tailieunhanh - Practical Design Calculations for Groundwater and Soil Remediation - Chapter 3

Plume di cư trong nước ngầm và đất Trong chương hai, chúng tôi minh họa các tính toán cần thiết cho trang web đặc điểm và điều tra khắc phục hậu quả. Nói chung, từ các hoạt động RI, mức độ của chùm trong khu vực vadose và / hoặc nước ngầm được xác định. Nếu các chất gây ô nhiễm không thể được gỡ bỏ ngay lập tức, họ sẽ di chuyển theo điều kiện thực tế phổ biến và mức độ của chùm sẽ mở rộng. Trong khu vực vadose, các chất gây ô nhiễm sẽ di chuyển xuống. | Kuo Jeff Plume migration in groundwater and soil Practical Design Calculations for Groundwater and Soil Remediation Boca Raton CRC Press LLC 1999 chapter three Plume migration in groundwater and soil In Chapter two we illustrated the necessary calculations for site characterization and remedial investigation. Generally from the RI activities the extent of the plume in the vadose zone and or groundwater is defined. If the contaminants cannot be removed immediately they will migrate under common field conditions and the extent of the plume will enlarge. In the vadose zone the contaminants will move downward as a free product or become dissolved in infiltrating water and then move downward by gravity. The downward-moving liquid may come in contact with the underlying aquifer and create a dissolved plume. In addition the VOCs will volatilize into the air void of the vadose zone and travel under advective forces with the air flow or concentration gradients through diffusion . Migration of the vapor can be in any direction and the contaminants in the vapor phase when coming in contact with the groundwater may also dissolve into the groundwater. For site remediation or health risk assessment understanding the fate and transport of contaminants in the subsurface is important. Common questions related to the fate and transport of contaminants in the subsurface include 1. How long will it take for the plume in the vadose zone to enter the aquifer 2. How far will the vapor contaminants in the vadose zone travel In what concentrations 3. How fast does the groundwater flow In which direction 4. How fast will the plume migrate In which direction 5. Will the plume migrate at the same speed as the groundwater flow or at a different speed If different what are the factors that would 1999 CRC Press LLC make the plume migrate at a different speed from the groundwater flow 6. How long has the plume been present in the aquifer This chapter illustrates the basic calculations needed to .