The Research About The Main Factors Which Effect On The Eluviation Of Heavy Metals In The Soil

The effect of rainfall, pH, nitrogen, phosphate on the leaching loss of Pb, Zn, Cd, As in the soil had been researched through leaching column simulation experiments and the effect of rainfall&vegetation and phosphorus&vegetation on the leaching loss of Pb, Zn, Cd, As in the soil been researched through the pot experiments. The principal results are as follows:In the same rainfall, the concent and total of the Pb, Zn, Cd in the leaching liquor was decreases gradually with the increased of the rainfall pH value, however, the concent and total of the As in the leaching liquor was increased gradually at the same time.The concent of the Pb, Zn, Cd in the leaching liquor was decreases gradually with the increased of the rainfall at the same rainfall pH value. However the total of the Pb, Zn, Cd in the leaching liquor had different variety rule with the increased of rainfall in different rainfall pH value.The total of the Pb, Zn, Cd in the leaching liquor was increased obvious with the increased of rainfall when the rainfall pH value was 3.0 and 4.5. While the total of the Pb in the leaching liquor was increased obvious with the increased of rainfall when the rainfall pH value was 5.3 and it has no change when the rainfall pH value was 7.0.Meanwhile, when the rainfall pH value was 5.3 and 7.0, the total of the Zn, Cd in the leaching liquor was increased obvious with the increased of rainfall when the rainfall was small and it had no change when the rainfall was large.There had no change about the concent of the As in the leaching liquor as the rainfall, while the total of the As in the leaching liquor was increased obvious with the increased of rainfall.The total of Pb leaching from the soil was more when there was no phosphorus or little Phosphorus, and it was decreases gradually with the increased of phosphorus usage, however it was no more change when the phosphorus usage great to a certain degree. The total of Zn leaching from the soil was salutatory increased with the increased of phosphorus usage. The total of Cd and As leaching from the soil was increased gradually with the increased of phosphorus usage, and the effect of the phosphorus usage was decreases gradually,The effect of the nitrogen usage on the leaching loss of Pb in the soil was not clear. The total of Zn and Cd leaching from the soil was decreases gradually with the increased of the nitrogen usage when some time later.When we plant rice in the pot for research, we found the follows results. When the rainfall was 20mm, the total of Pb leaching from the soil was less than it was 5.7mm,while the total of Zn, Cd and As leaching from the soil was more than it was 5.7mm. The total ofPb, Cd and As leaching from the soil was decreases gradually with the increased of the planting density of the rice. When the rainfall was 5.7mm, the total of Zn leaching from the soil has no obvious change. When the rainfall was 20mm, the total of Zn leaching from the soil was larger at no planting than little planting or densitily planting.When we plant pakchoi in the pot for research, we found the follows results. The concent of the Pb, Cd in the leaching liquor has no rules, and it need more research. When the rainfall was 20mm, the total of Zn leaching from the soil was no obvious change with the increase of the planting density. When the rainfall was 50mm or 80mm, the total of Zn leaching from the soil was increased at little planting and it was decreased at densitily planting.The total of As leaching from the soil was increased with the increased of the rainfall at the same planting density. When the rainfall was 20mm, the total of As leaching from the soil was no obvious change at the different planting density. When the rainfall was 50mm or 80mm, the total of As leaching from the soil was larger at no planting than it was planting.When we plant pakchoi in the pot for nitrogen research, we found the follows results. Urea had no obvious effect on the leaching loss of Pb in the soil. The total of Pb, Zn, Cd and As leaching from the soil was some increased with the increased of the nitrogen usage when it was no planting. With the increased of the nitrogen usage, the total of Zn and As leaching from the soil was obvious increased while the total of Cd was decreased when it was little planting. When it was densitily planting, the total of Zn, Cd and As leaching from the soil was much smaller at use nitrogen than no nitrogen.