tailieunhanh - Geochemical and Hydrological Reactivity of Heavy Metals in Soils - Chapter 3

Quan ngại về ô nhiễm kim loại nặng trong môi trường ảnh hưởng đến tất cả các các thành phần hệ sinh thái bao gồm cả các hệ thống thuỷ sản và trên mặt đất đã được xác định, với việc tăng sự chú ý đến hạn chế khả dụng sinh học của họ trong đất và nước ngầm. Khai thác mỏ kim loại, luyện kim, chế biến trên toàn thế giới đã bị ô nhiễm đất với các kim loại nặng trong vượt quá nồng độ nền đất tự nhiên. như vậy các hoạt động giới thiệu các chất ô nhiễm kim loại vào. | 3 A Web-Based Three-Dimensional Simulation System for Solute Transport in Soil Honghai Zeng Vladimir J. Alarcon William L. Kingery H. Magdi Selim and Jianping Zhu CONTENTS Introduction Three-Dimensional MRTM Model and ADI Method Three-Dimensional MRTM Model Boundary Conditions Three-Step ADI Method System Implementation Introduction Three-Dimensional Simulation System and Related Technologies Traditional Computing Model Web-Based High-Performance Computing Model J2EE Technologies Client Tier Web Tier Business Tier Resource Tier Results Conclusions Acknowledgment References 2003 by CRC Press LLC INTRODUCTION Concerns regarding heavy metal contamination in the environment affecting all ecosystem components including aquatic and terrestrial systems have been identified with increasing attention to limiting their bioavailability in the soil and groundwater. Metal mining smelting and processing throughout the world have contaminated soils with heavy metals in excess of natural soil background concentrations. Such activities introduce metal contaminants into the environment through gaseous and particulate emissions waste liquids and solid wastes. In addition to the soil contamination many mining and smelting sites have considerable surface water and groundwater contamination from heavy metals released and transported from contaminated soils. This contamination endangers water supply resources as well as the soil quality. Different processes including advection dispersion diffusion and adsorption work together or separately to determine the transport of contaminants in the groundwater. The movement of contaminants through the soil matrix to groundwater is primarily a liquid phase process Figure but the partitioning of the chemicals between sorbed and dissolved phases is a critical factor in determining how rapidly the contaminants leach Selim 1992 . The .