[机] after-treatment with bleaching powder

piǎo bái fěn hòu chǔ lǐ fǎ ㄆㄧㄠˇ ㄅㄞˊ ㄈㄣˇ ㄏㄡˋ ㄔㄨˇ ㄌㄧˇ ㄈㄚˇ