离心分离转速和时间对氨氮测定结果的影响

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中图分类号X830.5 文献标识码A 文章编号 1007-7731(2025)14-0084-04

DOI号 10.16377/j.cnki.issn1007-7731.2025.14.018

Influence of centrifugal separation speed and time on the determination of ammonia nitrogen

ZHU Chunxiang

(Ecological Environment Monitoring Station of Shucheng County,Lu'an 2313Oo, China)

AbstractTo investigate theeffctsofcentrifugal separationspeedand timeonthedeterminationresultsof ammonianitrogen,referring totheHJ535-20o9 Water QualityDeterminationofAmmoniaNitrogenNesler'sReagent Spectrophotometry,4 rotational speeds(1 000,2 000,3 000,and 4000r/min ）and 6 time durations(1,2,3,4,5 and 6 min)were set,totaling 24 treatments.The absorbance values of water samples with diferent turbidities (4.1,18 and 30 NTU) were measured,and Grubbs’one-sided test was used for mean value testing.The spike recovery rates under optimal treatment conditions were calculated.Meanwhile,the effects of 4 pretreatment methods raw water, centrifugal separation,flocculation precipitation,and flocculation precipitation + centrifugal separation on the ammonia nitrogencontentofthe watersamples were compared.The results showed that the minimum absorbance values for the 3 water samples with turbiditiesof 4.1,18and30NTU were 0.183,0.091andO.102,respectively,allcorresponding toa rotational speed of 4 OoO r/min and a time of 4 min.The mean test values G6 for time were1.563,1.280,and1.524,and the mean test values were 1.258,1.333,and 1.147,respectively. The spike recovery rates for the 3 water samples pretreated with flocculation precipitation + centrifugal separation (4 Ooo r/min, 4 min) ranged from 98% to 102% . The ammonia nitrogencontentof the same water sample,as determined bythe four diffrent pretreatment methods,ranked fromhigh to low as follows:raw water > centrifugal separation > flocculation precipitation > flocculation precipitation + （204 centrifugal separation.Thecomprehensiveresultsindicate that the pretreatment method combining flocculation sedimentationand centrifugal separation demonstrates optimal effctiveness inremoving turbidityinterference for ammonia nitrogen measurement.Under the experimental conditions of this study,therecommended centrifugation parameters are 4000r/min for 4 minutes.

Keywordsflocculation and sedimentation; centrifugal separation; ammonia nitrogen; turbidity

氨氮作为水环境和生活、养殖、工农业生产废水中的重要检测指标之一，主要以游离态氨或铵离子形态存在。（剩余6956字）