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Project findings

1. Project Implementation

The process of project implementation has been dominated, by the investment and operation phases. The major stages of the process undergone were (1) detail investment design, (2) achieving the public permission for constructions, (3) public tender, contracting and instalment out of the investments for infrastructure and equipment, (4) supervision of these works and (5) optimisation and demonstration of the IWPM-System.

2. EU-Life Project Management

During the EU-Life Project Management, the following problems had been encountered:

- The environmental impact assessment, which had to be delivered to the public authorities for permission of construction and operations later on, went very well. Small problems regarding the location of PCC (the connection pipe) could be resolved very quickly with full support not only of the public authorities, but also of some local NGOs, who were eager to get the IWPM Project "on track", because of the expected significant advantages for the water environment.
- During the period of public tender, a fierce competition between different construction companies and deliverers of machine equipments came up. A significant delay of several months was caused by the fact that contracts must not be signed, before any written complaints are settled, according to the German procurement law (which is in full compliance with the EU regulation in that respect).
- As everybody knows, the global financial crisis has hit the overall economic conditions with significant, indirect effect on the Project. During the phase of tendering, a sharp rise of unit prices in energy and steel came up, which led to an increase of construction and equipment costs in some parts (which, finally, led to the results that some components and investments became more expensive than expected.). Anyhow, the project management was successful, finally, to realise the Project within the main budget lines (even though some deviations in the sub-budgets could not be avoided).
- Some of the important wastewater producers within the IWPM catchment area have sharply decreased their production, or changed their produce profile. As a result of this, the organic loading (= wastewater inflow to STP1) went down by more than 20 %. This might sound as an advantage for the overall system function, but it was not. This, because the loading of nutrients has not decreased, and the balance between organic and nutrients (C:N:P) is now worse, respectively more difficult to handle than it was before.
To encounter this problem, some technical modifications in the design had to be realised, namely regarding the sludge scheme (EST).
The updated EIA showed that the combined biogas powered generator would not be economically or ecologically feasible anymore, after the biogas production is lower and all biogas will be utilised, directly, for digester warm-up and heating of buildings etc. The Project was modified, accordingly. As well as regarding the FBR.
- Regarding the partnerships and their added value, there was some change in the Project. Biwater has taken a subcontractor for delivery of machinery and equipment for MSBR and MCS. The collaboration with all partners and the new subcontractor (a local firm specialised in process technology and electrical equipment) went quite well, and the MSBR and MCS hardware were installed successfully and have shown very positive technical results.

3. Technical application

3.1 MSBR & FBR

One part of the innovative equipment to be installed was the MSBR Equ. 13 and FBR Equ. 23 for sludge liquor decontamination. The original planning was focused on an FBR - Floating Bio Reactor, for separated sludge-liquor decontamination (i.e. for nutrients reduction), installed in a concrete tank (buffer tank for equalisation of peaks, especially for Ammonia, which might inhibit the biological process of nitrification/denitrification).

The design works (mapping, plans, dimensioning and description as ToR for construction) have been completed, as scheduled.

To verify the process design, additional laboratory tests have been carried out for all installations and equipments of IWPM. These have turned out to be even more important than initially estimated, to adjust the IWPM-system exactly to the wastewater quantities and qualities and working conditions (which have undergone some significant changes, as already described in the last annual report).

These laboratory tests, plus the monitoring, chemical analyses and first experiences with test operations, led to the following results:

a) The MSBR (Multifunctional Sequencing Batch Reactor) has a much better performance and a much larger biological purification capacity than foreseen. The specific rate of BOD-removal as well as of N-removal is nearly 35 % higher than predicted. Additionally, the efficiency of the surface aerators was found to be nearly 20 % better than calculated and guaranteed by the equipment manufacturer. These very positive results are a combination of more efficient quality of process & control technology and better machinery than calculated, supported by a better wastewater quality (BOD- and N-degradability) than estimated.
b) The toxicity of the process wastewaters, coming from sludge dewatering devices, from the clear water overflow of the anaerobic digesters, from thickeners etc., contain an Ammonia-concentration of between 500 and 1,700 mg/l (approximately in the range as foreseen). What could not be foreseen (or: could not be taken for granted without major technical risks at the planning stage, before laboratory testing) was the fact, that the toxicity of the process wastewaters decreased to nearly zero, once the wastewater had undergone a stripping process, reducing the volatiles and ammonia.
c) Operational tests have revealed that, once the process waters are properly stripped and equalised, it is possible to use the biological capacity of the MSBR-reactor for process water purification.

