Device for water treatment

Ref-Nr: TDO0047

Device for treating urea-containing water

Technology abstract

An International organization is offering an installation for the treatment of urea containing water. Such device can be used for livestock accommodation but also for domestic toilets. It includes a nitrification and filtering unit. The purification and decontamination process of the urea-containing water can be carried out efficiently and cheaply. The system can be used for water recycling from urine waste in houses, hotels, campers and as a waste water plant for large infrastructures.

Technology Description

In densely populated areas and in farms, the purification of domestic waste water or animal excreta is an exceptionally costly and time-consuming process. The component of waste water that is difficult to remove is the urea (NH2CONH2) or salts of urea. As a matter of fact it is important to reduce the urea content not only to reduce environmental problems but also because it generates undesirable odours in the form of ammonia, and it also enhances the growth of algae. An International organization is offering an installation for the treatment of water containing urea. Such device can be used for livestock accommodation but also for domestic toilets. The device includes:
• Nitrification unit: this is adapted to oxidize urea to nitrate and carbon dioxide and it includes an oxygen feed, a gas discharge and a throughfeed to feed the waste water;
• Filtration unit: suitable filters are commercially available and comprise ultrafiltration and nanofiltration membranes and reverse osmosis membranes.

Innovations & Advantages

The main advantages of the proposed technology include:
• The proposed device system is innovative while it is composed by a combination of mature technologies thus it is easy to build a prototype and cost effective.
• The technology is useful not only for the purification of human waste but also for the purification of manure waste due to the large amount of urine in this kind of waste.
• Under the oxidizing conditions in the nitrification unit, other organic substances are also oxidized to carbonates/carbon dioxide. The water from the outfeed is re-usable for high-grade applications after nitrification and filtration. Depending on the types of filter used, even human consumption is possible with some further processing to optimise the taste
• The filters are easy to remove for periodic inspection of the residues. They can be replaced or cleaned after a period of time in order to prevent fouling or blockage.

Further Information

The proposed technology provides a device for treating urea-containing water and it includes an inlet which is connected to a nitrification unit adapted to oxidize urea to nitrate and carbon dioxide. The filtration unit is connected to the nitrification one and is provided with at least an outfeed for water purified by the nitrification and the filtration units. Using this device, it is possible to reduce in a simple way, or even fully remove, the urea content in water. For the transport of the liquid between different components, other transport means can be arranged within the device, such as for example one or more pumps to be connected to the infeed, throughfeed and /or outfeed. The best method for the nitrification unit is to use nitrifying bacteria which are able to perform the nitrification reaction steps in an efficient way maintaining a very compact structure for the device. The nitifying unit comprises a bioreactor but it can also include other micro-organisms and optionally chemical, electrical and or mechanical supports. All the components used for the proposed device are commercially available and proven.

Current and Potential Domains of Application

The proposed technology was originally developed for a water recycling unit to test in full-scale the research facility Concordia station in Antarctica which was opened in 2005. The water recycling unit was based on membrane technology. At an industrial scale the proposed technology can be considered as a product itself, as it can be built as a completely functioning remediation system/plant. The technology can be applied in all issues related to the purification and decontamination of waste water, especially urban waste water. It could be also used, in a small scale, as a system for water recycling from urine waste in houses, hotels, campers and in a big scale as a waste water plant for large companies or infrastructures (e.g. airports) or in highly populated areas. Also for the purification of manure waste, this technology can be useful due to the large amount of urine generated by this kind of waste.