FIELD OF THE INVENTION The present invention relates in general to a process for purification of sugar factory condensates and effluents in order to reduce pollution as well as making them reusable using a novel apparatus. BACKGROUND AND PRIOR ARTS Sugarcane is highly water intensive crop and consumes huge water during cultivation and contains about 70% water in it while it is fully matured. Sugar factories also consume huge fresh water from available sources during processing of sugarcane in various unit operations to produce sugar besides water available from sugarcane. Sugar industry is facing lot of challenges and problems in water management leading to indiscriminate use of fresh water, higher waste water discharge and thus faces legal action from statutory board. Growing awareness about environment protection, conservation of natural resources and enforcement of stringent pollution norms has necessitated a relook into the issue of water management in the sugar industry as a whole so as to minimize the use of fresh water and lower discharge of waste waters. At present about 528 sugar factories are in operation whose capacities vary from 1250 TCD to 16000 TCD. It is estimated that these sugar factories consume approximate 195 million tonnes of fresh water per annum for all its needs. Sugarcane itself contains about 70 % water which envisages huge potential not only to totally stop fresh water intake to the extent of zero fresh water requirement but also to produce surplus water which can be used for other useful purposes like potable water and can be an another by-product to generate revenue to make sugar factories more self –reliant and sustainable. Reconciling water needs with sustainable sugar production have been a major challenge for the sugar sector. Since the concept of zero discharge system which has come up to ensure essentially no discharge of pollutants into the environment, recovery of water gains primary importance.
1. By reusing process water, utilization of natural water resources is minimized.
2. Reuse of recovered water enhances the capacity of the industry to efficiently utilize available water as well as control its quality to the required level.
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Electrocoagulation was already proposed in the late 19th and early 20th century. The use of electro-coagulation with aluminium and iron was patented in 1909 in the United States (Stuart, 1947; Bonilla, 1947, Vik et al. 1984). Matteson et al. (1995) described an “electronic coagulator” in the 1940s, using aluminium anodes, and in 1956 a similar process in Great Britain using, in turn, iron anodes. Electro coagulation for treatment of wastewater is well known. GB449724 A describes an improved electro coagulation cell where the polarity of the current is reversed to improve the efficiency of the cell. Additionally, the combination of the electro coagulation cell with a secondary separation unit for removal of the coagulated particles formed in the electro coagulation unit is described. US 2009/0107915 do also describe a wastewater treatment plant comprising an electro coagulation cell and a downstream solids/liquid separator preferably comprising a settling section. WO2016056994 describes an apparatus for conducting an electro-Fenton reaction for decomposing organic, preferably aromatic, chemical compounds in polluted waste water. EP1174394 relates to an electro flotation reactor combined with other separation methods for treatment of wastewater. WO200405671 1 describes a method and apparatus for electrochemical treatment of contaminated aqueous media, comprising an electrochemical reactor and a sedimentation chamber optionally comprising lamellas for separation of particles from the water.
A known problem associated with electro coagulation units is that these treatment processes also tend to increase the total dissolved solids (TDS) content of the effluent, making it unacceptable for reuse within industrial applications. Thus to remove dissolved ionic species one has to use ion-exchange resin for demineralization of water and making it acceptable for industrial use. But use of ion-exchange resin is itself not cost effective and lot of water is waste during its regeneration. But capacitive de-ionization provides a better option for demineralization as described in US 20100065511 A1 patent. As far as sugar industry is concerned, there are growing pressures from the Central Pollution Control Board to further reduce the waste water generation from the sugar factories to the extent of 200 liters/ ton of cane. However, the present study is aimed at conserving natural resources by minimizing fresh water intake in sugar factories which ultimately shall also result in lower waste water generation from them.
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The present invention further explores the possibility of utilizing vapour condensate and waste waters as source for its utilization in irrigation after meeting out standards, miscellaneous factory operations and domestic needs after required treatment and to the extent to use it as potable water after extensive treatment by passing through a designed module. Further References
• Bonilla, C.F., 1947. Possibilities of the electronic coagulator for water treatment.Water and Sewage, 21–22
• Stuart, F.E., 1946. Electronic water purification. Water Sewage, 24–43.
• Vik, E.A., Carlson, D.A., Eikum, A.S., Gjessing, E.T., 1984. Electrocoagulation of potable water. Water Res. 18 (11), 1355–1360
• Matteson, M.J., Dobson, R.L., Glenn, J., Robert, W., Kukunoor, N.S., Waits, I.,William, H., Clayfield, E.J., 1995. Electrocoagulation and separation of aqueoussuspensions of ultrafine particles. Colloid Surface A. 104 (1), 101–109.
