Claims:We claim:
1. A process (300) for treating total and free cyanide from waste water, the process comprising:
adding (301) oxidative accelerator with the waste water having constant pH in range 10 to 11;
adding (302) hydrogen peroxide (H2O2) to the waste water treated with the oxidative accelerator; and
breaking (303) the hydrogen peroxide (H2O2) into OH radicals by Ultra Violet (UV) photo degradation process and reducing free cyanide and total into nonhazardous carbonate and nitrogen.

2. The process as claimed in claim 1, wherein the oxidative accelerator is cage complex solution.
3. A process (200) for treating total and free cyanide from waste water of coke plant, the process comprising:
feeding (201) the waste water to a reaction tank (201) with constant flow;
adding (202) oxidative accelerator in the reaction tank (101) containing waste water under constant pH in range 10 to 11 and feeding the waste water from the reaction tank (101) to an ultra violet (UV) feed tank (102);
adding (205) hydrogen peroxide from hydrogen peroxide (H2O2) dozing tank (104) to the ultra violet (UV) feed tank (102) with constant stirring;
transferring (206) the hydrogen peroxide containing feed water from the UV feed tank (102) to a UV machine (105) where the hydrogen peroxide breaks into OH radicals by photo degradation and reduce cyanide into nonhazardous carbonate and nitrogen and discharging purified water.

4. The process (200) as claimed in claim 3, wherein the oxidative accelerator added in feed water is macromolecular cage complex.
5. The process (200) as claimed in claim 3, wherein rotameter is used to adjust flowrate of feed.
6. The process (100) as claimed in claim 3, wherein optimize flow rate of hydrogen peroxide from the hydrogen peroxide dozing tank (104) to the UV feed tank (102) is in the range of 8 to 12 liter/m3.
7. The process (200) as claimed in claim 3, wherein the discharged purified water has free cyanide content in range 0.6 to 1 PPM.
8. The process (200) as claimed in claim 3, wherein the discharged purified water has total cyanide content in range 2 to 5 PPM, preferably 3 PPM.
9. The process (200) as claimed in claim 3, wherein UV C light of wavelength around is used to break hydrogen peroxide (H2O2) into OH radical through photo degradation.
10. The process (200) as claimed in claim 3, wherein the process (200) removes more than 90% of colour from the feed waste water.
11. A waste water purification system (100) for treating total and free cyanide from waste water of coke plant, the system (100) comprising:
a reaction tank (101) for reaction of oxidative accelerator with the waste water;
an Ultra Violet (UV) feed tank (102) connected with the reaction tank (101) for mixing hydrogen peroxide (H2O2) from dozing tank (104) to the waste water from the reaction tank (101); and
an Ultra Violet (UV) machine (105) for breaking the hydrogen peroxide into OH radicals using Ultra violet light and reducing component of free cyanide and total cyanide into carbonates and nitrogen.
12. The waste water purification system (100) as claimed in claim 11, wherein a portion of purified water is recirculated to the UV feed tank (102).
13. The waste water purification system (100) as claimed in claim 12, wherein recirculation ratio of 10:1 is maintained in the system.
14. The waste water purification system (100) as claimed in claim 11, wherein UV machine (105) consists of:
a stainless-steel shell fitted with quartz sleeves;
a plurality of UV light introduced through the quartz sleeves to make the UV light chamber water leak resistant;
an inlet port to facilitate entry of hydrogen peroxide containing feed into UV light chamber; and
an outlet port to facilitate exit of discharge and recirculation water.
15. The waste water purification system (100) as claimed in claim 11, wherein inlet port of the UV feed tank (102) is at the bottom and outlet port of the UV feed tank (102) is at top to provide sufficient time for the reaction.
16. The waste water purification system (100) as claimed in claim 11, wherein the waste water purification system (100) removes more than 90% of colour from the feed waste water.
