Fig. 3: Process Flow Diagram of the WTP of Dunakeszi
Table 3: Technical Data of the DMRV WTP in Dunakeszi
| Character of influent wastewater |
Domestic, industrial sewage |
| Total hydraulic capacity of WTP (Q) |
5,000 m3/day |
| Number of cleaning lines |
1 |
| Technical specifications of WTP: |
|
|
|
3,000 m3 |
- Volume of secondary settling tank
|
960 m3 |
- Dry sludge concentration in aeration tank
|
3.5 kg/m3 |
- Dry sludge quantity in aeration tank
|
10,500 kg |
- Dry sludge concentration in the secondary settling tank
|
5,6 kg/m3 |
- Dry sludge quantity in the secondary settling tank
|
5,376 kg |
2 Interpretation of the Industrial-Scale Experimental
Results at Szob
2.1 Description of the WTP and the Experiments
The technology using modified zeolite (ZeoRap®) was installed
and set to work first at one of the WTPs of the Danube-valley Regional Waterworks
(DMRV). The WTP of Szob is located in the Southern part of Szob city, on the
east bank of the Danube. The process flow diagram and the main technical data
of WTP are shown and summarized in Fig. 4 and Table 4. The WTP had two individual
cleaning lines during the experiments. The “zeolite line” applied the ZeoRap
technol-ogy while the other one served as a reference line. Water and sludge
quality data of the zeolite line were compared to that of the reference line.
Calculation of the modified zeolite (ZeoRap) demand of a 3-month experimental
operation is shown in Table 5. (The total duration of experi-ments was 10
months.)
The influents of the WTP frequently causes water and sludge
quality problems primarily during the fruit processing season in the fall.
During this period the effluent COD generally exceeds the standard value (75
mg/l) and the sludge volume index (SVI) was usually higher than 100 ml/g indicating
poor settling.
The experiments started on March 30, 2001 and were completed
on January 14, 2002. The concen-tration of ZeoRap was between 5 % and 10 %
(percentile values are expressed in gZeoRap/gdry
sludge x 100 units).
Wastewater and sludge samples were taken twice weekly. Daily
average water samples were col-lected from the influent wastewater and from
the effluent water of zeolitic and reference lines. Sludge samples were taken
from both aeration tanks and recirculation systems. (The sampling places are
shown in Fig. 4.)
Water samples were analyzed for pH, COD, filtered COD (CODf),
BOD5, TOC, NH4-N, Kjeldahl-N, NO3–N, total-P and suspended
solids. The quality parameters of sludge analyses were the follow-ings: (1)
sludge concentration and sedimentation in the aeration tank, (2) sludge concentration
and sedimentation in the recirculation system, (3) excess sludge concentration
and organic content, (4) daily quantity of excess sludge.
Fig. 4: Process Flow Diagram of the WTP of Szob
Table 4: Technical Data for the WTP of Szob
| Character of influent wastewater: |
Domestic and food industrial
(fruit processing) |
| Total hydraulic capacity of WTP (Q): |
1,000 m3/day |
| Volumetric capacity of zeolite technological line (Q1):
|
500 m3/day |
| Volumetric capacity of reference technological line (Q2):
|
500 m3/day |
| Technical specifications of both technological lines: |
|
- Volume of aeration tank (V1):
|
470 m3 |
- Dry sludge concentration in the aeration tank (SA):
|
~ 4.3 kg/m3 |
- Dry-sludge quantity in the aeration tank (GA):
|
~ 2,021 kg |
- Volume of secondary settling tank (V2):
|
235 m3 |
- Dry sludge concentration in the secondary settling tank (GS):
|
~10,6 kg/m3 |
- Dry-sludge quantity in the secondary settling tank (GS):
|
2,491 kg |
Table 5: Calculation of the ZeoRap Demand of a 3-month Experimental
at Szob
Zeolite demand to increase the zeolite content of dry
sludge up to 5%:
(GA) + (GS):= ~ 2,021 kg + ~ 2,491 kg = ~ 4,512 kg |
225 kg |
Zeolite demand to keep 5% zeolite concentration
Daily zeolite
removal with the excess sludge = 140kg dry sludge removal x 5% |
7 kg/day
210 kg/month |
| Zeolite demand to increase the zeolite content of dry sludge from 5%
to 8 %: |
135 kg |
Zeolite demand to keep 8% zeolite concentration
Daily zeolite removal with the excess sludge = 140kg dry sludge removal
x 8% |
11.2 kg/day
336kg/month |
| Zeolite demand to increase the zeolite content of dry sludge from 8%
to 10%: |
90 kg |
Zeolite demand to keep 10% zeolite concentration:
Daily zeolite removal with the excess sludge = 140kg dry sludge removal
x 10% |
14 kg/day
420 kg/month |
| Total zeolite demand = (225kg + 210 kg +135 kg + 336 kg + 90 kg + 420
kg) |
1,416 kg |
2.2 Experimental Data and Interpretation
The analytical data of experiments are shown in Figures 5
- 44. The structure and the oxygen up-take rate of activated sludge originating
from the aeration tanks can be seen in Photos 1, 2 and summarized in Table
6 respectively. pH and nitrate values are not involved in the evaluation,
be-cause (1) the ZeoRap does not have any effect on the effluent’s pH, (2)
the NO3 content of effluent water was generally less than 1 mg/l.