For these reasons, the process design and construction of the sludge liquor treatment facility had been modified as follows:

a) Process water stripping device, removing volatiles. The volatile gases can be used for the burners of the sludge heating at the anaerobic digesters. An additional effect is the protection of the atmosphere from greenhouse gases (because, otherwise these might be emitted from the wastewater). Additional stage, compared to the initial planning.
b) Equalisation of the sludge liquors in a concrete buffer tank; no change to the original planning.
c) Utilisation of the MSBR-capacity for biological purification of the stripped and buffered liquors; replacing the initially planned FBR machinery.

3.2 Energy consumption

In comparison to reference figures about average, conventional wastewater treatment plants, the power consumption of the WWTP Ostercappeln lies significantly below the maximum values. The power consumption of the WWTP Wittlage with an average of 18,0 kWh/(PE*a) is well below the minimal values of the data from literature. The WWTP Wittlage turned out to operate very efficiently in terms of power consumption, after the IWPM components MWP and EST had been installed and had come to full operations.

The figure shows the power consumption of the WWTP Ostercappeln (with IWPM pipe connection, but without IWPM related technical modifications) and the WWTP Wittlage (with all IWPM-components, including the modified water purification, MWP, and the enhanced sludge treatment, EST).
Due to the constant underloading and the applied treatment process (energy intensive aerobic sludge stabilisation with sludge age of above 20 days), the power consumption in Ostercappeln, before the installation of IWPM had been high as 71 kWh/(PE*a).
It can be stated that the application of IWPM has led to a reduced power consumption, respectively to an increased energy efficiency compared to conventional WWTP, especially for the IWPM - WWTP Wittlage, where the technical modifications (MWP, EST) have been realised, which are part of the overall IWPM concept.

4. Commercial application

During the dissemination activities undergone so far, there was quite a positive response from EU industry and utilities. The general idea of IWPM as a system with biologically activated connection pipes and computerised monitoring and remote control (covering two neighbouring catchment areas respectively wastewater treatment plants), was usually understood well by potential users, decision makers and experts.

Equally well was the acceptance the technical concept and solutions developed during the Project, namely for the innovative component MSBR with its relatively cheap floating device of surface aerators, operated at advanced energy efficiency.

The major burden for commercial application was found to lie in institutional and political issues:

- Unless the IWPM-idea is injected before the phase of engineering design, there will be no planning and no tender covering the IWPM-system - and tenders limited to a construction or modernisation of single sewage treatment plants cannot result in any integrated system, whatsoever;
- In many European countries (namely Poland, Germany, Romania and others), the responsibilities for wastewater management lies within municipalities or municipal associations. Wherever the IWPM-system is crossing boundaries of these municipal utilities, it is very unlikely that the technical/commercial optimum will be the driving force. The dominating force will usually be the relation between these two neighbouring utilities.

Technical and commercial application has been demonstrated to be possible and promising, as well for the IWPM-system as for IWPM-components. Anyhow, it is more likely that components can be utilised than the IWPM-system, due to the institutional/political restraints described above.

5. Effectiveness of Dissemination Activities

The response to dissemination activities and of the public media was quite positive (after the project participants had explained the technological background, which was not quite so easy.).

The inter-municipal and regional collaboration between neighbouring communities have definitely improved, as a result of the project-related communication (which might be taken as a positive side effect along the lines of other general EU objectives).

The effectiveness of the dissemination activities was proven by an unexpected institutional success: Following the participation of a number of workshops, open-door-days, guided visiting tours around the IWPM-demonstration facilities, citizens, municipal experts and members of the municipal council of a neighbouring town named Bohmte (not yet included in the EU-Life IWPM-Project) became interested, convinced and even enthusiastic about the economic and ecologic perspectives of IWPM. Following presentations from the IWPM-team and exhaustive discussions of alternative options, the Council decided that the City of Bohmte should join the WVW - Water and Wastewater Utility of Bad Essen and - as a member of this now integrated water management association consisting of three, instead of only two, sewage treatment plants, become the third catchment area and wastewater treatment plant to be connected with the existing two within the IWPM-system. This turned out to be easily done, as Bohmte is located not far away from the track of the PCC, connecting STP1 and STP2.

6. Analysis of Long-Term Benefits

The environmental benefits and long-term sustainability as well as the replicability, demonstration, transferability and co-operation have been unchanged, compared to what has been described in the project application and EU project contract.