Claims:
1. A process for treatment of wastewater effluent comprising
i) primary treatment of effluent stream for removing sulphide content and
ii) feeding the sulphide free effluent obtained in step (i) to the bioreactor
wherein said liquid stream is treated with ferrous sulphate to remove sulphide from the effluent.

2. The process as claimed in claim 1 wherein in the step (i) the liquid stream contains total sulphur compounds in the range of 100 to 1000 ppm.

3. The process as claimed in claim 1 wherein said effluent in step (ii) is substantially free of sulphide content.

4. The process as claimed in claim 1 wherein total sulphide content present in effluent of step (ii) is reduced to below detection limit preferably below 10ppm.

5. The process as claimed in claim 1 wherein temperature of effluent in step (ii) is reduced to ambient temperature.

6. The process as claimed in claim 1 wherein the pH of the effluent in step (ii) is in the range from 7 to 9.

7. The process as claimed in claim 1 wherein average COD of the effluent at the ETP outlet is 500 ppm.

8. The process as claimed in claim 1 to 7 is useful for Effluent Treatment Plant for maintaining temperature rise and pH of effluent in bioreactors to enhance ETP biological performance.

9. A method of enhancing biological performance in Effluent Treatment Plant comprising:

primary treatment of effluent stream for removing sulphide content by treating with ferrous sulphate and feeding obtained sulphide free effluent to the bioreactor by this means COD of the treated effluent is reduced to less than 500ppm.

10. The method as claimed in claim 9 wherein the temperature of effluent is reduced to ambient temperature and pH is in the range from 7 to 9.
, Description:FIELD OF INVENTION

The present invention relates to a pre-treatment method for liquid effluent stream of Effluent Treatment Plant (ETP) for improving its biodegradability. The present invention more particularly relates to a process for removal of sulphide containing compounds during primary treatment of effluent.

BACKGROUND OF THE INVENTION

High efficiency waste water treatment has become increasingly important and therefore there is a long felt need for a process for wastewater treatment in effluent treatment plant that overcomes associated problems in the bioreactors that caused a detrimental effect on Effluent Treatment Plant (ETP) biological performance.

Sulfide-containing waste streams are generated by a number of industries. It is emitted into the environment as dissolved sulfide in wastewaters. Due to its corrosive nature, biological hydrogen sulfide removal processes are being investigated to overcome the chemical and disposal costs associated with existing chemically based removal processes.

It is hypothesized that the sulphides during biological oxidation process get oxidized into sulphuric acid and due to generation of sulphuric acid, pH drops and temperature rises. Due to increased temperature and reduced pH; microbial growth is hampered and fresh biomass generation stops. Due to compromised biological performance, bioreactor efficiency in terms of its COD (Chemical Oxygen Demand) reduction efficiency drops drastically.

Article “Sulfide Precipitation in Wastewater at Short Timescales”; Water 2017, 9, 670; doi: 10.3390/w9090670. This article teaches that common and well-documented practice to manage sulfide related problems is addition of iron salts. Ferrous iron (Fe2+) reacts with sulfide (S2-) and precipitates as ferrous sulfide (FeS). The low solubility constant of ferrous sulfide (3.7 x 10 -19 g.mol2.L-2 at 18°C) implies that this method should be very effective and it is unlikely that sulfides will be released back into solution after the precipitate has formed.

Article “Pilot plant studies Biological process for sulphate removal from industrial effluent”; J.P. Maree et. al. April 1989. This article teaches that sulphate is converted to hydrogen sulphide in the anaerobic stage when an energy source, such as molasses, is added. The hydrogen sulphide is stripped off in a closed system from the anaerobic stage or in a special stripping stage, with a carrier gas such as nitrogen.

Article “Removal of sulfide in integrated anaerobic–aerobic wastewater treatment system”; A. Gangagni Rao, et al; Clean Techn Environ Policy 6 (2003) 66–71 DOI 10.1007/s10098-003-0194-y. This article teaches that industrial wastewater may contain sulfate along with other organic constituents. Sulfate, if present in the wastewater, will be converted to H2S under anaerobic conditions and this is hazardous. Subsequently, if the same wastewater is treated under aerobic conditions, a part of the air supplied will be utilized for oxidation of sulfide back to sulfate which leads to reduced efficiency of the aerobic treatment.