Based on the hydraulic and organic loads, as well as the
applied MZ concentration, the experimental period was divided into three periods.
These were:
| • 30 March 2001 to 18 June 2001 |
Low load |
7 kgZeoRap/day (5 %) operation |
| • 21 June 2001 to 26 Sept. 2001 |
Medium load |
11 kgZeoRap/day (8 %) operation |
| • 1 Oct. 2001 to 14 January 2002 |
High load |
14 kgZeoRap/day (10 %) operation |
The average values of organic and hydraulic loads in the
different periods were as follows:
| • Period of low load: |
257 kgCOD/day, 496 m3/day |
| • Period of medium load: |
419 kgCOD/day, 712 m3/day |
| • Period of high load: |
685 kgCOD/day, 836 m3/day |
Figures 5 to 22 show that both cleaning lines of WTP operated
satisfactory during the low load sea-son. In medium and high load season,
however the effluent’s water quality frequently exceeded the related standard
values and the quality of the effluent in the reference line was extremely
poor in many cases. Differences between the quality of the effluents of reference
and zeolite lines were the most significant during the high load period.
Fig. 21 and 22 show the effect of ZeoRap on sludge settling.
It can be seen that the Sludge Volume Index (SVI) measured in the zeolite
line was usually less than the critical value of 100ml/g during low and high
load season. SVI increased in both lines in high season, however the differences
between the reference and zeolite line were the largest in this season.
The suspended solid values, in conjunction with improved
sludge settling properties, were lower in the ef-fluent of zeolite line. The
lower suspended solid (SS) concentration generally resulted in a decrease
in COD. Differences, however between the COD values of filtered samples of
the two cleaning lines (See Figures 7 and 8) showed that MZ decreased the
COD of treated water by accelerating the biochemical oxidation, too. The lower
BOD5 values measured in the zeolite line also supports the above
statement.
Table 6: Oxygen Uptake Rate (OUR) of Water Samples
Originating from the Aeration Tanks of Szob
| Date of sampling |
09 April 2001 |
02 August 2001 |
01 October 2001 |
| Cleaning line |
Reference |
Zeolite |
Reference |
Zeolite |
Reference |
Zeolite |
| OUR (goxygen/kgsludgehour) |
15,2 |
18,0 |
16,5 |
19,6 |
18,0 |
22,0 |
| OUR expressed in the percent of the OUR measured in the
reference line (%) |
100 |
122 |
100 |
119 |
100 |
122 |
| OUR expressed in the percent of the OUR measured in the
refer-ence line on 9 April 2001 (%) |
100 |
118 |
109 |
129 |
118 |
145 |
|
Fig. 5 COD values measured in the effluents
of the Reference and Zeolite cleaning lines of Szob WTP |
|
Fig. 6 Differences between COD values measured
in the effluents of the Reference and Zeolite cleaning lines of Szob
WTP |
|
Fig. 7 COD values measured in the filtered
effluents of the Reference and Zeolite cleaning lines of Szob WTP |
|
Fig. 8 Differences between COD values measured
in the filtered effluents of the Reference and Zeolite cleaning lines
of Szob WTP |
|
Fig. 9 BOD values measured in the effluents
of the Reference and Zeolite cleaning lines of Szob WTP |
|
Fig. 10 Differences between BOD values measured
in the effluents of the Reference and Zeolite cleaning lines of Szob
WTP |
|
Fig. 11 TOC values measured in the effluents
of the Reference and Zeolite cleaning lines of Szob WTP |
|
Fig. 12 Differences between TOC values measured
