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Resource recovery

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We are facing a great challenge to deal more intelligently and responsibly with raw materials. That includes raw materials contained in sewage.

Wastewater is often considered a dirty and unpleasant substance, but it contains a range of valuable raw materials that can be recovered and reused for various applications. Resource recovery from wastewater is a process by which useful materials are extracted from wastewater and sewage sludge and converted into valuable products such as fertilizers, biogas and clean water.

This has many benefits, including environmental sustainability, cost savings and reduced pressure on natural resources

Cellulose Recovery

Cellulose is a natural polymer found in plant cell walls and is the most abundant organic material on earth. It has many industrial applications, including in the production of paper, textiles and biofuels. Cellulose can also be recovered from wastewater and sewage, where it is present in the form of fibrous solids.

After use, toilet paper is flushed down the toilet and enters sewage treatment. Here it is partially converted and the remainder is sent to an incinerator or to a landfill. This is a shame, we are throwing away a valuable resource!

What if this can be done differently?

When we can recover raw materials from our sewage, the amount of waste that ends up in landfills or is discharged into the environment is reduced. Also, these raw materials become reusable and thus we can make new products from them. In addition, we can reduce pressure on natural resources and promote a more circular economy.

benefits

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A few benefits of resource recovery at a glance:

Cost savings: 
Resource recovery from wastewater can be cost-effective because it reduces the need for costly waste disposal and can generate revenue from the sale of recovered resources.

Energy independence:
Biogas from anaerobic digestion of sewage sludge can be used as a renewable energy source, reducing our dependence on fossil fuels and promoting energy independence.

Water conservation:
Reuse of treated wastewater for various uses can help reduce pressure on freshwater resources and promote water conservation.

Climate change mitigation:
Resource recovery from wastewater can also help mitigate climate change by reducing greenhouse gas emissions from waste disposal and fossil fuel consumption.

Cirtec and resource recovery

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CirTec focuses on recovering cellulose from sewage

Some numbers:

The recovery of cellulose from wastewater and sewage offers several advantages, such as reducing the amount of waste going to landfills and producing a valuable raw material that can be used in various industries.

Reducing waste: 
Recovering cellulose from sewage reduces sludge growth and with that significantly reduces the amount of waste going to landfills or being incinerated.

Producing a valuable resource: 
Cellulose recovered from sewage can be used in various industries, including paper and pulp, textiles and biofuels.

Improving sewage treatment: 
Recovering cellulose from sewage can improve the efficiency of sewage treatment plants and reduces the amount of organic matter in treated wastewater.

Promoting sustainability:
Recovering cellulose from sewage can help promote a more sustainable and circular economy.

With technological advances, cellulose recovery from sewage is becoming increasingly efficient and cost-effective, making it a viable option for various industries. By embracing cellulose recovery from sewage, we can promote a more sustainable and circular economy and reduce our impact on the environment.

The Deployment of Inovative Technologies:

CellCap and CellPro

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Through the deployment of the CellCap and CellPro technology, cellulose is extracted from the sewage, after it has been stripped of other pollutants that we encounter in the sewer. Thus, the cellulose (base material of toilet paper), for which trees were cut down, is given a second life after a one-time use!

The origins for this method of resource recovery lie a few years in the past. For the development of a certain type of water treatment, a membrane bioreactor (MBR), a requirement was to greatly reduce the amount of incoming suspended solids to prevent the membranes from clogging. At that time, several methods of suspended solids removal were compared, including rotary belt (fine sieve) technology. As a result of those comparative tests, this technology was then introduced in the Netherlands.

Sewage treatment plants

The first CirTec fine sieve installations were then built, however, not for MBR plants, but for the more conventional wastewater treatment plants, for both municipal and industrial applications. 

Several studies were conducted at that time on the effects on the downstream treatment processes by the use of the CirTec IntenSieve, such as the effect on sludge growth, the aeration capacity, sludge volume index and the effect on final water quality.

After installing the technology, a close look at the separated material at a sewage treatment plant was taken and it was concluded that a large part of screenings consisted of fibrous material, toilet paper. The bycatch turned out to be cellulose, the main component of toilet paper. 

 

In addition to cellulose, screenings contain various other substances, such as seeds, pieces of vegetables, hairs, twigs and leaves, pieces of plastic, etc. If the cellulose is now to be used as a raw material, these contaminants must be removed from the screenings. For this purpose the CellCap has been developed, a combination of different sieving techniques with specific modifications as a result of which we have succeeded in removing the separated material in two different partial streams from influent of a sewage treatment plant. The first stream consists of the captured cellulose stripped of the vast majority of other solid particles other than cellulose. A second stream consists of the separated remaining particles, still called screenings.

The cellulose is dewatered, dried, hygienized and packaged and is ready for introduction to the market. Depending on market demand, further processing of the cellulose can be achieved (e.g. hammering in order to be able to offer the material as fluffy material, or compressed into pellets). For the second stream, studies on the fermentability of the material are currently taking place, with promising results.

In the Netherlands and Belgium, several municipal wastewater treatment plants are already equipped with the CirTec IntenSieve, although most were still supplied with the original intention of only capturing screenings to relieve the burden on the underlying treatment plant. Cellulose reprocessing is now making inroads in Europe. Pilot studies have been conducted in several countries and the first full-scale plants are operational or are under construction.

Industrial wastewater treatment plants

For industrial wastewater treatment plants, the focus is mainly on capturing suspended solids from the influent in order to relieve the downstream treatment and save costs, and less on recovering raw materials. But for these applications, it is conceivable to return the captured material to the cycle, or to offer it to digestors, for example, to make a useful contribution.

case studies

Stay in the Loop

17 April 2020 Stay in the LOOP Students at Berlin’s Fachhochschule Potsdam conducted research on the use, reuse and circular potential of toilet

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SMART Plant fact sheets

11 May 2020 SMART – Plant fact sheets As part of the Horizon2020 project SMART-Plant, fact sheets were prepared by Kompetenz Wasser Berlin

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Contact us

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Want to know more about what Cirtec can do for your company or organization? What are the possibilities to filter raw materials from your wastewater and reuse them, contact us or make an appointment in our calendar!