GB2515324A - Electrolytic advance oxidation processes to treat wastewater, brackish and saline water without hydrogen evolution - Google Patents

Abstract

A free radicals technology (FRT) electrochemical advanced oxidation process (AOP) for treating water and wastewater comprises injecting water and atmospheric air separately into a free radicals technology electrochemical advanced oxidation unit, supplying a DC current to electrodes comprising a titanium substrate coated with mixed oxides valve metals and passing water over the electrodes in the presence of ultraviolet radiation from a UV lamp positioned at the top of the unit. The process may generate hydrogen peroxide and ozone, and the hydrogen peroxide may decompose the ozone to generate hydroxyl radicals. Also disclosed is a hybrid FRT electrochemical advanced oxidation capacitive deionisation (CDI) process for treating contaminated brackish and saline water with organic pollutants and microorganisms, wherein the process comprises removal of suspended solids, colour, organic pollutants and eradication of the microorganisms and desalination to yield potable water for domestic or agricultural use (figure 6).

Description

Electrolytic Advance Oxidation processes to treat Wastewater, Brackish and Saline water without Hydrogen Evolution

Introduction

The future escalating world demand for safe water and the role of the present patent is in providing this life sustaining, essential fluid. However, water demand' will increase at an even greater rate, both now and in future years. Water is essential to life sustainability and as such is even more important than our dependence on oil.

Extraction of non-saline water from natural resources such as aquifers etc is rapidly depleting water sources, with climate change contributing to the lack of water replenishment of these natural water sources.

There is a need for an economic and potential process solution to ensure the future availability of safe drinking water for potable and other usage.

Several technologies have been developed to treat water, wastewater and brackish water of different sources.

The most popular technologies are: chlorination, bromination, reverse osmosis., ultra-violet, ozonation, bio-digestion, electrolysis lately CDI.

rrior art of electrolytic water and wastewater treatment process Electrolytic processes have been used for decades to treat water and wastewater.

Electrolysis is the process of causing a chemical reaction to occur by passing an electric current through a substance or mixture of substances, most often in liquid form. It is frequently results in the decomposition of a compound into its elements. To carry out electrolysis, two electrodes, a positive electrode (anode) and a negative electrode (cathode), are immersed into the material to be elecnolysed and connected to a source of direct (DC) electric current.

Tn electrolysis, there is a direct relationship between the amount of electricity that flows through the cell and the amount of chemical reaction that takes place.

Perhaps the best known example of electrolysis is the electrolytic decomposition of water to produce hydrogen and oxygen: 2H20 -I-energy * 2H2 + 02 Different types of electrodes have been used for electrolyses, some are sacrificial electrodes such as iron & aluminium and others non-sacrificial electrodes such as activated carbon, stainless steel, and titanium coated mixed oxides clectrodes etc. The sacrificial electrodes dissolve, releasing their metal ions. Besides reactive radicals, metal hydroxide floes are produced in the process. These electrolytically generated metal hydroxide flocs have a high adsorption capability and can thus bind to finely dispersed particles. In addition, there arc co-precipitation and occlusion precipitation reactions, in which dissolved organic and inorganic substances are precipitated. The precipitated substances can then be separated mechanically.

Non-sacrificial electrodes provide through electrolyses, electrolytic and oxidative processes that offer economically attractive and sustainable solutions for the purification of industrial process watcrs, and wastewaters. They arc a good alternative for substanccs that cannot bc brokcn down conventionally or that are oniy degradable at great expense.

Water and wastewater treatment via electrolytic oxidation process depend mainly on the hypochloros acid/chlorine. The by-products hypochloros acid/chlorine have limited capabilities to treat highly contaminated wastcwater.

Electrolysis prior art technology for water and wastewater treatment is mainly dependant on adding salt to generate chlorine and hypochlorous. The technology is not efficient in treating industrial wastewater.

A number of inventions for electrolytic water and wastewater treatment process arc known according to prior alt such as: U56274028, U56706168, 11S6689271, US20030106854, US20070029201, WO2012076940A1 W02010148432A1 US 8157972 EP515628, U.S. Pat. No. 4,406,758, US 4,511,411, DE3430616, US 2008/0237060, EP711730, US 2008/0237060, DE 19633342, US 6746593, WO 07/1 1908, 5607473, DE 19534736, US 8157972, US 6274028, US 7384564, US 6126838.

All the above prior art did not give any account regarding hydrogen generation, formation of oxyhydrogcn mixture and their entrapment within the generated sludge layers and the foam floatation during elecfrochemical process.

For that reason i has not been hug&y successful on the market and has not become commerciafly widespread.

Disadvantaues of prior art of electrolysis in water and wastewater treatment Hazardous gases ill the form of hydrogen and oxygen are normally generated in excess during electrolysis resulting in thc formation ofoxyhydrogen mixture.

During water treatment via electrolysis, hydrogen is generated at the cathode as a result of cathodic reduction in accordance with the following equation: 2H20 + 2e -4 H2 + 20H At the anodc oxygen is generated as a result of anodic oxidation in accordance with the following cquation: 2H20 02+ 4H + 4e The hydrogen and oxygen lead to the formation of an oxyhydrogcn mixture.

During electrolysis treatment of industrial wastewater, eywater, laundry wastewater and any other wastewater containing organic materials, the oxyhydrogen mixture entraps within the sludge layers and floatation foam.

Any spark or electrical discharge could cause an explosion, which could result in loss of human lives and serious damages.

Precious metal containing mixed metal oxide (MMO, such as Ru02, lrO2, Ti02, 5n02...) coated electrodes using titanium as substrate has revolutionized the electrochemical processes for water treatment.

Water and wastewater treatment by the electrolytic oxidation process using MMO coating electrodes dependant on adding salt to generate chlorine and hypochlorous acid. This is insufficient in trcating wastewatcr and toxic un-degradable organic contamination.

Furthermore, electrode materials tend to become fouled during the electrolytic oxidation process with various solutes and deposit scales and metallic oxides on the working suiface of the electrodes.

This lowers the efficiency and lifetime of thc electrodes. As a result of such deficiencies, the wastewater treatment system requires a relatively long time and high-energy expenditure to aclueve the desired results, at the electrical current densities that are typically employed.

In response to that, electrodes are subject to decrease in their efficiency. Therefore prior art techniques have to introduce periodically the reversal polarity of the electrodes such that a reversal of scaling process can take place to clean the electrodes.

It is known that the most damaging process resulting in severely reducing the service life of the electro catalytic coating of the titanium electrodes (electrodes coated with MMO) is polarity reversal. Current reversal will have a significant effect on the lifetime of the electrode.

As a result of this, electrodes are rendered inactive more frequently meaning uipment-related shutdowns are necessary for the replacement of ncw MMO electro-catalytic electrodes.

To rectify the electrodes fouling problem and to avoid reversal polarity, US pat. 815972 given state of art by reducing precipitate and fouling that typically occurs in water treatment system. This prior art included a softened water by-pass stream in which a flow through electrolytic element can be positioned. By eliminating exposure of the electrodes to hard water, scale formation on the clectrodes are reduced or prevented.

This prior art method is impractical when treating high flow rate of industrial wastewater. It also lowers the conductivity of the treated water or wastewater. As a result of lowering the conductivity, a higher current is required to proceed with the electrolytic oxidation process, resulting in high-energy expenditure to achieve the desired results.

Prior art of water and wastewater treatmeat by Electrolysis without hydroen gas generation, or reducing generated hydrogen problem.

