Claims:1. A process for removal of free cyanide (CN-) from CN- containing water comprising treating the CN- containing water with supramolecular metallo cage [L{M}] to remove the cyanide,
wherein the supra molecular metallo cage [L{M}] is
.
2. The process as claimed in claim 1, wherein the CN- containing water is industrial waste water.

3. The process as claimed in claim 2, wherein the industrial water is blast furnace waste water or coke plant water or combination thereof.

4. The process as claimed in claim 1, wherein the supra molecular metallo cage [L{M}] acts as a flocculent.

5. The process as claimed in claim 1, wherein the supramolecular metallo cage [L{M}] is in solid form or liquid form.

6. The process as claimed in claim 1, wherein the treatment of CN- containing water with supra molecular metallo cage [L{M}] is carried out by stirring.

7. The process as claimed in claim 6, wherein the stirring is carried out by mechanical stirring or magnetic stirring or combinations thereof.

8. The process as claimed in claim 1, wherein concentration of supramolecular metallo cage [L{M}] for CN- removal ranges from 5 mg/L to 20 mg/L and whereas retention time ranges from about 10 minutes to 30 minutes.

9. The process as claimed in claim 1, wherein optimal concentration of supramolecular metallo cage [L{M}] for CN- removal is 10 mg/L and whereas optimal retention time is 30 minutes.

10. A process for removal of free cyanide (CN-) from industrial water comprising treating the industrial water with supramolecular metallo cage [L{M}] as a flocculent through stirring to remove the cyanide impurities,
wherein the supra molecular metallo cage [L{M}] is
.
11. The process as claimed in claim 10, wherein the industrial water is blast furnace waste water or coke plant water or combination thereof.

12. Use of a supramolecular metallo cage [L{M}] for removal of free cyanide (CN-) from CN- containing water, wherein the supra molecular metallo cage [L{M}] is
.
13. A supra molecular metallo cage [L{M}]
.
14. A method for preparing supra molecular metallo cage [L{M}] as claimed in claim 13, wherein said process comprising reacting ligand L with copper sulphate in presence of a solvent
wherein ligand ‘L’ is

.

15. The method as claimed in claim 14, wherein the solvent is selected from a group comprising methanol or water or combination thereof.
16. The method as claimed in claim 14, wherein the method is carried out at a temperature ranging from about 25 ? to about 40 ? for a time duration from about 30 minutes to 60 minutes.

17. The method as claimed in claim 1, wherein the method further comprise isolation and/or purification of the supramolecular cage; wherein said isolation and/or purification is carried out by acts selected from a group comprising addition of solvent, addition of ionic resin, quenching, filtration, extraction and combination of acts thereof.

Dated this 07th day of July 2020
Signature:
Name: Durgesh Mukharya
To: Of K&S Partners, Bangalore
The Controller of Patents Agent for the Applicant
The Patent Office, at Kolkata IN/PA No. 1541
, Description:TECHNICAL FIELD
The present disclosure is in the field of chemical sciences. It generally relates to a process for removal of free cyanide (CN-) from CN- containing water comprising treating the CN- containing water with supramolecular metallo cage to remove the cyanide impurities. In particular, the present disclosure provides a process for removal of free cyanide (CN-) from industrial waste-water such as blast furnace waste-water, coke plant water, etc. The present disclosure also relates to the supramolecular cage and a method for preparing the supramolecular metallo cage.

BACKGROUND OF THE DISCLOSURE
Cyanides are used in a number of chemical synthesis and are also generated by metallurgical operations. Cyanide ion is one of the more obnoxious of pollutants in industrial waste waters because of its toxicity and have been a serious threat to the ecological systems and human health. It is produced as a waste product primarily by the steel, chemical and electroplating industries. Long-term exposure to even minute doses of cyanide can cause a significant increase in risk of health-related issues such as skin cancer, dyspnoea, tachycardia, unconsciousness, etc. Hence, it becomes important to remove cyanide from cyanide containing wastewater before it is discharged into the environment.
The wastewater from coke plant and blast furnace blow down are the contributors of aqueous cyanide emissions in the iron and steel industries. However, characteristics of cyanide from those sources are significantly different due to the presence of several other interferences. Cyanide present in the coke plant discharge is in association with other interferences such as ammonia, thiocyanate, sulfides, pyridine, oil, tar, phenol, cresol, benzol, PAH, etc. whereas the blast furnace blow down water contains various forms of cyanide along with high concentration of chloride and ammonia including other inorganic recalcitrant such as Fe, Na, K, SO42-, etc.