In general, methods are reported to remove sulphide by converting the same to Hydrogen sulphide. However, none of the literature addresses the problem relating to increase in temperature and pH drop in the bioreactors due to the presence of sulphides.

There are several challenges to consider. The unique problem of temperature rise and pH drop in bioreactor was hypothesized to be because of the fact that sulphide compounds present in the effluent get oxidized to sulphur containing acids during biological oxidation process and as a result elevates the temperature and decreases the pH. Because of higher temperature and lower pH in bioreactor, biological activity of the microorganisms was decreased and as a result lower COD reduction was observed at the outlet of ETP. This hypothesis was and later found to be true by the present inventors when sulphide containing compounds were removed from the effluent and both the problems of pH drop and temperature rise in bioreactor was resolved and COD reduction at the outlet of ETP was improved. Process of sulphide compounds removal from the effluent did not require any additional hardware at ETP as this was done during the routine primary treatment by converting it in to insoluble form and removal during primary clarification process.

Therefore, there is long felt need to develop a method to overcome the aforesaid problems of increase in temperature and pH drop problem in the bioreactors that caused a detrimental effect on ETP biological performance.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide a process for removal of sulphide containing compounds from liquid stream in effluent treatment plant.

It is another object of the present invention to provide a process to effectively curb the temperature rise and pH drop problem in ETP bioreactor.

It is another object of the present invention to provide a process to control bioreactor temperature and pH in an unconventional way which is very cost effective and easily implementable for overall enhancement in bioreactor performance.

SUMMARY OF THE INVENTION

According to an aspect of the present invention there is provided a process for treatment of wastewater effluent comprising:

i) primary treatment of effluent stream for removing sulphide content and
ii) feeding the sulphide free effluent obtained in step (i) to the bioreactor

wherein said liquid stream is treated with ferrous sulphate to remove sulphide from the effluent.

According to another aspect of the present invention there is provided a method of enhancing biological performance in Effluent Treatment Plant comprising:

primary treatment of effluent stream for removing sulphide content by treating with ferrous sulphate and feeding obtained sulphide free effluent to the bioreactor by this means COD of the treated effluent is reduced to less than 500ppm.

BRIEF DESCRIPTION OF FIGURES

The above and other aspects, features and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings wherein:

Figure 1 illustrates ETP outlet COD trend before and after FESO4 dosing.

Figure 2 illustrates that slight floating particles along with sludge is observed in all trails

DETAILED DESCRIPTION OF THE INVENTION

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.

Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the scope of the invention as defined by the appended claims and their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

The present invention relates to a pre-treatment method for liquid effluent stream in Effluent Treatment Plant that controls the temperature rise and pH drop in bioreactors. The present invention more particularly relates to a method of removal of sulphide containing compounds from liquid stream for improving its biodegradability.

Need of the present invention

During biological oxidation of wastewater there is a rise of 10°C to 15°C in its 1000 Kilo Litre (KL) bioreactors along with a sharp pH drop in ETP. The temperature and pH of the bioreactors used to reach up to 50°C and 5.0 respectively. The ETP outlet COD is more than 1000 ppm. This caused a detrimental effect on ETP biological performance. Therefore, there is long felt need to develop a process to overcome the said problems of increase in temperature and pH drop problem in the bioreactors that caused a detrimental effect on ETP biological performance.

Solution provided by the present invention

The present inventors have found from the temperature monitoring data across the ETP, which clearly indicates that the rise in temperature is happening due to biological activity and not due to some chemical reaction in the effluent as the temperature of effluent is in normal range up to Dissolved Air Floatation (DAF) system outlet.

The present inventors have surprisingly found that when sulphide containing compounds are removed from effluent, both temperature rise, and pH drop issues were resolved and there was tremendous increase in ETP biological performance.

The present inventors provide a process that effectively curbs the temperature rise and pH drop problem in ETP bioreactors. The present inventors have found that after implementation of the process of the present invention pH is above 5, preferably in the range of 7 to 8, Temperature is ambient, preferably below 50°C and COD of the ETP is below 1000 ppm.