Many attempts through research work and patents have been done to rectify the problem in reducing and eliminating the danger of the generated hydrogen and oxygen during electrolysis process, which includes: 1. Several mechanical means being applied such as efficient dilution using blower or ejector fans and removed by venting to the atmosphere. Blowing air at the surface of the electrolysis sweeps out the generated hydrogen and oxygen. But this method couldn't solve the problem especially when the oxyhydrogen mixture is entrapped within the sludge layer and tloated foam, which has been produced during the electrolysis process. Any spark or electrostatic contact within the foam could cause a huge explosion.

2. Gas diffusion electrode.

3. Ion-exchange membrane between the cathode and the anode.

4. Polymer membrane, semi-permeable to either hydrogen or hydroxide ions.

5. Using anthraqu none as hydrogen carrier by forming anthraqu none layer on the surface of the cathode material of electrolytic cell.

The state of prior art US pat. 20060249374 method for electrolytic disinfection without cathodic hydrogen evolution achieved by using oxygen consuming electrode in the foim of gas difthsion electrodes, comprise a water impermeable but oxygen permeable teflon film. A carbon layer acting as a porous electrode and metal wire netting or expanded metal, which serves for supplying current and for mechanical stability of the electrodes. The unit comprises an anode, which is positioned between the gas diffusion electrodes. The embodiment of the prior art invention consisting of titanium elcctrodcs coated with mixed oxides (Ru02 and IrO2) arc used as the anodc suitable to generate hypochlorite and hypochlorous acid, which is due to the anodic reaction of the chloride content of the water as shown in the following equations: 2cr CI, + 2e, Cl7 -I-H,O HOC1 + HC1 Hypochloros acid and chlorine have veiy limited capabilities to treat highly contaminated wastewater.

The Electrochemical Oxidation Potential (EOP) and the Relative Oxidation Activity of the hypochlorous acid are 1.49 and 1.1, whereas the hydroxyl radicals are 2.8 and 2.05, POP for chlorine is 1.36 (Munter, 2001) In a further embodiment of the prior art boron diamond doped elcetrodes (BDD) are used as the anode. The BDD electrodes are used when chloride content of the water is low and other disinfectant substances such as ozone, peroxidisulfate and hydroxyl radicals are to be generated as effectively as possible. The lime and fouling of the electrodes are usually removed by a periodic change of polarity.

BDD electrodes are expensive and have voltage limitation (over 4 volts damage the BDD coating) to treat high volume and contaminated wastewater.

Items 2-4 technologies are mainly used for the production of hydrogen peroxide.

The patented innovations for elimination of the generatcd hydrogen through the reduction process include, using gas diffusion cathodes, or using associated cathode ionic membrane, and others with cathode and anode membranes, being published such as US pat.No.4758 317, US. Pat.5M5700 and PP 0949205.

The energy and cost intensive proccss of the membrane, Gas diffusion electrode, Ion-exchange membrane between the cathode and the anode, polymer membrane, semi-permeable to either hydrogen or hydroxide ions and the complexity of the system makcs it unsuitable for water and wastewater treatment in general. For that reason none of these technologies gain any popularity or application in the vicinity of water and wastewater treatment market.

Re item 5 anthraquinonc Patentjp 9094580 using anthraquinonc to be formed on the surface of the cathode to reduce generated hydrogen into hydrogen peroxide.

BSAF developed a process using anthraquinon to produce hydrogen peroxide based on oxygen reduction.

The use of anthraquinone technology is costly and complicated. It limits electrolytic voltage applied to avoid the destruction of the anthraquinone, which some required to treat highly contaminated wastcwatcr and un-biodegradable material.

Anthraquinone method is expensive and incapable in treating high flow rate and volumes of water and wastewater.

Summary of the present inventioii

One of the main tasks of the present invention is to get high quality water in sufficient quantity at an affordable price from the unused ravage water.

The present invention is a process to treat and desalinate water, wastewater highly contaminated with un-degradable organic material and high TDS, brackish and saline water.

FRT-Electrochemical AOPs (Advanced Oxidation Process) and Hybrid FRT-Electrochemical AOPS-CDI (Capacitive Deionisation) technology is an essential and significant discipline in different sectors of water, wastewater, brackish and saline water treatment including clean synthesis, water desalination and sterilisation with long residual disinfection period.

It is capable of removing organic material, biological contamination, agglomerating suspended solids, colour, any metallic ions, salt ions, inorganic and organic complex ions in the industrial wastewater, brackish and saline water.

It has significant advantages such as its simple equipment, convenient operation and non-requirement of chemical substances for the sedimentation and tioc generation.

It allows the wastewater treatment to electrochemically oxidize and reduce the bio-organism and organic contaminants to non-hazardous inorganic substances.

The present invention technology is effective, low cost to run, and an eco-friendly alternative process for the removal of various recalcitrant contaminants from wastewater. It can be helpful in the recycling and treatment of wastewater producing high quality water at an affordable price.

Advanced Oxidation Processes (AOPs): The term Advanced Oxidation Processes (AOPs) describes a series of processes aimed at tackling pollution in watcr. They arc uscd for the treatment of organic and inorganic pollutants in wastewater. AOPs are based on the generation of reactive oxygen species (ROS) such as hydroxyl and oxygen radicals.

Generating hydroxyl radicals is possible via various ways such as photolytic, electrochemical, and sono-chemieal.

AOPs use water and wastewater treatment process by oxidation through reaction with highty reactive hydroxyl radicals (.OH).

AOPs involve the two stages: 1-the formation of hydroxyl radicals and 2-the reaction of the hydroxyl radicals with organic contaminants.

Below are relative oxidation activity of hydroxyl radicals (.011) compared with other oxidising agents (Munter, 2001 table 3).

Oxidising agent relative oxidation activity Positively charged hole on titanium dioxide Ti02+ 2.35 Hydroxyl radical 2.05 Atomic oxygen 1.78 Ozone 1.52 Hydrogen peroxide 1.31 Permanganate 1.24 Hypochlorous acid 1.10 Chlorine 1.00 Table 3. Relative oxidation activity of some oxidising agents (Munter, 2001).

The rate constants of the hydroxyl radicals are typically I 6 -I o times higher than the correspondrng reaction rate constants of molecular ozone (Munter 2001 Table 4) Organic compound Rate constant [M-1 s-i] *OH Alcohols 1o2_1 io8-io9 Aromatics 11o2 io8-io'° Chlorinated alkenes i03-104 1091011 9 10 Ketones 1 10 -10 N-containing orgaiiics 10102 1o8l0b0 3 9 It) Phenols 10 10 -10 Table 4. Reaction rate constants for ozone and hydroxyl radical for organic Compounds (Munter.

2001).

AOPs in general are cheap to install but involve high operating costs due to the input of chemicals such as hydrogen peroxide and ozone and energy rcquired.

Capacitive deioiiisation (CDI) Is a promising alternative technology in desalination. The basic concept of CDT is elecfrical potential induced surface adsorption of ions on to electrodes. It targets to remove the salt ions and an ionic material from a medium, by applying a voltage to a pair of electrodes. The electrodes made of porous carbon. The ideal electrode materials for CDI should be highly conductive, with a high surface area and suitable pore size. The salt ions such as charged sodium (Nat) and chloride (Cr) ions and other ionic material in the brackish water are adsorbed onto surfaces of the electrodes. In such a CDI device, when a low direct current ("DC) voltage is applied to the electrodes while the medium containing dissolved ions flows between the two electrodes, i.e., a positive electrode and a negative electrode, anions dissolved in the medium are absorbed and concentrated in the positive electrode, and cations dissolved in the medium are absorbed and concenLrate'J in the negative electrode. When current is supplied in a reverse direction, e.g.. by cicctnc.aliy s!urting the two electrodes, the conccntratcd ions arc dcsorbcd from the ncgativc electrode and positive electrode. Since CDI devices do not use a high potential difference, the energy efficiency thereof is high. Furthermore, CDI device does not require harsh chemical cleaning process.to reg:encrate the electrodes and are thus have a relatively low environmental impact.