It is known that coke is required for reduction process in blast furnace and in the coking operation (coal to coke conversion), several by-products such as water, oil, tar, ammonia, phenol, cresol, benzol, cyanides, thiocyanate, sulphides, pyridine, PAH, etc. are generated during cooling of exhaust gas from the coke oven. After separation in decanter, coke oven battery liquor is generated which is eventually sent to ammonia still (for scrubbing) to reduce further ammonia and cyanide concentration up to a certain extent. However, the effluent of ammonia still contains large amounts of cyanide, thio-cyanide, sulphur, etc. Further, it is treated by activated sludge process using aerobic stain bacteria in BOT plant.

In the blast furnace, small amounts of cyanides are formed and alkali metals (mainly sodium and potassium) play a major role in cyanide formation. The oxides, carbonates and silicates of the alkali metals contained in coke and the acidic flux (silicates such as feldspar) are reduced and vaporized in the hearth of the blast furnace at temperatures above 1300°C.
M2SiO3 + 3C= 2M + Si + 3CO (M = Na // K)
Sodium and potassium vapors react with nitrogen from the preheated blast air and with carbon from the coke to form sodium cyanide and potassium cyanide.
2M + 2C + N2= 2MCN (M = Na // K)
Sodium and potassium cyanides are present in gaseous form in the hearth (boiling points: (NaCN) = 1530 °C; (KCN) = 1625 °C). They are carried upwards in the rapidly moving gas stream to the cooler zone (T <1000 °C), where they condense and can decompose by reacting with CO2 to form carbonates.
2MCN+4CO2=M2CO3+N2+5CO
A part of the alkali cyanide reduces iron oxide with the formation of alkali oxide. A part of the alkali cyanide leaves the blast furnace with the top gas (Fig. 1).
2MCN+2FeO=M2O+2Fe+2CO+N2
Top gas (blast-furnace gas) consists of 40-60% nitrogen, 20-30% carbon monoxide, 20-25% carbon dioxide, 2-4% hydrogen etc. The scrubbing water of top gas contains dissolved cyanide (HCN, alkali cyanide) and complex cyanide (unidentified) along with Fe, SO42-, Cl-, NH4+ (details result given below) complexes (e.g. of iron). The scrubbing water can be used several times for purifying the top gas. Blow down water of gas cleaning plant of Blast furnace (BF) releases free and complex cyanide along with appreciable amount of chloride. Cyanide content of BF water is associated with alkali and alkali earth metal, iron, chloride and ammonia.

Thus, both blast furnace and coke plant water contain environmentally hazardous contaminants and also these water sources contain high amount of cyanide content above the permissible limit which causes impact on the environment. In light of the above, there is a need for innovative and cost friendly method that enables to reuse the blast furnace and coke plant water. Further, the method should be feasible from implementation perspective without making any changes in the ongoing process of heavy industry.

The present disclosure provides a method for removing cyanide from cyanide containing water. It highlights an interesting application of supramolecular chemistry for the removal of toxic components such as cyanide from industrial wastewater and progressive modification of the removal process in terms of its chemical and commercial aspects.

STATEMENT OF THE DISCLOSURE
The present disclosure relates to a process for removal of free cyanide (CN-) from CN- containing water comprising treating the CN- containing water with supramolecular metallo cage [L{M}] to remove the cyanide,
wherein the supra molecular metallo cage [L{M}] is
.
The present disclosure also relates to a process for removal of free cyanide (CN-) from industrial water comprising treating the industrial water with the supramolecular metallo cage [L{M}] as a flocculent through stirring to remove the cyanide impurities,

The present disclosure further relates to use of the supramolecular metallo cage [L{M}] for removal of free cyanide (CN-) from CN- containing water

The present disclosure further relates to the supra molecular metallo cage [L{M}] and a method for preparing the supra molecular metallo cage [L{M}].

