A pH adjustment system is an equipment used in the treatment of acidic or basic wastewater by adjusting the pH to a neutral range. pH is a measurement of the quantity of hydrogen ions that are present in a sample of water. The adjustment of pH values can be achieved using a measurement probe, a digital controller, or a signal-boosting pre-amplifier.
The controller can be programmed to signal a chemical dosing pump to inject chemicals into the process liquid so as to adjust the pH values toward the required set point. pH adjustment systems are offered by various manufacturers as individual components or assembled into a compact, skid-mounted system.
The most common application for a pH adjustment system is to move the pH level of wastewater to a neutral level in order for the wastewater to be within the limits prescribed by a discharge permit or a publicly owned wastewater treatment facility. PH adjustment systems are available in three working mechanisms that include a batch mode system, a concentrated mode system, and a continuous mode system.
Batch Mode
A batch mode pH adjustment system collects wastewater into a corrosion resistant tank, blends it, measures the pH and automatically injects caustic or acid in order to achieve a neutral pH. This system utilizes a level controller within the tank to regulate the batch size, therefore allowing for more accurate adjustment and better control over retention time. The batch-style mode is ideal in applications where the pH of wastewater generated varies over a wide range. Control of the tank level and the timing of the release enable you to let the wastewater mix and adjust by itself before dosing the neutralization chemicals.
Continuous System
A continuous mode pH adjustment system uses similar equipment to the batch system but it doesn’t retain the wastewater in the tank for neutralization. This type of pH adjustment system measures pH and adjusts on the go, with a continuous overflow from the tank. Alternatively, it can measure and adjust pH and flow inline without the need for a holding tank. This is an ideal option if the wastewater that is generated has a fairly uniform pH range. It is also less expensive due to the simpler control configuration.
Any pH adjustment system will often come with various components that are necessary to construct the entire system. These include tanks, level controls, valves, metering pumps, and system enclosures and pH controllers.
