A low-cost water re-use infrastructure has been designed to transfer treated wastewaters from industrial areas to companies that can make use of the streams.
Within Valencia, industrial areas exist in a variety of forms:
Mono-sectoral industrial parks (textiles, footware, agri-food, ceramic, automotive industries), and multisectoral.
Analysis of different projects shows that water used by companies can be classified in to five groups:
- High mineralisation water
- Ground water / tap water
- Decalcified water
- Partial demineralised water
- Completely demineralised water
PROECO (a project involving seven technical institutes throught the region) developed a three level filtration system that was based on these five levels while also having regard for the availability of significant amounts of wastewater through the industrial zones together with the number of companies located in the industrial zones. The three levels of the filtration system are:
- Removal of suspended solids using a filter 1-100micrometer
- Removal of colloidal and macromolecular particles using a filter 0,01-1 micrometer
- Partial demineralisation using nanofiltration and reverse osmosis
As each step leads to a greated level of purity, they provide the different grades of water that can be utilised by different industrial sectors. The developed methodology includes a water audit and diagnosis of water use (annual volume needed, water specification, process using water, etc) that must be completed for each industrial area.
Infrastructure of filtration and distribution of the treated water would be managed by an industrial management body.
The cost of treatment without the distribution costs associated would be around 1.5€/m3/hour processed.
Involvement of the main stakeholders linked to an industrial area such as: town councils, entities managing industrial areas, wastewater facilities, large water users, existing infrastructure
Evidence of success
Valencian Community (CV) has around 500 industrial parks and more than 25000 companies, some of industrial areas in the region have used a partial approach based on the PROECO development to implement water re-use systems.
The regional ministries of industry and environment are currently designing pilot scale projects based on PROECO as part of their promotion of circular economy policies on industrial areas.
The techniques are proved as a good solution in areas of water scarcity
Depending on the type of industrial area and the companies present (such as textile or agrifood), chemical oxygen demand (COD) levels may be high. In such cases, tertiary treatment such as ion exchange or dissolved air flotation may be required.
Potential for learning or transfer
Principle elements that make the PROECO solution attractive would be high water costs and discharge regulations.
The creation of a methodology and standardised feasibility study that could act as a pre-project analysis, identifying industry and infrastructure within industrial areas would be an advantage. Case studies of successful implementation should be developed.
Pilot trials of the PROECO approach will be carried out in industrial areas by the regional environment ministry of Valencian Community. Once implemented, the additional infrastructure would be an added value proposition for industrial areas.
If the treatment requirements were implemented at existing wastewater treatment facilities, the initial cost could be decreased further.
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