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
In order that the disclosure may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures. The figures together with a detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present disclosure where:
Figure 1 shows schematic representation of different zone of blast furnace.
Figure 2 shows synthetic scheme of supramolecular metallo cage [L{M}].
Figure 3 shows UV-Visible spectrum of supramolecular metallo cage [L{M}].
Figure 4 shows IR spectrum of supramolecular metallo cage [L{M}].
Figure 5 shows schematic reaction of supramolecular metallo cage [L{M}] with Blast Furnace (BF)/coke plant water.
DETAILED DESCRIPTION OF THE DISCLOSURE
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the description of the disclosure. It should also be realized by those skilled in the art that such equivalent products and methods do not depart from the scope of the disclosure. The novel features which are believed to be characteristic of the disclosure, as to 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. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure. Further, for the purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary.

Thus, before describing the present invention in detail, it is to be understood that this invention is not limited to particularly exemplified products and process parameters or methods that may of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only and is not intended to limit the scope of the invention in any manner.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example(s) and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative, falling within the spirit and the scope of the disclosure. Thus, the use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to various embodiments given in this specification.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of conflict, the present document, including definitions will control.

It must be noted that, as used in this specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a "solvent" may include two or more such solvents.

The terms "preferred" and "preferable" refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the invention.

As used herein, the terms "comprising", "including", "containing", "involving," and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Further, the terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a method that comprises a list of acts does not include only those acts but may include other acts not expressly listed or inherent to such method. In other words, one or more acts in a method proceeded by “comprises… a” does not, without more constraints, preclude the existence of other acts or additional acts.

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. Various singular/plural permutations may be expressly set forth herein for sake of clarity.

Any discussion of documents, methods, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

A detailed description for the purpose of illustrating representative embodiments of the present invention is given below, but these embodiments should not be construed as limiting the present invention.

As used herein, the phrase ‘supramolecular metallo cage’ or ‘[L{M}]’ refers to the complex of ligand (L) and the metal (M), which is useful for removing cyanide impurities.

The present disclosure relates to a process for removal of free cyanide (CN-) from CN- containing water comprising treating the CN- containing water with supramolecular metallo cage [L{M}] to remove the cyanide impurities, wherein the supra molecular metallo cage [L{M}] is
.
In an embodiment of the present disclosure, the CN- containing water is industrial waste water.

In another embodiment of the present disclosure, the industrial water is blast furnace waste water or coke plant water or combination thereof.

In an embodiment of the present disclosure, the supra molecular metallo cage [L{M}] acts as a flocculent.

In another embodiment of the present disclosure, the supramolecular metallo cage [L{M}] is in solid form or liquid form.

In yet another embodiment of the present disclosure, the treatment of CN- containing water with supra molecular metallo cage [L{M}] is carried out by stirring.

In still another embodiment of the present disclosure, the stirring is carried out by mechanical stirring or magnetic stirring or combinations thereof.

In still another embodiment of the present disclosure, the concentration of supramolecular metallo cage [L{M}] for CN- removal ranges from 5 mg/L to 20 mg/L and whereas retention time ranges from about 10 minutes to 30 minutes.

In still another embodiment of the present disclosure, the concentration of supramolecular metallo cage [L{M}] for CN- removal is 5 mg/L, 6 mg/L, 7 mg/L, 8 mg/L, 9 mg/L, 10 mg/L, 11 mg/L, 12 mg/L, 13 mg/L, 14 mg/L, 15 mg/L, 16 mg/L, 17 mg/L, 18 mg/L, 19 mg/L or 20 mg/L.

In still another embodiment of the present disclosure, the retention time is about 10 minutes, 11 minutes, about 12 minutes, about 13 minutes, about 14 minutes, about 15 minutes, about 16 about 17 minutes, about 18 minutes, about 19 minutes, about 20 minutes, about 21 minutes, about 22 minutes, about 23 minutes, about 24 minutes, about 25 minutes, about 26 minutes, about 27 minutes, about 28 minutes, about 29 minutes or about 30 minutes.
In still another embodiment of the present disclosure, the optimal and preferable concentration of supramolecular metallo cage [L{M}] for CN- removal is 10 mg/L and whereas optimal retention time is 30 minutes.

The present disclosure also relates to a process for removal of free cyanide (CN-) from industrial water comprising treating the industrial water with supramolecular metallo cage [L{M}] as a flocculent through stirring to remove the cyanide impurities,
wherein the supra molecular metallo cage [L{M}] is
.
In an embodiment of the present disclosure, the process is carried out at room temperature.

