The present disclosure in general relates to condensate treatment. In particular, the disclosure relates to a catalyst formulation, a process and an apparatus for treating evaporator condensate.
BACKGROUND OF THE INVENTION
Molasses based distilleries (ethanol manufacturing plants) generate large quantities of wastewater which is known as "raw spent wash". This spent wash is treated using multiple effect evaporation (MEE) process, which concentrates the spent wash to about 30-35% volume, while recovering the water from the spent wash in the form of process condensate which is also known as 'MEE condensate' or 'evaporator condensate'. In order to implement zero-liquid discharge norms laid down by the government, it is desired to reuse this MEE condensate for molasses dilution and fermentation, where normally significant quantity of raw or fresh water is consumed. The fermentation process currently adopted in industries involves dilution of molasses as per requirement using the MEE condensate treated by this process, followed by its fermentation using yeast (e.g. Saccharomyces cereviciae) with the help of enzymes and antimicrobial agents, to produce ethanol.
Similar problem is found in sugar mills, in which the sugarcane juice is boiled using a series of multiple effect evaporators. This is done to increase the sugar concentration of the juice (converting it into a thick syrup), so that it can be easily separated by the process of crystallization. In this process also, a large quantity of water from the juice is evaporated and condensed to obtain what is commonly known as "sugar process condensate", which is one of the wastewaters obtained in the sugar factories.
However, both distillery MEE condensate and sugar process condensate consists of high levels of chemical oxygen demand due to organic compounds such as volatile acids, higher alcohols, phenolics etc. and is also acidic (pH 3-6) in nature. Therefore, the condensate cannot be used for any process or application, without any treatment. As a result, various treatment technologies have been developed and utilized for treatment of the distillery MEE condensate and sugar mill condensate as follows:

Biological Treatment: This technology is based on the principle of biological anaerobic and aerobic digestion (or oxidation) of wastewater pollutants, using microorganisms (activated sludge) to reduce the dissolved COD and BOD, followed by flocculation, clarification and filtration (using sand filter, activated carbon filter etc.) to remove the biomass and other suspended solids.
The main limitation of this technology is that it requires the condensate to be cooled down to below 50 °C, which requires extra capital expenditure. Further, the technology requires very high hold up or retention time, difficult to operate, generates excessive sludge (solid waste) and there are frequent start-up and maintenance issues (due to high temperature and variations in the condensate properties). Finally, it is necessary to disinfect the treated water, to kill any microorganisms present so that the water can be safely reused for fermentation process and other applications. Due to these issues, many biological process-based condensate treatment units are not working across the country.
Reverse Osmosis: This technology is based on the principle of reverse osmosis, which physically removes the molecules dissolves in water by applying pressure across a semi-permeable membrane. The reverse osmosis is usually preceded by filtration (using sand filter, activated carbon filter etc.) to remove any suspended solids and also to prevent membrane clogging. As a result of this process, the water obtained is of good quality with very low COD/BOD values.
The main limitation of this technology is that it requires the condensate to be cooled down to below 60 °C, which also requires capital expenditure. Further, the process generates large quantity of reject wastewater stream (normally upto 40% of the inlet water) which is not reusable for any process and requires separate treatment. Therefore, the recovery of water after treatment is very low in this process. Further, due to directly feeding the condensate having high COD/BOD, the membrane fouling (due to bacterial growth and scaling) is very frequent. Furthermore, this approach requires high dosages of anti-fouling and anti-scaling chemicals to protect the RO membrane. Even after this, the life of RO membrane is not enough and it requires to be replaced and also makes the process difficult to operate.
Fenton's reagent: This type of catalyst is used to oxidize contaminants or waste waters. Compared to above technologies, fenton-like system has rapid catalytic reaction and simple to use in the treatment process of wastewater. The Fenton reagent is a solution of hydrogen peroxide (H2O2) with ferrous iron. The Ferrous ion (Fe2+) and hydrogen peroxide (H2O2)

generates hydroxyl radical free radical (OH) with stronger oxidability. However, the main limitation of this technology is that the hydrogen peroxide utilization rate is low, required pH is lower in reaction, catalyst is difficult to recycle, and yield of chemical sludge is large.
Patent literature CN105478155A discloses a heterogeneous Fenton type catalyst having low temperature catalytic activity, and the application in the industrial organic wastewater such as degrading phenol and dyestuff
Patent literature CN109772370A discloses a water purification beaded catalyst having a Fenton catalyst as a raw material. The raw material is granulated and formed, so that catalyst and co-catalyst are fixed on particle after molding.
There still exists a need in the art to develop a new method, product and apparatus to address the above shortcomings of the existing technologies. The present disclosure provides a new catalyst formulation, a process and an apparatus for treating the evaporator condensate generated from ethanol distilleries. An important aspect being that the catalyst formulation, the process and the apparatus relates to the wastewater treatment and recycling problem in molasses-based ethanol distilleries and thus the present invention lies in the field of green technology as it also provides an alternate way to utilize waste materials and provide an approach to reduce the environment burden.
SUMMARY OF INVENTION
The present disclosure relates to a catalyst formulation, a process and an apparatus for treating evaporator condensate. The catalyst formulation is composed of a ferrous salt, a zeolite, an inorganic acid; and optionally comprising iron powder, a minimum of one copper salt and/or a minimum of one manganese salt. The process involves treatment of the evaporator condensate with a combination of the catalyst formulation and an oxidizer formulation under aeration. The apparatus has components selected from vessel (reactor), cylindrical tube-type air diffuser(s), air blower(s) and filter(s).
The disclosed catalyst formulation, process and apparatus provide high efficiency COD reduction in evaporator condensate.
BREIF DESCRIPTION OF ACCOMPANYING FIGURES
Figure 1. Schematic representation of the disclosed process for treatment of evaporator
condensate.

