Denitrification
INOTEC's denitrification technology can be applied both ex situ (EBR) and in situ and is being used in a number of locations in both configuration at full-scale. Ex situ denitrificationn rates up to 20 mg/L Nitrate-N per hour can be achieved in field applications; this is dependent on temperature and water chemistry.
Mining, petroleum refining, and agricultural activities often produce large quantities of nitrate and metal containing wastewaters that require reclamation measures to minimize impacts, or potential future impacts, to downstream waters. This task varies from site to site, can be complex dealing with water chemistries that can change with time, and often represents a significant commitment for many years.
Nitrate is recognized as a high priority contaminant; hundreds of thousands of high concentration point sources and extensive groundwater contamination are the result of agricultural and animal farming activities across the US.Nitrate contamination has caused the shutdown of wells and rendered aquifers unusable as drinking water sourcesNitrate is a stable and highly soluble ion with a low potential for co-precipitation or adsorption. These properties make it difficult to remove using conventional water treatment technologies, such as lime softening and filtration. More sophisticated technologies—chemical denitrification, ion exchange, reverse osmosis, electrodialysis, and biological denitrification—can be used to remove nitrates from water. Biological denitrification has been demonstrated as a cost-effective means of removing nitrate from water. Nitrate reduction to nitrogen gas occurs as a series of steps, as follows:
NO3- --> NO2- --> NO --> N2O --> N2
In situ bioremediation is the application of biological treatment to the cleanup of contaminants in groundwater. This process creates subsurface environmental conditions, typically through oxidation-reduction manipulation, which induce the desired transformation via microbial catalyzed biochemical reactions. In situ bioremediation melds an understanding of microbiology, chemistry, hydrogeology, and engineering into a cohesive strategy for planned and controlled microbial degradation, reduction, and/or oxidation to achieve a specific goal. Key steps of in situ treatment include
Mining, petroleum refining, and agricultural activities often produce large quantities of nitrate and metal containing wastewaters that require reclamation measures to minimize impacts, or potential future impacts, to downstream waters. This task varies from site to site, can be complex dealing with water chemistries that can change with time, and often represents a significant commitment for many years.
Nitrate is recognized as a high priority contaminant; hundreds of thousands of high concentration point sources and extensive groundwater contamination are the result of agricultural and animal farming activities across the US.Nitrate contamination has caused the shutdown of wells and rendered aquifers unusable as drinking water sourcesNitrate is a stable and highly soluble ion with a low potential for co-precipitation or adsorption. These properties make it difficult to remove using conventional water treatment technologies, such as lime softening and filtration. More sophisticated technologies—chemical denitrification, ion exchange, reverse osmosis, electrodialysis, and biological denitrification—can be used to remove nitrates from water. Biological denitrification has been demonstrated as a cost-effective means of removing nitrate from water. Nitrate reduction to nitrogen gas occurs as a series of steps, as follows:
NO3- --> NO2- --> NO --> N2O --> N2
In situ bioremediation is the application of biological treatment to the cleanup of contaminants in groundwater. This process creates subsurface environmental conditions, typically through oxidation-reduction manipulation, which induce the desired transformation via microbial catalyzed biochemical reactions. In situ bioremediation melds an understanding of microbiology, chemistry, hydrogeology, and engineering into a cohesive strategy for planned and controlled microbial degradation, reduction, and/or oxidation to achieve a specific goal. Key steps of in situ treatment include
- Site evaluation designed to understand site chemistry (contaminant and co-contaminant types and forms), geological conditions, microbiology, and possible environmental changes and interactions
- Biotreatability testing using site waters
- Designing a treatment approach to provide desired contaminant removals and conduct of on-site testing
- The most important consideration is the ability to transmit and mix liquids in the subsurface
Cyanide Bio-oxidation
INOTEC’s cyanide removal system uses new fluidized bed reactor technology that enhances both biological and biochemical cyanide degradation and removal many fold. The technology has ~1/10 the power consumption of conventional aerobic treatment systems, 1/2 to <1/10 the footprint of conventional treatment systems, and can be powered in many locations using a solar grid.
Cyanide is used extensively in mining, electroplating, and circuit board manufacturing, and has been found in at least 29% of the 1,430 EPA's National Priorities List sites. It is well known that cyanide solutions placed in ponds or tailings impoundments undergo natural attenuation reactions which result in the lowering of the cyanide concentration. These attenuation reactions are dominated by natural volatilization of hydrogen cyanide, but other reactions such as oxidation including biooxidation, hydrolysis, photolysis,, and precipitation also occur. Natural cyanide attenuation occurs with all cyanide solutions exposed to the atmosphere, whether intended or not and it happens at slower rates in anoxic environments. In general, biological cyanide degradation is accomplished by stimulating indigenous bacteria through nutrient addition and optimizing growth conditions (i.e. pH, temperature , oxygen, etc.). Aerobic bacteria have a relatively high free cyanide toxicity threshold •200 to 280 mg/L – up to >600 mg/L in protected environments. pH ~ 7.0 to ~9.5 – optimum for cyanide degradation. Improved bioprocess technology allows cyainde to be rapidly treated in a bioreactor environment with the cyanide-free effluents used to rinse pads to achieve rapid cyanide removal.
Cyanide is used extensively in mining, electroplating, and circuit board manufacturing, and has been found in at least 29% of the 1,430 EPA's National Priorities List sites. It is well known that cyanide solutions placed in ponds or tailings impoundments undergo natural attenuation reactions which result in the lowering of the cyanide concentration. These attenuation reactions are dominated by natural volatilization of hydrogen cyanide, but other reactions such as oxidation including biooxidation, hydrolysis, photolysis,, and precipitation also occur. Natural cyanide attenuation occurs with all cyanide solutions exposed to the atmosphere, whether intended or not and it happens at slower rates in anoxic environments. In general, biological cyanide degradation is accomplished by stimulating indigenous bacteria through nutrient addition and optimizing growth conditions (i.e. pH, temperature , oxygen, etc.). Aerobic bacteria have a relatively high free cyanide toxicity threshold •200 to 280 mg/L – up to >600 mg/L in protected environments. pH ~ 7.0 to ~9.5 – optimum for cyanide degradation. Improved bioprocess technology allows cyainde to be rapidly treated in a bioreactor environment with the cyanide-free effluents used to rinse pads to achieve rapid cyanide removal.
Cyanide Tests
Comparison of bench and pilot-scale tests using treated rinse waters.
Under Construction