In an embodiment of the present disclosure, the process is carried out at a temperature ranging from about 25 ? to 40 ? for a time duration from about 20 minutes to 30 minutes.

In another embodiment of the present disclosure, the process is carried out in a container.

In yet another embodiment of the present disclosure, the process is carried out in a glass container.

In yet another embodiment of the present disclosure, the process comprises the step of stirring.

In yet another embodiment of the present disclosure, the stirring is carried out is by either a stirrer or a magnetic bead.

In yet another embodiment of the present disclosure, the stirring is carried out with a speed of 600-700 rpm.
The present disclosure also describes the use of a supramolecular metallo cage [L{M}] for removal of free cyanide (CN-) from CN- containing water, wherein the supra molecular metallo cage [L{M}] is
.
The present disclosure also provides a supra molecular metallo cage
.

In an embodiment, the present disclosure further provides a method for preparing supramolecular metallocage [L{M}] as described above, wherein said process comprising reacting ligand L with copper sulphate in presence of a solvent
wherein ligand ‘L’ is

The ligand L reacts with copper ions of the copper sulphate forming coordination complex with nitrogens of the ligand ‘L’. Thus, the obtained copper sulphate complexes of ligand L is termed as supra molecular metallocage [L{M}]. Further, the said supra molecular metallo cage [L{M}] compounds were characterized spectroscopically by both UV-Visible spectrum and IR spectrum of supra molecular metallocage [L{M}].

In an embodiment of the present disclosure, the solvent is either methanol or water or combination thereof.

In another embodiment of the present disclosure, the method is carried out at a temperature ranging from about 25 ? to 40 ? for a time duration from about 30 minutes to 60 minutes.

In yet another embodiment of the present disclosure, the method is carried out at a room temperature for a time duration from about 30 minutes to 60 minutes.

In an exemplary embodiment, the present disclosure provides a process for removing cyanide from solutions containing cyanide ions, wherein the process contains treating the CN- containing water with supramolecular metallo cage [L{M}] to remove the cyanide impurities, wherein the supra molecular metallo cage [L{M}] is
.
In another exemplary embodiment, the present disclosure relates to a process for removing cyanide from solutions containing cyanide ions, wherein the process contains treating the CN- containing water with the supramolecular metallo cage [L{M}] to remove the cyanide impurities, wherein the optimal concentration of supramolecular metallo cage [L{M}] for CN- removal is 10 mg/L and whereas optimal retention time is 30 minutes.

In yet another embodiment of the present disclosure, the method further comprise isolation and/or purification of the supramolecular metallocage; wherein said isolation is carried out by acts selected from a group comprising addition of solvent, addition of ionic resin, quenching, filtration, extraction and combination of acts thereof; and wherein the purification is carried out using ion exchange resin.

The present invention demonstrates that Supramolecular metallo cage [L{M}] can be employed in the removal of CN? from industrial waste water through homogenous phase by mixing the components. Supramolecular metallo cage [L{M}] disclosed in the present application is water soluble. Further, cage [L{M}] disclosed in the present application is not expensive and hence the entire process of removal of cyanide from the water becomes low-cost process.
The supramolecular metallocage [L{M}] act as a homogenous phase and as a flocculent. Mixing of the solid flocculent [L{M}] and waste-water is carried out through magnetic or mechanical stirring resulting in 65%-85% removal of the CN¯ within 30 minutes. The solvent used for the process was blast furnace waste water of steel plant which contained other interfering anions (Cl¯; 1000-1200 ppm, SO42¯; 90 ppm, NO3¯; 35 ppm, NO2¯; 1 ppm, CN¯; 3-6 ppm; NH3; 150 ppm) and it was again the source of CN¯ itself. The process includes mixing of [L{M}] with blast furnace waste-water with varying concentration range from 5g/m3 to 20 g/m3 of water.
An advantage of the present disclosure is that it provides a simple and cost-effective method for removal cyanide from a cyanide-containing waste-water by employing the supramolecular metallo cage [L{M}] which removes cyanides from the solution containing cyanide ions.
The foregoing description of the specific embodiments fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments in this disclosure have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Additional embodiments and features of the present disclosure will be apparent to one of ordinary skill in the art based upon description provided herein. The embodiments herein provide various features and advantageous details thereof in the description. Descriptions of well-known/conventional methods/steps and techniques are omitted so as to not unnecessarily obscure the embodiments herein. Further, the disclosure herein provides for examples illustrating the above described embodiments, and in order to illustrate the embodiments of the present disclosure, certain aspects have been employed. The examples used herein for such illustration are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the following examples should not be construed as limiting the scope of the embodiments herein.