Figure 2. Effect of H2O2 dosage at constant ferrous (Fe2+) dosage for treatment of low COD condensate
Figure 3. Effect of H2O2 dosage at constant ferrous (Fe2+) dosage for treatment of high COD
condensate
Figure 4. Effect of addition of acidified zeolite to the catalyst, for the treatment of high COD
condensate
Figure 5. Effect of addition of copper and manganese salts to the Fe+Ze catalyst, for the
treatment of high COD condensate
Figure 6. Effect of addition of iron powder to the Fe+Ze+Cu+Mn catalyst, for the treatment
of high COD condensate
Figure 7. Effect of aeration on COD reduction
Figure 8. Effect of aeration and temperature on COD reduction
Figure 9. Comparison of the developed catalyst formulation with commercially used/known
catalysts and process used for Fenton Oxidation for treatment of evaporator condensate.
Figure 10. Schematic representation of the disclosed process for treatment of evaporator
condensate in distilleries with pre-treatment step.
DETAILED DESCRIPTION OF THE INVENTION
While the disclosure is susceptible to various modifications and alternative forms, specific aspects thereof have been shown by way of examples and will be described in detail below. It should be understood, however that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the invention.
The present disclosure relates to a catalyst formulation comprising:
a) a ferrous salt
b) a zeolite
c) an inorganic acid; and optionally
d) iron powder
e) a minimum of one copper salts
f) a minimum of one manganese salt

In one of the embodiments, the catalyst formulation comprises ferrous salts from 40 to 70% by weight of the total formulation, preferably from 50 to 60 % by weight of the total formulation, most preferably from 55 to 60% by weight of the total formulation.
In one of the embodiments, the catalyst formulation comprises zeolite from 5 to 30 % by weight of the total formulation, preferably from 10 to 25 % by weight of the total formulation, most preferably from 15 to 20 % by weight of the total formulation.
In one of the embodiments, the catalyst formulation comprises inorganic acid from 5 to 20 % by weight of the total formulation, preferably from 10 to 20 % by weight of the total formulation, most preferably from 12 to 15 % by weight of the total formulation. In one of the embodiments, the catalyst formulation optionally comprises iron powder from 0 to 10 % by weight of the total formulation, preferably from 2 to 6% by weight of the total formulation, most preferably from 3 to 5 % by weight of the total formulation.
In one of the embodiments, the catalyst formulation optionally comprises copper salts from 0 to 5 % by weight of the total formulation, preferably from 1 to 3% by weight of the total formulation, most preferably from 1.5 to 2 % by weight of the total formulation.
In one of the embodiments, the catalyst formulation optionally comprises manganese salts from 0 to 5 % by weight of the total formulation, preferably from 1 to 3 % by weight of the total formulation, most preferably from 1.5 to 2 % by weight of the total formulation.
In one of the embodiments, the catalyst formulation comprises ferrous salts which are preferably selected from ferrous sulphate (anhydrous or hydrated) and ferrous chloride (anhydrous or hydrated) or a combination of all.
In one of the embodiments, the catalyst formulation comprises zeolites which are preferably selected from either natural or any synthetic zeolite or a combination of all.
In one of the embodiments, the catalyst formulation comprises inorganic acids which are preferably selected from liquid acids such as concentrated sulphuric acid (96-100%) w/w), phosphoric acid (85-100%) w/w), hydrochloric acid, nitric acid or solid acids such as sodium bisulphate and sulphamic acid or a combination of all. The acid is mainly used to acidify the

zeolite, and the overall catalyst formulation, so that when the catalyst is dosed in the water to be treated, the pH is reduced to the optimum range. Addition of acid also prevents oxidation of ferrous ions to ferric ions in the resulting solid mixture.
In one of the embodiments, the catalyst formulation comprises copper salts which are preferably selected from copper sulphate (anhydrous or hydrated) and copper chloride (anhydrous or hydrated) or a combination of all.
In one of the embodiments, the catalyst formulation comprises manganese salts which are preferably selected manganese sulphate (anhydrous or hydrated) and manganese chloride (anhydrous or hydrated) or a combination of all.
Another embodiment of the present disclosure relates to a process of preparing catalyst formulation.
In one of the embodiments, the process of preparing catalyst formulation comprises the following steps:
a) Acidification of zeolite powder with an inorganic acid in required quantity,
b) Addition of a ferrous salt in required quantity, and optionally
c) Addition of iron powder in required quantity,
d) Addition of a copper salt in required quantity.
e) Addition of a manganese salt in required quantity.
The resulting mixture is a free-flowing pale yellow powder.
Another embodiment of the present disclosure relates to a process of treating evaporator condensate. Figure 1 provides schematic representation of the disclosed process for treatment of evaporator condensate.
In one of the embodiments, the process of treating evaporator condensate comprises the following steps:
i) Collecting evaporator condensate in a vessel (reactor) of specific volume
depending on the condensate flow rate, hydraulic retention time and its chemical

properties and retaining evaporator condensate in a vessel (reactor)for a minimum
period of 4 hours, ii) dosing a catalyst formulation and oxidizer formulation in a specific ratio to the
collected evaporator condensate, iii) providing aeration to the collected condensate mixed with the catalyst and oxidizer
using air diffusers for a certain period of time, iv) withdrawing the condensate after reaction, v) clarifying and filtering the condensate to remove suspended solids to obtain treated
condensate.
In yet another embodiment, the process of treating evaporator condensate generated from wastewater of molasses-based ethanol distilleries further comprises optionally a pretreatment step, wherein wastewater is treated with a base to increase the pH of the wastewater to 4.5 or more, preferably 6.0 or more. Figure 10 discloses a schematic representation of the disclosed process for treatment of evaporator condensate in distilleries with pre-treatment step.
In yet another embodiment, the base is selected from sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, calcium carbonate or combination thereof, and the quantity of base is in the range from 500 to 10,000 ppm or mg/L of wastewater.
In yet another embodiment, the pretreated wastewater is supplied to a multiple effect evaporator to generate evaporator condensate. In case of molasses-based ethanol distilleries, the evaporator condensate is generated from a multiple effect evaporator. The multiple effect evaporator is an apparatus in which the spent-wash (wastewater produced after separating the ethanol after fermentation of molasses) is heated to recover the water in the form of evaporator condensate.
The pH of the spent wash is generally between 2.5 to 3.5. In the disclosed process, a pre-treatment step may be included to treat the spent wash itself, before evaporating it in the multiple effect evaporator to obtain the evaporator condensate. In this pre-treatment step, the spent wash is treated using a base in order to increase the pH of the spent wash to 4.5 or more, preferably above 6.0.

