木质素与丹宁对自然水体的污染主要来源于植物分解和造纸、制革工业的废水。它们往往同时存在于水体中,使水呈黄色,产生腐臭气味,并使自然水体中有机成份增多,耗氧量提高,溶解氧减少,直接影响水环境的好坏。因此,测定丹宁与木质素的含量常常是了解造纸、制革等工业废水对自然水体污染状况的主要指标。低浓度的丹宁与木质素的测定,我国多采用美国公共卫生协会等编著的“水和废水标准检验法”中的磷钨酸-碳酸钠分光光度法。方法原理是根据丹宁与木质素都含有能还原磷钨(钼)酸的芳族羟基团,在碳酸钠介质中它们将显色剂中的六价 Lignin and tannin pollution of natural water mainly from plant decomposition and paper, leather industry wastewater. They often exist in the water at the same time, making the water yellow, produce rancid odor, and make natural organic matter in water increased, oxygen consumption increased, dissolved oxygen decreased, directly affect the quality of the water environment. Therefore, the determination of the content of tannin and lignin is often the main indicator to understand the pollution status of natural water such as papermaking, tanning and other industrial wastewater. Low concentration of tannin and lignin determination, China more use of the American Public Health Association edited “Water and Wastewater Standard Test” in the phosphotungstic acid - sodium carbonate spectrophotometry. The principle of the method is that both tannin and lignin contain aromatic hydroxyl groups capable of reducing tungstophosphoric (molybdic) acid in the sodium carbonate medium, and their hexavalent