Innovative adsorption material containing carbon nanotubes for purification of waters with an ambition to replace granulated activated carbon in water treatment industry. ART SAND is focused on capturing of organic matters, so called micropollutants, especially pesticides, herbicides, fungicides, drugs, its metabolites and other organic pollutants originating from daily human activities. Material excels at passive microbial and viral disinfection without the need of using chemicals. It is three-dimensional, bulk material which can be filled into ordinary pressure filter without the needs of additional investment.
What ART SAND technology can do? Carbon nanotubes is well known allotropic modification of carbon. Their unique tubular structure provides them with stability, high kinetic of adsorption, big specific surface area and porosity. CNTs were studied for application in capture of wide range of organic molecules ranging from pesticides, drugs, volatile organic compounds, dyes, phenol to naturally occurring organics in water. We believe that CNTs are next generation of carbon adsorbent materials with broad range of possible applications. Significantly higher adsorption speed of CNTs compare to granulated activated carbon (GAU) is caused by better accessibility of adsorption sites on the CNT surface in comparison with relatively difficult to access pore system presented in GAC.
CAPTURE OF PHARMACEUTICALS FROM WASTE WATERS
ART SAND material captured 34 of 37 pharmaceutical substances found in waste waters sampled on the outflow behind classical technology used in municipal waste waters treatment plant (handles approximately 1.000.000 equivalent population. The material is able to capture wide range of different organic pollutants. Eight commonly used antibiotics were found between captured molecules.
PESTICIDES ADSORPTION FROM MODEL SOLUTION
Indicative adsorption capacity of ART SAND material was measured in model solution containing four pesticides (alachlor, chloridazon, metolachlor and metazachlor) commonly found in czech underground and surface waters. Adsorption capacity determined out of obtained adsorption isotherms was 165-514 mg of organic compounds per one gram of CNT. Thus, 1 m 3 of ART SAND material is able to capture 2,2-6,8 kg of organic matters from water. Long-term operational tests and more precise adsorption characteristic are currently undergoing.
RAPID ADSORPTION KINETICS
Speed of adsorption is a crucial and basic parameter which determine necessary contact time of water with adsorbent for its sufficient purification. CNT´s kinetic of adsorption is many times quicker compared with GAC. This is caused by the easier accessibility of adsorption sites on CNT outer surface which is all in contact with purified water. In the case of GAC, molecules must wander through an intricate networks of granule pore channels which takes time. In addition to that, smallest pore channels are even inaccessible for water because of water´s high surface tension. CNT reach adsorption equilibrium in minutes compared to tens of minutes in the case of GAC.
Adsorption material ART SAND has unique ability to passively disinfect water. CNT disrupt cell walls and effectively destroys bacteria and other microorganisms without the need to use chemicals. Disinfection process thus do not leave any un-wanted byproducts. Antimicrobial properties of ART SAND were tested on highly contaminated waste waters from municipal waste waters treatment plant. Material is able to disinfect even such contaminated water on level suitable for utilization of water for technical application.
|Wastewater||ART SAND technology|
|CUMI 22°C [KTJ/ml]||49120||131|
|CUMI 36°C [KTJ/ml]||29840||80|
|KOLI [KTJ/100 ml]||57000||89|
|ECOLI [KTJ/100 ml]||27700||16|
|ENTERO [KTJ/100 ml]||10700||11|
|CLO [KTJ/100 ml]||1000||0|
KUMI22°C … cultivable microorganism with growth specification at 22 °C
KUMI36°C … cultivable microorganism with growth specification at 36 °C
KOLI … coliform bacteria
ECOLI … Escherichia coli
ENTERO … intestinal enterococci
CLO … Clostridium perfringens
KTJ … colony forming units
Virotic pollution of water is no problem for new generation of ART SAND adsorption material. Waste waters from municipal waste waters treatment plant containing millions of virotic particles was completely purified by ART SAND. Virotic particles were captured inside of material, inactivated and destroyed during adsorbent regeneration cycle.
ART SAND material containing carbon nanotube is bulk adsorption material with the focus on the capture of organic compound dissolved in water, especially micropollutants. It can be used in same application where other adsorbent materials are commonly used (GAC). ART SAND technology is a new generation of adsorbent materials which utilize carbon nanomaterials and is suitable for: