DD156905A1 - METHOD AND DEVICE FOR DISINFECTING WASTEWATER BY INCORRECT ADDITION OF CHLORINE PRAEPARATES - Google Patents

Abstract

The invention relates to the field of chemical wastewater disinfection. The disinfection of wastewater from sanitary slaughter stations in slaughterhouses and infection departments in hospitals is carried out by means of chlorine or chlorine injections. Solution according to the invention: The addition of the disinfectant takes place in several small doses in succession, whereby a lower reduction in germs is obtained with a small amount of chlorine. The mixture of the waste water with the disinfectant is carried out in a reactor which is designed so that an intimate mixture is achieved by the turbulence generated therein. The reactor is designed so that it has no easily worn and moving parts.

Description

Field of application of the invention .:

The invention relates to a method for reducing the bacterial count in wastewater, preferably in waste water from slaughterhouses C. Sanitätsschlachtstellen); and hospitals (, Infection Department). Treatment with chlorine preparations, preferably with uhterchlorigsäure or their compounds, as well as a device to be used.

Characteristic of the known technical solutions:

It is known that by the addition of chlorine preparations, in particular by the addition of hypochlorous acid or their compounds, by cell wall diffusion living cells are killed. It is also known that immediately after the addition of these chemicals, a sudden decrease in the number of germs is recorded (primary Keimzahlsturz), this primary Keimzahlsturz is the more effective, the faster the mixing of the chlorine preparation with the wastewater and the greater the excess chlorine. The required high chemical fertilizer results in increased chemical costs and errors in sewage disposal and treatment facilities. If the disadvantages of hypochlorination are avoided, larger reaction tanks (60 minutes later) or dechlorination with appropriate chemicals (eg sodium thiosulphate) are required, which in turn leads to increased costs. It is achieved by combining chlorine gas with bromides or iodides or ozone with Broraiden and iodides a chemical disinfection of water and sewage is proposed. Simultaneous application

Chlorine dioxide and chlorine are known.

As a device for chlorination are discontinuous plants.

known, the tax expense is complicated and expensive.

Object of the invention:

The aim of the invention is to minimize the addition of disinfectant to the disinfectants and to use simple chlorine preparations C sodium hypochlorite solution or chlorine solution X- to minimize the cost of the chemicals, the disinfectant excess and the disturbances in the effluent discharge and treatment facilities to make it insignificant. Furthermore, with the device, it is intended to find a continuously operating solution which is easy to manufacture as well as easy to operate. Complicated control technology should be eliminated «.

15Darleg.ung. the essence of the invention:

The invention has the object to ^: basically, with simple. Disinfectants. (, Hypochlorous acid or its salts) '. and a simple device to achieve a sufficient microbial reduction in the wastewater without having to use amounts of chlorine which lead to such: chlorine excess concentrations that damage can occur in the systems of wastewater discharge and treatment. According to the invention the object is achieved in that small chlorine doses in short time intervals between three and four minutes' several times successively added to the wastewater. As a result, a primary Keimzahlsturz is generated with each addition.

The amount of disinfectant solution added depends on the chemical composition of the wastewater, as well as on the initial and required final germ count and should be determined experimentally beforehand. The primary bacterial decline is at. the same composition of the waste water always the same proportion of the initial germ count in the respective dosing process. In this respect, there is the possibility between, the parameters - start and Endkeirazahl

- Number of dosing operations

- amount of disinfectant solution per addition process

to optimize in order to obtain the required germ count reduction at the required maximum permissible excess chlorine quantity. «The determination of the parameters can be made according to the formula;

^N t ^{= N} o * ^ ⁿ take place.

H = germ count at the end of the degermination process N. = germ count at the beginning of the sterilization process ^ = proportion of residual germs per dosing process

1On = number of dosing operations. ,

The addition should be continuous * For this purpose, a simple device is used, which is installed in the waste water pressure line. This is an intimate mixture of disinfectant and wastewater.

