Many industrial wastes contain acidic or alkaline materials that require neutralization prior to discharge to receiving waters or prior to chemical or biological treatment. For biological treatment, pH in the biological system should be maintained between 6.5 and 8.5 to ensure optimum biological activity. Usually neutralization processes work better with the stepwise addition of reagents.
The neutralizer is modeled as a stoichiometric reactor. The excess (%) of the neutralizing agent is based on the stoichiometrically required amount and is used to adjust the flowrate of the neutralizing agent stream. If multiple components need to be neutralized, the user must specify the neutralization reactions for each of them. The extent of reaction represents the fractional conversion of the limiting or reference component. Note that the neutralizing agent (specified on the Operating Conditions tab) cannot be the reference component of a neutralization reaction. For more information on the material balances calculations, see Stoichiometric Reaction Operations: Modeling Calculations.
In terms of equipment sizing, this unit models a multi-stage (multi-tank) operation. The number of neutralization stages is always specified by the user. Then, in design mode, the user specifies the residence time of the liquid in the system (including all stages) and the program calculates the liquid volume of each stage and the number of parallel tank chains. In rating mode, the user specifies the vessel volume of each stage, the number of parallel tank chains, and the working to vessel volume ratio and the program calculates the residence time of the liquid in the system.
For volatile organic compound (VOC) emission calculations, it is assumed that the neutralizer behaves like a quiescent tank. The calculations are identical to those of the Clarification Model.
See Vacuum Pump Auxiliary Equipment Calculations.
1. Eckenfelder, W.W., Jr., 1989, Industrial Water Pollution Control, McGraw-Hill, NY.
The interface of this operation has the following tabs:
● Oper. Cond’s, see Neutralization: Oper. Conds Tab
● Volumes, see Continuous Vessel Operations (Design Mode): Volumes Tab and Continuous Vessel Operations (Rating Mode): Volumes Tab
● Reactions, see Stoichiometric Reaction/Fermentation Operation: Reactions Tab
● Vent/Emissions, see Reaction Operations: Vent/Emissions Tab
● Labor, etc, see Operations Dialog: Labor etc. Tab
● Description, see Operations Dialog: Description Tab
● Batch Sheet, see Operations Dialog: Batch Sheet Tab
● Scheduling, see Operations Dialog: Scheduling Tab