The novel process of the present invention in general relates to a pre-treatment method for liquid effluent stream in Effluent Treatment Plant and reduction of temperature rise and pH drop in bioreactors.

The novel feature of the process of the present invention is to control bioreactor temperature and pH in an unconventional way which is very cost effective and easily implementable for overall enhancement in bioreactor performance. The process of the present invention effectively curbs temperature rise and pH drop problem in its ETP bioreactors.

In an embodiment of the present invention there is provided a process for treatment of wastewater effluent comprising:

i) primary treatment of effluent stream for removing sulphide content and
ii) feeding the sulphide free effluent obtained in step (i) to the bioreactor

wherein said liquid stream is treated with ferrous sulphate to remove sulphide from the effluent.

In step (i) the liquid stream contains total sulphur compounds in the range of 100 to 1000 ppm.

The effluent in step (ii) is substantially free of sulphide content and wherein total sulphide content present in the effluent is reduced to below detection limit preferably below 10 ppm. The temperature of the effluent is reduced to ambient temperature. The pH of the effluent is in the range from 7 to 9.

In another embodiment of the present invention there is provided a method of enhancing biological performance in Effluent Treatment Plant comprising:

primary treatment of effluent stream for removing sulphide content by treating with ferrous sulphate and feeding obtained sulphide free effluent to the bioreactor by this means COD of the treated effluent is reduced to less than 500ppm.

wherein the temperature of effluent is reduced to ambient temperature and pH is in the range from 7 to 9.

In another embodiment of the present invention the pH of the effluent is maintained preferably in the range from 7 to 8 after implementation of the process of the present invention. Further, temperature of the bioreactor is maintained in the range from 35°C to 40°C after a nearly a week of initiating FeSO4 dosing. This lag was most likely due to the purging out of old effluent from the ETP system which was having higher sulphide content. COD of the ETP is below 1000 ppm, preferably below 500 ppm more preferably in the range from 300-400 ppm. The average COD of the effluent after nearly a week of initiating FeSO4 dosing at the ETP outlet is about 500 ppm with a maximum of about 1516 ppm and minimum of about 222 ppm.

In an embodiment, the present process provides at least 95% reduction in total sulphide content in the fluid stream contaminated with sulphide.

In an embodiment, the present process provides at least 97% reduction of total sulphide content in the fluid stream contaminated with sulphide.

In an embodiment, the present process provides fluid stream substantially free from sulphide content.

Thus, the present invention provides a novel process for the treatment of sulphide containing wastewater and a new treatment plant that provides advantages over the prior art, which is of substantial benefit in the treatment of wastewater.

According to the present invention, the process involves the following steps;
a) an effluent is added with ferrous sulphate solution or dry powder.
b) The contents are left to react for 10-15 minutes under mild stirring conditions at 10-15 rpm.
c) The entire mixture is sent to primary clarifier for separating the insoluble ferrous sulphide particles. The residence time in primary clarifier is approximately 3 to 4 hours.
d) The clear sulphide free effluent is the sent to bioreactor for treatment of COD.
e) The bottom settled ferrous sulphide sludge is pumped to filter press for sludge separation.
f) Mother liquor of filter press is sent to bioreactor for treatment of COD. The sludge cake is sent to outside treatment facility for land filling.

Thus, in another aspect the present invention provides a method of reducing total level of metallic species for example sulphide contamination of an industrial fluid.

In an embodiment there is provided a method for removal of total sulphides from the effluent in suspended form which can be easily removed during primary treatment.

In an embodiment the method comprising: contacting effluent fluid including metallic species contamination for example sulphide content, with ferrous sulphate and reducing the level of sulphide content in the fluid.

In an embodiment based on this the present invention ETP achieves at least 90% efficiency.

The present process/method can be applied to other high sulphide containing effluent streams for improving their biological treatment efficiency.

