● Zero pollution does not mean no discharge of pollutants.

The mission of “Establishment of Zero-Pollution Earth” defined by United Nations Environment Programme aims at creation of a clean, safe and prosperous home for all human beings. It is of rational choice from each individual to protect our environment and demonstrates our great ambition to achieve our goals. The key message given in this article is that, zero pollution does not mean no discharge of pollutants and instead it can be achievable through optimizing and controlling a sound balance between pollutants discharge and capacities of decontamination through treatment and natural environmental accumulation, which can be termed as “Principle of Equilibrium” between pollution and decontamination. Based on this principle, we propose and illustrate several key factors and synergistic pathways toward a pollution-free planet: quantitative determination on purification and wastewater; source control through green measures; minimization of negative side-effects; precise management through digitalized systems; and keeping sound balance between pollutants and natural purification. It should be noted that we would face a series of difficulties and challenges in moving forward to “Zero-Pollution Earth”. We should further develop theories, principles and tools to achieve the balance between quantity of pollutants and decontamination capacities. Environmentalists should work together to break through the bottleneck limited by “Principle of equilibrium” to establish new environmental remediation systems leading to “Zero-Pollution Earth”.

● Major challenges of air pollution control in China are summarized.

Air pollution is one of the most challenging environmental issues in the world. China has achieved remarkable success in improving air quality in last decade as a result of aggressive air pollution control policies. However, the average fine particulate matter (PM_2.5) concentration in China is still about six times of the World Health Organization (WHO) Global Air Quality Guidelines (AQG) and causing significant human health risks. Extreme emission reductions of multiple air pollutants are required for China to achieve the AQG. Here we identify the major challenges in future air quality improvement and propose corresponding control strategies. The main challenges include the persistently high health risk attributed to PM_2.5 pollution, the excessively loose air quality standards, and coordinated control of air pollution, greenhouse gases (GHGs) emissions and emerging pollutants. To further improve air quality and protect human health, a health-oriented air pollution control strategy shall be implemented by tightening the air quality standards as well as optimizing emission reduction pathways based on the health risks of various sources. In the meantime, an “one-atmosphere” concept shall be adopted to strengthen the synergistic control of air pollutants and GHGs and the control of non-combustion sources and emerging pollutants shall be enhanced.

● Modifying local environment can intensify the performance of flow-through electrodes.

Removing high-risk and persistent contaminants from water is challenging, because they typically exist at low concentrations in complex water matrices. Electrified flow-through technologies are viable to overcome the limitations induced by mass transport for efficient contaminant removal. Modifying the local environment of the flow-through electrodes offers opportunities to further improve the reaction kinetics and selectivity for achieving near-complete removal of these contaminants from water. Here, we present state-of-the-art local environment modification approaches that can be incorporated into electrified flow-through technologies to intensify water treatment. We first show methods of nanospace incorporation, local geometry adjustment, and microporous structure optimization that can induce spatial confinement, enhanced local electric field, and microperiodic vortex, respectively, for local environment modification. We then discuss why local environment modification can complement the flow-through electrodes for improving the reaction rate and selectivity. Finally, we outline appropriate scenarios of intensifying electrified flow-through technologies through local environment modification for fit-for-purpose water treatment applications.

● Express energy use and carbon emissions in understandable numbers.

There is a global need to reduce greenhouse gas emissions to limit the extent of climate change. A better understanding of how our own activities and lifestyle influence our energy use and carbon emissions can help us enable changes in activities that can lead to reductions in carbon emissions. Here we discuss an approach based on examining carbon emissions from the perspective of the unit C, where 1 C is the CO₂ from food a person would on average eat every day. This approach shows that total CO₂ emissions in China, normalized by the population, is 22.5 C while carbon emissions for a person in the US is 43.9 C. A better appreciation of our own energy use can be obtained by calculating carbon emissions from our own activities in units of C, for example for driving a car gasoline or electric vehicle a certain number of kilometers, using electricity for our homes, and eating different foods. With this information, we can see how our carbon emissions compare to national averages in different countries and make decisions that could lower our personal CO₂ emissions.

● The Beautiful China Initiative (BCI) provides Chinese wisdom for the sustainable development and welfare of all humanity.

