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