DESC:FIELD OF THE INVENTION

The present invention relates to a system for treating wastewater with oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride and removal of nitrated crude products obtained during the nitration of nitratable aromatic compounds generated during the nitration process from aqueous effluent solutions, so as to permit the disposal of the effluent.

BACKGROUND OF THE INVENTION

In recent times a strong effort has been made by industry and government to purify waste streams produced in processing plants for chemical products. Waste water purification operations are designed to handle a complex waste disposal stream formed from a variety of waste streams generated in a multiplicity of chemical plants producing a wide variety of chemical products. One component of the effluent of one plant is which is employed to remove organic waste components from liquid waste prior to conveying the purified water into fresh water systems such as rivers, lakes, and the like.

Although it is extremely difficult to design a simple system to handle a complex waste stream from a of chemical plants producing a variety of chemical products, such a system has been developed in a number of chemical complex areas. One component that adversely affects the operation of the activated carbon bed is a waste stream from chemical plants which contain a relatively high concentration of available chlorine, such as waste streams produced in calcium hypochlorite plants. Because of the complexity of the chemical nature of calcium hypochlorite, it is extremely difficult to economically remove all of the calcium hypochlorite and all of the available chlorine from the waste streams prior to discharge into the municipal sewer system.

Nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, Nitro-chlorobenzene by number of ways entered environment. Some research show that Nitro-phenol, Chloro nitro phenol or o-Nitrochlorobenzene are gene toxin. In nineteen eighty-two, European Union identified that Nitro-phenol, Chloro nitro phenol and nitro-chlorobenzene compounds are harmful, and difficult to degraded in the environment, and can cause the methemoglobinemia (Methemoglobinemia) of Mammals and people, and have carcinogenesis. Therefore, there is ban on certain Nitro-phenol, Chloro nitro phenol and nitro-chlorobenzene compounds, for preserving the ecological and environment form such pollutants.

Nitration waste water is deep reddish brown or yellow, mainly containing other organic impurities a small amount of such as nitric acid, sulfuric acid, nitrobenzene Nitro-phenol, Chloro nitro phenol and nitro-chlorobenzene compounds. Its chemical oxygen demand (COD) is 1000 to 1800mg/L, wherein, pH value is much smaller than 0, there is extremely strong acidity, this high COD and have the wastewater biological toxicity of extremely strong acidity large, be difficult to oxygenolysis and biological degradation, direct discharge is very big to environmental hazard, water quality can be caused to degenerate, people is also belonged to and to humans and animals, there is very large toxicity and cause sex change, it enters in body by respiratory system, Digestive tract and skin, cause poisoning, even cause death; Soil has very strong adsorption to nitro-compound, very easily accumulates in soil, therefore there is severe contamination of soil.

Method of wastewater treatment conventional present divided into three kinds, i.e. Physical, chemical method, biological process. Wherein, Physical is based on absorption method, and chemical method is based on the advanced oxidation processes in chemical oxidization method, and biological process mainly contains oxidation pond process, anaerobic biochemical etc. The cost of chemical method is relatively high, and during use, economy is very low; Nitration waste water acidity is extremely strong, is unfavorable for microbe survival, and therefore, biological process is also difficult to effectively process. Absorption method is less effective and relatively less applicable to industrial use for nitration waste water process

Nitrobenzene, Nitro-phenol, Chloro nitro phenol and nitro-chlorobenzene compounds are electron-withdrawing group because of its nitro and chlorine substituent, causes cloud density decline, oxidasic electrophilic on phenyl ring to attack and be obstructed, because of these aerobic biodegradation of such organic pollutant is difficult. For strengthening the chloride conversion containing nitro aromatic compound and degraded, scholars has carried out the aspects such as Advanced oxidation technologies and anaerobic biological treatment such as Fenton oxidation, photochemical catalytic oxidation, ozone oxidation. Domestic main starting with from aspects such as microbiological deterioration, catalytic ozonation, electrochemical process and charcoal absorptions has carried out nitro-chlorobenzene removal research.

Further the traditional method of treating effluent / waste water containing nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol also other phenol impurities generated during the nitration process was to treat it with slaked lime and chlorine gas. This process is costly as slaked lime has to be processed from quicklime by grinding rocks and treating it with water. Also, if we use lime, the powder creates dust, which also causes harm to the environment and also chlorine generated free chlorine during treating process which cause harmful environment and pollution.