, Description:A PROCESS AND SYSTEM FOR TREATING TOTAL AND FREE CYANIDE FROM WASTE WATER OF COKE PLANT
FIELD OF INVENTION:
[001] The present subject matter described herein, relates to a method and a system for treating total and free cyanide from waste water of coke plant. The present subject matter in particularly relates to a process and a system for photochemical degradation along with oxidative accelerator of both free and total cyanide into carbonate and nitrogen from industrial waste water using hydrogen peroxide.
BACKGROUND AND PRIOR ART AND PROBLEM IN PRIOR ART:
[002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[003] Cyanide (CN-) is considered among the most toxic compounds. It is one of the components in the effluent produced from iron and steel industries. Coking waste water contains a substantial amount of organic pollutants and Total cyanide or complex cyanide. Among total cyanide substantial amount of free cyanide (CN-) is also present in the water which is very lethal to the environment.
[004] According to state pollution control board the discharge limit of total cyanide is less than 0.2 ppm. Therefore, it is requirement of the central effluent treatment plant to discharge water that should meet the standard of 0.2 ppm of total cyanide (CN-) present in the system.
[005] Currently, the process used to reduce the content of cyanide from waste water is coagulation of FeSO4 which is capable of meeting the standards, but this process is not economical as a number of chemicals are used in this process. Also, this process produces a lot of hazardous sludge which needs to be address properly.
[006] Indian patent application Number: 201631044988 discloses a Supramolecular Metallo Cage as Flocculent for removal of free cyanide from waste water.
[007] Chinese patent CN105271583A discloses an advanced oxidation technique to be used along with the FeSO4 treatment to meet the norms set by state pollution control board, i.e., <0.2 mg/l of total Cyanide.
[008] Japanese patent JP2001347281A shows the method for treatment of both free and Total CN by combination of H2O2 and UV radiation.
[009] International patent WO9322249A1 explains a process and device for destroying Free and Complex Cyanides.
[0010] However, the processes described above are still in developing stage and there is no prototype found for treating coke plant waste continuously at pilot scale level.
[0011] To address the above issues a new process and system has been established wherein effect of photo chemical process on free and total Cyanide is disclosed. Also, impact of adding an oxidative accelerator is disclosed which enable breaking down all the free Cyanides and all complex cyanides.
[0012] The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
OBJECTS OF THE INVENTION:
[0013] It is therefore the object of the invention to overcome the aforementioned and other drawbacks in prior method/product/apparatus.
[0014] The principal objective of the present invention is to develop a process and system for combined oxidative removal and photochemical degradation of total cyanide from industrial waste water mainly coke plant waste water.
[0015] Another object of the present invention is to develop a process and system for combined oxidative removal and photochemical degradation of free cyanide from industrial waste water mainly coke plant waste water.
[0016] Another object of the present invention is to develop a continuous pilot plant for treating both free and complex cyanide from coke plant waste water.
[0017] Yet another object of the present invention is to optimize the conditions for photodegradation of cyanide for photochemical degradation along with oxidative accelerator of both free and total cyanide into carbonate and nitrogen.
[0018] Yet another object of the present invention is to provide a process and a system that has free cyanide removal efficiency greater than 90%.
[0019] Yet another object of the present invention is to provide a process and a system that has total cyanide removal efficiency greater than 95%.
[0020] These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taken into consideration with accompanying drawings in which preferred embodiments of the present subject matter are illustrated.
SUMMARY OF THE INVENTION:
[0021] One or more drawbacks of conventional method for treatment of waste water to remove free Cyanide and total, and additional advantages are provided through the method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.
[0022] The present subject matter relates to a method and system to remove total and free cyanide from coke plant waste water. In present invention, the toxic cyanide ions are photodegraded from the coke industry wastewater using UV radiation with strong oxidant Hydrogen peroxide (H2O2) and a strong oxidative reagent. This is facile technique for breaking down of cyanide into a nontoxic form in large scale and therefore, does not require further treatment.