Brief Summery of the presdilt inventioll The present invention relates to: A) FRT-Elcctrochcmical AOPs Is based on the generation of high reactive oxygen specious (ROS) such as hydroxyl radicals, hydrogen peroxide ozone and chlorine dioxide to attack wide range of organic, inorganic compound and micro organisms.

B) Hybrid FRT-Electrochemical AOPs-CDI FRT-Electrochemical AOPs is merged with CDI (capacitive deionisation), to form Hybrid FRT-Electrochemical AOPs-CDT that is in addition of its capability of treating organic material, biological contamination, and other issues of water contamination, it is capable of treating brackish and saline water and reducing wastewater's high TDS to any required level.

In accordance with the present invention, which has proven: * ERT-Electrochemical AOPs and Hybrid FRT-Eleetrochemical AOPs-CDI are alternative developed electro catalytic treatment to offer high advanced oxidation process, desalinating and disinfection technology.

* Eliminate gcncration of hazardous gases.

* Environmentally friendly process, cheap to install, economically attractive and sustainable solutions for the purification of industrial, process waters, and wastewaters.

* Thc energy required for operating thc system is cost effective can be provided by powcr supply, or solar power.

* Low operating cost to build up the system.

* No input chemicals required such as hydrogen peroxide and ozone to generate reactive oxygen species (ROS) such as hydroxyl radicals.

* Safe polarity reversal to clean the electrodes from scaling and fouling.

Three stages are involved with the operation of FRT-Electroehernical AOPs and Hybrid FRT-Electrochemical AOPs-CDI applications: 1-The first stage is electro-oxidation that gcnerates the free radicals i.e. hydroxyl, oxygen and chlorine radicals, (direct oxidation process) and oxidants i.e. hydrogen peroxide, ozone and chlorine dioxide (indirect oxidation process).

2-The second stage is that the generated hydrogen peroxides will enhance the decomposition of the generated ozone to form more hydroxyl radicals. To sunimarise: two ozone molecules will produce two hydroxyl radicals (Muntcr 2001) 203 -I-H102. 20H+ 302 3-The third stage, which involves photolytic-dissociation by applying liv radiation to the generated oxidants i.e. hydrogen peroxide and ozone to generate excessively more highly reactive hydroxyl radicals.

H202 * 2*OH th -I-H,O * H,07 + 2*Oll cio* + o* The action of hydrogen peroxide, ozone and chlorine dioxide molecules with the generated hydroxyl radicals' result significant improvement in the rates of decomposition of pollutants in aqueous solutions.

Hybrid FRT-Electrocheniical AOPs-CDI, performing the above mentioned 3 stages plus reducing the high TDS of the wastcwatcr to the required level and desalinate brackish and saline water.

Advantages of the present invention: * Treatment is based on Electrochemical Advanced Oxidation Processes (AOPS) to generate hydroxyl radicals with other ROS species in excess to initiate oxidative destruction of organics pollutants and micro-orgainism * Complete demineralisation of pollutants possible * No increase in salinity, which enables re-circulation * No disinfection by-products, in particular no halogenated compounds * Little or no sludge formation * Hygienic outflow water * Robust process -discharge critena can be met reliably * Available quickly -standby operation possible * Suitable for varying quantities and qualities of wastewater * Staff savings and increased reliability.

* No hydrogen gas generation.

* No dangerous oxyhydrogen mixture formation * Long residual disinfection period for at least 3 months.

* Safe reversal polarity * No added chemicals such as hydrogen peroxide and ozone to start AOPs (Advanced Oxidation Processes) treatment * Cost effective system * In treating wastewater the sludge separated from the wastewater is sterile with no bad odour problem.

Amon the prior art of AOPs treatment of water and wastewater are: 1-Hydro2en Peroxide/Ozone (HQQ) process: The addition of hydrogen peroxide to the aqueous solution of ozone enhances the decomposition ofth with the formation of hydroxyl radicals.

To summarise: two ozone molecules will produce two hydroxyl radicals (Munter, 2001): 201+H202 2*Oll+302 The action of both ozone molecules and the generated hydroxyl radicals results in a significant improvement in the rates of decomposition ofpo!lutants in aqueous solutions.

The Hydrogen Peroxide/Ozone (H202/03) system is used to treat water and wastewater.

The disadvantaes of Hvdroten Peroxide/Ozone (H,02LQ3) prior art technoloav are: 1-The System requires H202 storage tank and injection system, an ozone generator, liquid oxygen or compressed air tank, ozone diffusers, ozone contactor, an ozone off-gas decomposer, supply and discharge pumps and piping, mixing vessel monitoring and control systems.

2-Since O decomposes rapidly, it is required to be produced on site using a generator fed with dried compressed air or oxygen.

3-Ozone has low solubility in water, it requires injecting 6 parts in water, I part remains in water and S parts diffuse to the atmosphere. Ozone is highly hazardous to health. Cm-rent methods for removal of ozone in the off-gas include thermal destruction, catalytic reduction, or a combination of the two. These controls will add to the operational and capital cost of the system.

4-The effectiveness of H2O2/03 can be reduced by the presence of excess particulate matter or scaling parameters that foul the ozone gas diffusers.

5-The presence of radical scavengers will affect treatment performance, independent of the selected AOPs. More quantities of hydrogen peroxide and ozone are required to overcome the scavenged hydrogen peroxide by radicals' scavengers.

The complexity of the system, energy and cost intensive process, requiring safety regulations, makes it unsuitable for water and wastewater treatment in general.

The system did not gain any popularity in the water and wastewater treatment.

2-UV/03, UV/H202 and UV/03/H202 processes: The combination of UV radiation, ozone and hydrogen peroxide, or both significantly enhances the rate of generating free radicals. Ozone absorbs UV radiation at a wavelength of 254 nm (equation 14) producing hydrogen peroxide as an intermediate, which decomposes further to hydroxyl radicals (equation 15) (Muntcr, 2001): 03 02+O(1D) O(1D)+H20 H2O2 2*OH Hydroxyl radicals are generated when low and medium-pressure UV light is applied to treat water.

Dcstuction of organic compounds occurs by hydroxyl radicals reactions, coupled with direct photolysis and oxidation by molecular ozone and hydrogen peroxide.

Disadyantaes of UV/tlh, UV/11202 and UV/O3bO2 prior act treatment technolon are: The disadvantages are similar to 03/H202 system which require diffusers, liquid oxygen or compressed air tanks, contractor and mixing vessels, ozone off-gas catalytic decomposer.

tcmpcraturc controller, supply and discharge pumps and piping, monitoring and control system.

The complete system has complexity, energy and cost intensive processes, and requires safety regulations, which is 1101 suitable for water and wastewater treatment in general.

Thcrc arc other AOP technologies such as High Energy Electron Beam, Sonication Hydrodynamic Cavitation, 1i02-Catalyzcd LV Oxidation and Fentons Reaction.

These AOP systems require generally highly engineered processes, which leads to reduction in space requirement to achieve similar performance. However, due to the complexity of the process and high requirements for energy, operation and maintenance, advance systems inhere a higher risk of technical failure.

However overall, AOP units where special construction materials may be required to withstand increased corrosion but still expensive to operate owing to the usage of costly chemicals such as H202, increase the energy consumption. The system requires highly engineering desii and maybe engineers to run which add and inhere higher cost.

It should also be noted that the treated water with any technology available in the prior art, will be opened to re-infection within a few days, i.e. it has short residual disinfection period.

For that reason the treated water can be stored for up to 24 hours before being pumped to the point of use. After this time the water must be sent to the drain, otherwise it can experience a proliferation of bacterial growth that could be dctrimcntal to public health.

