Nitrate Water Contamination from Industrial Activities and Complete Denitrification as a Remediation Option

Abstract

Freshwater is a scarce resource that continues to be at high risk of pollution from anthropogenic activities, requiring remediation in such cases for its continuous use. The agricultural and mining industries extensively use water and nitrogen (N)-dependent products, mainly in fertilizers and explosives, respectively, with their excess accumulating in different water bodies. Although removal of NO3 from water and soil through the application of chemical, physical, and biological methods has been studied globally, these methods seldom yield N2 gas as a desired byproduct for nitrogen cycling. These methods predominantly cause secondary contamination with deposits of chemical waste such as slurry brine, nitrite (NO2), ammonia (NH3), and nitrous oxide (N2O), which are also harmful and fastidious to remove. This review focuses on complete denitrification facilitated by bacteria as a remedial option aimed at producing nitrogen gas as a terminal byproduct. Synergistic interaction of different nitrogen metabolisms from different bacteria is highlighted, with detailed attention to the optimization of their enzymatic activities. A biotechnological approach to mitigating industrial NO3 contamination using indigenous bacteria from wastewater is proposed, holding the prospect of optimizing to the point of complete denitrification. The approach was reviewed and found to be durable, sustainable, cost effective, and environmentally friendly, as opposed to current chemical and physical water remediation technologies.

Recent trends in nitrogen cycle and eco-efficient nitrogen management strategies in aerobic rice system

“…Once the concentration of NO 3 – exceeds the standard values, it may take several years and even decades to recover ( Wild et al, 2018 ). Following this, regulations in the use of synthetic N fertilizers undergoing climatic and soil conditions could play an important role in simultaneously decreasing the surplus N in the system, specifically NO 3 – pollution of groundwater ( Wick et al, 2012 ; Wild et al, 2018 ; Moloantoa et al, 2022 ). Although continuous efforts across the globe have reduced the NO 3 – concentrations, most of the regions worldwide still have levels exceeding the standards and suffering from groundwater contamination ( Abascal et al, 2022 ).…”

“…Once the concentration of NO 3 − exceeds the standard values, it may take several years and even decades to recover (Wild et al, 2018). Following this, regulations in the use of synthetic N fertilizers undergoing climatic and soil conditions could play an important role in simultaneously decreasing the surplus N in the system, specifically NO 3 − pollution of groundwater (Wick et al, 2012;Wild et al, 2018;Moloantoa et al, 2022).…”

Water Pollution from Agriculture and Industry

“…A definite part of the use of agricultural pesticides, which can flow directly from the fields into streams and subsurface sources, causes NO3-N contamination. The degree of industrial NO3-N both for upper and underground freshwater varies not fully recognized (Moloantoa et al, 2022) waterbodies has yet to be determined.…”

“…Distance from Sullage Carrier (meter) <25 25 The maximum, minimum and average concentrations of all the metals in water samples collected along lined section of the sullage carrier are shown in Table 8.…”

Growth performance and nutritional composition of Clarias gariepinus in flood-and-drain aquaponics coupled with three species of leafy vegetable

“…These bacteria colonize the surfaces of aquatic systems. Nitrifying bacteria thrive optimally at temperatures between 77 and 86 °F (Moloantoa et al, 2022). When temperatures fall below 32 °F or rise above 120 °F, these bacteria begin to die off, and aquatic system nitrification is halted.…”