Extraction of energy and raw materials from waste water The re-use of waste water and closure of the water chain are becoming increasingly important. Partly due to the shortage of fresh water and partly due to the sustainability objectives of our customers. By definition, the re-use of waste water involves customisation and an integrated technological approach. In some cases, it is also possible to extract energy and valuable raw materials from the waste water.
During anaerobic water purification, which is mainly used to treat highly concentrated organic waste water flows, bacteria convert organic substances in the water into biogas in the absence of oxygen. The methane in this biogas can then be used as a sustainable source of energy for electricity and heat production.
The extraction of raw materials, such as phosphate, from waste water is also one of the possibilities. Evides Industriewater has the knowledge and experience to ensure that these sustainable processes work optimally for you. Contact us free of obligation to arrange a meeting with one of our account managers.
RINEW: re-use of nutrients, energy and water from waste water
Many valuable raw materials can be recovered from waste water, such as water, paper fibres and phosphate. In the future, perhaps also zinc and gold. RINEW, which stands for Rotterdam Innovative Nutrients Energy and Water management, is a research study into the re-use of nutrients, energy and water originating from waste water in an innovative and sustainable way. RINEW is focused on waste water purification in urban areas, where the recovered raw materials are sold locally, where possible.
Working together in the water chain
RINEW began as a joint research project of Delfland Water Board, Hollandse Delta water authority, Rotterdam City Council and Evides Water Company. The Water Board of Schieland and Krimpenerwaard (HHSK) has now also announced that it wishes to take part in RINEW. RINEW is also one of the model projects in the Rotterdam Cooperation Waste Water Chain (RoSA).
Usable/re-usable results In order to realise a water, energy and raw material factory, the first step involves reducing or extracting water from the rough sewer water or from grey water. This is also called sewer mining or water mining. It has two aims: to produce a flow of sludge that can be fermented properly and a water flow that can easily be upgraded to a high quality.
Ceramic nano-filtration The technique that can be used for this first separation is called ‘ceramic nano-filtration’. Fine-screening is used as a pre-treatment method to prevent blockages of the nano-filtration. The material that is collected with the fine-screening contains a huge amount of paper fibres from toilet paper. This can also be made suitable for different recycling applications.
Stable operational management The challenge is to achieve stable operational management of the ceramic nano-filtration, in which particularly the control of membrane contamination is an important aspect. The plant has been operating stably since March 2015. It was discovered that contamination of the membranes can be effectively controlled using chemical cleaning.
In the time to come, the research will focus on optimising the ceramic nano-filtration (reducing the consumption of energy and chemicals and increasing the production of clean water), phosphate recovery and a fermentation step for the production of biogas (energy).
Sustainable Airport Cities. A unique trial for phosphate extraction at Schiphol Airport
With Amsterdam Airport Schiphol, Vewin and KWR Watercycle Research, Evides Industriewater is working on a unique project to extract phosphate from waste water: Sustainable Airport Cities. Phosphate is an increasingly scarce raw material that is used in the production of food. The extraction of phosphate from waste water is not only good for the environment, it also saves costs and is creating a unique cooperative relationship between the water sector and the aviation sector.
Phosphate: an indispensable raw material
Phosphate is indispensable as an important raw material for food production to enable humans, plants and animals to grow. However, the stock of phosphate is diminishing due to the increasing global need for food. In addition, a huge amount of phosphate is wasted due to the excessive use of fertilisers and the failure to extract phosphate from waste water. Europe does not have any phosphate mines and is dependent for its phosphate on countries in the Western Sahara, for example. The recovery and re-use of phosphate is therefore vitally important for the Netherlands and Europe.
The water cycle
The water cycle at Schiphol is comparable to that of a small city. This is therefore a good location for a pilot project for the sustainable recovery and recycling of phosphate. The extraction of phosphate from waste water improves the water quality in and around the airport. The purification process is becoming more and more efficient and fewer auxiliary substances such as chemicals are required.
The extracted phosphate is distributed in the surroundings of Schiphol – for example, to farmers. They can use the phosphate as chemical fertiliser and at the same time assess the sales product. The researchers then use the results as input to further improve the technologies and adapt them to the end user. This strengthens the economic feasibility of this method.
City of the future
The Sustainable Airport Cities project is aimed at motivating other sectors to help each other make their activities sustainable. This can be done using innovative technology from the water sector. For example, if hospitals, the administrators of frequently visited public buildings and other airports and cities adopt this initiative, many benefits can be expected in the future.
Sustainable Airport Cities is one of the first projects that has been launched in the framework of the Government’s top sector policy and is partly financed by the surcharge for Top Consortiums for Knowledge and Innovation (TKIs) by the Ministry of Economic Affairs. The Ministry has created nine top sectors in order to make concrete proposals to strengthen the competitive position of the Netherlands.