In conclusion the prior art of cessation of hydrogen gas generation during electro-catalytic process for waflewater treatment by applying different techniques of membranes is costly and unsuccessful in treating high volume of industrial wastewater contaminated with toxic organic compounds.

Most prominently, costs of AOPs are too high, since a continuous input of expensive chemical reagents such as hydrogen peroxide and ozone produced on line are required to maintain the operation of most AOPs system.

The field of the present invention:

1. Gcncrating Rcactivc Oxygen Species (ROS) ablc to attack a wide range of organic compounds and micro organisms.

2. Eliminating the hazardous generation of hydrogen and oxygen, during the electrochemical process.

3. Generated hydrogen peroxide enhances the decomposition of the generated ozone to produce highly reactive hydroxyl radicals.

4. UV photolytic-dissocialion of the generated hydrogen peroxides and ozone to produce highly reactive hydroxyl radicals.

5. Capable of treating highly toxic organic compounds resulting from industrial, pharmaceutical, hospital, etc wastewaters, reducing them into carbon dioxide and water, alternatively transforming toxic organic compounds into biodegradable materials.

6. Destruction of micro-organisms, algae, fungi and other colonies.

7. Converting sonic of the soluble inorganic compounds into insoluble substances for easy separation and filtration.

8. Agglomerating the suspended solids for easy filtration.

9. Providing the treated water, wastewater, and brackish and saline water to remain virtually sterile for a period up to 3 months and beyond. This is important for hot climate countries, especially if the water required to be stored in tanks for considerable period of time or travel for a long distance in the piping system.

Electrochemical Processes During electrolysis the following reactions take place: According to prior art, hydrogen gas is generated as a main cathodic reduction and major reaction according to the following equations: 4H0 + 4e -* 2H2 -F 40f1 1 2H++2c -0 H,t 2 Radical chlorine is generated from the natural chloride content of the water at the anode: CF-e---------0 Cr 3 2C1 -0 Cl7 4 Anode oxidation 2H90-4e 4Ht+2&, 5 According to the present new innovation, the following reactions takes place: H20 + 21-(f (Y+2c 6 2Ft+02+2e -0 H202 7 cr+ 02 -. ClO, 8 Hydroxyl radicals formed by the reaction of cxcitcd atomic oxygen with water: H,0+0 2'O}l 9 20H 0 H,02 10 Ozone generation at the anode: 02+ 0 0 03 11 Generated hydrogen peroxide enhance decomposition of the genemted ozone with the formation of hydroxyl radicals: H202+03 * 2011-{-302 12 UV photolysis of hydrogen peroxide, ozone and chlorine dioxide: H202 p 2011 13 03 1w j 02+0 14 03 +H20 liii H202+20H 15 0 +H,0 brip. H202 j....02'OH 16 dO, C10 +O 17 The most significant part of FRT-Electrochemical AOPs invention technology is: * The invention is to quote FRT-electrochemicai AOPs new device which substantially improved by comparison with prior art and with which electro-chemical Advanced Oxidation Processes (AOPs) of water and wastewater treatment can be carried out rapidly, easy to apply and in cost-effective manner.

* The cessation of hydrogen and oxygen production, during electrochemical AOPs within FRI cell, to avoid hazardous oxyhydrogen mixture entrapment within the sludge and generated floated foam. The cessation of the production of hydrogen and oxygen is achieved without the use of the expensive and complexity of air cathode or polymer electrolyte membrane.

* Direct electrochernical AOPs, which involve excessive generation of hydroxyl and oxygen free radicals to oxidise any undegradable big organic molecules in the wastewater.

* The generated hydrogen peroxide enhances decomposition of the generated ozone during AOPs to produce hydroxyl radicals.

* The combination of TJV photolytie of the generated ozone and hydrogen peroxide during electrolysis significantly increase the rate of generating free radicals, i.e. hydroxyl and oxygen radicals.

* UV/H202/03 process is the most effective in the reduction of COD, colour and turbidity of the treated wastewater.

* Photo-dissociation of chlorine dioxide (dO2) to highly reactive C1O and O radicals.

* No chemicals required such as hydrogen peroxide and ozone during AOPs.

Introduction of ordinary sized air-bubbles (1-to mm) and generation of micro-bubbles (t -tm, a micrometer is I o6 meter) and nano-scopic sized bubbles (I-lt)(i om, a nanometrc* is io meter. in water and wastewater during electro chemical AOPs. Ordinary bubbles as soon as they are formed rise to the surface and collapse. Micro bubbles remain longer in water whereas the smaller super nano-bubbles have lower buoyancy and remain suspended iii water or wastewater for a longer period of time. This can be evpaiued by Brownian motion particle theory. Super naiio-bubbies will oscillate randomly in different directions and remain in water/wastewater for long period ol time without being afibeted by b ucwancy.

Nano-bubbles encapsulate oxidants; when the nano-bubbles eventually burst will release the oxidants produced by the ERT electrochemical cell.

Due to this special unique technology, it is capable of providing the treated water and wastewater with residual disinfection period around 3-6 months.

This is important for hot climate countries especially if the water is to be stored in tanks for a considerable time or required to travel for a long distance in the piping system.

* Capable of treating almost all toxic organic materials without transfer to another phase.

Separating some toxic metallic ions and inorganic soluble compounds into insoluble compounds for easy separation and filtration.

* Safe reverse polarity is developed by this invention without causing any damage to the electrodes, to clean the electrodes from scales and fouls of various solutes. The fouls are formed by depositing scales and metallic oxides on the working surface of the electrodes.

The polarity reversal is accomplished by programming the power supply, wherein before changing polarity, voltage is decaying slowly down to zero volts within one-minute period.

Then after, while voltage is still at zero volts, polarity is reversed, then voltage will rise slowly back to its voltage power within one minute period without causing any damage to the electrodes. Total time taken for polarity reversal is two minutes. The power supply can be programmed to change polarity at any regular time periodically as required.

* Certain eleetrocatalyst is necessary to generate ozone and hydrogen peroxide but unnecessary for F RT elcetrochemical new innovation technology.

* The developed Hybrid FRT-Electrochemical AOPs CDI system is capable of trcating any biologically contaminated, polluted brackish and saline water into potable water for domestic or reuse for agriculture purpose.

Fields of applications

FRT-Electrochemical AOPs and Hybrid FRT-Electrochemical AOPs-CDI consider its technology as one of the most significant recent advances in water, wastewater treatment, brackish water and saline water.

The developed process has shown to be highly effective in treating the following: - * Biological Oxygen Demand (BOD) * Chemical Oxygen Demand (COD) * Turbidity * Suspended Matter * Colour * Total Dissolved Solids (TDS) reduction * Oxidation of Metal Ions (Ferrous, Manganese etc.) * Eradicate wastewater and sludge obnoxious smells * Reducing Viruses, Bacteria, Other Bio-Organisms down to zero * Fluonde removal * Grey water and vegetable wash water for reuse purpose * Scale control * Flocculation and coagulation * Clustering fibrcs & Oily matcrial for easy removal * Algae destruction * Clustering Oil for easy removal * Reducing salinity * Treating brackish and saline water

Description and mechanism of FRT technoloay

A) FRT Electrochemical AOPs To treat water and wastewater with TDS below I 000ppm.

FRT Elcctrochcmical AOPs changes cationic demand, i.e. uncharged particles into charged particles, causing agglomeration of suspended solids.

Solids are agglomerated to particle sizes in the range 30-50 microns. The agglomerated solids can be separated by various filtration systems either using dead end' or cross-flow' filtration technology.

Both the separated solids and filtrate (permeate) would have been subjected to the Free Radicals treatment and therefore can be considered virtually sterile.

Free radicals are generated within the water and wastewater to be treated by FRT-Electrochemieal cell. More particularly hydroxyl. oxygen and chloride radicals.

