滴灌条件下脱硫石膏对盐碱土改良效果及安全性的影响

Effect of flue gas desulphurization gypsum on the saline soil improvement and security under drip irrigation

为实现燃煤烟气脱硫废弃物再利用,使其能运用于新疆大面积盐碱地改良,在新疆农八师134团盐碱地施用脱硫石膏,研究滴灌条件下脱硫石膏对盐碱土壤理化性质以及土壤重金属含量的影响,评估脱硫石膏改良盐碱土的可行性和安全性。结果表明:盐碱地施用脱硫石膏后土壤容重降低,>0.25mm团聚体数量增加,土壤孔隙度增加;土壤pH值、碱化度和电导率降低,尤其在0-10cm、10-20cm土层改善效果明显;土壤中Na^+、Cl^-含量降低,0-10cm土层较其他土层Na^+含量下降明显,于对照相比下降40.62%,表层土壤中Ca^(2+)、SO_4^(2-)含量增加,有利于降低土壤盐碱危害;施用脱硫石膏对土壤Hg含量没有影响,Cr元素含量下降,各项重金属元素含量均远低于国家环境二级标准,说明施用脱硫石膏不会对土壤造成重金属污染。综上所述,脱硫石膏对盐碱地有一定的改良效果且不会对土壤安全造成威胁。

For realization of the coal -fired Flue gas desulphurization gypsum（FGD） recycling, and applying it in large area of alkali - saline land in Xinjiang, FGD gypsum was applied to saline - alkali land in Xinjiang Non- gBaShi 134, in order to study the influence of FGD gypsum on the properties and soil heavy metal content of sa- line soil physical and chemical under the condition of drip irrigation, and evaluate the feasibility and safety of FGD gypsum that improves saline alkali soil. The results indicated that application of FGD gypsum resulted in the decrease of soil bulk density; the saline -alkali 〉 0.25ram aggregate quantity increased, the soil porosity in- creased; soil pH value, alkalinity and electrical conductivity were reduced, particularly; the soil improvement effects that are in 0 to 10cm, 10 -20 cm soil layers were obvious; the contents of Na＋ and Cl- in the soil were reduced, the content of Na＋ in 0 to 10 cm soil layer decreased significantly, with fall of 40.62% compared to controls ; the contents of Ca2 ＋ and SO4^2- in the surface soil increased, which was benefited to reduce soil salinity hazard. The application of FGD gypsum had no effect on the content of Hg. The content of Cr element de- creased; the contents of heavy metal elements are far below the secondary standard of national environment, which indicated that application of FGD gypsum would not cause heavy metal pollution to the soil. To sum up, the FGD gypsum has certain improvement effect on saline -alkali land without soil security risks.