CODCr测量方法优化及其受营养盐胁迫研究

Optimization of CODCr measurement method and its application to nutrients

基于CODCr的K2 Cr2O7滴定法和HACH(哈希公司)DR6000,结合design-expert拟合分析,得到CODCr精确测量的最佳方案:消解液加入量为3 mL,K2 Cr2O7与H2 SO4-Ag2 SO4的加入比为1:5(V/V),K2Cr2O7溶液0.046 g/mL、H2SO4-Ag2SO4溶液3 g/L、HgSO40.038 g/支,恒温120℃消解2 h。同时,基于拟定的最佳方案分析了营养盐类对CODCr测定结果的影响,发现氨氮和亚硝态氮对测定结果有明显影响,而磷酸盐和偏磷酸盐对测定结果的影响较小。

Based on K2Cr2O7 titration of CODCr and HACH DR6000,combined with design-expert software fitting,the optimal method of measuring CODCr was obtained which showed that the amount of digestion solution was 3 mL,the ratio of K2Cr2O7 to H2SO4-Ag2SO4 was 1∶5(V/V),K2Cr2O7 solution was 0.046 g/mL,H2SO4-Ag2SO4 solution was 3 g/L,HgSO4 was 0.038 g/branch,and the digestion temperature was 120℃ for 2 h.At the same time,the effects of the nutrient salts on the determination of CODCr in optimal method were verified by experiments.The results showed that ammonia nitrogen and nitrite nitrogen had a great influence on the determination results,while phosphate and metaphosphate had little effect on the determination results.