Indian Patents. 230896:"A PROCESS FOR TREATING DYES WASTEWATER"

Title of Invention	"A PROCESS FOR TREATING DYES WASTEWATER"
Abstract	This invention relates to a process for treating dyes wastewater. The process comprises a primary step of chemical treatment followed by secondary and tertiary steps of biological treatment performed in bio-reactors.

Full Text	FIELD OF INVENTION This invention relates to a process for treating dyes wastewater. PRIOR ART The activated sludge is the most common biological method for treating dye wastewaters, in which the reduction of BOD (90%) and COD (40-507.) was comparatively higher than the colouring matter (10-30% Oil is et. al . 1991. Li and Zhams 1996 and Ahmed and Oil is 1984). The reduction in colouring matter in the activated sludge process has been ascribed, primarily due to its adsorption on the sludge, suggesting a little degradation of dyes during the treatment process (Srimuli and Karthikeyan 1999). Now a days, thei -e is a greater emphasis on the isolation of a noble microorganism capable of degrading a variety of dye?s. A large number of bacterial species capable of degrading azo compounds are Proteus spp., Enterococcusspp. , Streptococcus spp., Bacillus subtilis (Zissi et. al., 1997)., Closteridium spp., Pseudomonas 50pp. (Bumpus, 1995), Klebsiella pneumonia and Acetobacter liquefaciens (So et. al., 1990, Wang & Yuen 1996), Streptomyces spp. (Pasti et. al., 1991), Sphingomonas spp. (Kudhch et. al. 1997), Trametes versicolur, Bjerkandera adust (Heinfling et. al. 1997). Azo dyes do not degrade readily in presence of oxygen (Johnson et. al. 1978), whereas in the anaerobic conditions, these are reduced to colourless, toxic and carcinogenic amines (Zimmerman el. al. 1982). Only recently azo dyes have been reported to degrade aerobically (Bumpus 1995, Heinfling et.al. 1997, Pasti et al. 1995, Zissi et al . 1997), F'sedomonas sp K-l (Wong ?* Yuen 1996), Psedomonas S-42 (Bumpus 1995), Acetobacter liquefaciens (So et. al 1990) and Klebsiella pneumonia RS-13 (Wong & Yuen 1996) are the bacterial species which co—metabolically degrade the dyes in aerobic condition. OBJECT OF THE INVENTION An object of this invention is to propose to process for treating dye wastewater such as azo dyes, aniline dye and reactive dyes aerobically under the identical conditions. Another object of this invention is to propose to process for treating dyes wastewater which is cheap and requiring very little inputs. DESCRIPTION OF THE INVENTION According to this invention there is provided a process for treating dye wastewater comprising if, a. primary step of chemical treatment as herein described followed by secondary and tertiary steps of biological treatment as herein described performed in bioreactors followed by the step of polishing as herein described in and a wetland for treating the dyes under aerobic conditions. Important findings, which are reported for the first time for the treatment of azo dyes, are described below. The acidic azo wastewaters having a pH=2-4 are first neutralized using lime. This decreased their COD (20-70%), conductivity (40-70"n) and Cu (20-60%) as a result of precipitation of dissolved matters. This neutral wastewater is then fed continuously for example in 24 h into two serially arranged fixed film upf'o'v bioreactors. The bioreactors consisted of biofilm of consortium of aerobic microbes (from Institute of Microbial Technology, changigarh, Report of which is enclosed)developed on the surface of grits. The aerobic conditions in the bioreactor are maintained by continuous aeration, using an aquarium pump in the reactor. Microbially treated water is then passed through a constructed wetland haing Phragmites and Typha at a loading rate of for example 15 cm/day. The wetland has down flow pattern of hydraulic loading. The retention period of the wastewater in the bioreactors and constructed wetland is for example two days only, one day each in the bioreactors and constructed wetland. The reduction in COD levels as well as its load after treatment of azo dye waslewater's at successive steps in the bioreactors and constructed wetlands is shown in fig. 1, 2 of the accompanying drawings. During spectroscopic studies marked reduction in the size of peaks in the UV region after passing of dye wastewater through bioreactors and constructed wetland we re found and as shown in Fig. 3a, b of the accompanying drawings. The chromatographic studies revealed absence of dyes in the treated wastewater as shown in Fig.4 of the accompanying drawing which were present in the untreated wastewater. The GC mass studies also confirmed degradation of azo dyes during the treatment process. 36 peaks detected in the neutral azo wastewater decreased to 22 after treatment during winter, when micorbial activities are slow on account of low temperature (Fig. 5 a, b ) . The toxicity of treated wastewater was constantly monitored during itudy period, growing Gambusia fishes in a 15L bucket having submerged plants like Hydrilla and Ceratophyllum. The fishes grow and breed normally during more than six months of the study, establishing the fact that treated water is non toxic and can be safely discharged into the water courses. It was found that treated wastewater can be recycled back in the same industry. The treated wastewater also had no adverse effect on the growth of Cymopsis plants. These had well developed root nodules similar to control plants which were unhealthy and few in number in the plants growing in dye wastewater irrigated soils. The degradation of dissolved methyl red dye (50ppm) was also studied in bhe system during summer. The reductions of COD levels at different steps of the treatment systems are in the Fig. 6 a. The optical density of methyl red decreased > 957C after treatment in the system, also noted a marked reduction in size of peaks in both UV Visible range (Fig. 6 b,c), The GC mass studies of methyl red solution in methanol detected 64 peaks including that one of the solvent. The number of compounds decreased to two in the outflow after microbial treatments in the bioreactors and constructed wetland, affirming degradation methyl red in the treatment system (Fig. 7 a & b ) . Thus we have achieved significant degradation of dyes at two days retention perio 1. Further sludge production is minimum in our system. We have also studied degradation of methyl red by both puru culture of two different bacterial isolates from our system and also using their consortium. The complete decolorisation of methy red was achieved within 24 hour after inoculation of both pure isolates of bacteria as well s their mixed consortium. The treatment of dye wastewater released in the silicate process was also studied. The silicate process uses reactive dyes for printing, which are fixed in the concentrated solution of sodium silicate. We have developed method for the removal of sodium silicate in the dye wastewater, thereafter, the wastewater was inoculated with both pure isolates as well contort turn of the microbes. The complete decolourisation of the wastewater was achieved within 48 hours, being relatively faster in the contortium in comparison to the purt isolates, which establishes that the process system can treat a variety of dye wastewaters. CLAM: L, A process for treating dye wastewater comprising in a primary step of chemical treatment as herein described followed by secondary arid tertiary steps of biological treatment as herein described performed in bioreacours followed by the step of polishing as herein described in and a wetland for treating the dyes under aerobic conditions. 2. A process as claimed in claim 1 wherein the step of chemical treatments consists in the step of neutralization. 3. A process as claimed in claim 1 Wherein the aerobic conditions are maintained by continuous aeration; 4. A process as claimed in claim 1 wherein said bioreactors are upflow bioreactors, 5. A process for treating dyes wasU.-wat.er substantially as herein described and illustrated.