A chain reaction is triggered by free radicals to generate oxidants such as Hydrogen Peroxide, Ozone and other peroxides as well such as Chlorine Dioxide.

The combination of Free Radicals and Oxidants produce one of the strongest oxidising agents known, capable of destroying organic chemicals and micro-organisms, such as Bacteria, Viruses Spores, Cysts, Fungi, Algae etc reducing them down into CO2 and H20.

The generated hydrogen peroxide enhances decomposition of ozone to produce hydroxyl radicals.

The Oxidants (hydrogen peroxide, ozone and chlorine dioxide)) generated during ERT clectroehemical AOPs are subjected to UV-light photo-dissociation (UVIH2O2, llV!O/H2O2 and UV/C102) significantly enhances the rate of generating free radicals.

During electrolysis course, at the cathode the water molecule will be reduced to hydrogen peroxide instead of hydrogen gas generation. At the anode the water molecule will be oxidised mainly into ozone.

B) Hybrid ERT-Electrochemical AOPs-CDI To treat organically and biological polluted brackish and saline water and wastewater with high

TDS

The treatment process undergo two stages: First Stage: The water (the term water uscd to all typcs of water) subjected to FRT-Electrochemical AOPs treatment action to get rid of any organic compounds, COD degradation, removing colour and turbidity agglomerating suspended solids, eradicating obnoxious odour, oxidising metal ions such as iron content from Fe2 to Fe3, and manganese content from Mn2 to Mn4 for easy separation and filtration, destroying micro-organism reducing them into carbon dioxide and water, and reducing TDS by 10-20% Second stage: The water after first stage treatment is run through a filtration system, and then is pumped to the powered CDI cell with low direct current (DC) voltage. The salt ions, metallic ions, inorganic and organic complex ions (anions and cations) in the water are attracted and absorbed by the oppositely electrodes (cathodes and anodes) of CDI cell. This concentrates the cations and the anions on the cathodes and the anodes, while reducing the concentration of the cations and the anions in the water. The clean water then passes out through CDI unit.

When the cathodes and the anodcs saturation capacity with cations and anions are reached the water flow is stopped upon reversing the polarity of the supplied current. This causes the cations and the anions to desorb from the cathodes and the anodes where they have been accumulated. The concentrated water with the desorbed ions is then purged out from the CDI unit.

Thc yield clean water, which is then treated further to adjust the sodium content to render thc water suitable for domestic, aiculture or for rcusc purposes. Some of the produccd clean water is run back through the CDI cells when no DC-voltage is applied to clean them for the next voltage application cycle.

To purify onc cubic meter of brackish water with TDS S000ppm by RO required 10KW, while the Hybrid ERT-Eleetroehernical AOPs-CDI required 1-2 KW, with water recovery up to X5-90%.

This process consumes less power than any competing technology to deliver waters and energy savings.

Hybrid FRT-Electrochemical AOPs-CDI system produce disinfected water with 3-6 months residual disinfection period. Whereas CDI prior art, required sterilisation after desalinating process which last only 1-2 days.

Description of Preferred Embodiments

A) FRT mono-polar clectrochemical-AOPs Unit fig.2 * The FRT mono-polar elcctrochcmical-AOPs unit is built up within PVC corrosion proof cell body fig.la, with inner MMO (mixed metal oxides) coated titanium electrodes, known as DSA (Dimensionally Stable Anode). It is made from commercially pure titanium as substrate, to which an electro catalytic layer is composed of a mixture of noble and valve metal oxides, the selection of which and their ratio is decided by the treatment required.

* The MMO used for coating are: Ruthenium oxide (Ru02) Iridium oxide (1r02), Platinum oxide (Pt02), Stannous oxide (Sn02) Antimony pentaoxide (Sb205) and Titanium dioxide (Ti02). As mentioned earlier electrode coating will depend on the treatment required.

* The special FRT-Eleetrochemical AUPs unit design and the mixed oxide coating is used to reduce the over-voltage of hydrogen evolution at the cathode, and oxygen at the anode.

Instead forming oxygen, hydroxyl. and chloride radicals that have exceedingly destruction power to reduce any organic and microbiological material into carbon dioxide and water.

* The generated free radicals trigger a chain reaction to generate hydrogen peroxide, ozone, and chlorine dioxide.

* The free radicals and the oxidants destruction power to the pollution in the industrial wastewater is over tens of thousands times stronger and faster than treatment conducted by chlorination, ozonation, hydrogen peroxide or chorine dioxide * The number of the electrodes within the eel! depends on the type, purpose, flow-rate and origin of water or wastewater requiring treatment.

A) Hybrid ERT mono-polar electrochemical-AOPs-CDI Unit fig 6 FRI mono-polar electrochemical-AOPs unit combined with Cm fig.5 unit to form Hybrid FRI mono-polar electrochemical-AOPs-CDI unit fig. 6 to treat biological contaminated brackish water, saline water and wastewater with TDS over I 000ppm.

* The CDI (electro-adsorption systems) cell is mainly consists of graphite current collectors and porous activated carbon electrodes derived from coconut shell with a specific area of SOO m2 per gram. It works by sequestering ions, or other charged species, in the electrical double layer of ultra-capacitors. In other words the cations and anions in a salt solution will be attracted to oppositely charged electrodes. The graphite current collectors were alternatively positively or negatively biased.

* The CDT cell assembly consists of different numbers of sheets of activated carbon as electrodes. The number of the electrodes is related to the treatment reqLtirement i.e. volume flow rate and salts ions concentration.

* The CDI cell assembly consists of 12 sheets, (6 sheets anodes and ôsheets cathodes) with dimensions: 120X80X0.Smm.

* The CDI cell encapsulate within PVC container fig. 5 * The electrodes within the cell are chargeable by an applied DC potential in the range of ito 2V.

* CDI cell can be powered by power supply or solar panel.

Drawin2s description:

FRT-Electrochemical Cell Fiaure 1 FRT-Electrochcmical ccli (mono polar cell) made of 8 MMO (Ru02/lrO2) coated titanium electrodes, with dimensions: 6OmmX l2OmimXl.00mm.

Each of four pair electrode sets (anodes & cathodes) is welded with its long side on a titanium plate (3mm thickness) with 7mm gap between each electrode. Titanium threaded 6M bolt welded on the top of the welded plate. A 3mm width and 1mm thick plastic strip is fixed on one side of cach electrode as a separator to avoid short circuit.

Each set of the electrodes emerges through each other to form FRT-Electrochemical cell.

FRT-Eleetrochemical IJn it Fi2ure I a FRT-Electrochemieal Cell (FigI) encapsulated in PVC container, the lower side has an inlet connected to circulation pump. The top fixed with detachable lid with rubber washer seal to make it water prove. Watcr outlet pipe for circulation is fixed at the middle of the lid and connected to circulation tank. Two cell's electrodes fixed through the lid by rubber washers and nuts to make it water prove.

Tank (Ti Fthure lb Tank T made of PVC.

Capacity 1 75 cc, Dimensions: 700X500X500 mm Tank T has threc outlets connected to pipes 25mm diameter: 1-outlet at the lower part, fixed with valve V3, 2-sample outlet fixed with valve ViS, 3-outlet for drainage fixed with ViS.

FRT-Electrochemical laboratory pilot unit Fitaire Ic Consist of: 1. Tank-T to hold the water for the trial.

