Alva A K, Baugh T J, Paramasivam S, Sajwan K S
USDA-ARS, Vegetable and Forage Crops Research Unit, 24106 North Bunn Road, Prosser, WA 99350, USA.
J Environ Sci Health B. 2005;40(4):687-96. doi: 10.1081/PFC-200061601.
Organic amendments are sometimes applied to agricultural soils to improve the physical, chemical, and microbiological properties of the soils. The organic fractions in these soil amendments also influence metal reaction, particularly the adsorption and desorption of metals, which, in turn, determine the bioavailability of the metals and hence their phytotoxicities. In this study, a Quincy fine sandy (mixed, mesic, Xeric Torripsamments) soil was treated with 0 to 160 g kg(-1) rates of either manure, sewage sludge (SS), or incinerated sewage sludge (ISS) and equilibrated in a greenhouse at near field capacity moisture content for 100 days. Following the incubation period, the soil was dried and adsorption of copper (Cu) was evaluated in a batch equilibration study at either 0, 100, 200, or 400 mg L(-1) Cu concentrations in a 0.01M CaCl2 solution. The desorption of adsorbed Cu was evaluated by three successive elutions in 0.01M CaCl2. Copper adsorption increased with an increase in manure rates. At the highest rate of manure addition (160 g kg(-1) soil), Cu adsorption was two-fold greater than that by the unamended soil at all rates of Cu additions. With increasing rates of Cu additions, the adsorption of Cu decreased from 99.4 to 77.6% of Cu applied to the 160 g kg(-1) manure amended soil. The desorption of Cu decreased with an increase in rate of manure amendment. Effects of sewage sludge amendments on Cu adsorption were somewhat similar to those as described for manure additions. Likewise, the desorption of Cu was the least at the high rate of SS addition (160 g kg(-1)), although at the lower rates there was not a clear indication of the rate effects. In contrast to the above two amendments, the ISS amendment had the least effect on Cu adsorption. At the highest rate of ISS amendment, the Cu adsorption was roughly 50% of that at the similar rate of either manure or SS amendments, across all Cu rates.
有时会向农业土壤中添加有机改良剂，以改善土壤的物理、化学和微生物性质。这些土壤改良剂中的有机成分也会影响金属反应，特别是金属的吸附和解吸，而这反过来又决定了金属的生物有效性及其植物毒性。在本研究中，用0至160 g kg(-1)的粪肥、污水污泥（SS）或焚烧污水污泥（ISS）处理昆西细砂质（混合、中性、旱生干砂质新成土）土壤，并在温室中以近田间持水量的湿度平衡100天。培养期过后，将土壤干燥，并在0.01M CaCl2溶液中，于0、100、200或400 mg L(-1)的铜浓度下进行批量平衡研究，评估铜（Cu）的吸附情况。通过在0.01M CaCl2中连续三次洗脱来评估吸附铜的解吸情况。铜的吸附量随着粪肥施用量的增加而增加。在粪肥添加量最高（160 g kg(-1)土壤）时，在所有铜添加量下，铜的吸附量比未改良土壤高出两倍。随着铜添加量的增加，在160 g kg(-1)粪肥改良土壤中，铜的吸附量从施入铜量的99.4%降至77.6%。铜的解吸量随着粪肥改良剂施用量的增加而减少。污水污泥改良剂对铜吸附的影响与粪肥添加的情况有些相似。同样，在高污水污泥添加量（160 g kg(-1)）时，铜的解吸量最少，尽管在较低添加量时，没有明显的添加量效应迹象。与上述两种改良剂相反，焚烧污水污泥改良剂对铜吸附的影响最小。在焚烧污水污泥改良剂的最高添加量下，在所有铜添加量水平上，铜的吸附量约为粪肥或污水污泥相似添加量时的50%。
