Chemical Dosage Calculations
Earlier we discussed calculations used in the chlorination process; thus, a certain amount of information presented in this chapter is related to similar information previously presented. In this chapter, we again discuss chlorination, but as it relates to wastewater treatment.)
Chemicals are used extensively in wastewater treatment (and water treatment) operations. Plant operators add chemicals to various unit processes for slime-growth control, corrosion control, odor control, grease removal, biological oxygen demand (BOD) reduction, pH control, biosolids-bulking control, ammonia oxidation, and bacterial reduction, among other uses. In order to apply any chemical dose correctly, it is important to make certain dosage calculations. One of the most frequently used calculations in wastewater/water mathematics is the dosage or loading. The general types of mg/L to lb/d or lb calculations are used for chemical dosage, BOD, chemical oxygen demand (COD), SS loading/removal, pounds of solids under aeration, and WAS pumping rate. These calculations are usually made using either Equation 28.1 or Equation 28.2.