EXAMPLES
Example 1:
A. Synthesis of cryptand(L)
A solution of tris (2-aminoethyl) amine (0.90 ml, 6.01 mmol) in dry CH3OH (250 mL) was taken in a dropping funnel and Terephthaldehyde (1.3 g, 0.9 mmol) was dissolved in 250 ml dry CH3OH in another dropping funnel. These two dropping funnels were fitted in to the 2-neck 1-litre round-bottom flask equipped with a magnetic stirrer and 500 mL of dry CH3OH
was added to the flask. Tris (2-aminoethyl) amine solution was added drop wise (4-5 drops/min) along with Terephthaldehyde solution (6-7drops/min) into the round bottom flux which allows complete dispersion of each drop between the additions with constant stirring at room temperature. Two solutions were completely added in approximately 4 hours and constant stirring was continued for another 8 hours resulting in the formation of yellowish solution of Schiff base. Reduction of the above Schiff base was achieved by hydrogenating it with excess NaBH4 in portion (1.2 g) for 1 hour at room temperature and constant stirring continued further for 12 hours until the solution became colourless. The solvent was evaporated under reduced pressure and 200 mL of water was added into it. The Product was extracted via liquid-liquid extraction with dichloromethane (2 x 200 ml). The organic phase was separated and dried over Na2SO4. Evaporation of the filtrate under reduced pressure yielded a light yellowish semi solid which was washed with diethyl ether to get the desired colorless cryptand, L in 85% yield (1.43g).
B. Synthesis of CuSO4 complex of supramolecular metallo cage [L{M}]:
Preparation of complex 1 is shown in Fig. 2. To a solution of L (4.5 g, 7.5mmol) in CH3OH (10mL), solution of CuSO4·5H2O (3.5 g, 22 mmol) in CH3OH (10 mL) was added dropwise. Greenish-blue coloured precipitate was obtained immediately and the mixture was stirred further at room temperature. The precipitate was filtered off and the precipitate was washed with small amount of CH3OH and dried in a vacuum which yielded the desired CuSO4 complex in 72% yield (5 g). This process of preparation of supramolecular metallo cage [L{M}] requires a duration of about 30 minutes to 60 minutes. M.P: >200°C. C, H, N analysis: Experimental Values: % C = 47.10; % H = 5.93; % N = 12.21; Theoretical Values: % C = 46.70; % H = 5.76; % N = 12.33. FTIR in KBr disc (?/cm-1) (Fig. 4): 3431, 2920, 1633, 1467, 1120, 810, 619. UV-Vis analysis (Fig. 3): ?max = 695 nm (e = 210 M-1cm-1) and ?max = 834 nm (e = 335 M-1cm-1).
Properties of supramolecular metallo cage [L{M}]:
Chemical Formula: C36H54Cu2N8O8S2
Molecular Weight: 916.20
Color: Bluish green
Moisture Content: Nil
pH: 5.6 (pure H2O)
Solubility: H2O
Solubility in water: (g/lit) 8.00 g/Lit
Cost: 25000/kg
Stability Constant: ~104
Example 2:
The instant example describes a process for removing cyanide impurities from standard solution of CN- and the said process comprises the following steps:
1. Treatment of 10 ppm and 100 ppm standard solution of CN? with supramolecular metallo cage [L{M}] through stirring.
2. Fixing of the optimal concentration and retention time of the supramolecular metallo cage [L{M}] for the treatment of CN? contaminated industrial waste water.
3. Plant trial data with the supramolecular metallo cage [L{M}].

