The ubiquitous occurrence of microplastics (MPs) in the freshwater has attracted widespread attention. The Zhengzhou section of the Yellow River was the most prosperous region in ancient China, and the rapid urbanization, industrialization, and agricultural practices contributed to MPs pollution in aquatic systems recently, whereas the contamination status of MPs in the area is still not available. In this study, a total of fourteen sampling cross-sections were selected in the region to collect water samples systematically for the analysis of MPs pollution characteristics and potential risks. Results showed that abundance of MPs in the water were ranged from 2.33 to 15.50 n/L, with an average value of 6.40 ± 3.40 n/L, which was higher than it in other inland rivers from China. Moreover, the MPs of 0.5-2 mm were the dominant sizes in Yellow River of Zhengzhou region, and most of them were black fibres. The top three polymers were Polyethylene terephthalate (PET), Polyamide (PA) and Polypropylene (PP). High diversity indices of MPs observed at S3, S4, S5, S6, S7, and S8 for size, colour, polymer and shape indicated diverse and complex sources of MPs in those cross-sections. The MPs in water from Zhengzhou area of Yellow River probably degraded from textiles, fishing net, plastic bags, mulching film, packaging bags, and tire wear. The chemical risk assessment revealed a level III risk for study area, while S8 and S11 in which PVA or PAN with higher hazard score detected were categorised as class V risk. Coincidentally, probabilistic risk assessment showed a considerable ecological risk of MPs from Yellow River in Zhengzhou City, with possibility of 99.48 and 98.01 % adverse effect for food dilution and translocation-mediated mechanism, respectively. The results are expected to assistance for development of policies and ultimately combating MPs pollution.

A total of 30 surface soil samples were collected from the typical polluted area of Bengbu, Anhui province, Eastern China. The content characteristics, source identification, and risk assessment of heavy metals (Cd, Cu, Mn, Ni, Pb, and Zn) were studied based on the field investigation, sampling, indoor test, and statistical analysis. Results showed that the concentrations of Cd, Cu, Mn, Ni, Pb, and Zn showed different spatial variation and ranged from 0.48 to 1.84, 12.78 to 239.07, 287.14 to 491.96, 15.29 to 52.99, 13.28 to 68.82, and 28.83 to 184.79 mg/kg, respectively. Besides Mn, the contents of other metals have exceeded the local background value to a certain extent, and the higher concentrations recorded were found in the east of Bali channel. Source analyses indicated that Cd, Cu, Pb, and Zn were attributed to industrial emissions, vehicle exhaust pollution, and phosphate uses in agriculture, whereas Ni and Mn were mainly of natural origin. Among the six heavy metals, Cd posed the highest ecological risk with the proportion of 3.3% at a considerable level, 36.7% at a high level, and 60% at a very high level, Cu presented a low-to-moderate ecological risk, while others presented a relatively low risk in surface soils, suggesting that Cd and Cu, especially for Cd, should draw environmental concern.

Peroxymonosulfate (PMS) activation is an intriguing technology for refractory organic pollutant removal in wastewater treatment. Herein, a highly dispersed Mn-Ce bimetallic oxide on carbon nanotubes (MCC) was synthesized and applied to catalyze PMS for the degradation of phenol. The material was well characterized using a transmission electron microscope (TEM), N₂ adsorption–desorption isotherms, X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The synthesized MCC showed superior activity for PMS activation. The k value of phenol removal with MCC is 0.135 min⁻¹, which is greatly superior to that of CNT (6.17 × 10⁻⁵ min⁻¹) and Mn-Ce bimetallic oxide (3.18 × 10⁻⁴ min⁻¹). Electron paramagnetic resonance (EPR), along with radical quenching experiments, revealed that the activation of PMS by MCC for phenol degradation involves both radical and non-radical reaction pathways. Moreover, a synergic effect between Mn-Ce bimetallic oxide and CNT was identified to be responsible for the outstanding catalytic activity.

Peroxymonosulfate (PMS) activation has gained increasing attention for its water remediation. In this work, carbon nanotube-supported FeCo₂O₄ nanoparticles (FeCo₂O₄/CNT) were prepared and showed tremendous potential as a catalyst for PMS activation. The synergistic effect between FeCo₂O₄ and CNT in FeCo₂O₄/CNT promotes its better catalytic performance than individual CNT or FeCo₂O₄. The synthesized FeCo₂O₄/CNT could reach 100% phenol removal with a k value of 0.30 min⁻¹ within 15 min ([PMS] = 0.3 g L⁻¹, [FeCo₂O₄/CNT] = 0.3 g L⁻¹). FeCo₂O₄/CNT can adapt well to a wide pH range (4–9) and a complex water component (with inorganic ions or organic matter). Moreover, the catalytic mechanism investigation suggested that both radical and non-radical pathways are accountable for the efficient removal of phenol.

Heavy metal concentrations in surface sediments of the Dragon Lake were studied based on the field investigation, sampling, indoor test and statistical analysis. Pollution risk was assessed using geoaccumulation index (Igeo), potential ecological risk index (PERI) and sediment quality guidelines (SQGs). The level of enrichment for heavy metals in surface sediments decreased in the order of Cd>Zn>Cu>Ni>Pb>Mn. Igeo and PERI indicated Cd had the highest biological risk among the six heavy metals. The concentrations of Cd, Ni and Zn were between threshold effect level (TEL) and probable effect level (PEL), suggesting adverse biological effect occasionally occurred. Comparing the north and south of Dragon lake, the north of lake should be put in high attention due to the higher heavy metal concentrations. The metals (Cd, Zn, Cu, Ni, and Pb) were attributed to anthropogenic sources, including agriculture, industrial emissions and traffic pollution, whereas Mn was mainly from natural sources. The results can be used for water quality management of Dragon Lake.