Vízügyi Közlemények, 1935 (17. évfolyam)
Kivonatok, mellékletek - Kivonat az 1. számhoz
23 serves for a reaction room without filter material. As additional features of the installation, there are 6 one-chamber filter tanks on the Dabeg system, filled with active carbon ; they are 4-0 m high and 2-0 m in diameter. Furthermore there is a decarbonization device working with aeration, made of reinforced concrete. Process of the water purification : The chlorine, in a quantity determined by practical experience, is dosed into the raw water pipe before it joins the filters. The clorinated water passes through the reaction room, then enters the filter room. Part of the dissolved metals (the iron content almost entirely) is oxydized in the reaction room to such an extent as to be removable in the upper part of the filter layer by mechanical filtering. In order to remove a sufficient proportion of the manganese, it is desirable that the iron shall he retained in the upper part of the filter layer. The manganese that is not precipitated in the reaction room, is removed by chemical filtering in the middle and lower part of the filter material by the absorption effect of the manganese peroxide layer [»laced on the surface of the filter material. When chlorine is added in a suitable quantity, the activity of the manganese peroxide is constant, so that it is not necessary to regenerate it from time to time, which would require intermittent operation. The effluent of the quartz sand filters is free from iron and manganese, but it contains on an average, 1-5 ppm of chlorine. The residual chlorine is removed in the active carbon filter. The dechlorinizing effect of the carbon is an absorption phenomenon, and its rate depends on the porosity of the carbon. In our operation there is also no need to regenerate the carbon, because with filters on the Bollmann system organic matters decreasing the dechlorinizing effect, are removed by turning over and rubbing up the filter material. The washing of the quartz sand and carbon filters is done with chlorinated water, partly for bacteriologic, partly for chemical reasons. The quantity of the wash-water is under 2% of the water treated. The effluent of the carbon filter contains much carbon dioxide and no dissolved oxygen, therefore the water is of aggressive character and has to be decarbonized. To protect the water from bacteriologic contamination, the decarbonization is carried out in closed chambers that work by aeration. The air conducted to the decarbonization chambers and their protecting building passes through bacterium filters. The device serving to disperse the water is formed in such a way as to suck in the air needed for decarbonization, without any mechanical dosing of the air. Table 2 shows the variations in the composition of the water during the process of the treatment. The iron and manganese content of the raw water is 3-5 ppm. on an average, and it contains ammonia, nitrite and organic natter in a considerable quantity. The treated water is free from iron and manganese, and is unobjectionable from the chemical and bacteriologic point of view. VII. SOILS EROSION A NATIONAL MENACE. By H. H. BENNET and W . R. С HA PINK. Translated by K. GUBÁNYI. Translation into Hungarian of the original article published in the U. S. Dept. of Agric. Giro. 1928. Nr. 33.