1.Treatment of 10 ppm and 100 ppm standard solution of CN? with supramolecular compound through stirring:
A standard solution of K2[Zn(CN)4] (1000 mg/liters) in water was used to prepare 10 ppm/100 ppm standard solutions of CN?. These standard solutions were stirred for half an hour with supramolecular metallo cage and the solutions were subjected to filtration. The concentration of K2[Zn(CN)4] during experiment was 10mg/L. The strength of CN? in the filtrate (10 ppm standard) was found to be 0.35 ppm indicating 96.5% removal of the CN?. Standard experimental results demonstrated that the supramolecular metallo cage removes the cyanide from waste water through homogenous phase mixing within 30 minutes with more than 95% efficiency (Fig. 5). Later, different lab scale experiments were carried out with HBF & Coke plant water.
2. Fixing of the optimal concentration and retention time of the supramolecular metallo cage [L{M}] for the treatment of CN? contaminated industrial waste water
In order to fix the optimal concentration and retention time of the supramolecular metallo cage [L{M}] for efficient and quick removal of CN?, different concentration ranges of it were scanned with industrial waste water (e.g. blast furnace waste water). The blast furnace waste water contained different interfering anions like Cl¯; 1200-1500 ppm, SO42¯; 90 ppm, NO3¯; 35 ppm, NO2¯; 1 ppm, CN¯; 3-6 ppm. These solutions were stirred over a wide range of time intervals with supramolecular metallocage [L{M}] and the solutions were then filtered. The experiment was carried out by fixing the initial concentration from 5 mg/L and increased it up to 20 mg/L. The results are tabulated below. Here, CN? content in the feed sample (blast furnace blow down water) was 6.25 ppm. All the experiments were carried out in lab scale with the volume of 2 liters of water. The required quantity of compound was taken in 2 liters BF water or coke plant water and stirred for about 30 min followed by filtration through Whatman filter paper. Cyanide concentration of the filtrate was analyzed with ion selective electrode.
Table 1: Removal rate of free cyanide from the water
[L{M}] (5 mg/L) [L{M}] (10 mg/L) [L{M}] (20 mg/L)
Sample stirring
time
Conc.
of CN?
(ppm) % removal Conc.
of CN?
(ppm) % removal Conc.
of CN?
(ppm) % removal
10 min 2.55 59.4% 2.1 66% 1.98 68.32%
20 min 2.40 60.9% 2.05 67.2% 1.97 68.48%
30 min 2.22 64.4% 2.05 67.2% 1.98 68.32%
1 h 2.21 64.4% 2.0 68% 1.96 68.64%
2 h 2.21 64.4% 2.0 68% 1.97 68.48%
3 h 2.21 64.4% 2.0 68% 1.97 68.48%
4 h 2.21 64.4% 2.0 68% 1.97 68.48%
6 h 2.21 64.4% 2.0 68% 1.97 68.48%
12 h 2.21 64.4% 2.0 68% 1.97 68.48%

The tabulated results (table 1) shows that the removal rate of free cyanide was found to be 64% with concentration of compound 5 mg/L whereas if the concentration was increased up to 20mg/L, the removal efficiency was found to be increased upto 68.48%. Further increase in compound concentration up to 30 mg/L did not affect the removal efficiency much. Hence, the optimal concentration of compound for CN? removal was found to be 10mg/L whereas the optimal retention time was found to be 30 minutes and the process involved was homogenous phase mixing of compound and CN? waste water.
3. Plant trial data @5 m3/h with the supramolecular compound
Plant trial was carried out at By Product plant of Kalinganagar (KPO) @5m3/h with the supramolecular compound. The plant trial results showed that an approximate of 64-68% removal of cyanide was achieved. During trial, the water volume was 5m3 and the retention time was 30 min. The plant trial data is tabulated in the following table 2.
Table 2: Scale Up Trial for removal of cyanide with the supramolecular compound
Trial. No
Analysis No Before Treatment Average After Treatment Average % Removal
Cyanide (ppm) Cyanide (ppm) Cyanide (ppm) Cyanide (ppm) Cyanide
(ppm)

Trial No 1 1 7.29

7.24 2.40

2.40

66%
2 7.20 2.41
3 7.25 2.42
4 7.24 2.40
5 7.25 2.40

Trial No 2 1 6.09

6.07 1.52

1.51

68%
2 6.08 1.51
3 6.04 1.51
4 6.08 1.50
5 6.08 1.51

Trial No 3 1 7.28

7.23 2.51

2.49

65%
2 7.20 2.47
3 7.24 2.51
4 7.21 2.47
5 7.24 2.51

Trial No 4 1 7.30

7.32
2.61

2.61

64%
2 7.34 2.62
3 7.34 2.61
4 7.32 2.62
5 7.30 2.62

While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.