松花江水中天然有机物的提取分离与特性表征

Characterization of Isolated Fractions of NOM from Songhua River

将反渗透与XAD大孔树脂吸附技术相结合,对松花江水中天然有机物(NOM)进行了浓缩和分离,并采用紫外光谱、红外光谱、液相凝胶色谱、官能团滴定、1H NMR核磁共振等分析手段,对松花江水中NOM及其各分离组分和一种商用腐殖酸CHA的特性进行了比较和表征.结果表明,利用反渗透进行NOM浓缩对水中有机物具有很高的回收率;松花江水中NOM组成为:富里酸＞腐殖酸＞亲水部分;各组分芳香性为:腐殖酸＞憎水部分＞富里酸＞亲水部分,E4/E6与芳香性之间缺乏必然的联系;腐殖酸和商用腐殖酸具有较高的不饱和性,NOM和亲水部分次之,憎水部分和富里酸中饱和烃含量较多;紫外吸收较弱的有机成分对NOM分子量的贡献较大;NOM及其分离组分的总酸度为9.84～12.15 meq/g,羧酸含量为CHA＞亲水＞憎水＞NOM＞富里酸＞腐殖酸;NOM及其各分离组分的溶解性有机物构成以脂肪烃为主.

Natural organic matter （NOM） was concentrated from Songhua River using a reverse osmosis system. The hydrophobic fraction （HyO）, hydrophilic fraction （HyI）, fulvic acid （FA） and humic acid （HA） were fractionated by the XAD resin, and a commercial humic acid （CHA） was used for comparison. The FA fraction predominant in natural water and account for the large part of DOC, and the aromaticity of these fractions followed the order HA〉HyO〉FA〉 HyI. A weak relationship exists between the E4 / E6 and aromaticity. FTIR spectra revealed that the degree of saturation among these fractions was in the order of HyO≈FA〉HyI HA ≈CHA. Gel chromatograph results showed that the weaker ultraviolet-adsorption fraction of NOM contributed to the most part of molecular weight. Potentiometric titration indicated that the total organic acidity was in the range of 9.84- 12.15 meq/g, and carboxylic acidity decrease in the order of CHA〉HyI〉HyO〉NOM〉FA〉HA. ^1H NMR spectra demonstrated that NOM and the isolated fractions were predominated by aliphatic functional groups.