The base is selected from but is not limited to sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, calcium carbonate or any other base. The quantity of base required for this pre-treatment step is in the range from 500 to 10,000 ppm or mg/L of spent wash.
After this, the pre-treated spent wash is fed to multiple effect evaporator to generate the condensate. As a result of this pre-treatment, the characteristic of the condensate also changes and it shows lesser COD and BOD values, and higher pH, depending upon the pH of the spent-wash fed to the evaporator. Due to this, the evaporator condensate becomes easier to be treated using the disclosed process using the same catalyst formulation and oxidizer formulation (as already described above).
Hence, the final parameters (COD, BOD and pH) of the evaporator condensate obtained after pre-treatment are better for re-use and recycling purpose, than those obtained without the pre-treatment step.
In one of the embodiments, the evaporator condensate is received from wastewater treatment in molasses-based ethanol distilleries.
In one of the embodiments, the evaporator condensate is received from wastewaters obtained in the sugar factories.
In one of the embodiments, the process is carried out in vessel (reactor) in which the condensate can be retained for a minimum period of 6 hours and minimum aeration of 0.2 vvm (volume per unit volume per minute) and a minimum temperature of 50 °C and maximum temperature of 80 °C. Hence it is suitable for treatment of hot wastewaters such as evaporator condensate.
In one of the embodiments, the process is carried out in vessel (reactor) which is preferably cylindrical vessel with an height to diameter ratio of 0.5 : 1.0 to 2.0 :1.0, more preferably between 0.8 : 1.0 and 1.5 : 1.0.
In one of the embodiments, the aeration in the reactor is done with a cylindrical tube-type air diffuser(s) with a minimum pore size of 0.05 mm and a maximum pore size of 2.0 mm and the

pore density in each diffuser should be such that the minimum pore surface area is 0.01 m2 per m3 of the diffuser tube.
In yet another embodiment, the aeration is supplied with the help of air blower(s) having an air blowing capacity which is enough to maintain minimum 0.2 vvm aeration rate for the entire treatment duration (retention time) inside the reactor when it is completely filled with wastewater to its working volume. Air blower is the equipment which is used to supply or pump air to the reaction vessel by withdrawing the air from the atmosphere. It is placed outside the reactor.
In one of the embodiments, the hydraulic retention time of the reactor is minimum 4 hours, preferably 6-12 hours for treatment of distillery evaporator condensate.
In one of the embodiments, the condensate withdrawn after reaction from the vessel (reactor) is filtered with the help of sand filter or medium gravel filter or bag filter or cartridge filter or a combination of any or all of these, to remove the suspended particles or sludge generated during the reaction.
In one of the embodiments, the catalyst formulation and oxidizer formulation can be dosed at a ratio of 1:8 to 1:20, depending on the wastewater characteristics.
In one of the embodiments, the combined dosage of catalyst formulation and oxidizer formulation can be 50 to 2000 milligrams per liter (ppm) of evaporator condensate to be treated, having a COD value of up to 7000 milligrams per liter (ppm).
In one of the embodiments, the process preferably works under the following conditions (of the inlet condensate to be treated)
1. pH = 3 to 7, optimum pH = 3-4
2. Temperature = 50-90, optimum temperature range = 70-80
3. COD range = up to 7000, preferably below 5000 ppm.
4. Catalyst: Oxidizer ratio = 1:10- 1:20
5. Total dose of catalyst + oxidizer = 50-4000 mg/L
6. Hydraulic retention time = Minimum 4 hours, preferably 7-12 hours.
7. Aeration rate = 0.2 to 2.0 vvm (preferably 0.8-2.0 vvm)

In one of the embodiments, the oxidizer formulation is based on 100% hydrogen peroxide solution.
In yet another embodiment, the oxidizer formulation is based on 95 to 99% hydrogen peroxide solution and 4 to 5% acid.
In the one of the embodiments, the acid of the oxidizer formulation is selected form sodium bisulphate and sulphamic acid, preferably sodium bisulphate acid.
In one of the embodiments, the hydrogen peroxide solution is having a strength of 45 to 90%(w/w), preferably a minimum 50% (w/w).
Thus, the process uses a specific combination of chemical catalyst, hydrogen peroxide and aeration. The process of the present disclosure combines the effect of Fenton oxidation with aeration at high temperature (> 50 °C), preferably 50 °C to 90 °C, to reduce the level of COD and BOD in the condensate water.
The combination of the catalyst formulation and oxidizer formulation is based on a modified Fenton oxidation process (which is an advanced oxidation process) to generate highly active hydroxyl radical (OH0) ions which is formed due to the reaction between the catalyst formulation and oxidizer formulation. These hydroxyl radicals stepwise oxidize the organic molecules such as volatile acids, alcohols, phenolic compounds etc. present in the evaporatorcondensate, thereby breaking them to simpler molecules, hence reducing the chemical oxygen demand (COD). The process of the present disclosure combines a catalyst formulation and oxidizer formulation in a certain ratio, when dosed in the condensate and mixed for about 8 hours, reduces the COD value of the condensate significantly.
According to one of the embodiments of the present disclosure, aeration means passing or introducing air into the reaction vessel through the wastewater (evaporator condensate) using air blowers (installed outside the reactor) and diffusers (installed inside the reactor). Aeration helps to mix the evaporator condensate, dissolve oxygen in the water which is helpful for the oxidation reaction and also for physical removal of volatile molecules present in the water.

Aeration is combined with the Fenton oxidation described above to increase the process efficiency by 'physically' removing some of the volatile compounds which impart COD. This works similarly as the 'stripping', in which volatile compounds are transferred from the aqueous phase to the gas phase (atmosphere). Since some of the organics (COD) are removed by aeration, it decreases the required dosage of catalyst and oxidizer (to be available for the remaining COD), which in the absence of aeration would be higher. Also, aeration helps to increase the dissolved oxygen concentration which helps in the overall chemical oxidation process too. Finally, aeration also helps to mix the components so that high efficiency is maintained.
One of the important aspects of the present disclosure is that the disclosed method combines Fenton oxidation with aeration (passing air through the water at high rates) which enhances the overall process efficiency in terms of COD ad BOD reduction. Another aspect of the present disclosure is the addition of inorganic acid (such as sodium bisulphate, sulfamic acid etc.) to the catalyst formulation and oxidizer formulation to bring the pH of water between 3 and 5, in case the pH of water to be treated is more than 5. This is done to enhance the process efficiency, as Fenton oxidation works better at 3-5 pH range. Also, the catalyst formulation and the operating parameters such as catalyst formulation and oxidizer formulation dosage, aeration conditions and reaction temperature have been optimized specifically to suit the treatment of distillery and sugar mill process condensate so as to achieve upto 80% reduction on COD and BOD.
The over-all efficiency of the process is measured in terms of reduction in the chemical oxygen demand (COD) and biochemical oxygen demand (BOD). The COD and BOD reduction is between 30 and 80%.
Another embodiment of the present disclosure relates to an apparatus for carrying out the process of treating evaporator condensate.
In one of the embodiments, the apparatus for carrying out the process of treating evaporator condensate has the following components:
a) Vessel (reactor);
b) Cylindrical tube-type air diffuser(s);
c) Air blower(s); and

