The number of bone dust in animal feed is main reasons for high content of phosphorus in its waste water.
动物饲料中加入大量骨粉是其污水中含磷过高的主要原因，而常规活性污泥法对磷的去除率却很低。
2
The paper delineates the special features of boiler feedwater control and discusses the main problems pertaining to control systems.
该文阐述了锅炉给水控制的特点，并对给水控制系统设计的主要问题进行了分析。
3
The main connections between the plant and the rest of the site (i. e. feedstock, product, and utilities) require reinstatement as do the boiler feedwater and cooling water chemical dosing systems.