in the effluents of the Reference and Zeolite cleaning lines of Szob
WTP |
|
Fig. 13 Ammonium-N values measured in the
effluents of the Reference and Zeolite cleaning lines of Szob WTP |
|
Fig. 14 Differences between ammonium-N values
measured in the effluents of the Reference and Zeolite cleaning lines
of Szob WTP |
|
Fig. 15 Organic-N values measured in the
effluents of the Reference and Zeolite cleaning lines of Szob WTP |
|
Fig. 16 Differences between organic-N values
measured in the effluents of the Reference and Zeolite cleaning lines
of Szob WTP |
|
Fig. 17 Total phosphorous values measured
in the effluents of the Reference and Zeolite cleaning lines of Szob
WTP |
|
Fig. 18 Differences between total phosphorous
values measured in the effluents of the Reference and Zeolite cleaning
lines of Szob WTP |
|
Fig. 19 Suspended solids values measured
in the effluents of the Reference and Zeolite cleaning lines of Szob
WTP |
|
Fig. 20 Differences between suspended solids
values measured in the effluents of the Reference and Zeolite cleaning
lines of Szob WTP |
|
Fig. 21 Sludge Volume Index values measured
in the Reference and Zeolite cleaning lines of Szob WTP vs time |
|
Fig. 22 Differences between Sludge Volume
Index values measured in the Reference and Zeolite cleaning lines of
Szob WTP vs time |
The relationships (type and parameters of correlation) between
the water quality parameters measured in the effluents of both cleaning lines
are shown in Figures 23 to 28. Figures show that at smaller concentrations
there are linear relationships, which change to logarithmic ones in the case
of COD, BOD5 and suspended solids at higher concentrations.
Figures 29 to 34 show the improvement of effluent water quality
as a function of the quantity of Zeo-Rap. It can be seen that the percentile
values of water quality improvement in the case of COD, BOD5, NH4-H
and total-P increased with ZeoRap concentration. The percentile values however
decreased with ZeoRap concentration in the case of organic-N and suspended
solids. This later rela-tionship is apparently contradicted by the preliminary
laboratory experiments, however it should be taken into consideration that
the higher load belonged to the higher ZeoRap concentrations in every case
and the improvement in effluent water quality was significant at organic-N
and suspended solids, as well (See Figures 16 and 20), even if the percentile
values were lower.
The correlation between nitrification and ZeoRap concentration
is shown in Figure 35. Figure 35 shows that ZeoRap accelerates the nitrification.
For example the nitrification in the zeolite line was 42% larger at a 10 %
ZeoRap concentration.
Increasing ZeoRap concentration improved the sludge settling
properties, i.e., SVI decreased. There was a logarithmic correlation between
these parameters as shown in Figure 36.
The ZeoRap effect on decreasing the quantity of pollutants
(kg/day) is introduced on the example of COD in Figure 37. It can be seen
that the differences between the quantities of COD decomposed in the zeolite
and the reference lines rapidly increased with the applied ZeoRap concentration.
At 10 % ZeoRap concentration (ZeoRap demand was 14 kg/day) the COD decomposed
in the zeolite line was bigger by 40 kg than in the reference one. It means
that 1 kg ZeoRap decreased the effluent’s COD by 2.9 kg in the high load season.
