Industries are known for chemical waste products that will get out of the campuses as contaminated water. There is a constant need for water treatment  processes due to the following reasons.
Reusability
The first benefit that comes to mind while talking about wastewater treatment is its reusability. Water treatment is nothing but the removal processes of impurities created due to the industrial processes from the water. Once impurities are removed, the water will become clean and pure as it was before. Now, the industry can use this water again for its works. Similarly, the process will repeat itself until the quantity of water getting lost during purification reaches a considerable point.
Better for environment
You can use your common sense to know that polluted water will affect the environment. As everyone would know, industries will be releasing a range of toxic chemicals as waste products. All these waste elements will get mixed with the wastewater coming out of the industries. Some industries will mix this water with a natural water resource like a lake or river. Other industries will leave the water on the floor itself outside the industry. Both cases are not good for the environment and several diseases can spread to the local people because of this. So, wastewater treatment will help the environment for sure.
Reduced diseases
If all the impurities are removed from the industrial wastes, we can expect a healthy environment that will not cause water-borne diseases that can be deadly at times. Trees and plants can also stay away from diseases and decay due to this contaminated water if purified well.
Improved quality of drinking water
Nobody knows what are all the impurities getting mixed with our drinking water at the river due to industrial wastes. So, water treatment can help us get purified water.