2. FRT-Electrochcmical Unit Fig Ia 3. Power supply connected to ERT-Electrochemical cell.

4. Two valves, V4 and V6 5. Circulations pump P2.

FRT-Electrochemical AOPs Unit Figure 2 FRT-Electrochemieal AOPs cell is similar to FRT-Electrochemical cell Figl but coated with MMO (SnO2SbO2/Pt) and encapsulated within PVC cyclonic shape container, top diameter 250mm, bottom diameter 150mm, Height 400mm with detachable lid. The lower part of the cyclonic container has two inlets (a and b) that are mounted tangentially on the side of the conic cylindrical part of the cyclone body. Inlet-a is connected to circulation pump and inlet-b is connected to air pump/blower to jetting pressurized water or wastewater and air to FRT-cyclone unit.

DV lamp is fixed to PVC container's wall at 50mm above the FRT-electrochemical cell. Power to DV lamp is fed either via main or solar power.

At the apex of the lid a 25mm diameter outlet-c connected to 25mm diameter plastic pipe to circulate the trcated water or wastewater. Rubber washers and nuts connected to power supply or solar panel fix the electrodes of the FRT-Elcctrochcn1ical cell through the lid. The power to the FRT-electroehemical cell has controlled program polaity reversal facility.

FRT-Eleetrocheniical AOPs laboratory pilot Unit Finure 3 The laboratory pilot unit Fig 3 Consist of: 1. Tank-T 2. FRT-Elcctrochcmical AOPs Unit 3. Circulation pump P2 and valves V4, V6, VS and ViS 4. Power supply FRT Electrocliemical AOPs mini pilot Unit Fi2ure 4 The mini pilot imit Fig 4 Consist of: 1. Two filtration systems, Fl and F2 2. FRT-Electrochemical AOPs unit 3. Power Supply can be changed by solar panel if required as power source 4. Pumps,P1,P2, &P3 5. Valves Vl, V2, V3, V4, V5, V6, V7, V13, V14, V16 6. Tank-T CDI (Capacitive Deionisation) unit Fiure 5 The unit consist of: 1. Mono-polar CDI cell described above under article Description of Preferred Embodiments.

2. Valves,V9,V10,VII,V12 Hybrid ERT-Electrochemical AOPs-CDI unit Figure 6 The Hybrid unit Fig 6 consists of the combination of FRT Electrochemical AOPs Unit and CDT unit.

Hybrid FRT-Electrochemical AOPs-CDI mini Pilot unit flgure7 A combination of FRT-Electrochemical AOPs Mini Pilot Unit and CDI units Figures 4&5 Experiments and results Experiment No.1 Experiment conducted on tap water using ERT-Electrochemical laboratory pilot unit Fig.lc Power supply (0-l2volts, 0-100 amps) is connected to FRT-Electrocliemical cell.

Power controllcd via voltage control knob.

Power applied: Voltage: 4volts Amperage: lOamps.

Experiment conducted on, 150 litres tap water

Tap water specifications:

pH: 6.9.

TDS S6Oppm Hardness 275 ppm.

Few drops of detergent have been added to the water to create foam during electrolysis process to trap die generated oxyhydrogen mixture for test purpose.

Water continued circulation via pump P2 during the whole period of electrolysis process.

Hydrogen and oxygen gases excessively produced during electrolysis Hydrogen and oxyhydrogen mixture were tested as follows: Hydrogen gas: Using hydrogen detector/Hydrogen appliance model F[AR1 10 Oxyhydrogen mixture: Handful of the foam skimmed out of the surface of the water and exposed to spark, bang occurred resulted from oxyliydrogen mixture trapped in the foam.

Duration of eleetrochemieal process lasted 60 minutes.

Water analyses results after electrochemical process switched off: TDS: 500 Hardness*. 25Opprn PH: 7.4 Samples for test analysis were taken during electrolysis process.

Results are shown on table No.1 and graph Nol Experiment No.2 The experiment is conducted on tap water, using FRT-Electrochernical AOPs laboratory pilot Unit Fig 3.

The purpose of this experiment to compare the results of the present invention technology and prior art, in connection with the cessation of hydrogen gas generation, and production of hydrogen peroxide, ozone and chlorine dioxidc as main products.

Power supply (0-l2volts, 0-100 amps) is connected to FRT-Electrochemical AOPs Unit.

No power connected to TJV lamp.

Power controlled via voltage control knob.

Circulations pump P2 and air pump connected to main power.

cc of tap water poured into tanlc-T from its opened top.

Water and air are pumped and injected tangentially to FRT-Electrochemical AOPs unit to create cyclone and vortex motion.

Countless micro and nano-air bubbles generated due to formation of cyclone and vortex motions.

Micro and nano-bubbles along with the water stream are flowed tip to pass over the surfaces of the anodes and the cathodes of FRT-Electrochemical AOPs cell, and back to tank I through outlet-c.

Power applied: Voltage: 4volts Amperage: 1 Oamps.

Tap water specifications:

pH: 6.9.

TDS S6Oppm Hardness 2?Sppm.

Water continued circulation via pump P2 during the whole period of electrolysis process.

Duration of eleetrhemical process lasted 60 minutes.

Water Analyses results after eleetrochemical process switched oft pH: 8.5 TDS: 420 Hardness: l7Sppm Samples for test analysis were taken during electrolysis process.

Results are shown on table No.2 and graph No No.2 No hydrogen detected during the electrolysis process and oxyhydrogen mixture shows negative results after cxposcd to spark.

Experiment No.3 The experiment is carried on by FRT-Electrochemical AOPs mini pilot unit Fig.N0 4. with power to IJV lamp turned off Experiment conducted on 80% tap water mixed with 20% contaminated vegetable wash water.

Analysis results: PH: 6.2 COD: 4ôOOppm CFU: Over 500,000 cfu TDS: 700 Hardness: 32Oppm Turbidity: not clear Colour: reddish 150cc of die prepared contaminated wastewater fed through valve VI and pumped by pump P1 to filtration system Fl, to get rid of solids particles, debris and fouls before entering tank T. The filtered Wastewater from tank-T is circulated via pump P2 to filtration system F2 to separate the agglomerated suspended solids and the converted soluble organic and inorganic materials of the wastewater into insoluble matters during electrochemical AOPs process.

Filtered wastewater leaving filtration system F2 will be under low pressure. The loss in the flowing pressure is compensated by pump P3. The filtered wastewater is pumped via pump P3 tangentially to FRT-Electroehemical AOPs unit via outlet-a.

Air is introduced via air pump tangentially to FRT-Electroehemical AOPs unit via inlet-b.

Countless micro and nano-air bubbles generated due to the formation of cyclone and vortex motions. Micro and nano-bubbles along with the wastewater stream are flowed up to pass over the surfaces of the anodes and the cathodes of ERT-Electrochemical AOPs cell, and baclc to tank T through outlet-c.

Power to the FRT-Elecirociemical cell is provided by means of the power supply, alternatively can be provided through a battery charged via voltaic cell (solar panel).

Power applied: Voltage: 4volts Amperage: 20amps The power applied to FRT-Electrochemical cell whether via the power supply or the solar power has the facility of polarity reversal programme. Voltage and current are monitored and controlled during all the trials and experiments. Parallel connections to each pair of electrode cause current to pass across each electrode and solution.

\Vastewater continued circulation via pump P2 and P3 during the whole period of electrolysis process.

COD tests have been done every 30 minutes.

Duration of electrochemical process lasted 300 minutes Wastcwater Analyses results after elcetrochemical process switched off are: PH: 7.8 COD: Soppm CFL: 00.Oocfu TDS: 26Oppm Hardness: l3Sppm Turbidity: clear Colour: reddish colour removed Samples were taken during electrochemieal process for COD test.

Results are shown on table No.3 and graph No. 3 Experiment No.4 The same procedure from experiment No3, using same FRT-Electrochemical AOPs mini pilot unit Fig.N0 4. Power to UV lamp turned on.