|
|
| Fig. 23 Relationship between the COD
values measured in the effluents of the Reference and Zeolite cleaning
lines of Szob WTP |
Fig. 24 Relationship between the BOD5
values measured in the effluents of the Reference and Zeolite cleaning
lines of Szob WTP |
|
|
Fig. 25 Relationship between the TOC
values measured in the effluents of the Reference and Zeolite cleaning
lines of Szob WTP |
Fig. 26 Relationship between the ammonium-N
values measured in the effluents of the Reference and Zeolite cleaning
lines of Szob WTP |
|
|
Fig. 27 Relationship between the total-P
values measured in the effluents of the Reference and Zeolite cleaning
lines of Szob WTP |
Fig. 28 Relationship between the suspended
solids values measured in the effluents of the Reference and Zeolite
cleaning lines of Szob WTP |
|
|
Fig. 29 Difference between the COD
values measured in the Reference and Zeolite lines of Szob WTP vs. MZ
concentration |
Fig. 30 Difference between the BOD5
values measured in the Reference and Zeolite lines of Szob WTP vs. MZ
concentration |
|
|
Fig. 31 Difference between the NH4-N
values measured in the Reference and Zeolite lines of Szob WTP vs. MZ
concentration |
Fig. 32 Difference between the organic-N
values measured in the Reference and Zeolite lines of Szob WTP vs. MZ
concentration |
|
|
Fig. 33 Difference between the total
phosphorous values measured in the Reference and Zeolite lines of Szob
WTP vs. MZ concentration |
Fig. 34 Difference between the suspended
solid values measured in the Reference and Zeolite lines of Szob WTP
vs. MZ concentration |
|
|
Fig. 35 Difference between the nitrificating
activities measured in the Zeolite and Reference lines of Szob WTP vs
MZ concentration |
Fig. 36 Difference between sludge volume
index values measured in the Reference and Zeolite lines of Szob WTP
vs MZ concentration |
|
|
Fig. 37 Relationship betwen the decomposed
organic compounds expressed in COD in the Zeolite line of Szob WTP and
the MZ concentration |
Fig. 38 Sludge activity measured in
the Reference cleaning lines of Szob WTP vs. detention time |
|
|
Fig. 39 Sludge activity measured in
the Zeolite cleaning lines of Szob WTP vs. detention time |
Fig. 40 Relationshop between the activities
of the Reference and Zeolite sludges of Szob WTP |
|
|
Fig. 41 SVI of the Reference line's
sludge vs. detention time in the aeration tank of Szob WTP |
Fig. 42 SVI of the Zeolite cleaning
line's sludge vs. detention time in the aeration tank of Szob WTP |
|
|
Fig. 43 Chemical oxygen demand measured
in the Reference line of Szob WTP vs. detention time |
Fig. 44 Chemical oxygen demand measured
in the Zeolite line of Szob WTP vs. detention time |
The specific values of pollutants’ removal for the other
water quality parameters are the followings:
| • COD: |
2.9 kgCOD/kgZeoRap |
| • CODf |
0.7 kgCODf/kgZeoRap |
| • BOD5 |
0.3 kgBOD5/kgZeoRap |
| • NH4-N |
0.8 kgNH4-N/kgZeoRap |
| • Total-N |
0.3 kgTotal-N/kgZeoRap |
| • Total-P: |
0.3 kgTotal-P/kgZeoRap |
| • Suspended solids: |
2.3 kgsuspended solids/kgZeoRap |
Figures 38 and 39 show the values of sludge activity calculated
from COD as a function of the wastewa-ter’s detention time in the aeration
basin. Data show that there is no correlation between these parameters. The
sludge activity is practically independent from the detention time. There
is however, a linear relation-ship between sludge activities measured in the
reference and zeolite lines (See Figure 40).
The effect of detention time on SVI is described in Figures
41 and 42. Statistical analysis of the relation-ship between these parameters
is, however, inconclusive.
There is a very weak correlation between the effluent COD
and detention time. Based on this relationship the optimal detention time
in both aeration tanks is a large, i.e., 43 hours (See Figures 43 and 44).
The values of oxygen uptake rate (OUR), in conjunction with
the improved cleaning properties, were larger by 19 - 22 % in the zeolite
line. On increasing the hydraulic and the organic loads of WTP, OURs increased
by 18 % in the reference and 45 % in the zeolite line (See Table 6).
The microscopic pictures of recycled sludges, in harmony
with the visual examinations, showed that the sludge originating from the
zeolite line had a thicker structure (See Photo 1 and 2), which re-sulted
in better settling properties and more effective dewatering.
Photo 1: Microscopic Image of Recycled Sludge Originating
from the Reference Line of Szob
Photo 2: Microscopic Image of Recycled Sludge Originating
from the Zeolite Line of Szob
3 Cost to Benefit Analysis of ZeoRap and Determination
of Optimal ZeoRap Concentration
The data of water and sludge quality measurements of industrial-scale
experiments showed that the advantageous effects of ZeoRap technology increased
with the MZ concentration. It means that, with respect to water and sludge
quality, larger ZeoRap concentration yielded more favourable results. The
increase of ZeoRap, however is limited by its price and the other additional
costs of Zeo-Rap. Therefore, a determination of optimal ZeoRap concentration
requires a cost to benefit analysis.