SUMMAERY OF THE INVENTION
An apparatus for purification of sugar factory condensates and effluent, said apparatus comprising an inlet directly connected to the electro-coagulation unit (1) attached to an advanced oxygen chamber (1a) for dosing of hydrogen peroxide (H2O2) or ozone (O3) for advance oxidation process, a lamellar clarifier (2) connected further to said EC unit (1) for sludge removal, a pressurised sand filter (3) connected in series with said clarifier (2) to check escaping of micro particulate sludge-matter from the clarifier (2), an activated carbon column (4) connected in series with capacitive deionization column for further polishing of treated water, and a capacitive-deionisation/ ion-exchange column (5) connected in series with activated carbon filter (4) on one side and with the outlet on the other for due removal of mineral and hardness of from effluent/ condensate water wherein the use of ion exchange is total dissolved solid (TDS) dependent. The electro-coagulation unit (1) consists of three reaction chambers (6, 7 and 8) consisting of two metal preferably iron (Fe) electrodes in monopolar parallel (MP-P) arrangement, two terminals for electrical connection of electrodes in each reaction chamber i.e. electrical terminal (9, 10) for reaction chamber (6), electrical terminal (11, 12) for reaction chamber (7), and electrical terminal (13, 14) for reaction chamber (8), separated to each other by two partitions (16, 17) for allowing flash mixing of
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water before entering into the electro-coagulation chamber. The advanced oxidation chamber (AOC) (1a) is fed with ozone (O3), hydrogen peroxide (H2O2) wherein the concentration of H2O2 may be 0.2 mM - 50 mM for the required generation of Reactive Oxygen Species (ROS), especially OH- radicals, and/ or ultraviolet (UV) light may be employed to perform specific subset of reactions for advanced oxidation process involving artificial facilitation for the generation of said free radicals. The spirally arranged capacitive-deionisation (CDI) assembly (5) is consisting of current collector(s) (18, 19) at outer side, wherefrom each current collector is paired to activated carbon cloth (20, 21), separated from each other by porous non-conductive separator (22). A process for purification of sugar factory condensates and effluent, said process comprising steps of allowing the passing of said sugar factory condensates and effluent through an inlet directly connected to the electro-coagulation unit (1), manipulating the attached advanced oxygen chamber (1a) for dosing of hydrogen peroxide (H2O2) or ozone (O3),preferably in concentration of H2O2 may be 0.2 mM - 50 mM, for the due release of free radicals through advance oxidation process, allowing the passing of output from electro-coagulation unit (1) through a lamellar clarifier (2) for sludge removal, managing the flow of output from lamellar clarifier (2) through pressurised sand filter (3) connected in series with said clarifier (2), allowing the output from sand filter (3) through activated carbon column (4) connected in series with capacitive deionization column for further polishing of treated water, allowing further the flow through a capacitive-deionisation/ ion-exchange column (5) connected in series with activated carbon filter (4) on one side and with the outlet on the other for due removal of mineral and hardness of from effluent/ condensate water wherein the use of ion exchange is total dissolved solid (TDS) dependent, and further collection of the output generated. BREIF DESCRIPTION OF ACCOMPANYING FIGURES/ DRAWINGS
FIG. 1 illustrates an sugar industries effluent/ condensate treatment system comprising of a electro-coagulation unit (1) Attached tank for dosing of hydrogen peroxide or ozone for advance oxidation (1a), clarifier(2) connected to electro-coagulation unit for sludge removal from the treated water coming from electro-coagulation unit. Pressurised sand filter (3) connected in series with clarifier in order to remove micro sludge particle which are escaped from clarifier. Capacitive –deionisation/Ion-exchange column (4) are connected in series with sand filter (3) in order to remove mineral and hardness of from effluent/condensate water. So to bring total dissolved solid of effluent water upto the range of potable water. And for the
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polishing of treated water from capacitive deionization column a activated carbon column (5) is connected in series with capacitive deionization column. FIG.2 illustrates the design of electro-coagulation unit. It consist of three reaction chamber (6, 7, 8) as illustrates in diagram. Each chamber has two terminal for electrical connection of electrode indicated as (9, 10) for first chamber, (11, 12) for second chamber and (13,14) for third chamber. Each electro-coagulation chamber contain metal electrode (15) arranged as shown in fig.2.All three compartment are separated to each other by two partition (16, 17). These partitions allow flash mixing of water before entering into the electro-coagulation chamber. FIG.3. Diagrammatic illustration of lamellar clarifier. FIG.4 illustrates the layer arrangement of capacitive deionization (CDI) column. The CDI assembly consist of current collector (18, 19) at outer side. Each current collector is connected to Activated carbon cloth (20, 21).And each pair of current collector and activated carbon cloth is separated from each other by porous non-conductive separator (22). Layer (23) is non-conducting layer which prevent short-circuiting of 18 and 19 layers when they rolled up into spiral. FIG.5 illustrates the spiral arrangement (Circular cross section) of CDI apparatus as illustrated in fig.3. FIG. 6. Diagrammatic representation of electro coagulation process. OBJECTS OF THE PRESENT INVENTION The main object of the invention is to offer a process for purification of sugar factory condensates and effluents in order to reduce pollution. Another object of the invention is to make the condensates and effluent reusable using a novel apparatus. Yet another object of the invention is to offer a unique combination of apparatus having individual functions assigned so as to produce synergy in terms of removal of pollutants. Still another object is to offer a calorie efficient technique for purification of sugar factory condensates and effluents. Further object of the invention is to offer a cost-effective technique using a cost-effective apparatus for purification of sugar factory condensates and effluents.
