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Resource utilization of waste iron sludge from wastewater treatment plants can be achieved by leveraging iron sludge-based catalysts to construct Fenton-like systems. Notably，the pyrolysis temperature modulates the composition of metal and non-metal sites on the catalyst surface，thus affecting the activation of hydrogen peroxide（H2O2）. The catalysts prepared at different pyrolysis temperatures（400-700 ℃） were analyzed in terms of morphology，composition，structure and activity. It was found that the degradation efficiency of methylene blue（MB） could reach 92.0% within 100 min with the activation of H2O2 by the catalyst obtained at 700 °C. Additionally，the specific surface area and C content of the catalyst increased as the pyrolysis temperature increased from 400 ℃ to 700 ℃. The mechanistic investigation revealed that Fe0，C̿ C/C—C and C̿ O active sites on the catalyst surface were critical for the activation of H2O2，which facilitated MB degradation. Moreover，hydroxyl radicals（·OH） and singlet oxygen（1O2） were the dominant active species in the iron sludge-derived catalyst/H2O2 system，with superoxide radicals（O2·-） playing a minor role.

Plastic products are a significant component of the manufacturing industry and the plastic industry is closely related to economic and social development. As constraints from resources and environment tighten, rational disposal and utilization of waste plastics becomes crucial for the sustainable economic and environmental development. Currently, the variety of plastic products becomes abundant, and disposal technologies and application challenges are constantly updated. Considering the demand for highquality development of the industry and increasingly strict environmental protection requirements, a systematic analysis of the research progress of waste plastic disposal and utilization becomes urgent. In this study, the waste plastic disposal and utilization technologies are categorized into mechanical disposal of waste plastics, energy and resource conversion, regeneration recycling, and new technologies for disposal and utilization. These four types of technologies are expounded from the aspects of technical features, applicable conditions, and research progress. On the basis, facing the technical challenges and referring to the existing experience of developed countries, suggestions are proposed from the aspects of source reduction, sorted recycling of waste plastics, and technological innovation and transformation, hoping to provide a reference for the clean disposal and recycling of waste plastics in China.

Water security in the Haihe River Basin is an important component of China's ecological civilization and is vital for highquality national development of the country. Considering the development requirement for water security in the Haihe River Basin, we analyzed the problems regarding water security assurance from the perspectives of water resources, water environment, water ecology, and flood disasters. Subsequently, we predicted the development trend of water security in the Haihe River Basin by 2035 through data simulation. On this basis, an overall idea was proposed, that is, assuring water security in the Haihe River Basin by reinforcing measures for protecting water ecology, and highlighting the role of water resources carrying capacity. Focus should be placed on developing capacities regarding (1) systematic allocation and efficient utilization of water resources, (2) comprehensive improvement in water environment, (3) governance and restoration of basin ecology, and (4) prevention and emergency response of flood disasters. Furthermore, we proposed the following suggestions from a technological perspective: (1) implementing new strategies for the conservation and efficient utilization of water resources, (2) ensuring drinking water safety and improving water governance capacities, (3) establishing a water ecological pattern that features people-water harmony, and (4) developing a flood disaster prediction and response mechanism.

The newly revised Law of the People’s Republic of China on Prevention and Control of Water Pollution is crucial for pollution prevention and control in China. In this paper, we first review the achievements of the law in eight aspects since its implementation on January 1, 2018. Subsequently, we analyze the issues in implementing the law from four perspectives: (1) water environment management system and mechanism, (2) supervision over water pollution law enforcement, (3) drinking water source protection and groundwater pollution prevention, and (4) water pollution prevention and control. Accordingly, four countermeasures are proposed from the aspects of management system, law enforcement capabilities, water source protection, and pollution prevention. Specifically, efforts should be put into coordinated watershed management, river chief system perfection, and water quality improvement, thus to promote the up-to-standard discharge of industrial wastewater, pollutant interception and treatment of municipal pipe networks, recycling of municipal activated sludge, low-carbon and economical treatment of rural sewage, and rural non-point source pollution prevention.