A comprehensive review on nitrate pollution and its remediation: conventional and recent approaches

Recently, getting pure water easily is becoming a difficult task for the world. Different sources such as industrial, municipal, urban, and agricultural runoff are principal contributors to water pollution. Nitrate, an inorganic form of nitrogen, one of the water pollutants, can destroy water quality ecologically and clinically by causing eutrophication in the aquatic bodies and, methemoglobinemia (blue baby syndrome) in human infants, other health complications in animals. Traditionally, various methods have been trailed by the industries and wastewater plants to diminish the concentration of nitrate from the polluted water before discharging into the nearby water bodies. In the current decade, innovative, tremendous, and efficient technologies have been developed to reduce nitrate concentration and boost water quality. This paper highlights the most used physical and chemical approaches (ion exchange, reverse osmosis, adsorption, electrodialysis, electrocoagulation, electroreduction, etc.) and biological approaches (microbial, phytoremediation), other hybrid systems and their unique features. In addition, operational conditions, mechanisms, advantages, shortcomings, recent advancements, removal efficiency, and cost-effectiveness were discussed to help the world eliminate this significant problem associated with water pollution and further develop a sustainable hybrid system. Besides it, the paper presents the recovery procedure for nitrate and ammonium. From the detailed literature gathered, the hybrid technology was fantastic compared to stand-alone approaches. The biological methods were unmatchable with others regarding cost, energy consumption, nitrate reduction, nitrate removal, and energy harvest.

Automated summary

This paper discusses the most commonly used methods for reducing nitrate concentration and improving water quality, including physical, chemical, and biological approaches, along with their advantages and disadvantages. The study finds that hybrid technology is the most effective in terms of cost, energy consumption, and nitrate removal.