Advantages of the present invention

1. The process of the present invention is mainly for removing total sulphides from the effluent in suspended form which can be easily removed during primary treatment without the requirement of any additional infrastructure to resolve the problem of temperature increase and pH drop in bioreactors.
2. Performance improvement of ETP will enable to accommodate more effluent.
3. Reduction in temperature will reduce the wear and tear in bioreactors and improve the bioreactors life.
4. Performance improvement of ETP will reduce the consumption of polishing chemicals such as sodium hypochlorite which are used to meet the statutory norms prior to discharge.
5. Cost savings due to reduced usages of polishing chemicals.
6. Less handling of hazardous chemicals at ETP.

The invention shall now be described with reference to the following specific examples. It should be noted that the example(s) appended below illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the present invention.

EXAMPLES

The present invention is further described in the following non-limiting manner.

Example 1
500 milliliter effluent was taken in 1.0lt Erlenmeyer flask and 2.5 grams of dry ferrous sulphate powder was added to it and contents were allowed to react for ten minutes under mild stirring conditions on a magnetic stirrer. After the reaction is completed the insoluble ferrous sulphide is allowed to settle for fifteen minutes and the supernatant was decanted and checked for reduction in total sulphide. The initial total sulphide content present in effluent was 538 ppm and after treatment reduced to 21 ppm. Thus, an overall 96% reduction in total sulphide was achieved.

Example 2
500 milliliter effluent was taken in 1.0 lt Erlenmeyer flask and 1.5 grams of dry ferrous sulphate powder was added to it and contents were allowed to react for ten minutes under mild stirring conditions on a magnetic stirrer. After the reaction is completed the insoluble ferrous sulphide is allowed to settle for fifteen minutes and the supernatant was decanted and checked for reduction in total sulphide. The initial total sulphide content present in effluent was 464 ppm and after ferrous sulphate treatment reduced to 12 ppm. Thus, an overall 97% reduction in total sulphide was achieved.

Example 3
500 milliliter effluent was taken in 1.0 lt Erlenmeyer flask and 3.75 grams of dry ferrous sulphate powder was added to it and contents were allowed to react for ten minutes under mild stirring conditions on a magnetic stirrer. After the reaction is completed the insoluble ferrous sulphide is allowed to settle for fifteen minutes and the supernatant was decanted and checked for reduction in total sulphide. The initial total sulphide content present in effluent was 464 ppm and after ferrous sulphate treatment reduced to below detection limit. Thus, a complete reduction in total sulphide was achieved.

Example 4
Total sulphide content analysis of effluent from different sampling points were recorded as provided in the below table.

Table 1 (Before treatment)

Sr. No. Sampling point Total sulphide (ppm)
1 Sampling point-1 1030
2 Sampling point-1 475
3 Sampling point-2 453
4 Sampling point-3 491
5 Sampling point-4 475
6 Sampling point-5 792
7 Sampling point-1 842
8 Sampling point-2 1045
9 Sampling point-3 249
10 Sampling point-5 290
11 Sampling point-1 539
12 Sampling point-3 186
13 Sampling point-1 464

Table 2: Total sulphide analysis data of effluent after FeSO4 treatment

Initial FeSO4 treatment After treatment
Sulfide (ppm) Sulfide (ppm)
538 0.50% 21
464 0.50% 7
464 0.10% 134
464 0.20% 36
464 0.30% 12
464 0.50% 7.73
464 0.75% BDL
464 1.00% BDL
465 0.50% 7.73
420 0.50% 7.7
308 0.50% 30
566 0.50% 31
683 0.50% 33
952 0.50% 62

