Treating of wastewater

Fourth Official Post

Anaerobic Digestion is widely used to treat wastewater as it provides volume and mass reduction of the input material.

The water can come from the moisture content of the initial waste which was treated as well as the water which was produced in the microbial reactions.

After the Anaerobic Digestion, the waste water which comes out normally has increased levels of biochemical oxygen demand (BOD) and chemical oxygen demand (COD). This implies that the water has the potential to pollute the environment. Some may be named ‘hard COD’ as they cannot be converted by anaerobic bacteria onto biogas.

If this water is not treated and immediately mixed into watercourses, it will cause eutrophication. Eutrophication means an increase in compounds which contain nitrogen or phosphorus and causing more decay. It will cause a lack of oxygen and significantly reduce water quality and the population of organisms living in the water. Thus, further treatment is required and it normally will be an oxidation stage before it can be released.

Anaerobic Digestion helps by treating wastewater like Chlorination or the use of Ultraviolet (UV) light. Imagine that wastewater from industrials or housing estates is not treated and discharged into the oceans. Anaerobic Digestion also requires shorter retention time which means smaller tanks. Furthermore, it can also produce biogas. This is why anaerobic processes are widely used to treat wastewater even though it still requires further treatment after the processes.