3.1 Cost Elements of ZeoRap at Szob
| • Modified zeolite (ZeoRap) including transportation: |
0.272 EUR/kg |
| • Storage and supply of ZeoRap: |
0.002 EUR/kg |
| • Zeorap feeder: |
2 000.000 EUR |
All of the additional costs of ZeoRap operating full WTP
(both cleaning lines) by the ZeoRap method and accounting for the amortization
of the ZeoRap feeder by ten years yield the following:
| „2x7 kgZeoRap/day” operation |
ZeoRap (450 kg + 5 110 kg): |
1512.32 EUR |
| |
Storage and supply of ZeoRap: |
11.12 EUR |
| |
ZeoRap feeder |
200.00 EUR |
| |
Total |
1 723.44 EUR |
| |
|
|
| „2x11 kgZeoRap/day” operation |
ZeoRap (720 kg + 8 030kg): |
2 380.00 EUR |
| |
Storage and supply of ZeoRap: |
17.50 EUR |
| |
ZeoRap feeder |
200.00 EUR |
| |
Total |
2 577.50 EUR |
| |
|
|
| „2x14 kgZeoRap/day” operation |
ZeoRap (900 kg + 10 220 kg): |
3 024.64 EUR |
| |
Storage and supply of ZeoRap: |
22.24 EUR |
| |
ZeoRap feeder |
200.00 EUR |
| |
Total |
3 246.88 EUR |
3.2 Economic Efficiency of ZeoRap at Szob
a. Environmental penalty Saving
A new and more stringent effluent water penalty system will
be introduced in Hungary on January 1, 2003. Standard values for COD, BOD5,
NH4-N, total-N, total phosphorous and suspended solids-N, according to the
new regulation (9/2002. (III.22.) KöM-KöViM decree) are summarized in Table
7.
Based on the data of hydraulic load and water quality analysis,
the differences between the annual quantity of pollutants discharged above
the standard concentration from the reference and zeolite lines were calculated.
These quantities and the relating penalties are summarized in Table 8 and
Fig. 45. It can be seen that the penalty savings considarably increases with
ZeoRap concentration. For example while ZeoRap concentration changed from
8 to 10 %, penalty saving increased by 400 %. It should be mentioned, however
that that the organic load of WTP was not constant during the experiments.
Table 7: Standard Values and Fines for Effluent Water
in the Category of „Other Protected Area”
According to the 9/2002. (III.22.) KöM-KöViM Decree
|
Parameter |
Standard value* (mg/l) |
Penalty (EUR/kgpollutant**) |
| COD |
75 |
0.56 |
| BOD5 |
25 |
2.10 |
| NH4-N |
5 |
2.80 |
| Total-N |
15 |
2.80 |
| Total phosphorous |
2 |
22.40 |
| Suspended solids |
100 |
0.56 |
| Remark: |
* |
In the case of WTPs established
before January 1, 2003 standard values will be introduced gradually
over the next 15 years. During this period, the actual values of standards
will be deter-mined by the local environmental inspectorate in every
year. (Standards for the transient period is still unknown, therefore
the economic evaluation is based on the data of this table.) |
| |
** |
Quantity of pollutant discharged above the standard concentration
by WTP |
Table 8: The Differences of Annual Quantity of Pollutants
Discharged Above Standard Concentration
from Reference and Zeolite lines of Szob WTP with Various ZeoRap Concentration
and the Related Financial Penalties
Name of pollutant |
7 kgZeoRap/day |
11 kgZeoRap/day |
14 kgZeoRap/day |
| Delta quantity
of pollutant (kg) |
Penalty (EUR) |
Delta quantity
of pollutant (kg) |
Penalty (EUR) |
Delta quantity
of pollutant (kg) |
Penalty (EUR) |
| COD |
907.0 |
508 |
1550.1 |
868 |
9532.2 |
5 338 |
| BOD5 |
54.8 |
115 |
71.7 |
151 |
882.7 |
1 854 |
| NH4-N |
9.1 |
26 |
0.0 |
0 |
140.0 |
392 |
| Total-N |
0.0 |
0 |
0.0 |
0 |
0.0 |
0 |
| Total phosphorous |
74.8 |
1 676 |
74.4 |
1 666 |
123.3 |
2 761 |
| Suspended solids |
573.1 |
321 |
2056.0 |
508 |
7494.2 |
4 197 |
| Penalty saving (EUR) |
2 530 |
|
3 042 |
|
12 688 |
Penalty saving if both
lines are
operated by ZeoRap (EUR) |
5 061 |
|
6 085 |
|
25 377 |
| Remark: |
Of the COD and BOD5, in accordance with the 9/2002.