d) Filter
In one of the embodiments, the vessel (reactor) is preferably a cylindrical vessel with an height to diameter ratio of 0.5 : 1.0 to 2.0 :1.0, more preferably between 0.8 : 1.0 and 1.5 : 1.0. The vessel (reactor) for the process is such that it is suitable for treatment of hot wastewaters such as evaporator condensate. Preferably, the evaporator condensate can be retained for a minimum period of 6 hours and minimum aeration of 0.2 vvm (volume per unit volume per minute) and a minimum temperature of 50 °C and maximum temperature of 80 °C. Further, the hydraulic retention time of the reactor is minimum 4 hours, preferably 6-12 hours for treatment of distillery evaporator condensate.
In one of the embodiments, the cylindrical tube-type air diffuser(s) is preferably with a minimum pore size of 0.05 mm and a maximum pore size of 2.0 mm and the pore density in each diffuser should be such that the minimum pore area is 0.05 m2 per m3 of each diffuser tube, and the combined pore area of all diffuser tubes is minimum 0.004m2 per 100m2 reactor volume. The air is distributed in the reactor with the help of cylindrical tube-type air diffusers.
In one of the embodiments, the aeration is supplied with the help of air blower(s) preferably having an air blowing capacity which is enough to maintain minimum 0.2 vvm aeration rate for the entire treatment duration (retention time) inside the reactor when it is completely filled with wastewater to its working volume.
In one of the embodiments, the filter is preferably selected from sand filter or medium gravel filter or bag filter or cartridge filter or a combination of any or all of these. The treated MEE condensate from the reactor is filtered with the help of a filter, to remove the suspended particles or sludge generated during the reaction.
Embodiments defined in the following examples are for the purpose of illustration of the invention and not intended in any way to limit the scope of the invention.
Further, the present disclosure is described with reference to the tables/ figures etc. and specific embodiments; this description is not meant to be construed in a limiting sense. Various alternate embodiments of the invention will become apparent to persons skilled in the art, upon reference to the description of the invention. It is therefore contemplated that such alternative embodiments form part of the present invention.
EXAMPLES

The applicant would like to mention that the examples and comparative studies are mentioned to show only those specific details that are pertinent to understanding the aspects of the present invention so as not to obscure the invention with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
The following examples are given to illustrate the present invention and should not be construed to limit the scope of the present invention.
Example 1: Preparation of catalyst formulation 1
Take 40-45 kg Natural Zeolite powder and add 3-5 kg sulphuric acid (98%) and blend together for about 30-40 minutes. Add 40-45 kg ferrous sulphate monohydrate and blend the mixture for 10-15 minutes. Then add 5-10 kg iron powder and blend the mixture for another 10-15 minutes to give 100 kg final catalyst formulation.
Example 2: Preparation of catalyst formulation 2
Take 10-20 kg Natural Zeolite powder and add 10-15 kg sodium bisulfate monohydrate and blend together for 30-40 minutes. Add 55-60 kg ferrous sulphate monohydrate powder, 3-5 kg iron powder, 1-4 kg copper (II) chloride dihydrate powder and 1-4 kg manganese sulphate and blend together for 10-20 minutes to give 100 kg final catalysts formulation.
Example 3: Preparation of catalyst formulation 3
Take 44 kg Natural zeolite powder and add 3 kg sulphuric acid (98%) and blend together for about 30 minutes. Add 44 kg ferrous sulphate monohydrate and blend the mixture for 10 minutes. Then add 9 kg iron powder and blend the mixture for another 10 minutes to give final catalyst formulation.
Example 4: Preparation of catalyst formulation 4
Take 20 kg Natural Zeolite powder and add 15 kg sodium bisulfate monohydrate and blend together for 30 minutes. Add 57 kg ferrous sulphate monohydrate powder, 5 kg iron powder, 1.5 kg copper (II) chloride dihydrate powder and 1.5 kg manganese sulphate and blend together for 10 minutes to give final catalysts formulation.
Examples 1 to 4 are mentioned in table 1 below:
Table 1:

Catalyst formulation Example 1 (broader range) Example 2 (broader range) Example 3 Example 4
Ferrous salt (ferrous sulphate monohydrate) (per 100 kg) 40-45 kg 55-60 kg 44 kg 57 kg
Zeolite (natural zeolite powder) (per 100 kg) 40-45 kg 10-20 kg 44 kg 20 kg
Iron powder 5-10 kg 3-5 kg 9 kg 5 kg
Inorganic acid (sulphuric acid (98%), sodium bi sulfate monohydrate) (per 100 kg) 3-5 kg 10-15 kg 3 kg 15 kg
Copper salts (chloride dihydrate powder) (per 100 kg) — 1-4 kg — 1.5 kg
Manganese salt (manganese sulphate) (per 100 kg) — 1-4 kg — 1.5 kg
Example 5: Process of treating evaporator condensate (wherein evaporator condensate is from source 1)
Source 1 is evaporator condensate from molasses-based distillery having chemical oxygen demand (COD) value of 6000 mg/L, pH value of 3.5.
The process is carried out in the following way-
• Collecting the condensate of 80 °C temperature in the reactor equipped with air diffusers
• Adding 75 ppm catalyst formulation 1 and 925 ppm oxidizer formulation to the condensate
• Aerating the condensate at the rate of 0.7 vvm with the help of air blower for 7 hours.
• Stopping the aeration and passing the treated condensate through filtration process to get final treated condensate.

• The COD of the final treated condensate will be below 2000 ppm, while pH will be increased up to 4.5.
• The treated condensate is then used for standard molasses fermentation process, with the help of Saccharomyces cerevisiae for replacing 50-100 % raw water (fresh water) for molasses dilution.
Example 6: Process of treating evaporator condensate (wherein evaporator condensate is from source 2/different characteristic)
Source 2 is evaporator condensate from sugar mill having chemical oxygen demand (COD) value of 300 mg/L, pH value of 6.5-
The process is carried out in the following way-
• Collecting the condensate of 80 ° C temperature in the reactor equipped with air diffusers
• Adding 10 ppm catalyst formulation 2 and 110 ppm oxidizer formulation to the condensate
• Aerating the condensate at the rate of 0.5 vvm with the help of air blower for 6 hours.
• Stopping the aeration and passing the treated condensate through filtration process to get final treated condensate.
• The COD of the final treated condensate will be below 80 ppm, while pH will be increased up to 7.5.
• The treated condensate is then used for various applications like cooling tower make up water and in standard molasses fermentation process, with the help of Saccharomyces cerevisiae for replacing 50-100 % raw water (fresh water) for molasses dilution.
Comparative Example 1. Effect of H2O2 dosage at constant ferrous (Fe2+) dosage for treatment of low COD condensate
In this experiment, the base catalyst- Fe2+ was dosed in the form of ferrous sulphate hexahydrate (FeSO^FhO) so that the ferrous (Fe2+) concentration is fixed at 10 ppm (mg/L),

