Water filters

This term, inexact but understandable all over the world, denotes the utilities for additional treatment of water in places of final consumption. These utilities are involved in many kinds of human activities and employ considerable number of water- treating technologies – not only filtration. To be brief, let us turn our attention only to water filters used for acquiring high- quality drinking water for cooking and drinking in the households.

To acquire 1000 L of bottled water means to extract and put into bottles 1000 L of water, to deliver more than one ton of goods by both transport contractors and consumers and finally to dispose of 1000 packages made of durable materials including their liquidation.

To acquire 1000 L of filtered water means to produce and deliver a utility weighting approximately 0.08–1 kg (0.01 ton) that will be disposed of after about eight years.

These facts elucidate the incommensurability of ecological burden, high costs and technical complexity of non-water-plant ways of supplying high-quality drinking water for direct consumption. While the water-carrier was a biblical job, the designers of water filters found their job as late as in the 20th century. The development of water-plant technologies was accelerated by both the World Wars and, first of all, by the acknowledged effects of last decades' global ecological crisis upon the quality of drinking water.

Types of water filters

Efficiency of water filters

The most important condition of water filters' high efficiency is their non-overburdening by excessive flow of water. Numerical value of the prescribed water flow in liters per minute should not be much higher than the volume of the bed fillings in liters. This condition is not met by faucet filters which are usually hydraulically overburdened by one order of magnitude.

Moreover, the filter should

Efficiency of any filtering cartridge is not unlimited. The question "How shall I get to know that the cartridge is spent?" is thus pertinent. It is both possible and correct to equip the water filter eliminating (beside others) the nitrates with a control set for assessing the content of NO3- and the utility for dosing chlorine preparations by a set for assessing C12. But for each such aid the customer must pay. That is why it is sometimes sufficient – in case there is no health risk – to leave the decision upon the judgement of the user and instruct him/her, for instance, just to "exchange the cartridge of the mechanical filter when the flow becomes thinner".

Filtering cartridges filled with active coal represent a special case. They eliminate a wide range of heavy metals, organic and specific organic substances, chlorine, etc. The idea of a customer executing control is completely illusory. For the laboratory assessment of only a few indicators he/she would often pay more than for the filter itself. Moreover, the bed of active coal doesn’t absorb all the contaminants within the same period of time. The only realistic solution is a large volume of sorptive material in the filtering cartridge and an exchange of the cartridge long before its capacity is exhausted. According to the water-plant criteria the capacity of Dionela’s filtering cartridge FAM 1, for instance, is 38 000 liters. Nevertheless, the producer recommends exchanging it after two years' operation. Within this period of time an average family of four will filter less than 6 000 liters of water that is less than 16% of its capacity. The rest, approximately 84 %, is a safety reserve ensuring that even in case of the highest concentrations of the most easily "transiting" contaminants (usually carcinogenic THMs) these substances will not find their way through the filter.

Water filters DIONELA and OASA were designed to meet exactly these criteria.

Cost of filtering by the Dionela filter

Cost of water filter Dionela’s operation:
The calculation takes into account the eight-year service life of DIONELA. After exhausting its capacity the cartridge is exchanged for a regenerated one. The calculation was made for a family of four meeting all their needs of drinking water by dioneled water. That is – unlike purchasing the bottled water – financially acceptable. Eight liters for a family per day, 365 days a year for an eight year period of time… 23 360 liters of water. Compared to the bottled water you’ll get, without causing any damage to the environment and without complicated delivery, one liter of high- quality drinking water even 50 times cheaper!

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