SU1678770A1 - Method for disinfection of potable water - Google Patents

Abstract

The invention relates to methods of treating water with ultraviolet light and bactericidal agents and can be used to disinfect and preserve drinking water in various areas of the national economy. The aim of the method is to increase the speed of the disinfecting effect while ensuring the preservation of water, simplifying, cheapening and improving the environmental safety of the water treatment method. For carrying out the process, drinking water is sequentially treated with ultraviolet light at a dose of 0.24-0.325 mJ / cm2 and an antimicrobial agent, copper (II) ions in the amount of 0.75-1 mg / l. The method reduces the time of the disinfection process in comparison with the known one by a factor of 2 while reducing the irradiation dose, while maintaining a preserving effect. 3 tab.

Description

The invention relates to methods of treating water with ultraviolet and bactericidal agents and can be used to disinfect and preserve drinking water in various areas of the national economy.

The aim of the invention is to increase the rate of decontamination while ensuring preservation, simplification and cheapening of the method.

For carrying out the process, drinking water is successively treated with ultraviolet light at a dose of 0.24-0.325 mJ / cm and an antimicrobial agent with copper (II) ions in an amount of 0.75-1 mg / l.

The use of ultraviolet itself for 100% death of Escherichia coli in water requires a dose of UV radiation of 3-6.6 mJ / cm. At a dose of 0.325 mJ / cm2, only 26% of the introduced cells die.

The use of copper ions at a concentration of 1 mg / l Cu (II) for complete disinfection requires 2 hours, and 2.8 NO3 cells / ml remains alive for 30 minutes using the proposed method of 107 cells of microorganisms.

Comparative data are presented in table.1.

A dramatic increase in the decontamination efficiency when combining a low dose of UV irradiation (0.24-0.325 mJ / cm2) and copper at the level of PKD (0.75-1 mg / l) is observed at a high initial infection rate of 107 microbes in 1 ml of water, however, a preservative effect is also achieved.

The combination of small doses of ultraviolet radiation (0.325 mJ / cm2) and hydrogen peroxide in coO vj 00 4 XI O

At 5 mM, in 30 minutes, a residual concentration of E. coli 8-105cl / ml (80%) is achieved.

Example. According to physicochemical parameters, water complies with the requirements of GOST 2874-82 Drinking water is contaminated with E. coli microorganisms in the amount of 107 cells / ml. 20 ml of contaminated water are placed in a glass tube and, while stirring on a magnetic stirrer, irradiated with ultraviolet light from A 257 km at a dose of 0.325 mJ / cm2 (10 seconds with an argon-mercury low pressure lamp D5-30 placed at the object) . Then, 0.2 ml of a CuSo4 7H20 solution with a concentration of 0.1 mg / ml is added (the concentration of Cu2 + in the working solution is 1 mg / l) and at time intervals of 10.20.30 and 60 min samples are taken to determine the number of surviving cells. .

The amount of copper and irradiation doses are selected from the conditions that ensure 100% disinfection of water contaminated with 10 microbes per ml, for the shortest possible period of time.

The effect of the parameters on the efficiency of the method is shown in Table 2.

Reducing the dose of ultraviolet radiation, as well as increasing it, leads to a decrease in the disinfecting effect, which is expressed by an increase in the time required to achieve 100% death of microorganisms.

A decrease in the concentration of applied copper leads to the same result. The upper limit of the concentration of copper is limited to the MPC in water according to GOST 2874-82 Drinking water.

In order to confirm the preservative effect of copper ions in the water treated by the proposed method and known 3 days after the treatment, microorganisms were additionally added in an amount of 10 cells / ml. After 10, 30 and 60 minutes after the infection was carried out, water samples were taken and the content of surviving bacteria was determined. The results of the analysis are given in Table 3.

As follows from Table 3, 60 minutes after the introduction of an additional infection, the water treated by the proposed method is completely disinfected again, and the water treated by a known method

remains the same degree of contamination.

Compared with the known, the proposed method has the following advantages:

- increases the efficiency of disinfection, which is characterized by a decrease in the duration of the disinfection process from 60 minutes to 30, i.e. 2 times;

- makes it possible simultaneously with decontamination to achieve a preservative effect;

- is distinguished by ease of implementation, because does not require a chemical reagent to produce hydrogen peroxide;

- the method is cheaper and less energy consuming due to the use of widely available copper and the use of low doses of radiation;

- A more environmentally friendly and harmless method of water treatment is provided.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION Method for disinfection of drinking water, including irradiation with ultraviolet light followed by the introduction of an antimicrobial agent, characterized in that, in order to increase the rate of disinfection while maintaining water conservation, simplifying and cheapening the process, copper (I) ions are used as an antimicrobial agent. in an amount of 0.75-1 mg / l and irradiation with ultraviolet light is carried out in doses of 0.24-0.325 mJ / cm2. Table 1 Table 2 Ta bl and cz