探讨了硬度去除、天然有机物（NOM）去除和选定的NOM化学特性之间的关系，并评估了拟议消毒剂/消毒副产品规则中强化软化部分的含义。对于所检查的九个原水水源中的大多数，去除的溶解有机碳（DOC）量（绝对值和百分比）与沉淀的镁量密切相关。半对数模型很好地拟合了九种水中六种的数据（R2值和gt0.8）。对于初始DOC浓度较高的原水，DOC的绝对去除率更高。对于疏水性有机碳含量最高的水源，软化法去除DOC的效果最好。 比紫外线吸光度值越大，DOC去除率也越高。包括16个参考文献、表格和图表。

Relationships of hardness removal, natural organic matter (NOM) removal, and selected chemical characteristics of NOM were explored, and the implications of the enhanced softening portion of the proposed Disinfectants/Disinfection Byproducts Rule were assessed. For most of the nine raw water sources examined, the amount of dissolved organic carbon (DOC) removed (both on an absolute and a percentage basis) correlated strongly with the amount of magnesium precipitated. A semilogarithmic model provided a good fit to the data for six of the nine water (R2 values >0.8). Greater absolute removal of DOC was achieved for raw waters with higher initial DOC concentrations. DOC removal by softening was most effective for the raw water sources with the highest percentage of hydrophobic organic carbon. Greater specific ultraviolet absorbance values also corresponded to greater DOC removal. Includes 16 references, tables, figures.