Study Of The Modiifed Flue Gas Desulfuirzation Residue On Amending Acidic Soil And Heavy Metal Contaminated Siol

In this study, a modified flue gas desulfurization residue (MFGDR) was prepared by calcining a mixture of dry/semi-dry flue gas desulfurization residue, potassium feldspar and/or limestone powder in a suitable ratio and reaction conditions, which was constituted of soluble potassium, calcium, silicon and magnesium. The optimum material mass ratio of potassium feldspar, desulfurization residue and limestone was2.32:1:1.46, and the optimum reaction conditions was roasting2hours in1050℃with3.0Wt.%cosolvent. The available nutrient elements of the MFGDR were determined with6.49%K2O,28.63%CaO,14.46%SiO2,1.82%MgO in0.1mol L-1citric acid solution and the contents of heavy metal were far lower than the national standard.Field trials was conducted to research the effect of the MFGDR on acidic soil and rice planting. Application of the MFGDR was effective in raising soil pH, increasing soil available K, Ca, Mg and Si contents and decreasing available Cd and Pb concentration. There was a correlation between soil pH and the concentrations of available Cd and Pb in three concentration of MFGDR. Applied1200kg ha-1MFGDR on acidic soil was increasing the rice plant height, advancing heading date, grain yield of rice was increased by1493kg/ha, equal to26.1%compared with the CK. It also improved the quality of rice grain by reducing the chalky grain and amylase content, and the concentration of heavy metal in rice was all below the tolerance limit of contaminants in foods (GB2762-2005).A pot experiment was used to study the effect of three soil amendments (white mud, flue gas desulfurization residue and MFGDR) on Cd,Pb and Cu contaminated soil and maize planting. All amendments significantly increased the maize germination rate, plant height and biomass. The shoot biomass of maize increased in order was MFGDR> flue gas desulfurization residue> white mud under different treatmts. The concentration of Cd,Pb and Cu in root and shoot of maize was significantly decreased, and the contents of heavy metals in maize root were far higher than maize shoot. The soil pH is the main influencing factor on the acid extractable of Cd, Pb and Cu. Aplication of three amendments increased the soil pH, the effect of white mud and flue gas desulfurization residue was better than the MFGDR. The effect of decrease in extractable Cd concentration in order was flue gas desulfurization residue, MFGDR and white mud, in extractable Pb and Cu both was MFGDR, flue gas desulfurization residue and white mud. Suggested to application of MFGDR to Cd, Pb and Cu contaminated soil, not reduced the contents of acid extractable of Cd, Pb and Cu, but also improved the nutrient elements to soil.