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DETAILED DESCRIPTION OF THE INVENTION The wastewaters are characterized by high chemical oxygen demand (COD) contents of organic matter, dissolved solids, and suspended solids. Hence, the discharge of these types of wastewaters into urban wastewater treatment plants is not allowed, thus requiring a prior treatment. The most common treatment for these wastewaters is aerobic biological treatment. However, this treatment has some drawback such as high energy costs, large amount of sludge generation and the likes. The present invention had come up with a process comprising a combination of electro-coagulation, advance oxidation and capacitive-deionization, to successfully overcome said drawbacks. Electro-coagulation It involves in situ generation of coagulants by electrolytic oxidation of an appropriate sacrificial anode (iron and aluminium) upon application of a direct current. The metal ions that are generated hydrolyze in the electro-coagulator mainly at pH values in the range of 3.0–9.0 to produce various metal hydroxide complexes and neutral M(OH)3. These products are necessary for the removal of soluble or colloidal pollutants by virtue of various mechanisms including ionic complexation or ion exchange on the floc surface active sites, and the enmeshment of the colloidal pollutants into the sweep flocs. During or at the end of the process, flocs are removed either by sedimentation or by flocculation. Current theory of EC states that it involves several successive stages: a) Generation of metal ions. b) Hydrolysis of metal ions and generation of metal hydroxides and polyhydroxides. This is beyond question, it has been studied and explained for coagulation process in water treatment. c) Water is also electrolyzed in a parallel reaction, producing small bubbles of Oxygen at anode and Hydrogen at the cathode. d) Destabilization of the contaminants, particulate suspension, breaking of emulsions, and aggregation of the destabilized phases to form flocs. This part relative to colloids and suspended matter can be accepted because suspended solids and colloids in small quantities are not a problem for EC.
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e) Current theory of EC consider that chemical reactions and precipitation can occur during the EC process or that other cation or the hydroxyl ion (OH) form a precipitate with the pollutant. Advance oxidation process (AOP)
AOPs involve the two stages of oxidation discussed above: 1) the formation of strong oxidants (e.g., hydroxyl radicals) and 2) the reaction of these oxidants with organic contaminants in water. However, the term advanced oxidation processes refer specifically to processes in which oxidation of organic contaminants occurs primarily through reactions with hydroxyl radicals (Glaze et al., 1987). In water treatment applications, AOPs usually refer to a specific subset of processes that involve O3, H2O2, and/ or UV light. However, in this analysis, AOPs will be used to refer to a more general group of processes that also involve TiO2 catalysis, cavitation, E-beam irradiation, and Fenton’s reaction. All of these processes can produce hydroxyl radicals, which can react with and destroy a wide range of organic contaminants. But in our experiment either ozone or H2O2 is only used for hydroxyl ion generation. In presence of iron electrode and H2O2 fenton’s reaction occurs and process inside electrochemical cell is known as electro-fenton’s oxidation. Therefore, the present invention offers electro-coagulation either coupled with ozone generator or H2O2 dispenser, so that oxidation process could proceed with electro-coagulation. The present invention designed the Advanced Oxidation Chamber (AOC) wherein the concentration of H2O2 may be low i.e. 0.2 mM to 50 mM for the required generation of Reactive Oxygen Species (ROS) especially OH- radicals designed to purify effluents in tandem with the electro-coagulation process in electro-coagulation chamber. Capacitive deionization (CDI)/ Ion Exchange Column
CDI is a technology to deionize water by applying an electrical potential difference over two porous carbon electrodes. Anions, ions with a negative charge, are removed from water and are stored in the positively polarized electrode. Likewise, cations (positive charge) are stored in the cathode, which is the negatively polarized electrode. In a CDI cell, the water to be purified passes between positively and negatively charged electrodes. When the CDI cell is operated in its purification phase, electrostatic charges on the electrodes (plates) attract respective dissolved ions, whereby the ions are adsorbed out of the passing water and onto