[0023] In an embodiment, the present subject matter discloses a process for treating total and free cyanide from waste water of coke plant. The process includes: feeding the waste water to a reaction tank with constant flow; adding oxidative accelerator in the reaction tank containing waste water under constant pH in range 10 to 11 and feeding the waste water from the reaction tank to an ultra violet (UV) feed tank; adding hydrogen peroxide from hydrogen peroxide (H2O2) dozing tank to the ultra violet (UV) feed tank with constant stirring; transferring the hydrogen peroxide containing feed water from the UV feed tank (102) to a UV machine where the hydrogen peroxide breaks into OH radicals by photo degradation and reduce cyanide into nonhazardous carbonate and nitrogen and discharging purified water.
[0024] Yet another embodiment of the present subject matter discloses a waste water purification system for treating total and free cyanide from waste water of coke plant. The system includes a reaction tank for reaction of oxidative accelerator with the waste water; an Ultra Violet (UV) feed tank that is connected with the reaction tank for mixing hydrogen peroxide (H2O2) from dozing tank to the waste water from the reaction tank; and an Ultra Violet (UV) machine for breaking the hydrogen peroxide into OH radicals using Ultra violet light and reducing component of free cyanide and total cyanide into carbonates and nitrogen.
[0025] In an aspect, the present process and system results in removing more than 90% of colour of feed waste water.
[0026] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[0027] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0029] Fig. 1a illustrates a waste water purification system for removal of free and total cyanide, in accordance with an embodiment of the present subject matter;
[0030] Fig. 1b illustrates waste water purification system as shown in fig. 1a with flow and discharge, in accordance with an embodiment of the present subject matter;
[0031] Fig. 2a and 3 illustrates a process flow diagram for removal of total cyanide and free cyanide from the waste water, in accordance with an embodiment of the present subject matter;
[0032] Fig. 2b illustrate structure of EncryptCyn as used in the process illustrated in fig. 2a, in accordance with an embodiment of the present subject matter;
[0033] Fig. 4 illustrates a structure UV reactor of the waste water purification system of fig. 1, in accordance with an embodiment of the present subject matter;
[0034] Fig. 5 illustrates graph showing free cyanide removal efficiency with variation of dosing rate, in accordance with an embodiment of the present subject matter
[0035] Fig. 6 illustrates a graph showing total cyanide removal efficiency with varying dosage rate of H2O2, in accordance with an embodiment of the present subject matter;
[0036] Fig. 7 illustrates a graph showing continuous trial free cyanide removal efficiency, in accordance with an embodiment of the present subject matter; and
[0037] Fig. 8 illustrates a graph showing continuous trail total cyanide removal efficiency.
[0038] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0039] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
[0040] The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.
[0041] The present subject matter relates to a method and a system to remove total and free cyanide from coke plant waste water. The present invention treats total and free cyanide in the waste water by photochemical degradation along with oxidative accelerator to convert hazardous total and free cyanide into carbonates and nitrogen. Hydrogen peroxide is used in this process to break into OH radicals and reduce the cyanides present in the waste water.
[0042] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0043] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0044] Figure 1a illustrates a waste water purification system for removing free cyanide and total cyanide from the waste water is illustrated. The present waste water purification system 100 includes a reaction tank 101, Ultra violet (UV) feed tank 102, oxidative accelerator dosing tank 103, hydrogen peroxide dosing tank 104, and ultra violet (UV) machine 105. As shown in the figure 1, each tank is connected with other tank through a conduit or connecting pipe. The reaction tank 101 receives waste water or feed water from a conduit 106. The feed water has high amount of free cyanide of about 7 to 10 ppm and total CN around 50 to 80 ppm. The reaction tank 101 is connected to the oxidative accelerator dosing tank 103 via a conduit 107. Further, a rotameter 108 is provided in between the oxidative accelerator dosing tank 103 and the reaction tank 101 to maintain the flow of oxidative accelerator. The reaction tank 101 has means 101a for continuous stirring of the feed water present in the reaction tank. The means for continuous stirring 101a can be any mixing or blending, such as shaker or homogenizers. The stirring means 101a is provided to achieve efficient reaction in the reaction tank 101. The UV feed tank 102 is connected with the reaction tank 101 through a conduit 109 to supply the feed water from the reaction tank 101 to the UV feed tank 102. Further, a rotameter 110 is provided in between the UV feed tank 102 and the reaction tank 101 to control or maintain flow of the feed water or fluid from the reaction tank 101 to the UV feed tank 102.
