铬酸钠比色法分析废铬液中铬含量的影响因素  

Influence factors of sodium chromate colorimetry on chromium content in chrome waste liquid

作　　者：张玉洁 付丽红 ZHANG Yujie;FU Lihong(School of Light Industry Science and Engineering,Qilu University of Technology,Jinan 250353,China)

机构地区：[1]齐鲁工业大学轻工科学与工程学院

出　　处：《中国皮革》2019年第10期38-44,共7页China Leather

基　　金：国家自然科学基金(21606139)

摘　　要：铬酸钠比色法是测定废铬液铬含量的常用方法,但因铬含量不同,消耗的过氧化钠的量不同,造成铬液pH相差较大,而为降低溶液pH,又需加盐酸,使溶液中氯化钠含量增加.探讨了溶液pH和氯化钠含量对铬含量测定的影响.结果表明:酸性条件下,可用最大吸收峰位(243 nm)作测定波长,且溶液pH值应控制在5.4左右,氯化钠含量对铬含量的测定影响不大;碱性条件下,可用最大吸收峰位(371 nm)作测定波长,溶液pH值应控制在10.0左右,氯化钠含量对铬含量测定没有影响.用390 nm作测定波长可行,但测定结果偏低,pH值在10.0左右时相对误差为-7.5%.Sodium chromate colorimetry is the usual method of chromium content in chromium wastewater. Due to the different chromium content and sodium peroxide consuming content, it caused a large difference in pH value. In order to reduce the pH yalue, it is necessary to add hydrochloric acid, but sodium chloride content in the solution is increased. The effect of the pH value and the sodium chloride content on the chromium content assay was studied. It is found that, under the acid condition, the maximum absorption wavelength ( 243 nm) can be used as the measuring wavelength. The solution pH should be controlled around 5. 4, and sodium chloride content has little effect on the chromium content assay. Under the conditions of neutral and alkaline, the maximum absorption wavelength (371 nm) can be used as the measuring wavelength. The solution pH should be controlled in 10. 0, and sodium chloride content has no effect on the chromium content assay. Using 390 nm as the detection wavelength is feasible, but the results are lower, the relative error is -7. 5% under pH value of 10. 0.

关 键 词：铬酸钠比色法 铬含量 测定波长 氯化钠含量 废铬液 

分 类 号：TS59[轻工技术与工程—皮革化学与工程]