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the plates. The value-water now leaving the cell is deionized and purified. When the CDI cell is operated in its regeneration phase, the electrostatic charges on the plates are reversed (or, preferably, the plates are electrically shorted), whereby the ions which are no longer attracted leave the plates, and enter the passing regen-water. Now, the regen-water leaving the cell contains the contaminant ions—usually at a (much) heavier concentration than in the incoming water. In CDI, the contaminant ions are captured and stored by and in the electrodes, and are thereby removed from the purification-phase effluent (the value-water). Later, the concentrated contaminant ions are released into the regeneration-phase effluent (the regen-water). The combination of EC and CDI may be exploited for the established sugar industry in UP and Maharashtra and elsewhere in India as well as in developing nations. Since the invention, the process has taken an inexcludable role in refining industry by efficiently employing a variety of anode and cathode geometrics, combination of plates, rods and spheres as well as conscious alteration of fluidized bed spheres and wire mesh. Whereas coagulation of impurities may be achieved through chemical means as well, EC offers an edge in terms of cost as well as environmental sanity. EC heavily baits on the electrical and/ or ionic property of water contaminants like heavy metal ions, inorganic or organic colloids. Said contaminants are destabilized by the calibrated and optimized addition of ions comprising a charge opposite to that of the colloidal particles, which may further be removed by sedimentation and filtration. Thus EC, though exploits the same route of coagulation through cations, differs markedly from the later by containing less bound water and more sheer resistance.
The present invention, as earlier mentioned, illustrates a sugar industries effluent/ condensate treatment system comprising of an electro-coagulation unit (1) attached to a tank (1a) for dosing of hydrogen peroxide (H2O2) or ozone (O3) for advance oxidation, with a lamellar clarifier (2) connected further to said EC unit (1) for sludge removal. To ensure no escape of micro particulate sludge-matter from the clarifier (2), a pressurised sand filter (3) connected in series with said clarifier (2). Capacitive-deionisation/ Ion-exchange column (5) are connected in series with sand filter (3) in order to remove mineral and hardness of from effluent/ condensate water so as to bring total dissolved solid of effluent water upto the range of potable water. And for the polishing of treated water from capacitive deionization column
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an activated carbon column (4) is connected in between the pressurized sand filter (3) and capacitive deionization column (5). The design of the electro-coagulation (EC) unit is of prime importance and optimized in order to get the best result in given set of conditions wherein the contamination from industrial debris is the major source of pollution altering the inorganic content through the drainage of organic and inorganic industrial debris comprising natural organic matter (NOM) and dissolved organic carbon (DOC) as well. The inter electrode distance plays a major role which has been optimized, however kept open for further alteration case to case. Similarly, the electrode may be maintained either in monopolar or in bipolar connection mode, wherein the former comprises only one electrode, thereby requires the activity of another monopolar instrument as a dispersive electrode, and the later comprises both electrodes in the design. The present invention however comes up with pairs of electrode in partitioned chambers in order to assure proper mixing as well as proper electro-coagulation, wherein the use of ion exchange is total dissolved solid (TDS) of the input effluent dependent. The EC reactor may be of monopolar parallel (MP-P) or monopolar series (MP-S) or bipolar parallel (BP-P) types. In view of COD and turbidity removal as well as other allied performance criteria, it was found that monopolar parallel (MP-P) mode offers the best trade off between the cost and quality for electro-coagulation. EC variables such as current density, coagulant or charge loading rate (CLR), and flocculation methodology in terms of fast and slow, are taken into confidence for the present invention. The whole operation has been left for customization so as to ensure efficient working of the device depending on the input conditions and supply, for eg., a lower CLR generally cause greater DOC removal, whereas a higher CLR leads to less reactor resistance time and may require longer flocculation time or greater coagulant dosage for NOM removal in same or similar efficiency. All the process parameters are designed to get the maximum efficiency in terms of coagulant dose, electrical consumption, process speed, volumetric footprint and post EC flocculation requirements.