[0045] As shown in the figure 1a, the UV feed tank 102 is connected to a hydrogen peroxide (H2O2) dosing tank 104 through a conduit 111 to supply the hydrogen peroxide (H2O2) from the hydrogen peroxide (H2O2) dosing tank 104 to the UV feed tank 102. Further, the UV feed tank 102 also has stirring means 102a for efficient mixing of the hydrogen peroxide (H2O2) and the feed water treated with oxidative accelerator. The conduit 111 has a rotameter 112 to control flow of the hydrogen peroxide (H2O2) to the UV feed tank 102.
[0046] The UV feed tank 102 is further connected with the UV machine 105 through a conduit 113. The conduit 113 is provided to supply feed water treated with the hydrogen peroxide (H2O2) and oxidative accelerator from the UV feed tank 102 to the UV machine 105. Further, a conduit 114 is provided in between the UV machine 105 and the UV feed tank 102 to supply a portion of treated or filtered water to the UV feed tank 102. Further, another portion of the treated water from the UV machine 105 is discharged from the discharger 115.
[0047] In an embodiment of the present system, all feeds, such as feed water, oxidative accelerator, and hydrogen peroxide in the reaction tank 101 and the UV feed tank 102 are introduced at the bottom of the tank and all discharged are taken place at top of the tank. With the present arrangement, the reactants in the reaction tank and the UV feed tank got sufficient time to get reacted with the feed water. Further stirring means provide efficient mixture of the reactants.
[0048] As shown in the figure 1a, a recirculated conduit 116 is provided in between output of the discharger 115 and the reaction tank 101. The conduit 116 recirculate the discharge water from the UV machine 105 to the reaction tank 101 to increase efficiency of the system 100.
[0049] The oxidative accelerator pretreated feed water from the reaction tank 101 is discharged at double flow rate of flow rate of the feed water to the UV feed tank 102. Further, the conduit 116 recirculates the discharged water or purified water at the same flow rate as feed water flow rate into the reaction tank 101 to maintain the steady state balance in both the tanks 101, 102.
[0050] From the UV feed tank 102, the hydrogen peroxide mixed feed water is feed to the UV reactor or UV machine 105 at sufficiently higher flow rate to allow the feed water to complete several iterations before discharging out. The recirculation ratio is maintained in the UV machine 105 around 10:1. A higher capacity pump (not shown in the figure) is also installed to maintain such recycle ratio. During recycling a part of stream considered as tear stream and recycled back to the reaction tank 101 through the conduit 116. The intra recycle loop is set at the bottom of the UV feed tank 102 so that bottom portion gets reacted very fast.
[0051] Referring to figure 1b, the interloop recycle is responsible for recycling the whole fluid between the reaction tank 101 and the UV feed tank 102. The purpose of the recycling is to minimize the load of CN at the reaction tank 101 and rest can be disposed to the environment directly. The tapping of discharge from UV feed tank 102 is present at the top of the tank. Since the concentration at UV feed tank 102 changes gradually from higher to lower in upward direction (as mentioned in the figure), during the traveling of fluid from bottom to upper section, the concentration gets reduced automatically. The part of the fluid withdrawn from upper (1:1 ratio) is almost clean. The recycled part (which is around 50% of the total) again going back to the reaction tank 101 to reduce the load of CN in the reaction tank. Since the feed water in UV feed tank 102 is introduced at the bottom and after intra iteration from the UV reactor 105, the fluid is also discharged at the bottom (as mentioned in the figure), there will be always a higher CN level at the bottom of the UV feed tank and less at the surface or top portion of UV feed tank. This process initially requires 4 to 5 hour to get automatically stabilized and maintain the concentration as per requirement.
