SU948894A1 - Method for decontaminating effluents from vegetative form of bacteria - Google Patents

Description

(5) METHOD FOR DISINFECTING SEWAGE WATER FROM VEGETATIVE FORM OF BACTERIA

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The invention relates to methods for disinfecting CB from bacterial contamination and is used primarily in the disinfection of domestic water.

There is a known method of disinfection of wastewater (CB) in an acidic medium, characterized by a high efficiency of disinfecting water from Escherichia coli, and this indicator of water purification does not depend on changes in the composition of wastewater. Domestic water in most cases have a slightly alkaline nature of the medium. The implementation of the decontamination process with the use of acid / determines the change in pH from 8.0 to 1.0. Before discharging into the sewage system, it is necessary to raise the pH of the disinfected water to a pH of 6.5 7.0 SE.

Such variations with pH during the processes of purification (disinfection) of water do not

respond to the rational use of natural resources.

There is also known a method for disinfecting CB with bleach. Wastewater before treatment with bleach is subjected, if necessary, to alkalization by mixing with alkaline solutions. The high efficiency of wastewater disinfection with the method is guaranteed only by the preliminary removal of C2J suspension from them.

The disadvantage of this method is that the efficiency of the process of disinfecting water to a large extent depends on the level of contamination of CB suspended solids and on the degree of dispersion of impurities. An increase in organic impurities in water leads to an increase in the acidity of 20 CB and to an increase in the protective role of these impurities in relation to bacteria. Disinfection of water with chlorine is usually carried out as the final stage of water cleaning. When poor clarification

water does not exclude the likelihood of non-. complete decontamination, the consequence of which is the persistence of bacterial danger. Provision (A certain excess of bleach in CB does not contribute to an economical consumption of reagents and, in some cases, requires the degassing of decontaminated waters before discharge to prevent their corrosive danger.

The most useful to the proposed technical essence and the achieved result is the method of decontamination of CB, which consists in the processing of the latter in two stages: qc-ds in suspended alkaline medium. impurities from water and then disinfection of the precipitated suspension with chlorine gas NW 1. Deposition of suspended impurities in JQ SB occurs at pH 11 due to coagulation of protein contaminants. With this pH value, the sedimentation of the suspension from the water occurs, and a further increase in alkalinity of the preheat ensures decontamination of the DM and the settled suspension.

The aim of the invention is to increase the degree of decontamination and simplify the process.

The goal is achieved by the fact that according to the method, wastewater treatment from the vegetative form of bacteria is carried out with alkali at pH 13.8I. .

The method is carried out as follows:

Domestic domestic wastewater entering the settling tank-averager. The averaged waters are sent to a contact tank, to which an alkaline milk of lime milk is supplied from the tank. Gradually, the pH of the medium in the tank is increased and adjusted to It. . Disinfection of water in an alkaline medium with pH} k occurs during the two-hour contact of bacteria at room temperature. After settling, the disinfected water is sent to a neutralizer, where a solution of sulfuric acid from the tank is fed. Water after such disinfection is discharged into the sewer. In such waters, there are no live bacteria of the vegetative form; therefore, they do not constitute a bacteriological hazard after purification.

In addition, water disinfection can be achieved already in the first stage of purification without first clarifying the CB and thereby eliminating the bacteriological hazard in the subsequent stages of water disinfection from other types of pollution.

Example. Contaminated tap water is utilized by the bacteria most commonly found in household sewage. Agar cultures of Escherichia coli (E.SoP, 7904), staphylococci (St. aurens, T-23), brucel (Bg. Abortus, 19) and Listeria (L. monocytogenes, T-yi) of two-day growth are introduced into water samples. The pH of the samples to And and above by adding alkali and after two hours, the samples are neutralized with sulfuric acid. From neutralized samples, seeding is carried out on appropriate nutrient media. In a subsequent study, it was carried out according to the generally accepted method of microbiology. The effectiveness of water disinfection is judged by the absence of viable bacteria in water and sediment samples. The research results are presented in Table. 1 (the object of study is the analyzed CB sample with a concentration of microbial bodies in 1 ml). In tab. Figure 2 shows the dependence of water disinfection on pH (water infection density of 510 -510 microbial cells in 1 ml).

Claims (1)

Claim A method of disinfecting wastewater from the vegetative form of bacteria, including alkali treatment, characterized in that, in order to increase the degree of disinfection and simplify the process, the treatment is carried out at a pH of 13.8-14.