U.S. Pat. No. 4,693,832, issued Sep. 15, 1987 to M.M. Hurst, describes a method of preparing potable water by mixing into semi-finished water an aqueous solution of hypochlorous acid having a pH of between about 3 and about 6 in amounts which provide the water with a free chlorine residual of at least about 0.5 ppm. The aqueous solutions contain between 0.1 and 10 grams of HOCl per liter. The method employs dilute solutions of impure hypochlorous acid having high pH values. These HOCl solutions are stated to provide the water with free available chlorine residuals having improved stability. However, to obtain the required pH range it is necessary to supply a base to the hypochlorous acid solution or employ a method of preparation which will prepare hypochlorous acid solutions having the desired pH.

The separation of the organic constituents from the wastewater can be carried out for example by a possibly multi-stage extraction. A known process is the optionally multistage stripping of the organic constituents with steam, in which, in particular, low-boiling organic impurities are removed, and subsequent thermolytic or oxidative decomposition of organic constituents still present in the resulting wastewater.

European patent EP0953546A2 a process for the degradation of aromatic nitro compounds in waste water by heating the waste water to temperatures of 150 to 350°C under a pressure of 10 to 300 bar. The EP0953546A2 states that the treated wastewater can easily be biologically cleaned. The EP1593654A1 describes a process for the treatment of alkaline wastewater resulting from the scrubbing of crude nitrobenzene, wherein the crude nitrobenzene is prepared by adiabatic nitration of benzene with nitrating acid and then washed in an acidic scrub and then in an alkaline scrubber containing an alkaline wastewater Benzene is obtained in concentrations of 100 to 3000 ppm and nitrobenzene in concentrations of 1000 to 10000 ppm, with the benzene and / or nitrobenzene subsequently being separated from the alkaline wastewater, and optionally residual benzene and / or nitrobenzene from the alkaline waste water is removed by stripping, and the alkaline wastewater is then heated under exclusion of oxygen to temperatures of 150 to 500 ° C under pressure. The EP1593654A1 states that the effluents thus obtained can be discharged into a biological treatment plant after checking the phenolate content.

However, the decomposition of nitro compounds in state-of-the-art aqueous effluents produces ammonia which is detrimental in biological sewage treatment plants. A biological wastewater treatment supplied NH3 -containing effluent must first be subjected to a nitrification. Nitrification is the bacterial oxidation of ammonia (NH3) to nitrate (NO3-). It consists of two coupled subprocesses: In the first part, ammonia is oxidized to nitrite, which is oxidized to nitrate in the second subprocess. The nitrification is associated with production of acid (H+ formation), the pH is lowered when the acid formed is not neutralized, such as by reaction with calcium carbonate (CaCO3). The acid formed pollutes the buffering capacity of the water and can acidify the water or the soil. Since nitrifying microorganisms change their metabolites only in the neutral to slightly alkaline range, acidification can prevent the complete conversion of fish toxic ammonia / ammonia into sewage treatment plants (autoinhibition).

The nitrate formed is then subjected to denitrification to form N2 in a further stage of biological wastewater treatment. Denitrification is understood to mean the conversion of nitrogen bound in nitrate (NO3-) to molecular nitrogen (N2) by certain heterotrophic and some autotrophic bacteria, which are subsequently referred to as denitrifiers.

It would thus be desirable to provide a wastewater from the above process, which contains nitrogen in the smallest possible amounts, so that in particular a nitrification can be omitted as the first stage of a biological wastewater treatment. This would have great economic and environmental benefits. At the same time, the energy expenditure for generating said wastewater should be as low as possible.

Thus, the object of the present invention to provide a process for the treatment of effluents from the nitration of aromatic compounds, which does not have the aforementioned disadvantages or to a lesser extent. In particular, the ammonia content in the wastewater, which is obtained in the nitration of aromatic compounds and subsequent removal of organic constituents should be reduced. The subsequent denitrification in a first stage of a subsequent biological wastewater treatment should be avoided as far as possible. At the same time, the process should operate with the least possible expenditure of energy and should be technically easy to implement.

There is a need at the present time for an improved economical process for purifying waste streams containing high concentrations of available Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol and there is also need for purifying waste coning high concentration of calcium hypochlorite.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a process for oxidative reduction of waste streams containing nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound with calcium hypochlorite composition.

