This invention relates to compositions for treating industrial waste water which contains heavy metals, and more particularly to compositions for treating waste water which comes out of industrial plants using a process of metal coating, paint production, leather treatment, dyeing, production of medicine or production of lube oil. The compositions comprises natrolite, montmorillonite, calcium hydroxide, aluminum sulphate and catalyst agent.
An outflow of waste water which contains untreated heavy metals may cause contamination of lands or rivers. Furthermore, such untreated waste water may cause serious diseases, such as minamata disease caused by mercury poisoning, beause it is introduced into and accumulated in the human body through the food chain.
Industrial plants utilizing a process of metal coating, paint production, leather treatment, dyeing, production of medicine or production of lube oil generally discharge waste water containing various heavy metals. Consequently, effective methods of treating the various heavy metal containing waste water are strongly required in view of the environment protection and public hygine.
There have been proposed and used various methods of treating heavy metal containing waste water, i.e. neutralization method by using alkali, coagulation and precipitation method, ion exchange method, chelate compound formation method.
These conventional methods are limited in their treating effects and not economical. For treating waste water containing various kinds of heavy metals, the conventional methods have been combined when in use.