while the H2O2 (50% w/w solution) dosage was varied from 50 to 4000 ppm (mg/L) in the MEE condensate. The following conditions were maintained during the reaction-
(a) Initial pH = 3.8
(b) Initial COD = 1250 ppm (mg/L)
(c) Initial TDS = 120 ppm
(d) Temperature = 40 °C
(e) Retention time = 7 hours
After 7 hours, the solution is filtered, and the final COD is determined for each H2O2 dosage. The results are shown in Figure 2. The results show that COD was reduced significantly and that with increasing dosage of H2O2, there was an increase in % COD reduction. There was a significant rise in COD reduction when the dosage of H2O2 was increased from 200 to2000 ppm, and after that the curve started to flatten. Nevertheless, maximum COD reduction in this experiment was obtained at 4000 ppm of H2O2 (50% solution), and there could have been slightly more COD reduction at high dosage.
Comparative Example 2. Effect of H2O2 dosage at constant ferrous (Fe2+) dosage for treatment of high COD condensate
In this experiment, the base catalyst- Fe2+ was dosed in the form of ferrous sulphate hexahydrate (FeSO^FhO). Both ferrous (Fe2+) concentration and H2O2 (50% w/w solution) dosage was varied from 10-30 ppm (Fe2+) and 200 to 5000 ppm (mg/L), respectively in the MEE condensate. The following conditions were maintained during the reaction-
(f) Initial pH = 3.5
(g) Initial COD = 3200 ppm (mg/L) (h) Initial TDS = 110 ppm
(i) Temperature = 50 °C (j) Retention time = 7 hours
After 7 hours, the solution was filtered, and the final COD was determined for each set. The results are shown in Figure 3. The results show that COD was reduced significantly and that with increasing dosage of H2O2 at each Fe2+ dose, there was an increase in % COD reduction. In all the cases (Fe2+ = 10, 20 and 30 ppm), there was a significant rise in COD reduction when the dosage of H2O2 was increased from 200 to 3000, and after that the curve started to flatten. Nevertheless, maximum COD reduction in this experiment was obtained at 5000 ppm

of H2O2 (50% solution), and there could have been slightly more COD reduction at high dosage.
This experiment also shows the effect of Fe2+ dosage or in other words the ratio of Fe2+ to H2O2 on the % COD reduction. As the concentration of Fe2+ is increased, there is a rise in COD reduction at a particular H2O2 dosage. This means increasing the dosage of Fe2+ has a positive impact on COD reduction of MEE condensate and in this experiment, a maximum COD reduction of-59% was obtained at 30 ppm Fe2+ dose and 5000 ppm 50% H2O2 dose.
Comparative Example 3. Effect of addition of acidified zeolite to the catalyst, for the
treatment of high COD condensate
In this experiment, the base catalyst- Fe2+ (in the form of FeSO^FhO) was mixed with
acidified natural zeolite and then dosed to the MEE condensate.
Natural Zeolite (Ze) was acidified in the following manner. 4 grams of 98% sulfuric acid was
added to 48 grams of natural zeolite and blended for about 1 hour. The resulting mixture is
called "acidified zeolite". This acidified zeolite and FeSO^FhO were mixed in 1:5 weight
ratio to make the catalyst mixture, which is used in the experiments.
The experiments were carried out similar to the above-described comparative example 2. In this case, the mixed catalyst dosage was varied such that the individual concentration of Fe and Ze are varied from 10-30 ppm) and H2O2 (50% w/w solution) dosage was varied from 200 to 5000 ppm (mg/L) in the MEE condensate. The following conditions were maintained during the reaction-
(k) Initial pH = 3.5
(1) Initial COD = 3250 ppm (mg/L)
(m)Initial TDS = 110 ppm
(n) Temperature = 50 °C
(o) Retention time = 7 hours
After 7 hours, the solution was filtered, and the final COD was determined for each set. The results are shown in Figure 4. The results show that COD was reduced significantly and that with increasing dosage of H2O2 at each Catalyst (Fe+Ze) dose there was an increase in % COD reduction. In all the cases (Fe+Ze = 20, 40 and 60 ppm), there was a significant rise in COD reduction when the dosage of H2O2 was increased from 200 to 3000, and after that the curve started to flatten. However, at high dosage of Fe+Ze (60 ppm), the COD reduction

obtained did not flatten above 3000 ppm H2O2 dose (as observed in the previous experiment) and was also significantly more than that at lower dosages of Fe+Ze. Nevertheless, in all cases of this experiment, maximum COD reduction was obtained at 5000 ppm of H2O2 (50% solution), and there could have been slightly more COD reduction at high dosage.
This experiment clearly shows the positive effect of addition of acidified zeolite to ferrous sulphate hexahydrate on the % COD reduction. Further, as the concentration of Fe+Ze is increased, there is a rise in COD reduction at a particular H2O2 dosage, and that the overall COD reduction is more than that obtained with only Fe2+ under similar conditions. In this experiment, a maximum COD reduction of >61% was obtained at 60 ppm Fe+Ze dose and 5000 ppm 50% H2O2 dose.
Comparative Example 4: Effect of addition of Copper and Manganese salts to the Fe+Ze catalyst, for the treatment of high COD condensate
In this experiment, the Fe+Ze catalyst mixture prepared as described in comparative example 3 was mixed copper and manganese salts and then dosed to the MEE condensate.
The experiments were carried out similar to the above-described comparative example 3. In this case, along with Fe and Ze (both at 30 ppm), 10 ppm of copper sulphate pentahydrate (CUSO4.5H2O) and 10 ppm of MJ1SO4.7H2O was also added in the form for a single mixture. H2O2 (50%) w/w solution) dosage was varied from 200 to 5000 ppm (mg/L) in the evaporator condensate similar to previous experiments. The following conditions were maintained during the reaction-
(p) Initial pH = 3.6
(q) Initial COD = 4280 ppm (mg/L)
(r) Initial TDS = 120 ppm
(s) Temperature = 50 °C
(t) Retention time = 7 hours
After 7 hours, the solution was filtered, and the final COD was determined. The results are shown in Figure 5. The results show that COD was reduced significantly and that with increasing dosage of H2O2 there was an increase in % COD reduction. In this case also, there was a significant rise in COD reduction when the dosage of H2O2 was increased from 200 to 3000, and after that the curve started to flatten. However, the average COD reduction in this