(III.22.) KöM-KöViM decree, only COD was taken into account as a penalty
factor. |
b. Cost saving in sludge treatment
The surplus sludge is thickened at the WTP and then transported
by a subcontractor of DMRV to a waste dumping area. The cost of transportation
and deposition is 4 EUR/m3thickened sludge. Considering that the quantity
of ZeoRap containing thickened sludge is smaller in volume by 5 - 12 % than
that of tradi-tional thickened sludge, the total treatment cost (thickening,
transportation, deposition), in spite of the higher dry material content,
is lower in the case of MZ containing sludge. The yearly quantity and treat-ment
cost of reference and the ZeoRap containing sludges are summarized in Table
9.
Fig. 45: Differences between the Annual Quantities
of Pollutants Discharged Above the
Standard Concentration from the Reference and the Zeolite cleaning lines of
Szob
Table 9: Annual Quantity and Treatment Cost of Surplus
Sludge at Szob
| Name of cleaning line |
Reference line |
Zeolite line |
| Quantity of ZeoRap |
- |
7 kgZeoRap/day |
11 kgZeoRap/day |
14 kgZeoRap/day |
|
1 |
2 |
3 |
4 |
| Quantity of thickened sludge (m3/year) |
5 110 |
4 891 |
4 745 |
4 526 |
| Cost of sludge treatment (EUR/year) |
24 440 |
19 654 |
18 980 |
18 104 |
Differences between treatment costs
(1-2, 1-3, 1-4) (EUR/year) |
|
876 |
1 460 |
2 336 |
Differences between treatment costs
if both lines are operated by ZeoRap |
|
1 752 |
2 920 |
4 672 |
3.3 Summary of Benefits to Costs of ZeoRap
The economic advantage of ZeoRap technology as a function of
applied MZ concentration is as follows:
| Operation of 2x7 kgZeoRap/day, (5%) |
Penalty-saving: |
5 061 EUR/year |
| |
Cost-saving in sludge treatment: |
1 752 EUR/ year |
| |
Additional costs: |
-1 723 EUR/ year |
| |
Cost advantage: |
5 090 EUR/year |
| |
|
|
| Operation of 2x11 kgZeoRap/day, (8%) |
Penalty-saving: |
6 085 EUR/ year |
| |
Cost-saving in sludge treatment: |
2 920 EUR/year |
| |
Additional costs: |
-2 578 EUR/year |
| |
Cost advantage: |
6 427 EUR/ year |
| |
|
|
| Operation of 2x14 kgZeoRap/day, (10%) |
Penalty-saving: |
25 377 EUR/year |
| |
Cost-saving in sludge treatment: |
4 672 EUR/year |
| |
Additional costs: |
-3 247 EUR/year |
| |
Cost advantage: |
26 802 EUR/year |
Data show that the efficiency of ZeoRap benefits increase
significantly with the concentration. The optimal ZeoRap concentration and
the economic efficiency of ZeoRap, however, primarily depends on the standard
values, that will be determined for the Szob WTP. That is to say that the
optimal concentration will depond upon application of the environmental penalty.
The relationship between the economy of ZeoRap and environmental penalty is
shown in Figure 46. If the WTP, due to the high individual standards values
remains penalty-free in the future, the optimal ZeoRap concentra-tion will
be 5% (2X14 kgZeoRap/day).
