Wastes from large industrial enterprises are often extremely harmful for the environment and human health. Waste waters of Kazan Optical Mechanics Plant, for instance, are mainly polluted by heavy metal ions from a galvanizing room and synthetic surfactants from an optical room. Heavy metal ions are much more dangerous for our health, than synthetic surfactants (SS).

Synthetic surfactants are a class of soapy substances, which have a variety of chemical structures. Many of these substances are commonly used in manufacturing of washing powders and other kinds of household chemicals. Surfactants are less harmful, than heavy metals, but they do not decompose in natural environments and can accumulate there in significantly high concentrations.

Researchers from Kazan State University of Technology, Kazan Optical Mechanics Plant and the Institute of Organic and Physical Chemistry of Russian academy of sciences developed a system for partial local purification of waste waters and suggested using it in industrial processes. Experiments revealed that mixing waste waters from a galvanizing room and an optical room has led to decrease in toxicity of the mix. Quite an unexpected result can be explained by the chemical process of forming complex compounds from synthetic surfactants and heavy heavy metals.

General chemistry teaches us that surfactants in aqueous solutions tend to form micelles (micella in Latin means “a very small particle”). Some surfactants of synthetic origin form milecces, able to bind with heavy metal ions by means of adsorption. These properties of synthetic surfactants are well known and widely used for extracting metals by means of ionic flotation in mining industry, for instance.

 

 

Russian researchers suggested an elegant solution for detoxification of wastes – they mixed two types of wastes and checked their parameters. Photometry showed that concentration of heavy metal ions (copper, zinc, nickel and chrome) in the mix of two types of waste waters dropped significantly, compared to wastes from the galvanizing room. Tests on objects of biological origin also showed a great reduction of toxicity in the mentioned mix. These tests were performed on fresh-water unicellular organisms – infusorians. Various mixtures of water from two mentioned plant rooms were added to vials with water, rich in infusorians Paramecium caudatum. After three or four hours of exposure, survivors have been counted. The results were very interesting – in mixtures of waste waters from two plant rooms of any proportion there were more protozoan survivors, than in “pure” waste water solution with the same concentration of heavy metal ions.

Therefore, mixing of waste waters from the galvanizing room and the optical room of Kazan Optical Mechanics Plant led to a significant drop in toxicity and concentrations of polluting agents. Results of the research can serve as a basis for further studies of how waste water mixing affects active sludge of water and wastewater treatment facilities.