Since the input debris is expected to be of large volume with prolonged period, “slow” EC mode with less importance on pH, is found to be suitable for the present invention in terms of DOC and other particle removal. Since further, the electrode configuration, inter-electrode distance and surface area to volume ratio (S/ V Ratio) are the principal criteria determining
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energy consumption and efficiency thereof, said criteria are optimized with utmost precision to ensure optimum NOM removal under definite current input and current efficiency thereof. The present invention, as earlier mentioned, illustrates a sugar industries effluent/ condensate treatment system comprising of an electro-coagulation unit (1) attached to a advance oxidation chamber tank (1a) for dosing of hydrogen peroxide (H2O2) or ozone (O3) for advance oxidation, with a lamellar clarifier (2) connected further to said EC unit (1) for sludge removal. To ensure no escape of micro particulate sludge-matter from the clarifier (2), a pressurised sand filter (3) connected in series with said clarifier (2). Capacitive-deionisation/ Ion-exchange column (5) are connected in series with sand filter (3) in order to remove mineral and hardness of from effluent/ condensate water so as to bring total dissolved solid of effluent water upto the range of potable water. And for the polishing of treated water from capacitive deionization column an activated carbon column (4) is connected in between the pressurized sand filter (3) and capacitive deionization column (5). In sum, said EC (1) consists of three reaction chamber (6, 7, 8), wherein each chamber has two terminals for electrical connection of electrode, electrodes (9, 10) for first chamber, electrode (11, 12) for second chamber, and (13, 14) for third chamber. Each EC chamber contain metal electrode (15) arranged as shown in fig. 2. All three compartments are separated to each other by two partitions (16, 17), said partitions allow flash mixing of water before entering into the EC chamber.
The advanced oxidation chamber (AOC) (1a) for performing advanced oxidation process (AOP) is connected to the EC as earlier discussed and deliberated in diagram and figure as well, representing a specific subset of processes that involve ozone (O3), hydrogen peroxide (H2O2), and/ or ultraviolet (UV) light. In this analysis, as earlier discussed, AOPs are used to refer to a more general group of processes involving TiO2 catalysis, cavitation, E-beam irradiation, and Fenton’s reaction, having the potential of generating highly reactive free radicals especially hydroxyl radicals (OH-), which may react with and destroy a wide range of organic contaminants. For present invention, artificial facilitation for the generation of free radicals, especially OH- radical, are performed by employing either O3 or H2O2. In presence of iron (Fe) electrode and H2O2, fenton’s reaction occurs and processes inside EC cell is known as electro-fenton’s oxidation. The use of Fe-electrode offers an edge in terms of costs when the consideration comes to electrical and sacrificial electrode costs along with ensuring
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lower turbidity and colour compared to alternatives like aluminium (Al) electrode. Therefore, the present invention offers electro-coagulation either coupled with ozone generator or H2O2 dispenser, so that the oxidation process could proceed with electro-coagulation, as earlier mentioned. To ensure the purification at optimum level, capacitive deionization (CDI) system is further connected to the EC-AOP combo. CDI, as discussed earlier is a technology based upon the recognition of ionic absorption ability of electrically charged high surface area electrodes. Excess inorganic salts are excreted by virtue of this method wherein two porous carbon electrodes like activated carbon cloth are electrically charged for required electrosorption. The CDI assembly (5) (Fig. 3) as discussed, comprising current collector(s) (18, 19) at outer side, wherefrom each current collector is connected to activated carbon cloth (20, 21). Each pair comprising current collector and activated carbon cloth is separated from each other by porous non-conductive separator (22). Further, a non-conducting layer (23) for the prevention of short-circuiting has been put between layer 18 and 19 to ensure function in spiral formation. The spiral arrangement of above mentioned layer of CDI is also further illustrated and expressed in figure 4. The modus operandi of individual modules along with its efficiency is detailed through examples further: The water and condensate samples of different stages/unit operations from the selected sugar factories were collected for evaluation of water quality and microbial reactions. The samples of Fresh Water, Evaporator’s 1st Body Condensate, 2nd Body Condensate, 3rd Body Condensate, 4th Body Condensate, Pan Condensate, ETP inlet, ETP outlet, Spray Pond over flow, Hot UGR and Cold UGR were collected from seventeen sugar factories and were systematically analyzed for pH, Salinity (ppm), TDS (ppm), Conductivity. (ms), Chloride (mg/l), Calcium (mg/l), COD (mg/l), Total Soluble solids (mg/l), BOD (mg/l) and Total Acidity (mg/l). Data obtained from the analyses of different water samples reveals that less contaminated water like vapour condensates and spray pond overflow can be recycled easily after treating it with our module which consists of chamber for Electrocoagulation having Air floatation followed by carbon column and ion exchange column.
