Wastewater Treatment Plant Wwtp

Secondary treatment of sewage water primarily removes dissolved and suspended biological matter through processes like biological treatment, which helps reduce the biochemical oxygen demand (BOD) of the water. It does not increase BOD, which would be counterproductive to water quality.

Mechanical biological treatment (MBT) is a non-thermal technology used for waste to energy conversion. It involves mechanical sorting and biological treatment processes to break down organic materials, which can then be used for energy production. The other options involve thermal methods.