铬盐氧化法制备2-甲基-1,4-萘醌的废液成分分析

Component Analysis of Effluent from 2-methyl-1,4-naphthoquinone by Oxidation with Cr^(6+)

铬盐在硫酸催化下氧化2-甲基萘(2-MN)制备维生素K3的重要中间产物2-甲基-1,4-萘醌(2-MNQ),所得废液中含有大量的六价铬、三价铬、部分硫酸及少量2-MN及2-MNQ。通过紫外分光光度法等,分析了某工厂提供的和实验室制备2-MNQ所得的废液成分,得到废液各成分含量分别为:工厂废液中,总铬含量为88.74g/L,六价铬含量为46·60g/L,pH值为0.1,H^+含量为0.213mol/L,2-MN含量为2.52g/L,2-MNQ含量为0.77g/L;实验室废液中,总铬含量为41.97g/L,六价铬含量为13.25g/L,pH值为0.6,H^+含量为0.133mol/L,2-MN含量为2.52g/L,2-MNQ含量为0.65g/L。

2 - methyl - 1,4 - naphthoquinone （2 - MNQ）, which is important semi - finished products in the manufacture of vitamin K3 was synthesized by Cr^6＋ oxidized 2 - methyl naphthalene （2 - MN） in sulfuric acid. The obtained effluent contained a- mount of Cr^6＋ , Cr^3＋ , residual sulfuric acid, a little 2 - MN and 2 - MNQ. The UV - Vis method was used to analyze the compo- nent of effluent prepared in a factor and lab. The results show that the total chromium concentration is 88.74g/L, the Cr^6＋ con- centration is 46.60g/L, pH is 0.1, H^＋ concentration is 0. 213mol/L, 2 - MN is 2.52g/L and 2 - MNQ is 0.77g/L for the sam- ple from a factory. And the total chromium concentration is 41.97g/L, the Cr^6＋ concentration is 13.25g/L, pH is 0.6, H^＋ con- centration is 0. 133tool/L, 2 - MN is 2.52g/L and 2 - MNQ is 0.65g/L for the sample prepared in lab.