experiment at each H2O2 dose is found to be more (maximum -67% at 5000 ppm H2O2) than that obtained in the absence of Cu+Mn (described in the previous experiment).
This experiment clearly shows the positive effect of addition of copper and manganese salts to the acidified zeolite + ferrous sulphate combination.
Example 7: Effect of addition of iron powder to the Fe+Ze+Cu+Mn catalyst, for the treatment of high COD condensate
In this experiment, the Fe+Ze+Cu+Mn catalyst mixture prepared as described in comparative example 4 was mixed with iron powder and then dosed to the MEE condensate for treatment.
The experiments were carried out similar to the above-described comparative example 4. In this case, along with Fe (30 ppm), Zeolite (30 ppm), copper sulphate pentahydrate (10 ppm), mangenese sulphate heptahydrate (10 ppm), iron powder (5-10 ppm) was also added to the condensate. H2O2 (50% w/w solution) dosage was varied from 200 to 5000 ppm (mg/L) in the MEE condensate similar to previous experiments. The following conditions were maintained during the reaction-
(u) Initial pH = 3.3
(v) Initial COD = 4160 ppm (mg/L)
(w)Initial TDS = 146 ppm
(x) Temperature = 50 °C
(y) Retention time = 7 hours
After 7 hours, the solution was filtered, and the final COD was determined. The results are shown in Figure 6. The results show that COD was reduced significantly and that with increasing dosage of H2O2 there was an increase in % COD reduction. In this case also, there was a significant rise in COD reduction when the dosage of H2O2 was increased from 200 to 2000, and after that the curve started to flatten. However, the average COD reduction in this experiment at each H2O2 dose is found to be more (maximum -70% at 5000 ppm H2O2) than that obtained in the absence of iron powder (described in the previous experiment).
This experiment clearly shows the positive effect of addition of iron powder to the Fe+Ze+Cu+Mn catalyst combination.
Example 8: Effect of aeration on COD reduction

In this experiment, the condensate was treated with the combined catalyst formulation (Fe+Ze+Cu+Mn) of comparative example 4 and H2O2. The dosage of catalyst was 100 ppm, while the dose of 50% H2O2 solution was 1100 ppm so as to give a catalyst :H202 oxidizer solution dose of 1:11 w/w. Temperature was controlled at 40 and 68 °C. In one of the sets, aeration was provided at the rate of 1.5 vvm, while in other set, aeration was not provided. In control sets, no chemical dosage or aeration was provided. The average initial COD of the MEE condensate was around 6400 ppm, having a pH of around 3.2. The reaction was done for 6 hours.
The results are shown in Figure 7, which shows that in the absence of aeration, COD reduction of around 15% and 53% is obtained at 40 and 68 °C, respectively. On the other hand, in the presence of aeration, the COD reduction was enhanced to -68-70%. This shows that in the presence of aeration, the overall COD reduction can be increased at the same catalyst + oxidizer dose.
Example 9: Effect of aeration and temperature on COD reduction
Similar to example 7, the evaporator condensate was treated with the combined catalyst formulation (Fe+Ze+Cu+Mn) of example 7and H2O2. The dosage of catalyst was 100 ppm, while the dose of 50% H2O2 solution was 1100 ppm so as to give a catalyst :H202 oxidizer solution dose of 1:11 w/w. In this case, both temperature and aeration rate were varied. Temperature was controlled at 40, 55 and 68 °C, while aeration was provided at 0.5, 1.0 and 2 vvm. The average initial COD of the evaporator condensate was around 6200 ppm, having a pH of around 3.2. The reaction was done for 6 hours.
The results are shown in Figure 8, which shows that in upon increasing the temperature and aeration rate, the % COD reduction also increases. This shows that along with catalyst and oxidizer dosage, the aeration rate and temperature also positively affect the process efficiency. It could be concluded from the data that at temperature of 60-70 °C, and aeration rate of 1 -2 vvm, the best results (-70% COD reduction can be obtained) for an initial COD value of 6000-6500 ppm.
Example 10: Comparison of the developed catalyst formulation with commercially used/known catalysts and process used for Fenton Oxidation for treatment of MEE condensate.

Currently there are no known commercialized catalysts and processes for Fenton oxidation treatment of the MEE condensate obtained from molasses-based distilleries and sugar mill process condensate. However, based on literature survey, Fe2+ ions have been generally used as the catalyst using hydrogen peroxide as oxidizer for treatment of different other types of industrial wastewater.
The lab scale experiment described below was carried out to compare the performance of the novel developed catalyst formulation and treatment process, with the generally used treatment process using Fe2+ ions for treatment MEE condensate obtained from molasses-based distillery.
Commercially used/Known catalyst: Ferrous sulphate monohydrate (Fe2S04.H20) is used as the catalyst.
The catalyst formulation used for this experiment as given in table 2 below is as per present invention:
Table 2:

component % w/w
Natural Zeolite 20
Sodium bisulphate 15
Ferrous sulphate monohydrate 57
Iron powder 5
Copper chloride dihydrate 1.5
Manganese sulphate monohydrate 1.5
Process:
The process parameters adopted for both known catalyst and catalyst formulation of present invention was same in terms of initial COD, pH, catalyst dose, hydrogen peroxide dose and temperature of treatment. In case of process as per present invention, aeration was also provided to the reaction mixture while it was not provided in the known process, as shown in Table 3.
Table 3:

Parameter Known process Process as per present invention
Initial COD 6200 6200
pH 3.24 3.24
Catalyst Dose 100 mg/L 100 mg/L
H2O2 dose 1000 mg/L 1000 mg/L
Temperature 60°C 60 °C
Aeration rate 0 vvm 1.0 vvm
Reaction Time 6 hours 6 hours
The solution was filtered, and the COD was determined every hour during the reaction. The results are shown in Figure 9. The results clearly show that after each time interval, higher COD reduction was obtained using the catalyst formulation and process of present invention which shows the higher efficacy of the developed catalyst formulation and process for the treatment of evaporator condensate of molasses-based distillery.
Example 11: Treatment of Semi Kestner evaporator condensate of sugar mill using the process of present invention.
Experimental Conditions:
• Condensate sample = Semi Kestner Evaporator BCM Babhnan
• Volume taken = 500 mL (lab scale)
• Aeration rate =0.5-1.0 vvm
• Retention time =4-6 hours (batch)
• Temperature =60-80 °C
Treatment results: COD reduction
Table 4: At 60+2 °C

Initia ■ Dose (ppm) Fina
Initial Initial
Reactio 1 COD Fina Fina

50%

COD pH 1 TDS Catalys t H2O
2 n Time (h) CO D reductio n lpH 1 TDS

296 8.45 50 5 65 6 128 56.8% 7.86 79

10 90 6 112 62.2% 7.79 74

10 130 6 96 67.6% 7.76 75
Table 5: At 65+2 °C

Initial COD Initial pH Initia
1
TDS Dose (ppm) Tim e(h) Fina 1
CO D COD
reductio n Fina lpH Fina
1
TDS

