Water is the driving force of all nature; a more sustainable future can only be achieved by concerted actions on water starting now.

A model that predicts the masses of microplastics in river networks is a step forward in our goal of tackling global plastic pollution.

Although we know that microplastic is a huge contaminant of water resources, a connection between its source and its fate is largely missing. Combining a high-resolution microplastic release model with a fate model in rivers and lakes allows the prediction of masses of microplastics in each river section on a country level.

The rapid urbanization in China calls for an expansion of urban wastewater treatment systems, which in turn may exacerbate climate impacts. With an extensive and integrated application of existing low-carbon technologies for wastewater treatment, sludge disposal and water reuse, it is possible to substantially decouple urban water stress mitigation from greenhouse gas emissions.

Efficiency is only one of the parameters involved in solar evaporation that should be improved to make it practical. Depending on the application, various factors of merit should be taken into consideration, as discussed in this Perspective.

Wastewater-based epidemiology was widely used to monitor the spreading of COVID-19. We should now build on the knowledge acquired over the past three years to extend the use of the technique to a wide range of human health and lifestyle aspects.

Treatment of brackish groundwater can help to alleviate potential competition for freshwater resources between the power sector and other sectors in water-stressed regions.