溶解性有机物在土壤含水层处理系统中的变化

通过实验室模拟土壤含水层处理(SAT)的土壤柱系统研究了二级处理出水中溶解性有机物(DOM)的荧光特性在SAT系统中的变化.利用XAD树脂将二级处理出水中的DOM分为5个部分:疏水性有机酸(HPO-A),疏水性中性有机物(HPO-N),过渡亲水性有机酸(TPI-A),过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI).结果表明,TPI-N中的类芳香族蛋白质荧光物质在SAT系统中优先去除.经过SAT系统处理后,类芳香族蛋白质荧光物质和类溶解性微生物代谢产物荧光物质在HPO-A,HPO-N,TPI-A和HPI中的相对含量升高.各组分中带有3～5个稠合苯环的荧光物质,以及激发波长/发射波长(λex/λem)=390～410nm/456～476nm的类腐殖酸荧光物质在SAT系统中的去除率低于相应组分中以溶解性有机碳(DOC)表征的整体有机物的去除率.不同组分中的其他荧光物质在SAT系统中去除行为不同.

Changes of dissolved organic matter in soil-aquifer treatment system

The changes of fluorescence characteristics of dissolved organic matter (DOM) during laboratory-scale soil-aquifer treatment (SAT) soil columns were studied. Using XAD resins, DOM was fractionated into 5 fractions: hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N) and hydrophilic fraction (HPI). Aromatic protein-like fluorescent materials in TPI-N were preferentially removed during SAT. The raletive content of aromatic protein- and soluble microbial byproduct-like fluorescent materials in HPO-A, HPO-N, TPI-A and HPI increased as a result of SAT. The removal rates of fluorescent materials with three to five fused benzene rings and humic acid-like fluorescent materials with excitation wavelength/emission wavelength (λex/λem) of 390~ 410nm/456~476nm in each DOM fraction during SAT were lower than those of organics (on average) comprising dissolved organic carbon (DOC) in corresponding fraction. Other fluorescent materials in different fractions exhibited distinct removal behavior.