Another object of the invention is to provide a process for economically oxidative reduction the available waste streams containing nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound treating with waste streams of calcium hypochlorite.

Another object of the invention is to provide a composition comprising calcium hypochlorite; calcium ion and Chloride.

The present disclosure describes a process for preparing the composition, comprising calcium hypochlorite; calcium ion and Chloride.

There is a need at the present time for an improved economical process for purifying waste streams containing high concentrations of available waste streams containing nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound content generated during the nitration process is treated with waste produced in calcium hypochlorite generating plants.

According to the invention, the method comprises the following steps:
a) single-stage or multi-stage washing of the waste streams containing nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound with calcium hypochlorite composition form waste stream to obtain at least one organic phase sludge and at least one aqueous phase and separation of the aqueous phase or the aqueous phases,
b) optionally removing organic constituents from at least part of the aqueous phase or aqueous phases obtained in step (a) by stripping, preferably at room temperature,
c) removal of organic compounds from at least part of the aqueous phase or aqueous phases resulting from step (a) or step (b) by oxidative degradation,
d) optionally supplying at least a portion of the aqueous phase resulting from step (c) to a biological wastewater treatment.

Another object of this invention to provide a process for reducing the available Acidic Effluent content and chemical oxygen demand (COD) 1000 to 1800mg/L of waste streams

Another object of the invention is to provide a process for economically treating waste streams containing high concentrations of available nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol content with waste streams formed in chemical plants which produce calcium hypochlorite.

Still another object of the invention is to provide a process for treating waste streams formed in plants generating impurities during the nitration process is treated with calcium hypochlorite in order to permit contact between these purification streams and activated carbon beds employed in water purification systems.

Still another object of the invention is to provide a process of treating wastewater employing calcium hypochlorite composition form waste stream. The said calcium hypochlorite composition form waste stream of the present disclosure demonstrates a synergistic effect while treating the wastewater.

These and other objects of the invention will be apparent from the following detailed description thereof.

DETAILED DESCRIPTION OF THE INVENTION
The present invention is to provide an oxidative reduction of waste streams containing nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound with calcium hypochlorite composition.

The present invention is to provide a process for reducing the available nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol content of waste streams and also control the high concentration of calcium hypochlorite from another waste stream.

In one embodiment of the invention is to provide a composition comprising calcium hypochlorite; calcium ion and Chloride.

An embodiment present invention is a process for preparing the composition, comprising calcium hypochlorite; calcium ion and Chloride.

An embodiment present invention is an improved economical process for purifying waste streams containing high concentrations of available waste streams containing nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound content generated during the nitration process is treated with waste produced in calcium hypochlorite generating plants.

An embodiment present invention, the method comprises the following steps:
a) single-stage or multi-stage washing of the waste streams containing nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound with oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride to obtain at least one organic phase sludge and at least one aqueous phase and separation of the aqueous phase or the aqueous phases,
b) optionally removing organic constituents from at least part of the aqueous phase or aqueous phases obtained in step (a) by stripping, preferably at room temperature,
c) removal of organic compounds from at least part of the aqueous phase or aqueous phases resulting from step (a) or step (b) by oxidative degradation,
d) optionally supplying at least a portion of the aqueous phase resulting from step (c) to a biological wastewater treatment.

It is a primary object of this invention to provide a process for reducing the available Acidic Effluent content and chemical oxygen demand (COD) 1000 to 1800mg/L of waste streams