150cc of the prepared contaminated wastewater from experiment No 3 fed through valve Vi and pumped by pump RI to filtration system Fl, to get rid of solids particles, debris and foLds before entering tank T. Power to UV lamp is provided from main. Alternatively can be provided through solar panel.

The wastewater is passing through the liv radiation zone before returning back to tank T. Power applied: Voltage: 4volts Amperage: 20amps.

COD tests have been done every 30 minutes.

\Vastewater continued circulation via pumps P2 and P3 during the whole period of electrolysis process.

Duration of electrechemical process lasted 240 minutes.

\Vastewater Analyses results after electrochemical process switched off are: PH: 7.8 COD: 30ppm CFL: 00.O0cfu TDS: 255ppm Hardness: l4Oppm Samples were taken during electrochemical process for COD test.

Results are shown in table No.4 and aph No.4 The purpose of this experiment is to prove the influence of the photolytic dissociation power on hydrogen peroxide and ozone in generating hydroxyl radicals for increasing the destruction power of COD.

Samples were taken during electrochemical process for COD test.

Results are shown on table No.4 and graph No. 4 Experiment No.5 Hybrid FRT Electrochemical AOPs-CDI pilot unit fig.7 was used to conduct experiment No.S.on brackish water.

i20litres brackish water mixed with 3Olitres contaminated water, to form l5olitres of contaminated brackish water for the trial

Brackish water specifications:

PH: 7.2 TDS: 2600ppm Sulphate (SO24): lSOppm Phosphate (PO24): lOOppm Chloride (C[): i000ppm Hardness: 300ppm Turbidity: not clear Colour: reddish COD: 4600 Bacteria: 500,000cffi The l5olitres of the contaminated brackish water pumped through filter Fl to tank T. The process consists of two stages: Stage A FRT-Electrochemical AOPs unit Electrochemical Process Valve V7 and VS closed, valves VS and V6 opened, pumps P2 and P3 turned on and so air pump.

\Vatcr started circulation from tank T to FRT-elcctrochcmical AOPs unit and back to tank T. Power to LIV lamp is turned on vai main power.

Power applied to FRT-electrochemical AOPs unit is: 4volts-40amps via power supply.

The treatment process lasted 90 minutes, procedure described in experiment No.4.

Chemical analysis results after power switched off: pH: 8.5 TDS: 2400 Sulphate (5Q2-): l2Oppm Phosphate (PO4): 92ppm Chlonde (Cfl: 92Sppm Hardness. 210 Turbidity: clear Colour: reddish colour removed COD: lSOppm Bacteria: 0.00 Stage B CDI Unit Desalination Process: The powers to the FRT-Electrocliemical AOPs cell, UV lamp and air pump turned off Valves V7, VS, opened, valves VS. V6, V9, V10, VII closed, pumps P2 and P3 turned on.

The treated water started circulation from tank T to filter Fl passing valve 4 and FRT-Elcctrochcmical AOPs unit to CDI unit back to tank T through valve VS The power applied to CDI unit is 1.5 volts. The treatment continued for 20 minutes with switching off intervals to release the captured ions and flushed them out of the unit through valve VI 2 The treatment was conducted in a continuously recycling system. The cycle consists of two main steps. First step is, 1.5 volt power applied to the CDI unit for 3mintutes. The second step, the power turned off for 25 seconds, and then turned on with the opposite polarity of 1.5 VDC to disrobe the ions in the electrodes that have been absorbed during CDI process for the regeneration process of the electrodes. Polarity reverse again to continue the CDI process.

Duration of CDI process lasted 2Ominutes Chemical analysis results after power switched off: PH: 8.00 TDS: 29Oppm Sulphate (S024): Spprn Phosphate (P034: 2ppm Chloride (Cr): llQppm Hardness**. 46 Results arc shown on table No.5 Instruments and analytical methods used are: 1. Chlorine total: DPD colorimetrie method, using Hach DR/700 colorimeter 2. Hardness: Calmgite eolorimetrie method using Hach DR/700 colorimeter.

3. pH:Orion model 450 4. TDS: Hanna TDS meter 5. Hydrogen peroxide: Palintest photometer 7100.

6. Chlorine dioxide: Palintest photometer 7100 7. COD: Digestion with potassium dichromate/mercuric sulphate using Hach photometer DR/700 S. Hydrogen gas: Using hydrogen detector/Hydrogen appliance model FIAR1 10 9. Oxyhydrogen mixture: By exposing the generated foam during electrolysis to spark Discussion and Chemistry of the present Innovation 1 -The results of Experiment No!:

Experiment No I based on prior art technology.

Hydrogen and oxygen gases are generated as major product.

Cathodic reduction mainly dominated by hydrogen gas generation as a main cathodic reaction according to the following equations: 4H0 + 4e * 2H7 + 40H 2H++2e Oxygen gas generated at the anode as a result of anodic oxidation.

2H20-4e 4t + 207 Chlorine is generated as result of anodic oxidation of the natural chloride content of the water according to the following cquations: Cr-e -* Cl 2C1 Cl2 Results of chlorine's formation during eleetroehemical process are summarised on table 1 and graph No.1.

2 -The results of experiment No.2 The purpose of this experiment to compare the present new invention with the prior art of electrolysis.

Air and water are introduced separately and tangentially into FRT-Electrochemical AOPs cyclonic unit, through inlets (a & b) by means of the air pump and circulation pump P3 which generañng a higIi-pccd cyclone and vortex motion. Nano-hubbles are generated as result of tile friction between the swirling layers of the air bubbles and water.

The special designed of this FRT Electrochemical AOPs unit new innovation produces micro and nanoscopic sized bubbles (8-10 nanometers) in water. Ordinary bubbles (1mm diameter) quickly risc to the surface and collapse whereas the smaller nanoseopic sized bubbles called nano-bubbles have lower buoyancy and remain suspended in water for a longer period of time. Based on the Bro\vnian motion particle theory, nano-bubblcs will randomly drift and remain in water for an extended period of time without being affected by buoyancy.

The nano-bubbles contain the oxidants eventually burst, releasing the oxidants produced by the FRI electrocheniical cell.

Due to this special unique technology, experiment proved that it is capable of providing the treated water with residual disinfection period around 3-6 months and.

The high-speed stream of micro and nano-air bubbles mixed with the water employ a centrithgal force in FRT cyclone unit. Due to centrifugal forces, water gains a relative high motion in the radial direction and the spinning micro and nano-air bubbles will be concentrated at the core of the vessel forcing them to pass over the cathodes and the anodes.

The stream of micro and nano-air bLibbles increase the turbulence, causing to break down any fouling and increase scrubbing power to remove fouls or scales on tile cathodes.

Oxygen in the form of micro bubbles are generated during anodic oxidation wiiil mix with the injected air bubbles during the circulation process. This will create micro and nano-air bubble highly concentrated with oxygen which are passing over cathodes and anodes during electrolysis and circulation process.

The highly concentrated stream of micro and nano-air bubbles with oxygen passing over the cathodes shifting the cathodic reduction completely from hydrogen gas generation into hydrogen peroxide generation.

H90 p 2H+ 0+2e 2t+O7+2e p H7O2 The results of experiment to.2 shown in table No2 and graph No2 proved that cathodic reduction dominated mainly by hydrogen peroxide generation, with no hydrogen gas detected.

At the same time the high concentrated sfream of micro and nano-air bubbles rich with oxygen gas that passing over the anode shifting the anodic oxidation mainly in favour of ozone generation as major product. 02-0

The generation of hydrogen peroxide and the ozone as a result of cathodic reduction and anodic oxidation in the water enhance the decomposition of ozone with the formation of hydroxyl radicals.

