Project Background

Utah is one of the driest states in the United States, with 90% of its 54 million acres being extremely dry. The groundwater in South Jordan City, Salt Lake County, Utah is contaminated by tailings, so there is no drinking water source in the area. Most of the city's drinking water is purchased from water suppliers in the Uintah Mountain and Provo River regions. The Utah government has funded the DPR demonstration project to test the feasibility of implementing the DPR program locally in the future. The demonstration plant will operate for 3 to 5 years, providing a reference framework for the formal implementation of the future DPR plan.

The water source for the DPR demonstration project is the treated wastewater from the South Valley Sewer system. The DPR demonstration plant adopts advanced process combinations to achieve high water quality goals and successfully implements a robust wastewater treatment process with multiple barriers and decontamination methods. The demonstration plant consists of five different process parts, namely Ozonation, Biologically Active Filter (BAF), Ultrafiltration (UF), Granular Activated Carbon (GAC), and UV Disinfection.

After undergoing ozone oxidation treatment, the influent filtrate from the membrane bioreactor enters the advanced treatment process section. Ozone is a strong oxidant that can decompose organic pollutants. After the ozonation process, there is a biologically active filtration process that provides growth media for organisms and further decomposes pollutants. The ultrafiltration process filters out microorganisms, while the granular activated carbon treatment process adsorbs residual trace pollutants. The final step of the DPR demonstration project is the ultraviolet disinfection process, which can effectively eliminate pathogens in water.

challenge

The success of the DPR plan depends on the public's acceptance and opinions on DPR. Due to the general lack of public awareness of DPR, it is necessary to spend time explaining knowledge about wastewater reuse and purification treatment to the public. The future success of the DPR demonstration project largely depends on decision-making based on monitoring data, so project engineers face the challenge of how to continuously monitor the organic pollutant content in the process in real time. The purpose of wastewater treatment technology is to remove organic pollutants that are harmful to human health and environmental damage from source water and wastewater. Therefore, it is crucial to have a set of easy-to-use and reliable water quality monitoring methods, among which the most important is to be able to understand and measure the organic content in the water during the initial and subsequent processes.

Solution

The DPR demonstration plant in South Jordan, Utah uses total organic carbon measurements as the main Key Process Indicator (KPI), therefore requiring the use of a TOC analyzer that can flexibly measure sample streams of multiple different water qualities. In order to meet the monitoring requirements, the demonstration factory selected the Sievers M5310 C TOC analyzer, which uses membrane conductivity (MC) detection and ultraviolet persulfate oxidation technology. Figure 2 shows the overall process flow diagram and various process parts of the demonstration plant.

Perform TOC monitoring at the beginning of the DPR process. Closely monitor the wastewater entering the DPR demonstration plant from the wastewater treatment plant, and adjust the deep treatment process based on the monitoring results. Perform TOC monitoring again after the biological activity filtration process to ensure the removal rate of pollutants. After the UV disinfection process, the final water quality can be determined through TOC analysis.

Conclusion

Many regions are facing the problem of drinking water shortage, and innovative solutions such as the DPR project are a better choice for improving local drought resistance and independent water supply in the future. With this strict water quality monitoring system, water treatment plants can make decisions based on monitoring results and use accurate and reliable monitoring data to eliminate public distrust of new drinking water sources such as DPR. The TOC analysis method for monitoring organic matter is a simple and powerful approach that can be used to optimize processes, ensure water quality, and meet regulatory requirements. South Jordan City has chosen the Sievers M5310 C analyzer to successfully demonstrate the feasibility of the DPR project and provide a reference framework for future such projects, thereby providing sufficient safe and affordable drinking water for the local community.

References

[1]:Whotcott,G.,&Rasmussen,J.(2019,July 29). South Jordan City–DPR Demonstration Project. Arizona Reuse Symposium. Symposium conducted at the meeting of Water Reuse Arizona&AZ Water Association,Flagstaff,AZ.