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Example 1: Electro-coagulation for Water Treatment (Fig. 5) Electro-coagulation (EC) is a primary technique for treatment of waste water from industrial, agricultural as well as other source(s). The EC process creates in the water to be purified, the metal hydroxide flocks by electro dissolution soluble anode (iron or aluminium). At pH values close to neutral or acidic (4-7), aluminium and iron dissolved in their cationic form, react with water to form divers complexes such as Al2(OH)5 + , Al2(OH)2 4+ , Al(OH)3, Fe(OH)2 or Fe(OH)3. These forms act as coagulant; aggregates of particles are formed, decanted and water is then "purified." The electric field in the electrolytic cell induces the migration of colloidal particles to the anode, which has the effect of increasing the probability of encounter, thus promoting the coagulation - flocculation. The electrolysis of water also induces the formation of small bubbles of oxygen and hydrogen (whose average size is less than 100 micrometers) respectively to the anode and cathode. These bubbles consist mainly of hydrogen because oxygen is the formation of a secondary reaction, often of minor importance to the anode. These micro bubbles are absorbed by the flocculated material and lead them to rise. The impurities can then be treated by flotation. The foam can be formed of poor stability and oxidizable materials fall to the bottom of the decanter. Despite this, many light and heavy particles remain suspended and we must resort to their separation by settling or filtration. Electro-chemical reaction during electro-coagulation process:- During electro-coagulation process, aluminum and iron dissolved in their cationic form, react with water to form divers complexes such as Al2(OH)5 + , Al2(OH)2 4+ , Al(OH)3, Fe(OH)2 or Fe(OH)3. These forms act as coagulant; aggregates of particles are formed, decanted and water is then "purified."
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Energy consumption during electro-coagulation:- There is variation in energy consumption with electrolysis time at various current densities for mild steel and aluminium. This shows that energy consumption increases with an increase in current. The E.C. (kWh/m3) for the removal of organic pollutants was calculated by Equation (1) In general, the energy consumption at low current density are close for mild steel and aluminium, and it increased with the rising the current density in mild steel. Electrode consumption during electro-coagulation process Effect of anode dissolved with electrolysis time for various current densities for mild steel and aluminium. The electrode consumption can be estimated using Faraday’s law and the amount of flocs generated can be estimated stoichiometrically by equation (2).
Where F is Faradays constant (96485.3C/equiv.), M is the atomic weight of iron and n is the valence. The figures show that the anode dissolved with mild steel was more than five times that while using aluminium at the same current density.
nFMItm=
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Example 2 Working of carbon column Activated carbon filtration (AC) is effective in reducing certain organic chemicals and chlorine in water. It can also reduce the quantity of lead in water although most lead-reducing systems use another filter medium in addition to carbon. Water is passed through granular or block carbon material to reduce toxic compounds as well as harmless taste- and odor-producing chemicals. There are two basic types of water filters: particulate filters and adsorptive/ reactive filters. Particulate filters exclude particles by size, and adsorptive/reactive filters contain a material (medium) that either adsorbs or reacts with a contaminant in water. The principles of activated carbon filtration are the same as those of any other adsorption material. The contaminant is attracted to and held (adsorbed) on the surface of the carbon particles. The characteristics of the carbon material (particle and pore size, surface area, surface chemistry, density, and hardness) influence the efficiency of adsorption. The characteristics of the chemical contaminant such as the tendency of the chemical to leave water are also important. Compounds that are less water soluble (hydrophobic) are more likely to be adsorbed to a solid. A second characteristic is the attraction of the contaminant to the carbon surface. If several compounds are present in the water, strong absorbers will attach to the carbon in greater quantity than those with weak adsorbing ability. These combined factors enable the activated carbon material to draw the molecule out of the water Example 3 Working of ion - exchange column
Standard, strong-acid cation resins for water softening, metal removal, and demineralizing applications are prepared by sulfonating preformed crosslinked polystyrene beads. The dried copolymer is slurried in concentrated sulfuric acid, heated to 212°F (100°C), and held at this temperature for several hours until the sulfonation reaction is completed. After cooling, the resin is separated from the acid and slowly hydrated and rinsed with water. Similarly Standard anion resins based on polystyrene copolymers are prepared by causing amines to react with the chloromethylated copolymer intermediate. Suspended or colloidal matter coats the surface of ion-exchange resin particles, thereby blinding the exchange sites on the surface
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as well as the pores leading to the internal exchange sites. Pretreatment by coagulation or filtration can remove suspended matter before the water reaches the ion-exchange unit. Vigorous backwashing is usually effective in removing dirt that has accumulated in the resin bed and on the particles. The backwash flow rate should be as high as possible without forcing resin from the vessel. The operation may require opening the top of the vessel and mechanically stirring the resin bed to eliminate any resin slumps. Backwashing should continue until the wash water is clear Example 4 Results obtained after treating with our module The module was developed after confirmation of results through repeated investigation in laboratory. The plant level trial was conducted with the module at two different sugar factories and the mean of results are shown in table No. 1. It was observed and concluded from the results obtained after electrocoagulation, passing through carbon column and ion-exchange column of 1st vapour condensate that TDS reduced by 91% and COD by 83.6%. In case of 2st vapour condensate the reduction was 92.8% in TDS and 76.8 % in COD. Results obtained after treatment with module in common condensate revealed the reduction of TDS and COD by 91.9% and 77.0% respectively. The results of spray pond water indicate reduction in TDS and COD by 75.1 % and 86.3 % respectively. ETP inlet water treatment also showed the promising results after treatment by module thereby reducing TDS by 69.1% and COD by 88.2%. The variation in pH was observed in various effluents which finally reach to neutrality during the electro-coagulation process. The ideal time required for this process is 30 mins with a power consumption of 1.40KWh/ 1000lit. Electrode consumption will depend on pollution load. The sample of treated water produced thru this module is suitable and in accordance with the CPCB norms, hence this module is found promising sustainable, cost effective and eco-friendly. Table No. 1: TDS and COD Reduction in % after treatment with module