Full Text

FIELD OF INVENTION
This invention relates to a process for treating dyes wastewater.
PRIOR ART
The activated sludge is the most common biological method for treating dye wastewaters, in which the reduction of BOD (90%) and COD (40-507.) was comparatively higher than the colouring matter (10-30% Oil is et. al . 1991. Li and Zhams 1996 and Ahmed and Oil is 1984). The reduction in colouring matter in the activated sludge process has been ascribed, primarily due to its adsorption on the sludge, suggesting a little degradation of dyes during the treatment process (Srimuli and Karthikeyan 1999).
Now a days, thei -e is a greater emphasis on the isolation of a noble microorganism capable of degrading a variety of dye?s. A large number of bacterial species capable of degrading azo compounds are Proteus spp., Enterococcusspp. , Streptococcus spp., Bacillus subtilis (Zissi et. al., 1997).,
Closteridium spp., Pseudomonas 50pp. (Bumpus, 1995), Klebsiella pneumonia and Acetobacter liquefaciens (So et. al., 1990, Wang & Yuen 1996), Streptomyces spp. (Pasti et. al., 1991), Sphingomonas spp. (Kudhch et. al. 1997), Trametes versicolur, Bjerkandera adust (Heinfling et. al. 1997).
Azo dyes do not degrade readily in presence of oxygen (Johnson et. al. 1978), whereas in the anaerobic conditions, these are reduced to colourless, toxic and carcinogenic amines (Zimmerman el. al. 1982). Only recently azo dyes have been reported to degrade aerobically (Bumpus 1995, Heinfling et.al. 1997, Pasti et al. 1995, Zissi et al . 1997), F'sedomonas sp K-l (Wong ?* Yuen 1996), Psedomonas S-42 (Bumpus 1995), Acetobacter liquefaciens (So et. al 1990) and Klebsiella pneumonia RS-13 (Wong & Yuen 1996) are the bacterial species which co—metabolically degrade the dyes in aerobic condition. OBJECT OF THE INVENTION
An object of this invention is to propose to process for treating dye wastewater such as azo dyes, aniline dye and reactive dyes aerobically under the identical conditions.
Another object of this invention is to propose to process for treating dyes wastewater which is cheap and requiring very little inputs.
DESCRIPTION OF THE INVENTION
According to this invention there is provided a process for treating dye wastewater comprising if, a. primary step of chemical treatment as herein described followed by secondary and tertiary steps of biological treatment as herein described performed in bioreactors followed by the step of polishing as herein described in and a wetland for treating the dyes under aerobic conditions.
Important findings, which are reported for the first time for the treatment of azo dyes, are described below.
The acidic azo wastewaters having a pH=2-4 are first neutralized using lime. This decreased their COD (20-70%), conductivity (40-70"n) and Cu (20-60%) as a result of precipitation of dissolved matters. This neutral wastewater is then fed continuously for example in 24 h into two serially arranged fixed film upf'o'v bioreactors. The bioreactors consisted of biofilm of
consortium of aerobic microbes (from Institute of Microbial Technology, changigarh, Report of which is enclosed)developed on the surface of grits. The aerobic conditions in the bioreactor are maintained by continuous aeration, using an aquarium pump in the reactor. Microbially treated water is then passed through a constructed wetland haing Phragmites and Typha at a loading rate of for example 15 cm/day. The wetland has down flow pattern of hydraulic loading. The retention period of the wastewater in the bioreactors and constructed wetland is for example two days only, one day each in the bioreactors and constructed wetland. The reduction in COD levels as well as its load after treatment of azo dye waslewater's at successive steps in the bioreactors and constructed wetlands is shown in fig. 1, 2 of the accompanying drawings.
During spectroscopic studies marked reduction in the size of peaks in the UV region after passing of dye wastewater through bioreactors and constructed wetland we re found and as shown in Fig. 3a, b of the accompanying drawings.
The chromatographic studies revealed absence of dyes in the treated wastewater as shown in Fig.4 of the accompanying drawing which were present in the untreated wastewater.
