Engineering aspects, pathways and mechanisms of nitrogen removal

Wastewater treatment seems to be one of the sources of increasing the availability of freshwater as other sources are diminishing. This means wastewater treatment and recirculation will play a significant role in the issues of freshwater shortage and environmental protection. Wastewater treatment can be considered as a tool generated by engineers and scientists to counter the various threats caused by wastewater and to enhance the water quality. However, the main concern with wastewater treatment reuse or recirculation is its composition (i.e. nutrients (nitrogen; N, phosphorus; P), chemicals and pathogens) which can be detrimental to human health and aquatic life and can present environmental hazards. There are several technologies for wastewater treatment, one of these systems is constructed wetlands system. Constructed wetland are engineered systems that are used globally for their low operation and maintenance costs, low energy requirements and ease of operation; they are aesthetically pleasing treatment systems and are environmentally friendly compared with conventional wastewater treatment processes. Moreover, it can treat many types of wastewater.