S. No.
Types of effluents
TDS
COD
1
1st vapour condensate
91.0
83.6
1.
2nd vapour condensate
92.8
76.8
2.
Common vapour condensate
91.9
77.0
3.
Spray Pond Water
75.1
86.3
4.
ETP inlet
69.1
88.2
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The laboratory trials were also conducted with water treatment module having capacitive deionization for demineralization and the results so obtained are mentioned in table No. 2. The results were at par with ion-exchange resin used for demineralization. Hence it can be used as substitute. Table No. 2: Reduction (%) in TDS Content by using capacitive deionization
Particulars
TDS(Before CDI treatment) in ppm
TDS(After CDI treatment) in ppm
Reduction in TDS (%)
Vapour Condensate
240
60
75
Spray Pond
1296
390
70
ETP inlet
2980
1072
64
INDUSTRIAL APPLICATION Sugarcane cultivation and its processing in factories allegedly mandate a huge amount of fresh water supply both in the farm land as well as in the factories. It is estimated that these sugar factories consume approximate 195 million tonnes of fresh water per annum for all their needs. It has been claimed by several surveys that on an average a factory that can crush about 2,500 tonnes of cane per day (tpcd) needs 25 lakh litres of water per day. In addition there is a need for co-generation of electricity, which is integrated in most of the large factories, using a hopping amount of 2,000 litres of water per MW per day, setting aside further water requirements for distillation to make alcohol (primarily ethanol). Thus by mid April, 2016, sugar factories in Maharashtra may had used up of 7.68 lakh litres of water by crushing 76.8 tonnes of sugarcane, an enormous amount for a drought prone state. For 2014-15 seasons, even a conservative dataset reveals that 70 factories in Marathwada, Maharashtra, crushed around 15.4 tonnes of sugarcane using 23.14 million cubic metres of water using the acclaimed lowest estimate of 1500 litres per tonne, that too amounting to a hopping number. Thus not surprisingly, sugarcane is claimed to consume 71% of Maharashtra’s irrigated water, whereas merely 18% of the state’s cultivable land amounting to 22.5 million hectare is irrigated. Scenario is similar for UP and other sugar producing states.
However, sugar industry rebuts those stands by claiming the need of 2000 – 2500 litres of water to produce one kilogram of sugar, wherein the crop itself is a 12-18 month crop and the intake should be observed as distributed over the whole period unlike other crops.
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Judging the claims from both sides, very recently the government has revised standards by mandating a discharge of water not more than 200 litres per tonne of sugarcane crushed as against the earlier limit of 400 litres of water per tonne of sugarcane crushed. This move may help the Central Pollution Control Board (CPCB) as well as State pollution boards and watchdogs implement scientific measures to be adopted by sugar industries to use water more efficiently. Here comes the importance of the present invention, which may save million litres of fresh water by treating surplus condensate and effluent in order to make them reusable and thereby reducing pollution. The present invention amends the existing techniques, combines said techniques in a novel and unique way as no earlier thought had been shed on claimed novel combination in order to achieve the most efficient outcome, and therefore, having a great commercialization potential apart from the benevolent means it offers.