The GC mass studies also confirmed degradation of azo dyes during the treatment process. 36 peaks detected in the neutral azo wastewater decreased to 22 after treatment during winter, when micorbial activities are slow on account of low temperature (Fig. 5 a, b ) .
The toxicity of treated wastewater was constantly monitored during itudy period, growing Gambusia fishes in a 15L bucket having submerged plants like Hydrilla and Ceratophyllum. The fishes grow and breed normally during more than six months of the study, establishing the fact that treated water is non toxic and can be safely discharged into the water courses.
It was found that treated wastewater can be recycled back in the same industry. The treated wastewater also had no adverse effect on the growth of Cymopsis plants. These had well developed root nodules similar to control plants which were unhealthy and few in number in the plants growing in dye wastewater irrigated soils.
The degradation of dissolved methyl red dye (50ppm) was also studied in bhe system during summer. The reductions of COD levels at different steps of the treatment systems are in the Fig. 6 a. The optical density of methyl red decreased > 957C after treatment in the system, also noted a marked reduction in size of peaks in both UV Visible range (Fig. 6 b,c),
The GC mass studies of methyl red solution in methanol detected 64 peaks including that one of the solvent. The number of compounds decreased to two in the outflow after microbial treatments in the bioreactors and constructed wetland, affirming degradation methyl red in the treatment system (Fig. 7 a & b ) .
Thus we have achieved significant degradation of dyes at two days retention perio 1. Further sludge production is minimum in our system.
We have also studied degradation of methyl red by both puru culture of two different bacterial isolates from our system and also using their consortium. The complete decolorisation of methy red was achieved within 24 hour after inoculation of both pure isolates of bacteria as well s their mixed consortium.
The treatment of dye wastewater released in the silicate process was also studied. The silicate process uses reactive dyes for printing, which are fixed in the concentrated solution of sodium silicate. We have developed method for the removal of sodium silicate in the dye wastewater, thereafter, the wastewater was inoculated with both pure isolates as well contort turn of the microbes. The complete decolourisation of the wastewater was achieved within 48 hours, being relatively faster in the contortium in comparison to the purt isolates, which establishes that the process system can treat a variety of dye wastewaters.

CLAM:
L, A process for treating dye wastewater comprising in a primary step of chemical treatment as herein described followed by secondary arid tertiary steps of biological treatment as herein described performed in bioreacours followed by the step of polishing as herein described in and a wetland for treating the dyes under aerobic conditions.
2. A process as claimed in claim 1 wherein the step of chemical
treatments consists in the step of neutralization.
3. A process as claimed in claim 1 Wherein the aerobic conditions
are maintained by continuous aeration;
4. A process as claimed in claim 1 wherein said bioreactors are
upflow bioreactors,
5. A process for treating dyes wasU.-wat.er substantially as herein
described and illustrated.

Documents:

538-del-2000-abstract.pdf

538-del-2000-claims.pdf

538-del-2000-correspondence-others.pdf

538-del-2000-correspondence-po.pdf

538-del-2000-description (complete).pdf

538-del-2000-drawings.pdf

538-del-2000-form-1.pdf

538-del-2000-form-19.pdf

538-del-2000-form-2.pdf

538-del-2000-form-3.pdf

538-del-2000-gpa.pdf

538-del-2000-petition-138.pdf

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Patent Number

230896

Indian Patent Application Number

538/DEL/2000

PG Journal Number

13/2009

Publication Date

27-Mar-2009

Grant Date

28-Feb-2009

Date of Filing

26-May-2000

Name of Patentee

THE SECRETARY, DEPARTMENT OF BIOTECHNOLOGY

Applicant Address

BLOCK 2,C.G.O. COMPLEX, LODI ROAD NEW DELHI -110003,INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	DR. K.P.SHARMA	BOTANY DEPARTMENT, RAJASTHAN, JAIPUR-4 INDIA
2	DR. SUBHASINI SHARMA	ZOO DEPARTMENT, UNIVERSITY OF RAJASTHAN,JAIPUR-4 INDIA

PCT International Classification Number

C02F 3/14

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA