Which process involves using natural or artificial wetlands to treat wastewater?

The process that involves using natural or artificial wetlands to treat wastewater is known as constructed wetlands. Constructed wetlands are designed ecosystems that utilize wetland vegetation, soils, and associated microbial processes to improve water quality. They mimic the functions of natural wetlands, providing an efficient method for treating both agricultural and municipal wastewater.

In constructed wetlands, wastewater flows through a substrate that supports the growth of plants. These plants, along with microorganisms in the soil, help in the breakdown of pollutants, absorption of nutrients, and removal of contaminants from the water. This method not only helps in treating wastewater but also contributes to habitat creation, carbon sequestration, and enhanced biodiversity.

This approach contrasts with the other options. Composting is a process of decomposition for organic matter, generally not involving the treatment of wastewater. Filtration refers to separating particles from liquids or gases, which, while related to treatment processes, does not actively involve such ecosystems. Incineration is a waste treatment process involving combustion to reduce waste volume but does not utilize biological or wetland processes for treating wastewater.