As cost-effective and high-efficient oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride. The oxidative reduction composition of calcium hypochlorite has potential applications in waste water treatment and sludge disposal. The oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride wherein wastewater treatment based on the oxidative reduction mechanisms of nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound. The oxidative reduction composition of calcium hypochlorite approaches were effective in pollutants removal and membrane fouling mitigation for wastewater treatment, but also contributed to sludge dewatering and resource recovery for sludge disposal. The ClO- and large generated free active radicals (i.e., reactive chlorine species and reactive oxygen species), which possessed strong oxidative ability, were the primary contributors to the pollutants decomposition, and colloids/microbes flocs disintegration during the hypochlorite treatment process. The performance of oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride treatment has highly associated with various factors (i.e., pH, temperature, hypochlorite types and dosage). In combination with the reasonable activators (i.e., Fe2+ and ultraviolet), auxiliary agents, and innovative processes (i.e., hydrothermal and electro-oxidation), the operational performance of hypochlorite technology could be further enhanced. The feasibility and benefits of oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride application for wastewater and sludge treatment are analyzed, and the existing challenges are overcome with the same. The oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride provide a technology for wastewater treatment and sludge disposal on large scale.
Calcium hypochlorite is an inorganic compound with formula Ca(OCl)2. It is the main active ingredient of commercial products called bleaching powder, chlorine powder, or chlorinated lime, used for water treatment and as a bleaching agent. Calcium hypochlorite is stable and has greater available chlorine than sodium hypochlorite. Calcium hypochlorite is a white solid, although commercial samples appear yellow. Calcium hypochlorite is strongly smells of chlorine, owing to its slow decomposition in moist air.
The oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride in presence of caustic soda the pH of water increases when the composition react with nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound hypochlorite dissolved in water, two processes of oxidation and the disinfection processes. These are hypochlorous acid and the less active hypochlorite ion. The pH of the water determines how much hypochlorous acid is formed.
Chlorine removes electrons from the outer shell of the atoms of living organisms, destabilizing the structure until the organism is dead. When sodium hypochlorite is added to water, it forms an OCl- (hypochlorite) ion that is called free chlorine. This ion should not be confused with chlorine gas. Free chlorine is what most municipal water treatment facilities use for disinfection.
If large amounts of water are stored, it may be useful to change from free chlorine to combined chlorine. Free available residual chlorine can be converted to monochloramine. The conversion is completed by adding an ammonia solution to the chlorinated water at a ratio of 4:1, free chlorine to ammonia.

The wastewater usually contains, in addition to water, residual amounts of benzene, nitrobenzene, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound and nitrobenzene as well as nitrophenols. The effluent resulting contains benzene in concentrations of 10 to 3000 ppm, preferably 100 to 1000 ppm and nitrobenzene in concentrations of 500 to 10,000 ppm, preferably 1200 to 8000 ppm. The wastewater also usually contains nitrophenolates in a concentration of 1000 to 20,000 ppm, in particular 2,000 to 8,000 ppm. The unit ppm in the context of the present invention basically refers to parts by weight.

In an embodiment, the calcium hypochlorite of calcium in the composition is in an amount ranging from about 0.05% (w/w) to 10% (w/w).

In another embodiment, the hypochlorite of calcium, sodium or potassium in the composition is in an amount of about 0.05% (w/w), about 0.09% (w/w), about 0.05% (w/w), about 0.10% (w/w), about 0.1% (w/w), about 0.2.5% (w/w) , about 0.25% (w/w), about 0.5% (w/w) , about 0.5% (w/w), about 1.0% (w/w) , about 1.0% (w/w), about 5.0% (w/w), about 5.0% (w/w), about 6.0% (w/w), about 6.5% (w/w), about 8.5% (w/w), about 8.5% (w/w), about 9.5% (w/w), about 9.5% (w/w), about10.0% (w/w).

In a preferred embodiment, subsequent to step (a) and before carrying out step (b) or step (c), the benzene, nitrobenzene, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound and nitrobenzene which is still present and is not dissolved are separated off from the wastewater.

The separation of the non-dissolved benzene, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound and nitrobenzene can take place by means of separators, settling tanks or other phase separation equipment. Preferably, a settling tank is used. Said separation can alternatively be carried out in the form of an extraction.

In an embodiment, the composition optionally comprises charcoal. The composition comprises charcoal demonstrates synergistic effect with oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride, wherein the charcoal supports the reaction between water content of the wastewater and composition comprises calcium hypochlorite; calcium ion and Chloride, and facilitates the increase in the life span of the chlorine free radicals released from hypochlorous acid. The charcoal also provides reaction surface area for reaction between the chemicals in the water and oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride, wherein the free radicals released, such as chlorine and hydroxide disinfects the wastewater by killing microorganisms, such as bacteria, virus and fungi, algae and protozoans. The combinatorial effect of oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride and charcoal in the composition provides for wastewater treatment which is equivalent to activated sludge treatment (degradation of organic matter) and disinfection step of tertiary treatment, known in the general wastewater treatment. Thus, the composition of the present invention aids in treatment of wastewater without the need of secondary treatment and tertiary treatment, which are time consuming, but still yields treated water equivalent to the standard of treated water subjected to secondary treatment and tertiary treatment.

The oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride a cost-benefit by using 3% calcium hypochlorite (Effluent of other company) for the treatment of wastes.

The calcium hypochlorite is obtained as a by-product of stable bleaching powder, for oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride. The composition of calcium hypochlorite can now be used for treating wastes that earlier had to be disposed of. This helps protect our environment in addition to providing an economic benefit to the industry. Another chemical that could be potentially used to treat industrial effluents is sodium hypochlorite, but there were two significant benefits of using calcium hypochlorite over sodium chlorite. First, one mole of sodium hypochlorite contains half the amount of chlorine compared to calcium hypochlorite, and the second is that calcium hypochlorite is cheaper than sodium hypochlorite.

Example:
1. The whole process is carried out at room temperature.
2. 500 gm of acidic effluent is extracted, by washing nitro-compound which contains phenolic impurities, to a round bottom flask equipped with a stirrer.
3. oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride is gradually added to the flask while continuously stirring. Eventually, the effluent loses colour, going from red to colourless.
4. It takes 400 gm of Hypochlorite to remove the effluent's colour and reduces the COD of effluent.
5. Once the stirrer is stopped, a filtration process is initiated to remove sludge.
6. The clear colourless Mother liquor is then used for analyses of COD.

Result
The results of our experiment are mentioned in the table below:
Acidic Effluent Treated Effluent
Appearance Reddish colour Colourless
pH 2.0 7.0
COD 1550 630

The oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride reduce COD and colour effectively with smooth handling and less pollution compared to Lime and Cl2 gas treatment.

Content of oxidative reduction composition comprises calcium hypochlorite; calcium ion and Chloride:
Sr. No. Parameters Range
1 pH 11- 12
2 Available Chlorine, % 3 – 5
3 Calcium, % 1.5 – 2
4 Chloride, % 12 – 13

EXAMPLE 1
The wastewater obtained after washing of the nitro-compound thus obtained contains aromatic nitro compound containing 100-7000 ppm by weight of phenolic components and 100-10000 ppm, by weight of other aromatic components, 100-3000 ppm benzene and 100-1000 ppm nitrobenzene and 1000-5000 ppm hydrochloric acid is mixed with 1000-10000 ppm of calcium hypochlorite solution obtained form second waste stream and the pH is adjusted to 10.5. The weight ratio of the calcium hypochlorite to the aromatic nitro compound present in solution is 2:1. This mixture is stirred at room temperature for a period of 1 to 10 hours, during which time extensive gassing is observed due to the elimination of nitrogen. During this reaction the pH of the mixture decreases to 10.0-10.1 due to decomposition of the aromatic nitro compound to form carbon dioxide and conversion of the carbon dioxide to sodium carbonate and sodium bicarbonate. The pH of the effluent is periodically readjusted during the reaction to pH 7. After the simulated waste effluent composition had been stirred for 1 to 10 hours,. The solution following this treatment is analyzed for aromatic nitro compound and found to contain less than 10-100ppm indicating that about 90% of the aromatic nitro compound present in the simulated waste solution was degraded. No ammonia or chloramine odors are detected in the solution during the two hour reaction.

EXAMPLE 2
A sample composite waste effluent from a calcium hypochlorite waste generating process was obtained and analyzed. Analysis of the sample showed the following:
______________________________________
Component PPM
______________________________________
Calcium Hypochlorite 2200
Calcium Chlorate 450
Sodium Chloride 750
______________________________________
This sample has a pH of 10.5.

A sample composite waste effluent from a obtained after washing of the nitro-compound waste generating was obtained and analyzed. Analysis of the sample showed the following:
______________________________________
Component PPM
______________________________________
Nitrobenzene 1185
Phenolic 103.0
hydrochloric acid 239.1
______________________________________
This sample has a pH of 4.5.

