Acid-base pollution of water pollution.

Acid-base pollution means PH of water is abnormal. Generally speaking, PH of normal water is between 6.5 and 8.5. When PH is less than 6.5 or greater than 8.5, it means the water has been polluted by acids or alkalis.

The acid substances mainly come from wastewater of acid plants, chemical plants, viscose fiber plants, acid pickling shops and mine drainage and acid rain.

The alkali substances mainly come from wastewater of pulp mills, paper mills, alkali works, printing and dyeing mills, leather making plants and refinery. Both acid substances and alkali substances increase the corrosivity of water. Therefore, water pipes, hydraulic buildings and ships can be damaged. Abnormal PH causes death of aquatic life, especially microorganism, thus the self cleaning capacity of water decreased, biotic population altered. Fishes and shrimps can even die out.

Then, how can we prevent acid-base water pollution? First, the leak of acids or alkalis is strictly forbidden. Second, control emissions of sulfur dioxide to alleviate the damages caused by acid rain. Third, wastewater that contains acids or alkalis must be discharged after the neutralization treatment.