tailieunhanh - Applications of Environmental Aquatic Chemistry: A Practical Guide - Chapter 6

Tổng Tài sản của chất lỏng pha Nonaqueous và hành vi của chất lỏng giai đoạn nhẹ Nonaqueous trong dưới bề mặt 6,1 Các loại và tính chất của chất lỏng pha NONAQUEOUS Theo Để Hoa Kỳ Cơ quan Bảo vệ Môi trường (EPA) (USEPA, 2004), như của 30 tháng 9 2003 có hơn 439,000 phiên bản rò rỉ bồn chứa dưới lòng đất (Lust) đã được báo cáo trên toàn quốc. Được khởi xướng đã dọn tại hơn 403,000 của Những trang web này, và các trang web có hơn 303,000 Been sạch lên. Những tồn đọng của các trang web. | 6 General Properties of Nonaqueous Phase Liquids and the Behavior of Light Nonaqueous Phase Liquids in the Subsurface TYPES AND PROPERTIES OF NONAQUEOUS PHASE LIQUIDS According to the . Environmental Protection Agency EPA USEPA 2004 as of September 30 2003 more than 439 000 releases from leaking underground storage tanks LUSTs have been reported nationwide. Cleanups have been initiated at more than 403 000 of these sites and more than 303 000 sites have been cleaned up. The backlog of sites still to be cleaned up is more than 136 000. The majority of these LUSTs contained petroleum hydrocarbons which are a mixture consisting mainly of compounds having very low solubilities in water. Petroleum hydrocarbons and their components are commonly called nonaqueous phase liquids NAPLs . This chapter and Chapters 7 and 8 are an introduction to understanding the environmental behavior of these important pollutants. NAPLs are nonpolar or low-polarity liquids that are minimally soluble in water. Gasoline and diesel fuels oils chlorinated solvents and pesticides are examples. In contact with water nonpolar liquids do not dissolve appreciably in water but remain as separate immiscible liquid phases called NAPLs. NAPL substances are comprised of molecules that are nonpolar or weakly polar and therefore have only weak attraction to polar water molecules but relatively strong London force attraction to other NAPL molecules see Chapter 2 Section . Therefore NAPLs are not very soluble in water and if mixed into water separate into a distinct liquid phase with a well-defined boundary between the NAPL and the water that is usually visually observable. The boundary interface is a visible physical dividing surface between the bulk phases of the two liquids. Many NAPLs are mixtures of different hydrocarbon compounds with varying low solubilities. The phase boundary does not prevent compounds within the NAPL from 2007 by Taylor Francis Group LLC. dissolving into the water. Over .