Application of Denitrification in Wastewater Treatment

Denitrification proved to be beneficial for the removal of excess nitrogen compounds from sewage and wastewater. Water bodies are polluted with nitrate compounds due to leaching from crop fields, the use of nitrogen-containing chemicals from residential sewage, and industrial effluents. Wastewater is supplied with additional carbon sources such as methanol, glycerin, acetate, and more, to enhance the denitrifying activity of the bacterial species. 

Negative Impact of Denitrification on Human Health

High levels of nitrate in the wastewater may find their way to the aquatic systems which causes harmful effects to humans and aquatic organisms alike. Some of the diseases seen are:

•  Birth Defects – Pregnant women consuming water with high levels of nitrate may lead to defects in the organization of neural tubes (formation of brain and spinal cord) in the foetus.
• Methemoglobinemia – Nitrate leads to allosteric changes in the haemoglobin structure to methemoglobin containing ferric ions (Fe3+) causing increased affinity for oxygen and tissue hypoxia due to low delivery of oxygen to the tissues.
• Thyroid Malfunction – Nitrate competitively inhibits the binding of iodine which lowers the level of thyroid hormones causing fatigue, heart-rate elevation, weakness, and dizziness.
• Cancer – Consumption of nitrates may cause endogenous compounds to turn into carcinogens in the colon cells and other body tissues, hence causing cancer. 

Eutrophication and Denitrification

Excess nitrate causes eutrophication and algal blooms in marine water bodies allowing microbes with nutrient sources to flourish. They also increase aquatic plant growth which can limit the carbon and nutrient resources to other water organisms. Hence, causing the death of certain fishes, and other organisms.