We Claim:
1. An apparatus for purification of sugar factory condensates and effluent, said apparatus comprising:
a) an inlet directly connected to the electro-coagulation unit (1) attached to an advanced oxygen chamber (1a) for dosing of hydrogen peroxide (H2O2) or ozone (O3) for advance oxidation process,
b) a lamellar clarifier (2) connected further to said EC unit (1) for sludge removal,
c) a pressurised sand filter (3) connected in series with said clarifier (2) to check escaping of micro particulate sludge-matter from the clarifier (2),
d) an activated carbon column (4) connected in series with capacitive deionization/ ion exchange column for further purifying the treated water and
e) a capacitive-deionisation/ ion-exchange column (5) connected in series with activated carbon filter (4) on one side and with the outlet on the other for due removal of mineral and hardness of from effluent/ condensate water so as to bring total dissolved solid of effluent water upto the range of potable water wherein the use of ion exchange is total dissolved solid (TDS) dependent.
2. The apparatus as claimed in claim 1, wherein said electro-coagulation unit (1) consists of three reaction chambers (6, 7 and 8) separated to each other by two partitions (16, 17).
3. The apparatus as claimed in claim 1 and claim 2, wherein said reaction chambers (6, 7, 8) of said electro-coagulation unit (1) comprising essentially of two terminals for electrical connection of electrodes in each reaction chamber i.e. electrical terminal (9, 10) for reaction chamber (6), electrical terminal (11, 12) for reaction chamber (7), and electrical terminal (13, 14) for reaction chamber (8).
4. The apparatus as claimed in claim 1 and claim 2, wherein said partitions allow flash mixing of water before entering into the electro-coagulation chamber.
5. The apparatus as claimed in claim 1 and claim 3, wherein said electrodes are metal electrodes preferably iron (Fe) electrodes.
6. The apparatus as claimed in claim 1 and claim 3, wherein said electrodes in said electro-coagulation chamber are in monopolar parallel (MP-P) arrangement.
7. The advanced oxidation chamber (AOC) (1a) as claimed in claim 1, wherein ozone (O3), hydrogen peroxide (H2O2), and/ or ultraviolet (UV) light may be employed to perform specific subset of reactions for advanced oxidation process.
8. The advanced oxidation process as claimed in claim 1 and claim 6, involves artificial facilitation for the generation of free radicals, especially OH- radical, by employing either O3 or H2O2.
9. The advanced oxidation process as claimed in claim 1 and claim 6, wherein the concentration of H2O2 may be 0.2 mM - 50 mM for the required generation of Reactive Oxygen Species (ROS), especially OH- radicals.
10. The capacitive-deionisation (CDI) assembly (5) as claimed in claim 1, consisting of current collector(s) (18, 19) at outer side, wherefrom each current collector is paired to activated carbon cloth (20, 21).
11. The capacitive-deionisation (CDI) assembly (5) as claimed in claim 1 and claim 8, wherein said pairs of current collector and activated carbon cloth are separated from each other by porous non-conductive separator (22).
12 The capacitive-deionisation (CDI) assembly (5) as claimed in claim 1 is in spiral arrangement.
13. The capacitive-deionisation (CDI) assembly (5) as claimed in claim 1 and claim 10, wherein a non-conducting layer (23) has been put between layer 18 and 19 for the prevention of short-circuiting in spiral formation.
14. A process for purification of sugar factory condensates and effluent, said process comprising steps of:
a) allowing the passing of said sugar factory condensates and effluent through an inlet directly connected to the electro-coagulation unit (1),
b) manipulating the attached advanced oxygen chamber (1a) for dosing of hydrogen peroxide (H2O2) or ozone (O3) for the due release of free radicals through advance oxidation process,
c) allowing the passing of output from electro-coagulation unit (1) through a lamellar clarifier (2) for sludge removal, d) managing the flow of output from lamellar clarifier (2) through pressurised sand filter (3) connected in series with said clarifier (2), e) allowing the output from sand filter (3) through activated carbon column (4) connected in series with capacitive deionization column for further polishing of treated water, f) allowing further the flow through a capacitive-deionisation/ ion-exchange column (5) connected in series with activated carbon filter (4) on one side and with the outlet on the other for due removal of mineral and hardness of from effluent/ condensate water so as to bring total dissolved solid of effluent water upto the range of potable water, and g) further collection of the output generated. 15. The process for purification as claimed in claim 14, wherein the free radical generation involves generation of reactive oxygen species (ROS), especially OH-, through the interplay of hydrogen peroxide (H2O2) or ozone (O3). 16. The process for purification as claimed in claim 14, wherein the concentration of H2O2 may be 0.2 mM - 50 mM for the required generation of Reactive Oxygen Species (ROS), especially OH- radicals.