一体化自循环蒸馏装置制备与氨氮检测性能分析

Device preparation and performance analysis of the integrated self-cycle distillation unit for ammonia nitrogen detection

由于水中悬浮物和钙镁离子的干扰,在使用纳氏试剂测定废水中氨氮时需要对水样进行预处理.蒸馏是较为常用的一种预处理方法,传统的蒸馏装置存在占地面积较大、损耗冷却水剂量较大等缺点,所以使用自主研发的新型节约用水一体化自循环蒸馏装置进行了蒸馏预处理实验.结果表明,相比于传统的蒸馏装置,其节水效率提高了30~60倍.标准样品回收率实验表明,氨氮质量浓度为1~100 mg/L的水样,其回收率为97.85%~99.53%,精密度小于3%,当氨氮质量浓度超过100 mg/L时,需要将水样稀释之后再使用该装置蒸馏.实际样品的加标回收率实验表明,新型蒸馏装置的加标回收率约为95%,误差为0.99%~4.88%.

Due to the influence of suspended solids,calcium and magnesium ions in water,water samples should be pretreated in the determination of ammonia nitrogen with Nessler s reagent.Distillation is a more commonly-used pretreatment method.The traditional distillation unit has several disadvantages,such as large area,the loss of large amount of cooling water and so on.A new water-saving self-cycle distillation unit was developed in this paper.The experimental results showed that the water-saving efficiency of the new unit had been increased by 30 to 60 times compared with the traditional distillation unit.The standard addition recovery experiments had shown that the recovery rate of the new distillation instrument was 97.85%~99.53%for the water sample with ammonia nitrogen mass concentration of 1~100 mg/L.And the precision was less than 3%.The water samples containing over 100 mg/L ammonia needed to be diluted before the distillation process by this instrument.The experimental results had shown that the standard recovery rate of spiking by the new distillation unit was about 95%,and the error was 0.99%~4.88%.