[0052] These arrangements of inlet and outlet ports enables a complete reaction and destruction of total CN before discharging out from the top of the tank.
[0053] Working of the water purification system:
[0054] Referring to figure 1 and 2 together, the reaction tank 101 is pretreatment tank of present system, where macromolecular cage complex or oxidative accelerator reacts with free cyanide present into the feed water. The feed water from feed tank is introduced in reaction tank along with a specified dosing rate of macromolecular cage complex solution. The discharge of the reaction tank goes to UV feed tank. In UV feed tank hydrogen peroxide from the dozing tank is introduce with constant flow rate along with discharge from the feed tank. Contents from the UV feed tank to the UV light chamber is maintained at sufficiently higher flow level so that it will complete several iterations before discharging out. One outlet is provided at the bottom of the UV feed tank for discharging of treated water. From UV feed tank, mixture of feed and hydrogen peroxide is transferred to UV machine where hydrogen peroxide splits into OH radicals. Referring to figure 4, the UV machine 105 consist of stainless-steel shells fitted with quartz sleeves. These quartz sleeves are provided to stop dirt and dust to accumulate on the UV light chamber and block powerful rays of UV light to treat contents of the UV light chamber. Two UV light bulbs are provided of 141 watts each through these sleeves to make it water leak proof. All the rays of UV light incident on the waste water bodies. All the water from the UV machine 105 is recirculated back in the UV feed tank.
[0055] The photo degradation process is done for around 1 hour. The recirculation ratio is maintained here around 10:1. A high capacity pump is also installed to maintain such recirculation ratio. During recycling a part of stream considered as tear stream are recirculated back to the reaction tank 101.
[0056] Fig. 2 illustrates a process flow diagram for removal of total and free cyanide from waste water of coke plant, in accordance with an embodiment of the present subject matter. At step 201, feed water containing high amount of free cyanide of about 7 to 10 ppm and total Cyanide around 50 to 80 ppm is transferred to the Reaction Tank (shown in figure 2) with constant flowrate. Constant flow rate of the feed water is maintained with the help of a rotameter.
[0057] At step 202, oxidative accelerator is added in the reaction tank containing feed water. The mixture of feed water and oxidative accelerator is continuously stirred. In one embodiment macromolecular cage complex is used as an oxidative accelerator.
[0058] At step 203, after 45 minutes of adding oxidative accelerator in the reaction tank, the pH of the feed water is maintained in the range about 10 to 11 by pH correction process to provide optimal conditions for reaction.
[0059] At step 204, the feed water in the reaction tank is pretreated with EncryptCyn before introducing the feed water to a UV feed tank (illustrated in figure 2). The feed water treated with EncryptCyn is introduced in UV feed tank. Further, the structure and formula for EncryptCyn is shown in the figure 2b.
[0060] At step 205, Hydrogen peroxide (H2O2) from a dozing tank is added in the treated feed water in the UV feed tank with constant flow rate. The constant flow rate of the hydrogen peroxide is measured by a rotameter. Further, a plurality of rotameter is placed at different locations before and after the plurality of tanks to maintain the flow of liquid from one tank to another for proper mixing and reaction. Further, the Hydrogen Peroxide is introduced in the UV feed tank with different ratio of 5 (l/m3), 10 (l/m3), 15 (l/m3), 20 (l/m3).
[0061] At step 206, the feed water containing hydrogen peroxide (H2O2) from the UV feed tank is transferred to a UV light chamber. In the UV light chamber, the added Hydrogen peroxide of the feed water splits into OH radicals by photo degradation and reduce the free cyanide and total cyanide into non-hazardous carbonate and nitrogen. All the organic pollutants and cyanide are generally not very sensitive towards UV light particularly UV C of wavelength around 250 nanometers. This wavelength will cause photo degradation of organic microorganisms and converts it into nucleic acid, but it is not sufficient for degradation of toxic organic pollutants and cyanide contain metal cyanide or metal cyanide compound. When hydrogen peroxide (H2O2) irradiate with UV C light it produces very strong OH radical which can destroy any organic compound in its vicinity. One molecule of H2O2 can produce two moles OH radical which then instantly reacted with all kind of metal cyanide and metal complex cyanide and photo degraded the cyanide into carbonate and nitrogen.
