The technique of application of mathematical models for management of doses of reagents on a preparatory stage of process of water purification is considered.

There are considered tasks of the disinfection of drinking water and waste water with the help of the integrated computer-aided electrolysis unit, there was shown its environmental and energy efficiency. There are given feasibilities to parameters of the technological process for anolyte generation with membrane electrolysis of sodium chloride solution for disinfection of water in public water supply pipelines and sodium ferrate by virtue of electrochemical dissolution of iron anode in alkaline NaOH solution for the use in wastewater treatment plants. There are considered principles of operation and design solutions for modules of Integrated Economic Analysis (IEA) for the production of anolyte and ferrate and practical possibilities of their automation.

The article highlights the hazardous impact of waste on the environment; emphasizes the expediency of introducing engineering protection and vital functions safety procedures into the overall process of environmental protection; prioritizes the prevention of fresh water supplies pollution through adequate wastewater treatment. The authors provide classificatory characteristics of wastewater and propose a classification of wastewater treatment methods. The authors claim that treatment eco-efficiency may be related to flotation technology application.

The method of biochemical removal of compounds of sulfur and ammonium from the water polluted by slags of metallurgical production, and also sewage of the metallurgical and coke-chemical entities is researched. The removal kinetics the sulfidsoderzhashchikh of connections is considered by an anaerobic microbiological method.

The article describes the main causes of pollution natural environment of milk production. The main indicators of pollution of soil, air and water as a result of discharge of sewage into the river Oka have been analyzed. The improved wastewater treatment system of the dairy industry has been offered.

In work the impact on water solutions of heavy metals salts and colloids, which are difficult to brought out of water, by the avalanche streamer discharge is considered. It is shown that discharge changes quantitative structure of separate free ions and radicals in solutions, transferring them to insoluble connections. Reduction in solutions of heavy metals ions and destruction of colloids is shown. Clarification of solution and formation an insoluble deposit at impact on manganese acid potassium and metilorange метилоранж is shown. It is shown that application of avalanche streamer discharge over a surface of solution leads to water purification from heavy metals ions and organic inclusions.

In article the main environmental problems of mechanical engineering in Russia are studied, sewage of etching and galvanic shops is basic of which. The analysis of system of sewage treatment of the galvanic shop of the entity of a machine-building complex of LLC EPO "Signal" (city of Engels, Saratov region) is carried out. The main source of pollution surrounding the environment on this production is the galvanic shop which according to FZ-116 of June 21, 1997 was carried to hazardous production facilities. After galvanic process the chromcontaining drains are formed, for their cleaning at the entity the reagent method (neutralization) which efficiency reaches to 60% is used. The carried-out analysis of sewage of LLC EPO "Signal" after neutralization showed that content of cations of heavy metals and oil products exceeds standard rates of dumping into a city collector and requires additional systems of cleaning. In article it is offered to upgrade the existing scheme of sewage treatment of LLC EPO "Signal", due to use of an obratnoosmotichesky membrane and ozonization. The advanced system of cleaning will provide decrease in pollution till 95–98%. The calculated concentration of cations of heavy metals in drains of LLC EPO "Signal" after three-stage cleaning are much lower than maximum permissible dumping that will allow to provide the closed water recirculation and to use the purified water for washing of details, and also to liquidate penalties against the entity

Nowadays water treatment process is significant and of great interest due to the difficult environmental situation caused by industrial and household activities of people. It is important to maintain the water treatment quality at the proper level, as it directly affects human health. Eventually the state of the water source may be changed, so it is necessary to adapt the water treatment process to these changes. It is necessary to constantly monitor not only the state of an incoming water source, but also the results of each water treatment. An early warning system was developed to response to a possible abnormal situation, in which drinking water quality parameters are out of rage, in time. Physical and chemical parameters of water source and drinking water obtained after purification as well as operated factors, which affect the water treatment quality, are controlled regularly and form time series system. The procedure of possible abnormal situation detection consists of two stages. The first stage includes modeling and forecasting the water source state factors based on vector autoregression approach. At the second stage piecewise linear regression dependences of quality factors (with a response break) from physical and chemical parameters of water source and operated factors, which characterize the work of water treatment system, are used to forecast drinking water quality parameters. In addition, for each indicator of drinking water quality there is its own model of optimal order based on the modeling sample of the optimal volume. The system quality is estimated using a test sample.

The article reflects the peculiarities of the water balance for example, Sue "Vodokanal of St. Petersburg", noted the relevance of the research topic defines the processes of water supply and sewerage, marked by their features, and a brief description of these processes with their technological advantages at the regional level, detail the ecological-economic situation of the Northwest region on the example of the city of St. Petersburg, is the main problem of the region is the hygroscopic of large industrial enterprises of the region. Following is the definition of capacious production, on the basis of the analysis provided the most water-intensive industries. State unitary enterprise "Vodokanal of St. Petersburg"-strategic enterprise carrying water of drinking quality for residents of the city of St Petersburg and the treatment of waste water before discharging to the water body. The detailed technological cycles company SUE "Vodokanal of St. Petersburg", separated and briefly described for each production area of water resources. The study describes the main technical aspects of water supply and sanitation in the city and proposed activities to increase sales and decrease per cent loss businesses Sue "Vodokanal of St. Petersburg", reflects the main regulations governing registration of water balance for other enterprises, the pros and cons of making a water balance calculation.

In work existence of microbic communities in hot water supply of Ulyanovsk is defined and biological properties of the allocated bacteria are studied.