BDL- Below Detection Limit

Table 3
NEW ETP OUTLET COD TREND (before and after FeSO4 dosing)
Sr. No. pH Temperature (°C) COD (ppm)
BEFORE FeSO4 Dosing
1 6.10 47 4215
2 5.71 45 4851
3 5.40 46 6154
4 4.36 48 5906
5 7.16 49 5754
6 5.35 52 5854
7 5.50 51 5487
8 4.05 53 5932
9 5.96 50 4636
10 5.95 49 4362
11 6.17 45 3924
12 6.70 48 3828
13 6.29 48 4593
14 6.49 47 4597
15 6.51 47 3708
16 6.44 49 4615
17 6.28 50 2923
18 6.33 52 4060
19 6.31 51 3714
20 6.87 49 2407
21 6.54 50 2024
22 6.56 49 2306
23 6.70 48 3114
24 6.77 41 3532
25 6.60 40 2931
26 6.49 51 2034
27 6.40 53 1384
28 6.70 54 1096
AFTER FeSO4 DOSING
29 7.14 47 1291
30 7.53 47 1155
31 7.32 46 1049
32 7.25 45 1098
33 7.41 43 355
34 7.38 44 657
35 7.51 42 614
36 7.09 41 856
37 7.41 41 468
38 7.23 40 544
39 8.37 40 468
40 7.49 39 513
41 7.61 37 350
42 7.74 38 358
43 7.53 39 222
44 7.64 40 326
45 7.70 37 446
46 7.56 38 586
47 7.67 39 347
48 7.59 40 366
49 7.47 41 294
50 7.70 40 333
51 8.05 38 288
52 8.05 39 248
53 7.93 41 293
54 8.09 40 338
55 8.00 41 430
56 8.07 39 494
57 7.68 38 808
58 7.77 39 904
59 7.67 40 801
60 7.90 39 1516

Conclusion: After FeSO4 dosing the temperature range reduces from 40-54oC to 37-41oC after a week of initiating FeSO4 dosing in the bioreactor.
After FeSO4 dosing the pH range increases from 4 to 7 to 7 to 8 after a week of initiating FeSO4 dosing in the bioreactor.

Table 4
Primary treatment optimization after FeSO4 dosing
Effluent volume PAC ppm 2% PAC soln Poly ppm 200 ppm poly soln
200 ml 150 1.5 ml 1 1 ml
200 ml 200 2.0 ml 2 2 ml
200 ml 300 3.0 ml 3 3 ml
200 ml 400 4.0 ml 5 5 ml

PAC: Polyaluminium chloride, Poly: Polyelectrolyte. These chemicals are routinely used in ETP as flocculating and coagulating agents

Table 5

EXPT set PAC ppm Poly ppm Settling speed Clarity Remarks
Set-1 150 1 Same settling Same clarity In all trials, slight floating particles along with sludge observed
Set-2 200 1 Same settling
Set-3 300 1 Same settling
Set-4 150 2 Same settling Same clarity
Set-5 200 2 Same settling
Set-6 300 2 Same settling

PAC: Polyaluminium chloride, Poly: Polyelectrolyte. These chemicals are routinely used in ETP as flocculating and coagulating agents

Conclusion:

Results (from Table 4 and Table 5) of primary coagulation and flocculation treatment of effluent after FeSO4 dosing did not cause any adverse impact on effluent quality for its secondary treatment in Bioreactors.

Table 6: Historical data of Effluent treatment plant (DAF and MBBRs) temperature monitoring without present treatment.

S.NO. DAF OL MBBR-1 MBBR-2
Temp. manual (oC) Temp. Online (oC) Temp. manual (oC) Dissolved oxygen (ppm) Temp Online (oC) Temp manual (oC) Dissolved oxygen (ppm)
1 37 49.7 48.5 Not done 48.2 47.5 Not done
2 36 50.6 50.5 48.6 49.5
3 35.5 48.5 48.5 48.7 49
4 35.5 48.6 48.5 48.7 49
5 38 44.5 44.5 1.29 46.1 46 0.63
6 38 46.1 45.5 1.48 46.4 46 0.69
7 36 49.1 49 1.78 47.3 48 0.37
8 36 49.5 50 1.58 47.6 48 0.55
9 35 48.7 49 1.71 47.9 48 0.78
10 35 48.2 48 1.37 47.9 48 0.52
11 35 47.3 47 1.61 46.5 47 0.51
12 35 47.1 48 1.9 46.4 47 0.31
13 33.5 44.3 44 0.81 45.7 46 0.88
14 34 43.4 44 1.02 45.7 45.5 0.91
15 34 44 44 1.29 43.8 44 0.45
16 33 44.7 44.5 1.21 44.3 44 0.52
17 34 43.3 43 1.65 43.6 44 0.67
18 36 47.9 52.5 1.3 49.4 49.5 0.54
19 36.5 Not required 46.5 1.15 Not required 43.5 0.37
20 37 47.5 1.6 44 0.35
21 37.5 47.5 1.48 44.5 0.39
22 38 48 1.36 45 0.49
23 38 48.6 1.75 45.5 0.65
24 41 49.5 2.1 47 0.51
25 38 49 1.68 46 0.85
26 38.5 49 1.75 46 0.84
27 39 39.5 1.74 47 1.06
28 33 40 - 41 Not done 42 - 43 Not done
29 33 39 - 40 41 - 42
30 38 50 - 51 48 - 49
31 39 52 - 53 48 - 49
32 40 53 - 54 48 - 49

