| Heavy metal contaminants in the soil with a long-term cumulative effects, poor mobility, long residence time, interaction, biodegradable, toxic and other characteristics, and its environmental effects related to soil, water, plants, animals and humans, once the soil polluted by heavy metals will be difficult to repair. Universal, long duration and refractory rational, hidden, complex nature, which are the four characteristics of lead contamination in soil. The pollution will be permanent when the water or soil is polluted by lead, and lead can be absorbed by terrestrial or enriched by aquatic organisms. It will cause great hurt to human health when lead enters the body and accumulates in the human body through the food chain.In this thesis, sorption of Pb(II) on soil was studied by batch technique and migration of Pb(II) in soil was also studied by soil column leaching experiment, the sorption and migration mechanisms were also discussed. It provided some reference to predict the behavior of environmental chemicals in the soil, and the effects of Pb (II) to environment; it is significance to guide the development of the environmental standards of soil and the use strategies of lead management; prevention of soil lead contamination hazards to humans occurs has important theoretical and practical significance.The sample of soil was characterized by using XRD, FTIR and Nitrogen adsorption desorption in detail.The sorption and migration behavior of Pb(â…¡) in soil were investigated as a function of shaking time, solid content, pH, ionic strength, humic acid (HA) and soil column thickness, leaching time, concentration drizzle, drizzle amount, prediction and prevention the risk of lead contamination. We can obtain the following conclusions from the results of sorption and migration of heavy metals in soil:(1)The main component of farmland soil in Zibo area is very similar to bentonite, the surface has hydroxyl groups, Al-O-Si and Si-O and other functional groups.(2)When pH<6.5, with the increase of pH, the adsorption rate gradually increases, increases to a certain extent, the adsorption rate of the adsorption rate reached their highest point, with the pH remains stable without change; however, When pH>8, with the rate of adsorption pH value increases and decreases.(3)When pH<6.5, HA promote the adsorption of Pb (II) on soil, however, inhibitory effect when pH>6.5. (4)Adsorption capacity of soil to Pb (â…¡) is large, when containing Pb (â…¡) pollutants into the soil, adsorption begins until the saturated state; when adsorption is saturated of the certain thickness of soil, along with the increase of the amount of pollutants leaching, the adsorption saturation line will move to deep, Pb (â…¡) will shift to deep.(5)Different depth of soil has different adsorption ability, Pb (â…¡) is mainly accumulated in the upper and accumulation of the soil is large, deeper soil lead levels far below the soil surface and within the natural range of content, so groundwater not affected by lead contamination.(6)For the sewage irrigation area, it need to determine the adsorption layer of soil saturation values at different depths through experiments and predict the actual local situation. As much as possible to prevent and eliminate the damage to groundwater, it must not exceed the maximum adsorption performance of the soil. |
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