Modern day wastewater treatment plants must use a variety of physical, chemical and biological processes to meet effluent treatment guidelines. During the course of treatment these plants consume a variety of different chemicals. In some treatment plants an alkali is used to provide the alkalinity required to maintain effective biological activity and for pH control. This paper will discuss the role that alkalis play in wastewater treatment. Therefore, this report will have three sections. The first section defines the term alkalinity, what it is and what it is not. The second section examines why alkali chemicals are used for wastewater treatment. The third and final part presents facts as to why magnesium hydroxide is the alkali of choice for these applications.

Reprinted with Permission from Martin Marietta Magnesia Specialties