A bio digester tank, also known as a biodigester, is a sewage treatment system that uses anaerobic digestion to break down organic waste, including human waste, into methane gas and nutrient-rich effluent. This process occurs in an oxygen-free environment, making it an environmentally friendly and odorless method of waste treatment.

Bio digester tanks are commonly used as an alternative to traditional septic tanks in areas where there is limited space or poor soil conditions for conventional sewage disposal systems. They are also popular in eco-friendly construction projects and off-grid locations.

The bio digester tank consists of a sealed underground chamber where organic waste is deposited. Microorganisms naturally present in the waste break down the organic matter through anaerobic digestion, producing biogas (primarily methane) and a nutrient-rich effluent

The biogas produced by the bio digester can be captured and used as a renewable energy source for cooking, heating, or electricity generation. The effluent, which is partially treated, can be safely discharged into the soil or further processed for reuse in irrigation or other applications.