pH ORP

N e u t r a l i z a t i o n / P r e c i p i t a t i o n / D e t o x i f i c a t i o n

Both in water and wastewater treatment and also in industrial processes pH is of great practical importance. The acidity or
alkalinity of a process medium plays a key role in many chemical or biological reactions as well as in mechanical/ physical
actions. A number of reactions – in precipitation and detoxification, for example – may only take place if the pH condition
is properly controlled. A “misadjusted” pH can cause a variety of serious effects, of which corrosion is the most common.
Therefore, at a low or high pH neutralization treatment often is required.

In the area of municipal and industrial wastewater treatment
extreme pH conditions may result in the following
harmful effects:
• Microorganisms in biological purification processes are
sensitive to acidic and alkaline conditions. Therefore, the
pH of the sewage is supposed to be in the neutral range
of pH 7. At pH levels of less than 5 or larger than 10 the
activity of the bacteria practically ceases.
• pH values of 6.5 and lower result in gradual destruction
of metallic materials and mechanical components, and
even in damage of the sewer network.
• The solubility of many substances varies with the pH level
and temperature. Undesirable and obstructive precipitation
of solids may be the result.
Today’s legislative regulations and environmetal directives in
many countries already require that trade effluents may
only be discharged into municipal sewer systems if the pH
is bet ween 6.5 and 8.5. For this reason, industrial dischargers,
for instance, breweries and dairies, often have to pretreat
its effluent in a neutralization plant.