inhibiting the expression of AMPK pathway-related genes, SREBP-1c, FAS, ACC, and PPAR-γ, as well as upregulating the levels of Nrf2, HO-1, and γ-GCS. These results indicate that MO attenuates lipid accumulation in vivo via AMPK/Nrf2 pathway activation, suggesting that MO could serve as a dietary supplementation or medication for treating hyperlipidemia.