An east coast environmental consulting firm has been utilizing the YSI 600XL multi-parameter water quality sonde to aid in remediation of contaminated groundwater and soil. The sonde monitors pH, conductivity, dissolved oxygen, ORP, and temperature. Water quality data collected is used to monitor the cleanup effectiveness of an air sparging process.
Air sparging involves injecting oxygen into the contaminated groundwater. The presence of oxygen helps to remove semi-volatile aromatic hydrocarbon contaminants in the groundwater by expiditing biodegradation and volatilization. As oxygen passes through the groundwater, contaminants are carried from the saturated zone to the unsaturated zone and eventually exit as vapors. The benefit of this in-situ process is that remediation occurs in the soil, instead of stripping and cleaning the contaminants at another location.
Air sparging is essential, as it increases the rate of decomposition by microorganisms. As oxygen levels rise, the microbe’s ability to break down contaminants increases. The increased biodegradation ultimately translates into a faster remediation process.
The air sparging interval was set at two minutes during cleanup. Pure oxygen was injected into the soil, carrying contaminants to 16 different purging wells.
The YSI 600XL was vital in screening this process. Three sondes, each able to monitor conductivity, salinity, and dissolved oxygen, were placed downwell to monitor the remediation process’ success.
With the help of the 600XLs, the firm was able to ensure oxygen was spreading throughout the remediation zone and better understand how the procedure was affecting the groundwater’s quality. Since oxygen consumption directly correlates with contaminant levels, the data also helped the firm verify how much contamination was in certain areas.
The 600XL was chosen because of its unique ability to measure dissolved oxygen to levels as high as 50 mg/L without requiring sample movement. This was ideal, as the firm anticipated extremely high levels of oxygen. An additional YSI sonde with a flow cell was used to verify data accuracy.
The YSI sondes have been reliable, accurate, and easy to use, according to representatives from the firm. The YSI 600XL has enabled it to complete the project efficiently while ensuring complete ground and water remediation will occur.