Fig. 46: Economy of ZeoRap vs. Environmental Penalty
4 Evaluation of Industrial-Scale Experiments Accomplished
at Dunakeszi
The process flow diagram and the main technical data of the
WTP of Dunakeszi were introduced in Chapter 2.1, Figures 4 and Table 4. The
evaluation of experiments started on March 20, 2002 and finished on October
5, 2002 is introduced in Figures 47 – 72. Figures show that similarly to the
WTP of Szob, the sludge and the critical water quality parameters considerably
improved in the course of zeolite operation. The specific values of pollutants’
removal at the WTP of Dunakeszi were the followings:
| • COD: |
3.3 kgCOD/kgZeoRap |
| • BOD5 |
1.2 kgBOD5/kgZeoRap |
| • NH4-N |
0.1 kgNH4-N/kgZeoRap |
| • Total-N |
0.5 kgTotal-N/kgZeoRap |
The annual environmental penalty to be paid applying the
traditional (modified zeolite-free) and the ZeoRap technologies in different
ZeoRap concentrations are as follows:
| • |
114 588 |
EUR (traditional technology) |
| • |
46 828 |
EUR (ZeoRap technology at 5 % MZ) |
| • |
3 320 |
EUR (ZeoRap technology at 10 % MZ) |
| • |
0 |
EUR (ZeoRap technology at 15 % MZ) |
Taking into consideration the additional costs of ZeoRap
technology its economical efficiency at the WTP of Dunakeszi is as follows:
| • |
64 828 |
EUR (ZeoRap technology at 5 % MZ) |
| • |
105 616 |
EUR (ZeoRap technology at 10 % MZ) |
| • |
106 380 |
EUR (ZeoRap technology at 15 % MZ) |
|
Fig. 47 COD values measured in the effluent
of Dunakeszi WTP during reference operation vs. date of sampling |
|
Fig. 48 NH4-N and BOD5values
measured in the effluent of Dunakeszi WTP during reference operation
vs. date of sampling |
|
Fig. 49 COD values measured in the effluent
of Dunakeszi WTP during zeolite operation vs. date of sampling |
|
Fig. 50 NH4-N and BOD5
values measured in the effluent of Dunakeszi WTP during reference operation
vs. date of sampling |
|
|
|
|
Fig. 51 Effluent COD as a function of organic load
of Dunakeszi WTP during reference operation |
Fig. 52 Relationship between sludge age and COD
measured in filtered effluent of Dunakeszi WTP during reference operation
|
|
|
|
|
Fig. 53 Relationship between sludge activity and COD measured
in the effluent of Dunakeszi WTP during reference operation |
Fig. 54 Relationship between sludge activity and COD measured
in filtered effluent of Dunakeszi WTP during reference operation |
|
|
|
|
Fig. 55 Relationship between substrate respiration and organic
load of Dunakeszi WTP during reference operation |
Fig. 56 Sludge activity as a function of sludge age at the
Dunakeszi WTP during reference operation |
|
|
|
|
Fig. 57 Sludge concentration vs. sludge volume index at the
Dunakeszi WTP during reference operation |
Fig. 58 Sludge concentration vs. sludge settling at the Dunakeszi
WTP during reference operation |
|
|
|
|
Fig. 59 COD measured in original effluent vs. organic load
of Dunakeszi WTP during zeolite operation |
Fig. 60 COD measured in filtered effluent vs. organic load
of Dunakeszi WTP during zeolite operation |
|
|
|
|
Fig. 61 Relationship between sludge age and COD measured in
original effluent of Dunakeszi WTP during reference operation |
Fig. 62 Relationship between sludge age and COD measured in
filtered effluent of Dunakeszi WTP during reference operation |
|
|
|
|
Fig. 63 Effluent NH4-N concentration as a function of organic
load of Dunakeszi WTP during reference operation |
Fig. 64 Sludge settling as a function of sludge concentration
at Dunakeszi WTP during zeolite operation |
|
|
|
|
Fig. 65 Average COD values of effluent vs. average zeolite
concentration at Dunakeszi WTP during zeolite operation |
Fig. 66 Average NH4-N values of effluent vs. average zeolite
concentration at Dunakeszi WTP during zeolite operation |
|
|
|
|
Fig. 67 Relationship between biological activity of zeolite
(5 %) and reference operations of Dunakeszi WTP |
Fig. 68 Relationship between biological activity of zeolite
(10 %) and reference operations of Dunakeszi WTP |
|
|
|
|
Fig. 69 Relationship between biological activity of zeolite
(15 %) and reference operations of Dunakeszi WTP |
Fig. 70 Substrate respiration as a function of average zeolite
concentration at Dunakeszi WTP |
|
|
|
|
Fig. 71 Specific NH4-N load of Dunakeszi WTP vs. zeolite concentration
supplied |
Fig. 72 Relationship betwen sludge volume index and zeolite
concentration at Dunakeszi WTP |