To sunimarise: two ozone molecules will produce two hydroxyl radicals H90,+03 -P 20l-I+30, The action of the hydrogen peroxide and ozone molecules and the generated hydroxyl radicals result in significant improvement in the rates of decomposition and destruction of pollutants and microorganism iii the wastcwater The chlorine free radicals generated from the anodic oxidation of the natural content of chloride ions in the watei; will be mainly oxidized into chorine dioxide due to the excessive oxygen flow during the aeration and electrolysis process. ClOy

The chionne dioxide will add more benefit in the destruction of the pollutants and microorganism.

Results are summarised on table No.2 and graph No.2 3-The results of experiment No.3 1W power is off According to the present invention, the cathodic reduction producing hydrogen peroxide (H202) instead of hydrogen (H2), and the anodic oxidation producing mainly ozone (03) instead of oxygen (02).

Hydrogen peroxide (H202) and ozone (03) generated in the ERT-Eleetroehemical cell are simultaneously react to form hydroxyl radicals 203+H202 2OH+30 The hydroxyl radicals (0H) have high oxidation potential route. It is the predominant removal mechanism of COD, micro-organism and other organic contaminants.

Generally, the reaction of hydroxyl radicals and organic compounds will produce water, and carbon dioxide.

Hydrogen peroxide, ozone and chlorine dioxide generated during FRT-electrochemical AOPs assisting to a high extend in treating the wastewater.

Results are summarised on table No.3 and graph No.3 4 -The results of experiment No.4 TJV power is turned on.

The cathodic reduction producing hydrogen peroxide (H202) instead of hydrogen (H2), and the anodic oxidation producing mainly ozone (05) instead of oxygen (02).

According to present invention the hydroxyl radicals route is thc predominant removal mechanism of COD, micro-organism and other organic contaminants.

During circulation process of the treated wastewater along with the generated hydrogen peroxide, ozone and chlorine dioxide are passing through the UV radiation (hi)) zone. This will subject the hydrogen peroxide, ozone and chlorine dioxide to the photolytic dissociation power of the liv radiation (hi)) to generate hydroxyl radicals ( OH) chlorine oxide and oxygen radicals.

To summarise: one hydrogen peroxide molecule will produce two hydroxyl (2 X OH) radicals) and ozone molecule will produce two hydroxyl radicals (2 X OIl) as well. Chlorine dioxide will undergo photolytic dissociation to generate chlorine oxide and oxygen radicals H20, hi 2011 a O hu. O+O Q+H7O-H9Q7 hi 20H.b C102 h C10+0 The rate constants of the hydroxyl radicals are typically -io times higher than the corresponding reaction rate constants of molecular ozone ( Murner 2001,tablc 4).

Hydroxyl radicals are non-selective in nature and they can react without any other additives and with a wide range of contaminants whose rate constants are usually in the order of 106 to io9 mol L-ls-l (Munter, 2001).

In the present invention excessive hychoxyl radicals (011) arc generated from three sources: 1-Hydroxyl radicals (OH) are generated from the hydrogen peroxides produced from the cathodic reduction that decompose the ozone produced from tile anodic oxidation.

203+H202 20H+302 2-Hydroxyl radicals (Oil) generated from the photolytic dissociation of H202 in wastewater by LIV irradiation as shown above in equation (a) 3-Hydroxyl radicals (OH) are generated with dircct photolytic dissociation of ozone 03 in wastewater by LIV irradiation, as shown above in equation (b) These excessive generations of hydroxyl radicals destroy organic pollutant molecules and microorganism reducing them into carbon dioxide and water.

Among the Advance Oxidation Processes (AOPs) tested, UV/H202/03 process was the most effective in the reduction of COD, colour and turbidity of the treated wastewater.

Comparison between COD reduction of experiments 3 and 4 proved that COD reduction much more higher in experiment 4 when liv power is turned on.

Results are summarised on table No.4 and graph No.4 The results of Experiment No.5 The resuhs of contaminated brackish water with organic pollutants and microorganism undergo two categories: i-To purit\' and free the brackish water from the organic pollutant and micro-organism by FRT-Electrochemical AOPs unit's treatment as per experiment 4.

2-The brackish water undergo desalination process to remove all the metallic and the non-metallic cations, and anions, along with the inorganic and organic complexes cations and anions by the CDI unit treatment.

Results shown on table No. S

Claims (14)

1. Claims 1. FRT'-Elccfrochcmical AOPs process treating water and wastcwatcr, wherein water and atmospheric air are injected separately into FRI electrochernical AOPs unit arc used as starting material and, as electrolyte, titanium substrate electrodes coated with mixed oxides valve metals are used, wherein the air saturated with oxygen and water are injected and pumped tangentially and separately into the ERT-Electrochemical AOPs, wherein UY lamp place at the top of the FRT-Electrochemical cell wherein the water flows over the electrodes will pass through the UV radiation, DC current is supplied to the electrodes by means of power supply.
2. 2. Hybrid FRI-Electrochemical AOPs-CDI treating contaminated brackish and saline water with organic pollutants and microorganism, whereas treatment process undergoes two stages, stage a-removal of all the suspended solids, colour, organic pollutants and eradicate the microorganism, wherein stage b-desalinating process to yield potable water for domestic use or agriculture purposes.
3. 3. Safe polarity reversal FRI-Electrochemical AUPs as claimed in claim 1 wherein changing polarity by decaying the voltage gradually down to zero, and raise it again gradually and slowly to the same voltage to clean the electrodes from scales and deposits without causing any damage to the electrodes.
4. 4. FRI-Electrochemical AOPs as claimed in claim 1 wherein water and atmospheric air are injected separately and tangentially to FRT-Electrochemical AOPs unit, wherein cyclone and vortex motion are formed, super nano-scopic air bubbles are produced, and wherein concentrated super nano-air bubbles flow over the anodes and the cathodes via the circulation pump.
5. 5. FRI-Eleetrochemical AOPs as claimed in claim 1 wherein water and atmospheric air are injected separately and tangentially to FRT-Electrochemical AUPs unit creating strong turbulence of micro and nano-air bubbles, leading to strong scrubbing power to remove any fouls, scales and metallic ions deposited on the electrodes.
6. 6. FRT-Electrochemical AOPs as claimed in claim I wherein the electrolysis process is carried out with no hydrogen gas generation.
7. 7. ERT-Electrochemical AOPs as claimed in claim 1 wherein electrolysis process is carried out and wherein hydrogen peroxide and ozone are generated.
8. 8. ERT-Electrochemical AOPs as claimed in claim I wherein the generated chlorine radicals are oxidized to chlorine dioxide.
9. 9. FRT-Electrochemical AOPs as claimed in claims 7 wherein hydrogen peroxide and ozone are generated, the hydrogen peroxide decompose the ozone to generate hydroxyl radicals.
10. 10. FRI-Electrochcmical AUPs as claimed in claim 7 wherein the generated hydrogen peroxide and ozone passing over the liv lamp, are subjected to a photolytic dissociation power generating hydroxyl radicals.
11. 11. FRT-Electrochemical AOPs as claimed in claim 8 wherein the generated chlorine dioxide passing over the liv lamp is subjected to a photolytic dissociation power generating chlorine oxide and oxygen radicals.
12. 12. FRT-Electrochemical AOPs as claimed in claims 7, 8 and 11 wherein bydroxyl, hydrogen peroxide, ozone, chlorine dioxide, chlorine oxide, and oxygen radicals are canled on to treat the water and wastcwater.
13. 13. FRT-Electrochemical AOPs as claimed in claims 9 and 10 wherein the excessive generation of hydroxyl radicals are the basis and predominant treatment of the water and wastewater.
14. 14. FRT-Electrochemical AOl's as claimed in claims I and 2 wherein the nano bubbles encapsulate thc hydrogen peroxide and the chlorine dioxide remains suspended in the water for a period of 3-6 months provide the treated water and wastewater with 3-6 months residual disinfection period.