Drinking Water Disinfection in Amman, Jordan
TrojanUV Solutions

The Zai Water Treatment Plant in Amman, Jordan was required to install UV treatment to treat Cryptosporidium and Giardia.

Cryptosporidiosis is a gastrointestinal disease caused by species of parasitic protozoa called Cryptosporidium. Several species of Cryptosporidium exist in nature. However, water-borne illness is generally caused by Cryptosporidium parvum or Cryptosporidium hominis.

During the oocyte spore phase of this pathogen’s life-cycle, individual oocysts are capable of surviving for long periods of time outside a host organism and can survive in water. When ingested by a host, symptoms of infection can include gastrointestinal upset and fever. Immuno-compromised are at particular risk and infection in such individuals can result in death.

UV light passing the cell wall and damaging the genetic material of a pathogen
Figure 1. UV light passing the cell wall and damaging the genetic material of a pathogen.

Cryptosporidium is a threat to public health due to the resistance of oocysts to chlorine-based disinfection methods. Many jurisdictions have put regulations in place to ensure both efficient monitoring of surface waters, and installation of additional treatment barriers at treatment plants that detect Cryptosporidium.

Disinfection Of Cryptosporidium With UV Technology

Cryptosporidium oocysts are resistant to chlorine due to thick walls surrounding their intra-cellular structure. However, UV can penetrate these walls (Figure 1) and damage the genetic structure (DNA) in the cells, rendering the organism incapable of multiplying and causing infection. This method of disinfection is commonly referred to as inactivation.

UV treatment is expressed in terms of UV dose and it is recognized that a UV dose of 40 mJ/cm2 results in greater than 4-log (99.99%) of most pathogens including Cryptosporidium

Bioassay Validation

Calculating UV dose can be done in several ways. Bioassay validation (Figure 2) is one example of UV system performance testing in which UV dose is measured by taking samples of live microorganisms both before and after exposure to UV-light through the UV system undergoing testing.

Several internationally-recognized approaches for bioassay validation exist, and testing UV systems using live microorganisms in this manner ensures that any internal components of a UV system which might influence UV dose delivery are taken into account when evaluating how a UV system performs.

Installation: Zai Water Treatment Plant, Amman, Jordan

The King Abdullah Canal is the primary source of drinking water for Amman. It receives its water from Lake Tiberias (also known as the Sea of Galilea) and the Yarmouk River.

The TrojanUVSwift installation at the Zai Water Treatment Plant

Over 100 kilometers long, the canal is uncovered and exposed to run-off. It was classified by the Jordan Ministry of Health as a Category 3 Water Source. The Zai Water Treatment Plant, which takes raw water from the canal, was required by the Ministry to install UV treatment to treat Cryptosporidium and Giardia (another potential pathogen) as a result of this Category 3 classification.

Miyahuna Water operates the Zai Water Treatment Plant. During the design of the UV treatment installation at Zai, Miyahuna recognized that using UV systems that have been pre-validated through bioassay testing was the best way to ensure reliable UV dose delivery.

UV disinfection system undergoing performance evaluation through bioassay testing
Figure 2. UV disinfection system undergoing performance evaluation through bioassay testing.

As a result, Miyahuna purchased four TrojanUVSwift™ UV disinfection systems. These systems were pre-validated using bioassay guidelines published by the United States Environmental Protection Agency (USEPA), to deliver a bioassay proven UV dose of 40 mJ/cm2.

This level of treatment was selected for the Zai facility, as well as two additional treatment plants operated by Miyahuna Water to provide a 3-log inactivation of Cryptosporidium.

UV, an Attractive Option for Drinking Water Disinfection

UV disinfection is an attractive option for drinking water disinfection and should be evaluated as a barrier to pathogens by water treatment plants trying to reduce dependence on chlorine disinfection or trying to treat chlorine-resistant pathogens such as Cryptosporidium.

UV systems pre-validated using globally-recognized bioassay guidelines deliver the most reliable UV treatment. For the Zai Water Treatment Plant and other treatment facilities operated by Miyahuna Water, the delivery of a UV dose of 40 mJ/cm2 was considered suitable for a greater than 3-log removal of Cryptosporidium for the city of Amman.

Details of Miyahuna Water UV Installations in Jordan

Treatment PlantsTreatment DetailsTrojanUV System Installed
Zai WTP• Peak Design Flow: 12,240 m3/hr
• Delivered UV Dose: 40 mJ/cm2
• UV System: TrojanUVSwift™ 6L24
• Number of UV Systems: 4
Ras Al Ain WTP• Peak Design Flow: 500 m3/hr
• Delivered UV Dose: 40 mJ/cm2
• UV System: TrojanUVSwift™SC D12
• Number of UV Systems: 2
Ruseifah WTP• Peak Design Flow: 287 m3/hr
• Delivered UV Dose: 40 mJ/cm2
• UV System: TrojanUVSwift™SC D06
• Number of UV Systems: 3