Conclusion:
The temperature monitoring data indicates that up to DAF temperature of the effluent is in the ambient range (33-41oC) and after entering in the bioreactor the temperature starts increasing (40-54oC) due to biological oxidation of sulphide to Sulphur containing acids.

Table 7: Effluent treatment plant temperature and air monitoring
Sr. No ETP inlet Temp. (oC) EQ-1 Temp. (oC) EQ-2 Temp. (oC) MBBR-1 Air (M3/ hr.) MBBR-2 Air (M3/ hr.)

1 44.5 38.5 36.5 4300 1630
2 50 39 37 4520 1420
3 49 39 37.5 4460 1640
4 47 39 38.5 4520 1670
5 47 39 38 4470 1610
6 47 39 37.5 4226 1635
7 47 39 35.7 4174 1706
8 48 39 38 4166 1620
9 48.5 39 37.5 4274 1640
10 47 38 37 4258 1730
11 48 38 37 4310 1540
12 49 37.5 36.5 4428 1470
13 49 38 36.5 4370 1438
14 *** 37.5 37 4461 1393
15 *** 38 37 4234 1687
16 48 39 37 4318 1891
17 *** 38.5 38 4420 1513
18 *** 38.5 38 4246 1682
19 46 38 39 4290 1699
20 *** 38 39 4361 1581
21 46.5 37 39 4152 1708
22 46 36.5 39 4242 1639
23 47 37.5 38.2 4218 1648
24 48 39 39 4236 1640
25 47 39 39 4157 1668
26 46.5 39.5 40 4166 1649
27 47.8 40 40 4200 1619
28 48.5 40 41 4183 1648
29 49.5 40.5 41.5 4168 1620
30 46 40.5 41 4106 1659
31 49 40.8 41.5 4142 1679
32 46 40 41 4270 1647
33 48 40 41 4141 1677
34 48.5 40 40.5 4254 1692
35 48 39 39.5 4356 1598
36 46.5 39 40 4156 1681
37 46 38.5 39.5 4148 1748
38 45 38 39.5 4214 1731
39 45.5 39 40 4162 1789
40 46 38.5 40 4280 1618
41 46 37.5 40 4112 1704
42 45.5 38 39 4224 1660
43 45.5 37.5 39 4366 1560
44 45 37 39 4411 1337
45 45 37.9 38.5 4267 1637
46 45.5 37.5 38.5 4284 1651
47 47 38 39 4253 1625
48 48 38 39 4214 1598
49 48 38.5 39 4194 1644
50 49 38 39 4220 1683
51 49 38.5 39.2 4226 1616
52 49 39 40 4122 1723
53 49 39.5 40.5 4138 1645
54 49 40 40 4248 1743
55 48 40 40 4374 1654
56 47 40 39 4448 1628
57 44 39.5 38.5 4175 1708
58 45 40 39 4157 1649
59 46 39 38 4194 1494
60 46 39 38 4241 1684
61 46 39 38 4254 1646
62 46 39 37 4298 1546
63 45 39 37 4221 1679
64 44 39 37 4247 1716
65 45 40 38 4245 1659

EQ-1= Equalization tank-01
EQ-2=Equalization tank-02
MBBR-1= Bioreactor tank-01
MBBR-2= Bioreactor tank-02

Conclusion: The temperature of effluent at the receiving side of ETP is in the range of 44-50oC. During equalization and DAF stage the temperature comes down to ambient range (35-43oC). Monitoring of air was done to ensure that low bioreactor performance is not due to reduced aeration of bioreactors. The air monitoring data indicates that sufficient aeration was provided in the bioreactors (>4000 M3/hr. in MBBR-1 and >1300 M3/hr. in MBBR-2).