The device (,, PIG. 1)} is designed as follows:

A planter 1 is bolted to an upper cap 2 and a lower cap 3. In this tube is an outer slices welded pipe 4 and in this one. inner tube 5 welded with discs inserted. At the lower closure lid 3, a feed pipe 6 is guided through the main pipe, through which the waste water is introduced into the mixing device. Next to it is the supply nozzle for the disinfectant 7. The sewage-disinfectant mixture must now pass through the outer lower ring. "At the aperture 8 it enters the inner ring. In the 2 »layer, the wastewater passes through the opening 9. There it passes the inner and then the outer ring to pass through the opening 10 in the 3 · layer, which in turn is designed as the first. After sufficient flow and reaction time, ie three to five minutes, a further addition of disinfectant is appropriate. The number of disinfectant additions is determined as previously explained

 The uppermost layer is designed so that the mixture 'first the

inside and then the outer ring happens. The discharge of the sterilized mixture through the nozzle 11 »Ggfls. several devices can be operated in series »The cross-section of the individual catches is to be selected depending on the amount of water and dimensioned so that the required turbulence is achieved. To clean the mixing device, the blind flange 1 and / or 2 can be loosened and the tubes 4 and / or 5 pulled out and cleaned. "

Ausivhrungsbeispiele:

The invention will be described below with reference to two embodiments! explains:

Embodiment 1: The waste water of an infection department

6-1

with a total germ count of 10 ml. is down to one germ count

2 -1 of .10 ml to reduce. By adding 7.5 mg of chlorine / 1. as sodium hypochlorite ("sodium hypochlorite"). ' is a germ reduction around SOfo possible »Uni the demanded reduction up to

2 -1

To achieve 10 ml, four doses of 7.5 mg / 1 chlorine each are required. The added amount of chlorine is 30ng / 1 in total. The expected chlorine surplus is TO - 12 mg / l.

To the same Keimzahlreduzierung in. Once added, the multiple amount of chlorine is required (about 70-80 mg / l). The chlorine excess is then about 40-50 mg / l. The wastewater of the infection department is to be pumped from a storage tank by a mixing device with four Chlorzugabestellen to promote. The term should total about 12 minutes, amount. Then the desired germ reduction is achieved »

Embodiment 2: At. Carrying out epidemic slaughter in a slaughterhouse, disinfection is required for all wastewater containing sodium hypochlorite. The chlorine excess should be kept as low as possible. There are four sewer manholes from the confluence shaft of all infectious waste water to the point of discharge into the municipal sewage system. The whole. Flow time is 20 minutes. The shafts are approximately equal

5 -1 far apart. The germ count of 1o ml is up

2 -1

1o ml to reduce. J5s is possible to add chlorine in four places. As a result, a primary germ count reduction of 82 % would have to be achieved per addition. The required quantity of chlorine must be determined by tests. "Dosing devices must be attached to the four addition wells and the disinfectant introduced into the wastewater.

Claims (3)

Claim: 1, method for disinfecting wastewater, such as wastewater from sanitary and epidemic slaughterhouses, infectious departments of hospitals, etc. to achieve the hygienic view required germ counts, characterized in that the known addition of chlorine preparations, in particular sodium hypochlorite (chlorine bleach) and chlorine gas solution with continuous flow of the waste water in several doses in succession « 2. The method according to item 1, characterized in that with continuous addition 'of chlorine preparations directly into the turbulent flow in the precipitation sewer pipe at several points in succession, either from a common or from several individual Dosiergefäßen. 3 · Device for carrying out the method according to item 1, characterized in that in an outer tube shell 1 two nested tubes 4 and 5, which are provided with welded plate-like plates, are introduced, so that in the. emerging channels as it flows through the wastewater-dosing agent mixture turbulent flow is formed and a good mixing of the media takes place, which supports the primary Keinzahlsturz «