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Multi Multi Multi Multi- - - -Criteria Assessment of Water and Criteria Assessment of Water and Criteria Assessment of Water and Criteria Assessment of Water and Wastewater Technolo

Wastewater Technolo Wastewater Technolo

Wastewater Technologies gies gies gies

There were three stages to the MCA. The first was to come up with a list of technologies for inclusion. The second was to gather information about the performance of those technologies against the 13 criteria, and to score the performance of each technology against each criterion. The final was to multiply performance by criteria weighting and sum total performance for each technology.

3.3.1 3.3.1 3.3.1

3.3.1 Selection of Technologies Selection of Technologies Selection of Technologies Selection of Technologies

The technologies for consideration in the MCA process were selected on the basis of their suitability for the types of situations in remote Australian settlements i.e. small populations with no connection to a reticulated water or sewerage service. In the case of wastewater technologies they were also selected to represent a range of treatment types, whereas all the water treatment units selected were small-scale reverse osmosis units.

They had to be commercially available at the time of the research i.e. not in development. The technologies included in the MCA are shown in Table 17.

Table 17. List of Technologies for MCA

Category Manufacturer Model Name Description

Water Novatron 750 BWE Mains powered RO, 750L/day

Novatron 2000 BWE Mains powered RO, 2,000L/day

Abtech RO1000E-LP Mains powered RO, 1,000L/day

Abtech RO2000E-LP Mains powered RO, 2,000L/day

Citor 2TM Mains powered RO, 2,000L/day

Wastewater Ozzi Kleen RP 10 Aerobic treatment plus chlorination.

Econova Novaclear 10EP Membrane bioreactor.

Econova Novaclear 10EP Membrane bioreactor with chlorination.

Advantex AX20 Packed bed treatment.

Envirocycle 10 NR Aerobic treatment plus UV.

3.3.2 3.3.2 3.3.2

3.3.2 Performance of Technologies Performance of Technologies Performance of Technologies Performance of Technologies

A telephone survey of the manufacturer or retailer of the technologies listed in Table 17 was carried out to gather information about their performance against the 13 criteria.

This information is summarised in Table 31 and Table 32 in Chapter 4.

Once this information was gathered, the performance across the range of technologies was considered and a ‘performance score’ was assigned for the performance of each technology against each criterion. As for the weighting, scoring was carried out in different ways to determine the sensitivity of the MCA model. Three different scoring methods were used:

1. A ‘local scale’ scoring process (Belton & Stewart 2002) in which the best performing technologies was given a score of 100 if it performed best against that criterion. The worst was given a score of ‘0’. Where performance could be quantified, a linear value scale was applied, as described in the example below.

When all the alternatives were considered to perform equally, a score of 50 was given to every unit.

2. Similar to above, with the best performing technology being given a score of 100 and then all other technologies scored as a percentage based on their relative performance. This meant that the range of scores was not as great.

3. A local scale process which involved ranking each technology from 1 (worst) to 5 (best) for performance against each criterion. When all the alternatives were considered to perform equally, a score of 3 was given to every unit.

An example of the scoring processes used is as follows. For the criteria ‘robust and reliable’, there are two indicators: the warranty offered with the technology, and the expected service life. The average was calculated for this criterion since it has two indicators. So the score for each technology for the ‘robust and reliable’ criterion is the average across the two indicators.

The performance of each of the wastewater technologies against these two indicators was as follows:

• Ozzi Kleen RP10 – 25 year warranty on tank (best), 30 year service life

• Novaclear 10EP – 15 year warranty on tank, 35 year service life (best)

• Novaclear 10EP w/ disinfection – 15 year warranty on tank, 35 year service life (best)

• Advantex AX20 – 5 year warranty on unit, 20 year service life

• Envirocycle 10NR – 15 warranty on structure & fittings, 20 year service life.

Using Scoring Method 1, the Ozzi Kleen RP10 was assigned a score of 100 for its warranty, as it had the longest of all the technologies considered. The Advantex AX20 got a score of 0 as the 5 year warranty was the worst performance in the category. The range between best and worst was 20 years. The Novaclear units both got a score of 50

since their warranty of 15 years is at the midpoint between the worst performer and the best performer. The same score was obtained by the Envirocycle.

Using Scoring Method 2, the Ozzi Kleen RP10 was assigned a score of 100 for its warranty, as it had the longest of all the technologies considered. The Novaclear units both got a score of 60 since their warranty of 15 years is 60% of the 25 years offered by Ozzi Kleen. The same score was obtained by the Envirocycle. The Advantex AX20 got a score of 20 (5 years being 20% of 25 years).

Using Scoring Method 3, which works in the opposite direction, the Advantex AX20 got a score of 1 as the worst performer. The two Novaclear units and the Envirocycle all scored 2 as they were equal in performance. The Ozzi Kleen RP10 was assigned a score of 5.

The same calculation was repeated using each methodology for service life, with the Novaclear units being the best performers. The scores assigned to each technology for the two indicators using all 3 scoring methods are shown in Tables 18-20. N.B. The average was calculated for this criterion since it has two indicators. So the score for each technology for the ‘robust and reliable’ criterion is the average across the two indicators.

Table 18. Example of Scoring Method 1 for wastewater treatment technologies:

Ozzi Kleen RP10

Novaclear 10EP

Novaclear 10EP + Cl

Advantex AX20

Envirocycle 10NR

Warranty score 100 60 60 0 60

Service life score 67 100 100 0 0

Average 83.5 80 80 0 30

Table 19. Example of Scoring Method 2 for wastewater treatment technologies:

Ozzi Kleen RP10

Novaclear 10EP

Novaclear 10EP + Cl

Advantex AX20

Envirocycle 10NR

Warranty score 100 50 50 0 50

Service life score 86 100 100 57 57

Average 93 75 75 28.5 53.5

Table 20. Example of Scoring Method 3 for wastewater treatment technologies:

Ozzi Kleen RP10

Novaclear 10EP

Novaclear 10EP + Cl

Advantex AX20

Envirocycle 10NR

Warranty score 5 2 2 1 2

Service life score 3 4 4 1 1

Average 4 3 3 1 1.5

3.3.3 3.3.3 3.3.3

3.3.3 Assessment of Assessment of Assessment of Assessment of Technologies Technologies Technologies Technologies

After scoring of each of the technologies against each criterion using the 3 different scoring methods was carried out, a simple linear additive model was used to assess overall performance, using the equation from Section 2.4.1.

This meant that the score for each technology was multiplied by the criterion weighting for each of the 13 criteria. Where there were 2 indicators for a single criterion, the technology’s performance score was taken as the average of the scores across the indicators. The resultant total score gave an indication of the technology which had the best overall performance for the group whose weightings were applied.

The four different weightings were applied to each of the three different scoring methods and the results of each combination of weight and score are presented in Chapter 4.

The commercial names of each of the technologies were changed in the presentation of results of the multi-criteria assessment. They have been re-named Technologies A, B, C, D and E in both the water and wastewater categories. This has been done because the purpose of this research was to develop and demonstrate the use of a sustainability-oriented MCA framework for comparison of performance, rather than to recommend specific technologies to consumers. More extensive practical testing would be required if this were the desired purpose of the research and therefore the commercial names of each unit have been replaced by a single letter.

3.4 3.4 3.4

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