INTERNATIONAL ASSOCIATION FOR
                                    THE DEVELOPMENT OF EDUCATION IN VIETNAM ( AIDEV )

                            DESCRIPTION OF A MINI-SYSTEM FOR PRODUCING CLEAN WATER

The process of water production is continuous and thus is very practical for water distribution. Grossly speaking, the system consists of three pomps, a vat of decantation ( eventually a spare vat ) , and a group of pipes linking the different elements.

1. The entrance .

The entrance is a pomp drawing the water of a source (pool, river, lake or quite other source of fresh water), called feeding pomp and which pumps the water to be treated in a pipe up to the point PC1. This pomp has a capacity of 14m3 / hour.

2. The injection of chemical N°1.

At the point PC1 is put a doseuse pomp. Chemical N°1 is dosed beforehand and stocked in one bowl placed next to the pomp. It serves for making coagulate the solid elements ( impurity ) contents in thewater. The doseuse pomp N°1 inhales the chemical of the bowl and injects it into the circuit the point PC1 to a rhythm dosed beforehand.

3. The injection of chemical N°2.

Water containing coagulated impurity circulates in pipe up to the point PC2. At this point is placed another doseuse pomp N°2 and next to this one a spare bowl of the chemical N°2 dosed in advance. Chemical N°2 serves for making floculate the impuriies that are already coagulated in the water. The pomp N°2 inhales the chemical N°2 of the bowl and injects it into circuit in the point PC2, according to one
rhythm dosed beforehand. The water containing elements already floculated circulates, under the pressure of the feeding pomp, in piping up to the vat of decantation.

4. Vat of decantation.

The vat of decantation was conceived thanks to a software of application. Its form, its dimensions, sound vent being calculated in a optimum manner to guarantee that floculated impurities go down quickly to the bottom of the vat.Clean water, already cleared out from impurities is in the upper part of the vat and can be simply withdrawn regularly thanks to its weight across one conduit placed at the top of the vat. The surface of water above the vat is equipped with an supplementary implement allowing to eliminate the floculated impurities which float there. Residual impurities deposited at the bottom of the vat can be evacuated regularly or through a pipe to a nearby place without the risk of pollution because the chemicals N°1 and 2 are of natural origin and disappear by themselves.

5. The addendum of a spare vat.

The mini-system of production of clean water in principle stop at  the point where water is withdrawn from the end pipe which is placed at the top of the vat of decantation. Depending on the local situation and particular characteristics of use (the rush hours ), the users may need a spare vat ( for instance one of 20 m3 ) and a pomp of distribution to harmonize the rhythm of use. This belongs to the province and payable by the users. Eventually, one may add another doseuse pomp containing a desinfectant ( chlore )