chemical gradening

例句：

1. 1. The company uses a chemical gradening process to improve the quality of its products.
   该公司使用一种化学分级处理过程来提高其产品的质量。
2. 2.During the chemical gradening process, the wastewater is treated and then discharged into the environment.
   在化学分级处理过程中，废水被处理后排放到环境中。
3. 3. The chemical gradening process helps to reduce the amount of pollutants in the water.
   化学分级处理过程有助于减少水中污染物的量。