Cataly
St 50% H2O2

152 8.10 40 10 130 4 48 68.4% 8.34 45
340 8.43 45 10 130 5 112 67.1% 7.90 65
368 8.30 49 10 130 4 128 65.2% 8.10 72

6 104 71.2% 6.95 76
Table 6: At 75+2 °C

Initial COD Initial pH Initia
1
TDS Dose (ppm) Tim e(h) Fina 1
CO D COD
reduct -ion Fina lpH Fina
1
TDS

Cataly s t 50% H2O2

296 8.70 37 10 130 4 112 62.2% 7.65 67

6 72 75.7% 7.60 70

5 65 4 144 51.3% 7.98 65

6 96 67.6% 8.10 74
312 8.36 50 10 130 5 88 71.8% 7.11 80

5 65 5 112 64.1% 7.53 65

Table 7: At 80+2 °C

Initial COD Initial pH Initial TDS Dose (ppm) Time (h) Final COD COD
reduc-tion Final pH Final TDS

Catalyst 50% H2O2

256 8.38 48 7.5 97.5 4 104 59.3% 8.31 77

6 72 71.8 8.25 83

12.5 162.5 4 88 65.6 8.10 74

6 56 78.12 7.44 89

15 195 4 64 75.0% 7.38 84

6 48 81.2% 7.10 94
BOD reduction
Table 8:

Initial BOD Reaction Temp °C Dose (ppm) Time (h) Final BOD BOD
reduction

Catalyst 50% H2O2

135 60±2 5 70 6 78 42.2%

10 90 6 70 48.1%

10 130 6 50 62.9%
84 65±2 10 130 6 28 66.6%
Throughout the experiment, the inlet COD was mostly between 250-350 ppm, pH was around 8.3-8.7 and the Total dissolved solids was between 40-50 ppm. The condensate obtained from Semi Kestner Evaporator of sugar mill can be treated using the process and catalyst formulation of present invention to obtain significant reduction in COD and BOD. It is observed that all the 3 factors tested - product dosage, retention time and reaction temperature, affect the process efficiency in terms of COD and BOD reduction. For instance,

o At low dosage of catalyst formulation (70 ppm), low temperature (60-65+2 °C)
and 4-5 hour retention time, a COD reduction of around 51-60%) was obtained
from an initial COD value of 296-312 ppm. o At high dosage of catalyst formulation (140 ppm), higher temperature (75-80+2
°C) and 6 hour retention time, a COD reduction of around 65-75%) was obtained
from an initial COD value of 296-312 ppm. o At further higher dosage of catalyst formulation (105-210 ppm), higher
temperature (80+°C) gives higher COD reduction (70-81%>) after 4-6hour retention
time. o Similarly, the BOD reduction increase from 40-50%) obtained at lower dosage and
lower temperature, to more than 60%> at higher dosage (140 ppm) and higher
temperature (65 °C).
The pH of the water is reduced from -8.5 to -7.5 on average basis under all the conditions tested. Based on the experiment, it is found that 65-70%> COD reduction and similar BOD reduction may be obtained at catalyst formulation dose of 10 + 130 ppm, retention time of 5-6 hour and reaction temperature of -75 °C, at an initial COD and BOD values of 250-325 ppm and 80-130 ppm, respectively. Higher dosage, higher temperature and higher retention time may give better results (70-80%> COD reduction). The odour of the condensate water was also reduced significantly after treatment. The temperature of the outlet may be 10 °C lower than the inlet temperature.
FULL SCALE RESULTS:
A full-scale plant based on the process of present invention was commissioned in an Indian sugar mill for treatment of sugar mill evaporator condensate (20-35 m3/hour). The table below shows 2-months data obtained from the plant, showing significant reduction of COD (60-80%) at an inlet COD of 250-400 ppm, 55-60 °C, aeration rate of 0.2 - 0.4 vvm and 6-8 hours hydraulic retention time.
Table 9:

Sr. no. Catalyst Dose 50% H2O2D0 Hydraulic Retention Temper ature °C Inlet Parameters Outlet Parameters COD
reduction

pH COD
(ppm) pH CO D
(PP m)
1. 5 65 7.5 55-60 6.8 280 7.20 68 75.7
2. 5 65 7.5 55-60 6.7 416 7.10 128 69.2
3. 5 65 7.5 55-60 6.5 380 7.00 160 57.9
4. 5 70 7.5 55-60 6.5 380 7.00 120 68.4
5. 5 70 7.5 55-60 6.5 380 7.50 100 73.7
6. 5 70 7.5 55-60 6.5 380 7.50 80 78.9
7. 5 70 7.5 55-60 6.5 350 7.50 70 81.6
8. 5 70 7.5 55-60 6.5 320 7.64 70 81.6
9. 5 70 7.5 55-60 6.5 380 7.50 80 78.9
10. 5 80 6 55-60 6.5 380 7.50 70 81.6
11. 5 80 6 55-60 6.5 350 7.50 80 78.9
12. 5 80 6 55-60 6.5 380 7.60 80 78.9
13. 5 80 6 55-60 6.5 320 7.70 80 78.9
14. 5 80 6 55-60 6.5 380 7.60 90 76.3
15. 5 80 6 55-60 6.5 380 7.70 80 78.9
16. 5 80 6 55-60 7.5 260 7.40 80 69.2
17. 5 80 6 55-60 7.4 300 7.70 80 73.3
18. 5 80 6 55-60 8.3 560 7.50 120 78.6
19. 5 100 6 55-60 6.5 380 7.40 112 70.5
20. 8 140 6 55-60 6.5 326 7.50 56 82.8
21. 8 140 6 55-60 7.0 292 7.60 64 78.1
22. 8 140 6 55-60 7.0 292 7.40 32 89.0
23. 8 140 6 55-60 7.0 304 7.50 60 80.3
24. 8 140 6 55-60 7.5 243 7.60 74 69.5
25. 8 140 6 55-60 6.6 320 7.15 80 75.0
26. 8 140 6 55-60 6.5 328 7.10 84 74.4
27. 8 140 6 55-60 6.5 340 7.20 80 76.5
28. 8 140 6 55-60 6.5 340 7.10 86 74.7
29. 8 140 6 55-60 6.8 338 6.50 90 73.4