The Beautiful China Initiative (BCI) is a vivid embodiment of the harmonious coexistence between humans and nature during modernization. Implementing the BCI is an effective method for achieving the goals of building a beautiful China, while offering a “Chinese solution” to global sustainable development. This article summarizes the progress and main experiences of the BCI, as well as analyzing the primary challenges facing its future development. Finally, five policy recommendations are proposed, which emphasize the importance of top-level design, coordinated planning, and a robust support system in the implementation of the BCI.

● Wastewater treatment targets and processes change with demands.

The “dual-carbon” strategy promotes the development of the wastewater treatment sector and is an important tool for leading science and technology innovations. Based on the global climate change and the new policies introduced by China, this paper described the new needs for the development of wastewater treatment science and technology. It offered a retrospective analysis of the historical trajectory of scientific and technological advancements in this field. Utilizing bibliometrics, it delineated the research hotspots within wastewater treatment, notably highlighting materials genomics, artificial intelligence, and synthetic biology. Furthermore, it posited that, in the future, the field of wastewater treatment should follow the paths of technological innovations with multi-dimensional needs, such as carbon reduction, pollution reduction, health, standardisation, and intellectualisation. The purpose of this paper was to provide references and suggestions for scientific and technological innovations in the field of wastewater treatment, and to contribute to the common endeavor of moving toward a Pollution-Free Planet.

● A system of environmental optical monitoring technology has been established.

The achievement of the targets of coordinated control of PM_2.5 and O₃ and the carbon peaking and carbon neutrality depend on the development of pollution and greenhouse gas monitoring technologies. Optical monitoring technology, based on its technical characteristics of high scalability, high sensitivity and wide-targets detection, has obvious advantages in pollution/greenhouse gases monitoring and has become an important direction in the development of environmental monitoring technology. At present, a system of environmental optical monitoring technology with differential optical absorption spectroscopy (DOAS), cavity ring-down spectroscopy (CRDS), light detection and ranging (LIDAR), laser heterodyne spectroscopy (LHS), tunable diode laser absorption spectroscopy (TDLAS), fourier transform infrared spectroscopy (FTIR) and fluorescence assay by gas expansion (FAGE) as the main body has been established. However, with the promotion of “reduction of pollution and carbon emissions” strategy, there have been significant changes in the sources of pollution/greenhouse gases, emission components and emission concentrations, which have put forward new and higher requirements for the development of monitoring technologies. In the future, we should pay more attention to the development of new optical monitoring techniques and the construction of stereoscopic monitoring system, the interdisciplinarity (among mathematics, physics, chemistry and biology, etc.), and the monitoring of greenhouse gases and research on atmospheric chemistry.

● The safety and health of soil face global threats from widespread contamination.

Soil is a non-renewable resource, providing a majority of the world’s food and fiber while serving as a vital carbon reservoir. However, the health of soil faces global threats from human activities, particularly widespread contamination by industrial chemicals. Existing physical, chemical, and biological remediation approaches encounter challenges in preserving soil structure and function throughout the remediation process, as well as addressing the complexities of soil contamination on a regional scale. Viable solutions encompass monitoring and simulating soil processes, with a focus on utilizing big data to bridge micro-scale and macro-scale processes. Additionally, reducing pollutant emissions to soil is paramount due to the significant challenges associated with removing contaminants once they have entered the soil, coupled with the high economic costs of remediation. Further, it is imperative to implement advanced remediation technologies, such as monitored natural attenuation, and embrace holistic soil management approaches that involve regulatory frameworks, soil health indicators, and soil safety monitoring platforms. Safeguarding the enduring health and resilience of soils necessitates a blend of interdisciplinary research, technological innovation, and collaborative initiatives.

�?Recent advances in promising CCUS technologies are assessed.

Carbon capture, utilization and storage (CCUS) technologies play an essential role in achieving Net Zero Emissions targets. Considering the lack of timely reviews on the recent advancements in promising CCUS technologies, it is crucial to provide a prompt review of the CCUS advances to understand the current research gaps pertained to its industrial application. To that end, this review first summarized the developmental history of CCUS technologies and the current large-scale demonstrations. Then, based on a visually bibliometric analysis, the carbon capture remains a hotspot in the CCUS development. Noting that the materials applied in the carbon capture process determines its performance. As a result, the state-of-the-art carbon capture materials and emerging capture technologies were comprehensively summarized and discussed. Gaps between state-of-art carbon capture process and its ideal counterpart are analyzed, and insights into the research needs such as material design, process optimization, environmental impact, and technical and economic assessments are provided.