For the treatment of industrial waste water, technological processes appropriate to the nature of the pollutants and the characteristics of waste water are used. In the advanced waste water treatment phase, ion exchange was imposed as a specific technological process. In addition to the fact that ion exchange allows advanced wastewater treatment, in the regeneration process, heavy metal ions can be retained as useful products.
The use of natural zeolites with high ion exchange capacity in advanced wastewater treatment processes with heavy metal ions is an efficient and perspective method. Exhausted zeolites can be used for other purposes without causing environmental pollution.
Natural zeolites are used in the treatment of waste water in the chemical, pharmaceutical, food, metallurgical, and urban wastewater treatment.
Residual waters of different origin and with different impurities, contain organic pollutants and inorganic salts with interchangeable cations: NH4 +, Cu2 +, Pb2 +, Zn2 +, Cd2 + etc.
The problem of removal or reduction of ammonia concentration in wastewater is closely related to maintaining ecological balance. The special selectivity of natural zeolites of the clinoptilolithic type for ammonium ion allowed them to be used in the process of purifying waste water containing ammonia.
In many countries, experiments on zeolite volcanic tuffs have taken place to contain cations of heavy metals from solutions.