Hành vi của các kim loại nặng trong đất: Hiệu lực của vật chất hữu cơ hòa tan Ô nhiễm kim loại nặng của đất đã nhận được nhiều sự chú ý đối với thực vật hấp thu, suy thoái của hệ sinh thái vi sinh vật đất, và ô nhiễm nước ngầm hoặc nước bề mặt (Cunningham et al, 1975;. Riekerk và Zasoski, 1979). Tăng thuốc trừ sâu, chất thải đô thị như từ chối, thành phố trực thuộc Trung ương và bùn thải và chất thải động vật trên đất nông nghiệp hoặc vườn cây ăn trái đã dẫn. | 10 Behavior of Heavy Metals in Soil Effect of Dissolved Organic Matter Lixiang X. Zhou and . Wong CONTENTS Introduction Fractionation and Characterization of DOM DOM Sorption in Soil DOM Biodegradability DOM Effect on Heavy Metal Sorption in Soils Metal Dissolution as Affected by the Origin and Concentrations of DOM Metals Bio-Availability as Affected by DOM Summary Conclusions Future Research Needs References INTRODUCTION Heavy metal contamination of soils has received much attention with regard to plant uptake deterioration of soil microbial ecology and contamination of groundwater or surface waters Cunningham et al. 1975 Riekerk and Zasoski 1979 . The increased application of pesticides urban wastes such as municipal refuse and sewage sludge and animal wastes on farmland or orchards led to heavy metal accumulation in soils. Cu concentrations of as high as 1000 mg kg in poultry litter and pig manure were not uncommon due to the supplement of Cu in animal feed as a common practice for many years Van der Watt et al. 1994 Giusquiani et al. 1998 . In many orchard soils especially for the well-aged orchard the Cu level has exceeded more than 300 mg kg due to the application of Bordeaux mixture as 2003 by CRC Press LLC pesticide for decades Aoyama 1998 . The application of organic wastes such as animal manure crop residues green manure and forest residues is very common practice to provide nutrients and to improve soil physical properties in many countries. In China the practice of land application of farmyard manure can be traced back 2000 years which effectively maintains high soil fertility and productivity. It is generally considered that these materials can immobilize metals by sorption of metal in particulate organic matter which reduces the metal bioavailability in the contaminated soil. However the effectiveness of in situ immobilization of metals by organic wastes depends on the origins and .
