气相分子吸收光谱法测定印染废水中氨氮的影响因素

采用气相分子吸收法光谱测定印染废水中的氨氮,并对相关影响因素进行探讨。结果证实,硫化物和尿素会对氨氮的测定产生负干扰,硫化物干扰可用乙酸锌-乙酸钠固定液沉淀法去除,尿素干扰可以用稀释法去除,但仅适用于氨氮质量浓度0.10 mg/L且稀释后尿素质量浓度≤100 mg/L的水样;苯胺、浊度和色度对测定无干扰,可直接检测。

Determination of Ammonia Nitrogen in Printing and Dyeing Wastewater by Gas Phase Molecular Absorption Spectrometry

Gas phase molecular absorption spectrometry was adopted to determine the ammonia nitrogen in printing and dyeing wastewater, and the related influencing factors were discussed. Results confirm that, in printing and dyeing wastewater, sulfide and urea produce negative interference. The sulfide interference can be removed by zinc acetate and sodium acetate precipitation meth-od, while the urea interference can be removed by dilution method. But the dilution method is only suitable for the water sample with the concentration of ammonia nitrogen more than 0. 10 mg/L and the concentration of urea less than 100 mg/L after dilution. Ani-line, turbidity and colority don’t interfere with the determination.