[0062] At step 207, a portion of treated water from the UV light chamber is recirculated back into the UV feed tank and other portion of UV light chamber are discharged. All the portion of water from UV feed tank is getting recycled back to the UV feed chamber. From the UV feed tank 102, there is inter recycle loop and the ration of splitting is 1:1. One portion of water getting recycled to the reaction tank 101 and one portion of water get discharged.
[0063] As shown in the figure 1a, one steam of recirculated water (herein referred as tear steam) is recirculated back into the reaction tank along with feed raw water steam. This recirculation enhances overall efficiency of the system.
[0064] In the complete process for removing free cyanide and total cyanide from waste water, air circulation is maintained continuously in the waste water treatment plant or system to maintain dissolve oxygen level in each step for complete reaction. After completion of the reaction the water discharged has pH around 7.
[0065] Figure 3 illustrates another embodiment of the present process for removal of free cyanide and total cyanide from the waste water. In the process 300, at step 301 an oxidative accelerator is added with the waste water having constant pH in range 10 to 11. At step 302, hydrogen peroxide (H2O2) is added to the waste water treated with the oxidative accelerator. At the step 303, the mixture of the waste water, oxidative accelerator, and hydrogen peroxide (H2O2) are exposed to Ultra Violet (UV) photo degradation process where the hydrogen peroxide (H2O2) breaks into OH radicals by and reducing free cyanide and total into nonhazardous carbonate and nitrogen for treating total and free cyanide from waste water.
[0066] The present process for removal of cyanide and total cyanide from the waste water results in removing more than > 90% of colour from the feed stream.
Free Cyanide Removal Efficiency
[0067] Referring to figure 5 showing free cyanide removal efficiency with variation of dosing rate. It can be inferred from the graph that the result of system 100 is efficient, and it is capable to remove almost 95% cyanide from the waste water. The variation H2O2 dose is done with constant pH of 9 to 10. It is observed that dosing rate of 8 liter /m3 is the optimizing dosing rate in terms of cost effectiveness and the effective removal rate of cyanide removed. From the present process and the system, the maximum free cyanide is reduced from 12 to 0.6 ppm. The optimized duration of exposure of UV is around 45 minutes.
Total Cyanide Removal Efficiency
[0068] Referring to figure 6 showing total cyanide removal efficiency in varying dosing rate of H2O2. Considering dosing rate is varied from 5 lit to 26 per m3 of waste water to optimize the best whole process. The Total Cyanide in feed from diversion tank is varying from 45 to 100 PPM. In each case after treatment the total Cyanide is reduced to 2 to 13 PPM. It can be inferred from the graph that the process and the system has efficiency >95% for removal of free Cyanide and > 90% for removal of Total Cyanide.
Continuous Trial Total CN removal efficiency and Continuous Trial free CN removal efficiency
[0069] Reference may be made to figure 7 and 8 showing continuous trial free cyanide and total cyanide removal efficiency. It shows the continuous trial output for 8 hours of period. The system explained above enable the process to run continuously with almost same level of efficiency. Figure 6 and 7 reveals that initially 1 hour is required for adjusting the system and once it is adjusted the performance level is maintained continuously for n unit of time without any adverse effect on the process.
[0070] The Continuous trial is also coming out with very promising results the average free Cyanide removal efficiency is around greater than 90% and also total CN removal efficiency is also coming around greater than 90%. This also proves that with 8 lit/m3 dosing rate the new integrated novel process is capable of removing more than 90% both free and total Cyanide from the waste water.
[0071] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[0072] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.
[0073] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.