Pathways toward a pollution-free planet and challenges

● Zero pollution does not mean no discharge of pollutants. ● Control of sound balance between pollution and decontamination capacities is important. ● Key pathways to achieve balance between pollution and decontamination capacities are given. 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”.