大型厌氧填埋场中铁的分布特征及迁移行为研究

Distribution Characteristic and Migration Behavior of Fe in Large-Scale Anaerobic Landfill

以北京南郊某大型厌氧填埋场为例,对不同填埋龄垃圾中的铁含量、价态转换及形态分布进行研究。结果表明,该厌氧填埋场填埋龄为3～10年的垃圾中Fe含量变化范围为18532.8～26897.2 mg/kg。由于微生物的异化铁还原作用,Fe(III)不断被还原为Fe(II),Fe(II)/Fe(III)从0.51上升到1.01。形态分析结果表明:Fe在不同填埋龄垃圾中的形态分布规律基本一致,残渣态含量最高,可氧化态和可还原态次之,酸可溶解态含量最低,可还原态受环境因素影响极大,硫化物对Fe形态分布影响最显著。

As a variable valent metal,the environmental behavior of Fe has significant effect on the migration of metal and degradation of organic matter in landfill.In the study,the total amount,valence conversion and speciation of Fe in different deposit age waste from a large scale anaerobic landfill in southern Beijing were analyzed.The result shows that 1） the total amount of Fe was 18532.8 26897.2 mg/kg in 3 to 10-year waste;2） Fe（III） is reduced to Fe（II） continuously and Fe（II）/Fe（III） ratio rises from 0.51 to 1.01 by dissimilatory iron reduction;3） the form distribution of Fe in different deposit age waste is generally identical：the highest content is residual fraction,following the reducible and oxidable fraction,and the acid soluble fraction is of the least.Reducible fraction is the most easily affected by environmental conditions,and sulfide has the most notable impact on the form distribution of Fe.