30. 8 140 6 55-60 6.9 370 6.80 84 77.3
31. 8 140 6 55-60 6.9 272 7.10 62 77.2
32. 8 140 6 55-60 7.9 300 6.60 60 80.0
ADVANTAGES:
The disclosed invention relates to a catalyst formulation and an improved process for
waste recycling and is therefore environmentally friendly.
The overall capital expenditure of the disclosed process is lower than that of the
conventional biological treatment process (based on anaerobic-aerobic digestion).
The disclosed process is easy to start and stop. This means it can be started up and
stopped whenever required (unlike the biological process which requires minimum 1
month to start up to full capacity and also once started, it is required to continuously
monitor and operate). This is not a limitation for the Reverse Osmosis (RO) process
also.
The disclosed process can be operated both in batch and continuous mode, unlike
biological treatment which is generally operated in continuous mode.
The disclosed process can work at more than 50 °C and it is not required to cool down
the water to ambient temperature. In both RO and biological oxidation processes, it is
currently required to cool the water to below 50 °C.
The retention time of the process is lower (6-12 hours) than that of biological
treatment (more than 2-3 days).
The disclosed process recovers more than 90% of the water after treatment and there is
minimum sludge production. In case of RO, 30-40 % water is wasted as reject, while
the biological process produces large quantity of waste sludge.
The disclosed process reduces the temperature of MEE condensate by 10-15 °C,
therefore reduces the cost reducing the temperature using separate equipment.
The advantages of the disclosed invention are thus attained in an economical, practical, and facile manner. While example have been shown and described, it is to be understood that various further modifications and additional configurations will be apparent to those skilled in the art.

We Claim:

1. A catalyst formulation for treatment of evaporator condensate comprising:
a) a ferrous salt from 40 to 70% by weight of the total formulation;
b) a zeolite from 5 to 30 % by weight of the total formulation;
c) an inorganic acid from 5 to 20 % by weight of the total formulation; and optionally
d) iron powder from 0 to 10 % by weight of the total formulation;
e) a minimum of one copper salt from 0 to 5 % by weight of the total formulation;
f) a minimum of one manganese salt from 0 to 5 % by weight of the total formulation.

2. The catalyst formulation as claimed in claim 1, wherein the ferrous salt is from 50 to 60 % by weight, preferably from 55 to 60% by weight of the total formulation.
3. The catalyst formulation as claimed in claim 1, wherein the zeolite is from 10 to 25 % by weight of the total formulation, preferably from 15 to 20 % by weight of the total formulation.
4. The catalyst formulation as claimed in claim 1, wherein the inorganic acid is from 10 to 20 % by weight of the total formulation, preferably from 12 to 15 % by weight of the total formulation.
5. The catalyst formulation as claimed in claim 1, wherein the iron powder is from 2 to 6 % by weight of the total formulation, preferably from 3 to 5 % by weight of the total formulation.
6. The catalyst formulation as claimed in claim 1, wherein the copper salt is from 1 to 3%> by weight of the total formulation, preferably from 1.5 to 2 % by weight of the total formulation.
7. The catalyst formulation as claimed in claim 1, wherein the manganese salt is from 1 to 3 % by weight of the total formulation, preferably from 1.5 to 2 % by weight of the total formulation.

8. The catalyst formulation as claimed in claim 1, wherein the ferrous salt is selected from ferrous sulphate (anhydrous or hydrated), ferrous chloride (anhydrous or hydrated) or a combination thereof.
9. The catalyst formulation as claimed in claim 1, wherein the zeolite is selected from natural, synthetic zeolite or a combination thereof.
10. The catalyst formulation as claimed in claim 1, wherein the inorganic acid is selected from concentrated sulphuric acid (96-100% w/w), phosphoric acid (85-100% w/w), hydrochloric acid, nitric acid, sodium bisulphate, sulphamic acid or a combination thereof.
11. The catalyst formulation as claimed in claim 1, wherein the copper salt is selected from copper sulphate (anhydrous or hydrated), copper chloride (anhydrous or hydrated) or a combination thereof.
12. The catalyst formulation as claimed in claim 1, wherein the manganese salt is selected manganese sulphate (anhydrous or hydrated), manganese chloride (anhydrous or hydrated) or a combination thereof.
13. A process of preparing the catalyst formulation as claimed in claim 1, comprises the following steps:

a) acidifying zeolite powder with an inorganic acid,
b) adding a ferrous salt, and optionally
c) adding iron powder,
d) adding a copper salt,
e) adding a manganese salt.
14. A process for treatment of evaporator condensate comprising steps of:
i) collecting evaporator condensate in a vessel (reactor) of specific volume
depending on the condensate flow rate, hydraulic retention time and its chemical

properties and retaining evaporator condensate in a vessel (reactor) for a minimum
period of 4 to 12 hours; ii) dosing a catalyst formulation and an oxidizer formulation at a ratio of 1:8 to 1:20
to the collected evaporator condensate of step (i) to form a mixture; iii) providing aeration in the range of 0.2 to 2.0 vvm to the mixture of step (ii) using
air diffusers for a certain period of time, iv) withdrawing the condensate after reaction; v) clarifying and filtering the condensate to remove suspended solids to obtain treated
condensate.
15. The process as claimed in claim 14, further comprises optionally a pretreatment step, wherein wastewater from molasses-based ethanol distilleries is treated with a base to increase the pH of the wastewater to 4.5 or more, preferably 6.0 or more.
16. The process as claimed in claim 15, wherein the base is selected from sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, calcium carbonate or combination thereof, and the quantity of base is in the range from 500 to 10,000 ppm or mg/L of wastewater.
17. The process as claimed in claim 15, the pretreated wastewater is supplied to a multiple effect evaporator to generate evaporator condensate.
18. The process as claimed in claim 14, wherein the oxidizer formulation is 100% hydrogen peroxide solution, or the oxidizer formulation is 95 to 99% hydrogen peroxide solution and 4 to 5% acid.
19. The process as claimed in claim 14, wherein the process is carried out at a temperature in the range of 50 °C to 90 °C and at a pH of 3 to 7.
20. The process as claimed in claim 14, wherein the combined dosage of catalyst formulation and oxidizer formulation is in the range of 50 to 4000 milligrams per liter (ppm) of evaporator condensate, having a COD value of up to 7000 milligrams per liter (ppm).
21. An apparatus for treatment of evaporator condensate comprising:

(i) a vessel (reactor) for collecting and retaining evaporator condensate;
(ii) a minimum of one cylindrical tube-type air diffuser providing aeration to a mixture, wherein the mixture is collected evaporator condensate dosed with a catalyst formulation and an oxidizer formulation at a ratio of 1:8 to 1:20;
(iii)a minimum of one air blower; and
(iv)a minimum of one filter removing suspended solids to obtain treated condensate.
22. The apparatus as claimed in claim 21, further comprises optionally a multiple effect evaporator to generate evaporator condensate from the pretreated wastewater.