chemistry need oxygen

• 化学需氧量

chemistry need oxygen的用法和样例：

例句

1. The results showed that magnesium hydroxide had good effect for decoloring and suspended substance removal,meanwhile,removal rate of chemical oxygen demand was also quite high.
   研究结果表明，氢氧化镁在印染废水的处理过程中，具有良好的脱色效果和悬浮物的去除效果，对化学需氧量的去除率也相当高。