One liter of waste effluent obtained after washing of the nitro-compound was treated with One liter of waste effluent from a calcium hypochlorite waste generating process effluent at room temperature ranging from about 25° to about 35° C. Upon sterring the pH adjusted to 10.0 to 10.5. This mixture is stirred at room temperature for a period of 5 hours, during which time extensive gassing is observed due to the elimination of nitrogen. During this reaction the pH of the mixture decreases to 10.0-10.1 due to decomposition of the aromatic nitro compound to form carbon dioxide and conversion of the carbon dioxide to sodium carbonate and sodium bicarbonate. The pH of the effluent is periodically readjusted during the reaction to pH 7. After the simulated waste effluent composition had been stirred for 5 hours,. The solution following this treatment is analyzed for aromatic nitro compound and found to contain 90 ppm indicating that about 93% of the aromatic nitro compound present in the simulated waste solution was degraded. No ammonia or chloramine odors are detected in the solution during the two hour reaction.

EXAMPLE 3
A number of batch experiments are conducted with a simulated waste effluent containing 1200 ppm Nitrobenzene and sodium chloride. One hundred parts by weight of this simulated waste effluent is reacted with 2400ppm Calcium Hypochlorite solution at room temperature under varying conditions of pH and reactor residence time. The pH of the simulated waste effluent is maintained at the desired level by the addition of 10 percent sodium hydroxide solution as described above in Example I. The data from this Example appear in Table below and show a good correlation between the decomposition of Nitrobenzene and Calcium hypochlorite, thus substantiating the 4.5 to 1 Calcium hypochlorite to Nitrobenzene molar stoichiometry.

Examples Nitrobenzene
ppm Calcium hypochlorite
ppm pH temp Reaction time
hour Decomposition of Nitrobenzene

1 1185 2287 11.5 25 4 95%
2 1235 2496 10.8 25 4.5 96%
3 1503 3000 10.3 24 5.2 97%
4 1456 2850 11.2 26 5.5 92%
5 900 400 9.2 23 2.0 60%
6 1005 200 7.4 23 5.0 30%
7 800 2100 11.9 24 6.0 99.0%

The data in the above table suggest that under stoichiometric operating conditions at about 25° C the reaction rate reaches a maximum at a pH value between 10.0 and 11.5 and weight ratio of the calcium hypochlorite to the aromatic nitro compound present in solution is 2:1 are most favourable for the decomposition of aromatic nitro compound.
,CLAIMS:We Claim,
1. A process for oxidative reduction of waste streams containing aromatic nitro compound comprises:
e) treating of the waste streams containing aromatic nitro compound with second waste stream containing calcium hypochlorite composition form to obtain at least one organic phase sludge and at least one aqueous phase and separation of the aqueous phase or the aqueous phases,
f) optionally removing organic constituents from at least part of the aqueous phase or aqueous phases obtained in step (a) by stripping, preferably at room temperature,
g) removal of organic compounds from at least part of the aqueous phase or aqueous phases resulting from step (a) or step (b) by oxidative degradation,
h) optionally supplying at least a portion of the aqueous phase resulting from step (c) to a biological wastewater treatment.

2. The process for oxidative reduction as claimed in claim 1 wherein waste streams containing aromatic nitro compound contains phenol, nitrobenzene, nitro-phenol, chloronitrophenol, chlorophenol, dinitrophenol.

3. The process for oxidative reduction as claimed in claim 1 wherein the reaction temperature is 20? to 35?.

4. The process for oxidative reduction as claimed in claim 1 wherein the reaction time is 1 hour to 12 hour.

5. The process for oxidative reduction as claimed in claim 1 wherein the reaction pH is 10.0 to 11.5.

6. The process for oxidative reduction as claimed in claim 1 wherein, waste streams containing aromatic nitro compound treating with waste streams of calcium hypochlorite in weight ratio of the calcium hypochlorite to the aromatic nitro compound present in solution is 2:1.

7. The process for oxidative reduction as claimed in claim 1 wherein, a waste effluent from a calcium hypochlorite waste generating process comprising calcium hypochlorite; Calcium Chlorate and Sodium Chloride.

8. The process for oxidative reduction as claimed in claim 1 wherein, process for purifying waste streams containing high concentrations containing Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound content generated during the nitration process is treated with waste produced in calcium hypochlorite generating plants.

9. The process for oxidative reduction as claimed in claim 1 wherein, a process is further treated with activated carbon beds employed in water purification systems.

10. The process for oxidative reduction as claimed in claim 1 wherein, process for oxidative reduction of waste streams containing nitrobenzene, Nitro-phenol, Chloro nitro phenol, chloro phenol, dinitro phenol, aromatic nitro compound with calcium hypochlorite solution.

Dated this 01th Day of Feb 2023