DE4116128A1 - Purificn. of water supply for domestic consumption - by treatment with mixt. of nitrate-selective anion exchanger and weak acid cation exchanger to give germ-free, low nitrate, partially desalted water - Google Patents

Abstract

Process for producing a disinfected, low nitrate, partially desalted drinking water for domestic use comprises treating the available unrefined water with an ion exchanger mixt. consisting of at least 30% of a nitrate selective anion exchanger whose functional gps. are charged with 70-100 % HCO3(-) ions, and a weak acid cation exchanger in the H(+) form. The ion exchanger mixt. may also include 10-20 % of a strong acid cation exchanger in the H(+) or Na(+) form and a nitrate selective anion exchanger in the Cl(-) or SO4(2-) form. USE/ADVANTAGE - For preparing relatively small amts. of purified water for domestic consumption starting with normal supply water. The process can be carried out using a simple appts. which is generally in the form of a filter through which the water flows from a reservoir vessel into a receiver such as a bottle. After treatment the water is germ-free and has a low nitrate content and reduced salt content. Only small amts. of the ion exchanger mixt. are involved and pollution of the environment is very low.

Description

The present invention relates to a method for manufacturing small amounts of sterilized, low-nitrate, partially desalinated drinking water for home use.

Compliance with maximum levels of ingredients in drinking water is through physical, chemical or biological treatment of the raw water available. For softening, nitratelemi Renewal and partial desalination of drinking water using an ion exchanger many methods are described in the literature. All these ver driving are unsuitable for solving the problem of follow-up germination during the treatment or storage of drinking water, which was obtained from a domestic water supply.

The object of the invention is the known technical processes through a new uncomplicated process using ions exchangers. It should be done with simple means and without significant investment costs good effects in the extraction of hygienically perfect, low-nitrate, partially desalinated drinking have water and the generally existing regeneration problem to solve.

The object was achieved according to the invention in that the drinking water in stock briefly before use with an ion exchange mixture consisting of a nitrate-selective anion exchanger whose functional groups are loaded with 70 to 100% HCO ₃ ⁻ ions, a weakly acidic cation exchanger in the Form as main components and, if appropriate, with a strongly acidic cation exchanger in the H⁺ or Na⁺ form and a nitrate-selective anion exchanger in the Cl⁻ or SO ₄ ^- form. The proportion of the anion exchanger in the HCO ₃ ⁻ form should be at least 30 percent by weight in the mixture. The strongly acidic cation exchanger optionally contained in the mixture as well as the nitrate-selective anion exchanger in the Cl⁻ or SO ₄ ^- form are contained in the ion exchanger mixture in each case in a proportion of 10 to 20 percent by weight.

The ion exchange mixture used can be of benefit to the consumer in a filter device of various types to the consumer upstream. So z. B. in coffee or tea making tion in the commercial household appliances used for this the ion exchange mixture in a suitable manner (e.g. in containers, Filter, bag). The existing water flows through the ion exchange mixture and is after the exchange of disinfection directly used for the purpose. The forced passage can course of the water can be controlled. When the temperature rises the exchange effect will improve.

Advantages of the method according to the invention are the low outlay amount of the ion exchange mixture, a short contact time with the water, a high efficiency in the removal of germs, of nitrate and salt reduction. The environmental impact becomes very kept low. In contrast to known methods, it is excluded Lich the amount of water required for food preparation.

The invention will be explained using the following exemplary embodiments will.

example 1

Example 2

Claims (2)

1. A process for producing a sterilized, low-nitrate, partially de-salted drinking water for domestic use, characterized in that the raw water present is mixed with an ion exchange mixture consisting of at least 30% of a nitrate-selective anion exchanger whose functional groups contain 70 to 100% HCO ₃ ⁻- Ions are loaded, and a weakly acidic cation exchanger is treated in the H⁺ form. 2. The method according to claim 1, characterized in that the ion exchange mixture used further comprises a proportion of 10 to 20% each of a strongly acidic cation exchanger in the H⁺ or Na⁺ form and a nitrate-selective anion exchanger in the Cl⁻ or SO _4th ^- shape contains.