People may start doubting their usage of industrial products if they get to know the number of wastes dumped into the environment by these companies. However, one could not blame industries for producing wastes as it is a natural process. But these industries and large-scale companies can think of the treatment of this contaminated water before mixing them with the world. As people may get diseases because of this polluted water emission, they must consider this. All they should do is hire water treatment plants  or create one to clean or purify the water coming out of their premises. The following are the various processes through which the contaminated water from the industries can get purified.
Removal of bulky particles
At first, the waste coming from the industries will be full of bulky wastes that would be visible to the naked eye itself. You should remove these particles beforehand. However, you can separate the bulky particles into two categories of wastes. The first category would be bulky in sizes like plastics and other elements. The second category would be bulky by weight and fine by structure. Sand particles may come under the second category. However, you can use the screening equipment for removing bulky particles and grift removal equipment for removing sand and other minute particles.
Aeration for minute impurities
You cannot say that the water is pure only after removing the bulky elements from it. If the water should get purified to about 90%, you should remove even those micro impurities that are hidden to your eyes. You can deal with these micro impurities with microorganisms like bacteria as they will consume these impurities to convert them into nitrogen and water.
Final processing
Once the water is purified to about 90%, filtration and disinfection will be done on them.