Magnetized Uv Advanced Oxidation Processes (AOP)

Advanced Oxidation Process (AOP) eliminate highly active substances in wastewater

Highly active organic substances, such as pharmaceuticals (antibiotics, hormones, ...), agrochemicals (biocides, pesticides) and their metabolites, are increasingly being detected in wastewater and therefore find their way into drinking water again and again. Often these are drug residues that get there via the consumers. Even industrial wastewater can be contaminated with highly active substances.

AOP (Advanced Oxidation Process) are efficient oxidation processes processes, being enabled to sefely inactivate highly toxic and active substances to remove same from wastewater.

Advanced Oxidation Process has been used in various  industrial wastewater treatment.

Common to all oxidation processes is the formation of a very oxidizing environment during the wastewater treatment, in which the pollutants are converted to bio-available water ingredients. With a sufficiently long treatment, the mineralization essentially takes place into carbon dioxide, water and salts.

Advanced oxidation processes (AOPs) are treatments which rely on the accelerated generation of hydroxyl radicals (OH), one of the most powerful oxidizing agents in nature.OH radicals react and destroy any organic and inorganic contaminants in water and wastewater. The most popular AOPs are based on the combination of ozone or Uv light with different chemicals,such as Uv/H2O2, ozone/H2O2 and photo-Fenton (UV/H2O2/Fe). Another high-potential process is photocatalysis,incorporating semiconductor catalyst with UV or solar light.

Emerging AOPs include hydraulic and ultrasound cavitation, arc plasma and other OH-generating processes. AOPs are considered the only viable treatment methods for effluents containing refractory, toxic, and non-biodegradable materials, and their major advantages are complete mineralization of organics (without any sludge or waste stream) and easy combination with biological processes.

APPLICATIONS

DEGRADATION OF WATER AND WASTEWATER CONTAMINANTS

Advanced oxidation processes are the only commercially available technology able to completely destruct non-biodegradable water and wastewater contaminants. Target compounds include pesticides, taste&odor chemicals, emerging contaminants and more. UV-based AOPs were marked as Best-Available-Technology by the USEPA for tertiary treatment of wastewater for indirect potable reuse

DISINFECTION- INACTIVATION OF PATHOGENIC MICROORGANISMS

Hydroxyl radicals (HO•) can inactivate microorganisms through lipid peroxidation and/or damage to membrane integrity, DNA and proteins. Lipid peroxidation, that is the conversion of unsaturated lipids to polar lipid hydroperoxides, results in decreased membrane fluidity and alters membrane properties.

INCREASE WASTEWATER BIO-DEGRADABILITY

Oxidants such as OH radicals are known to degrade large (non-biodegradable) organic molecules into small biodegradable ones. This is usually done through the addition of OH to aromatic rings, which facilitates ring-opening by bacteria in the biological treatment, and allows biodegradation. Treating 'hard' wastewaters with AOP increase the wastewater biochemical oxygen demand (BOD), improving subsequent biological treatment.

4.     Problems of Conventional Uv Oxidation Process

The principle of Uv oxidation is to irradiate photocatalyst (usually anatase TiO₂) with a certain wavelength of ultraviolet light to generate conducting electron (e-) and valence band hole (h+), which oxidate and degrade pollutants.

Among them,Photoelectron have strong reducibility,while valence band hole deprive the electrons of HO₂-, OH-, organic (RH)etc adhered on the surface of the photocatalyst and undergo a series of reactions to generate hydroxyl radicals·OH.The oxidation ability of OH is only second to fluorine.Itsoxidation function is almost non-selective. It oxidizes and mineralizes difficult-to-degrade organics.Pesticides, dyes, surfactants,and odorous substances etc all can be effectively treated with photocatalytic technology for disinfection, decolorization, deodorization, etc treatment.The pollutants can be completely degraded into CO₂, H₂O and inorganic salts.

However,Uv oxidation reaction rate is slow and the photon is inefficient etc whichrestricted its application in practice.

Magnetized Uv Advanced Oxidation Process

Magnetization have a certain effect on the physical and chemical properties of water,such as  increasing the absorption coefficient in the range of less  than 400nm and bigger than 600nm,increasing D.O,and  decreasing surface tension. It also affects the state of water molecules and ions in the water solution, thereby affecting the Uv oxidation process and results.

Circulate wastewater under magnetic field can achieve magnetization and improve oxidation effect (including the combination of UV irradiation and magnetization before UV irradiation or simutaneously).

Under the effect of a certain external magnetic field, the physical and chemical properties of the water will change to a certain extent,such as pH,viscosity,dispersion coefficient,surface tension,electrical conductivity,etc.Dissolution,crystallization,wetting,solidification,precipitation and microbe metabolic processes are affected as well.The effect of the magnetic field on water also has an obvious memory effect.The external magnetic field changed the physical and chemical properties of the wastewater,weakened its "cage effect", which facilitates the "out-of-cage reaction", reduces the probability of recombination of free radicals,also facilitates the smooth processing of the reaction.

The reaction rate is doubled.Compared with conventional Advanced Oxidation,the magnetic advanced oxidation produces higher ·OH (hydroxyl radical) rate,the reaction rate is faster, the hydraulic residence time is shorter, and the required reactor chamber is smaller;

COD removal rate is improved.Because magnetic system reduces the probability of free radical recombination,which is equivalent to more hydroxyl radicals.

The COD removal rate is increased over 10% than traditional AOPs.

Reduced chemical consumption.Because the magnetic field can reduce the recombination of free radicals,which indirectly reduces chemical consumption.

Unique features of the magnetized Uv oxidation Process

1) Use magnet device as enhanced photocatalytic oxidation.

2) Use dual oxidant system as enhanced photocatalytic oxidation.Magnetic photocatalytic oxidation uses foamed nickel coated with nano TiO₂ as the photocatalyst net and  Uv lamp as the light source and H₂O2 etc chemicals.

Traditonal AOP such as Fenton activates H₂O₂ by adding Fe²⁺ as catalyst to release more hydroxyl radicals(·OH) and degrade organic pollutants.

However,high-concentration and refractory wastewater requires huge amount of free radicals to degrade.The dual oxidant system activate each other, and generate different kinds and huge amount of free radicals to effectively degrade pollutants.

Magnetized Uv oxidation consumpts 30% less chemicals and has 10% higher efficiency than traditional AOPs.

Applications:

1)Treatment of high-concentration refractory organic wastewater,such as chemical, pharmaceutical and other industries;

2)High chroma wastewater treatment in printing and dyeing, dye intermediates and other industries;Landfill leachate treatment;

3)The pretreatment of the wastewater from the coking, petrochemical,rubber auxiliary chemical and chemical industries containing benzene ring or the effluent after biochemical treatment.

Kindly contact us for more information if you have any industrial wastewater treatment request.

Email:bwf.enviro@gmail.com