Pollutions: what is pH (hydrogen index)
Before purification industrial wastewater often has pH indexes, that are distinct in different ways from normal. Water with pH indexes at the limit 6,5...8,5 is considered as safe. As for the degree of acidity, wastewater can differentiate in the following way:
|Neutral wastewater||pH 6,5-8|
|Mildly aggressive wastewater||weakly acidic||рН 6-6,5|
|weakly alkaline||рН 8-9|
|Aggressive wastewater||highly acidic||рН less than 6|
|highly alkaline||рН more than 9|
The process of pH degree normalization is called neutralization. In some cases the primary neutralization is needed before the purification of wastewater, as the superacidity along with the superalkalinity cause the premature corrosion of containers, pipelines and equipment units, which are the parts of wastewater treatment facilities.