Hidrológiai Közlöny 1959 (39. évfolyam)

1. szám - Dobos Alajos–Páter János: A homokszűrő baktériumvisszatartó képességének vizsgálata

66 Hidrológiai Közlöny 1959. 1. sz. Dobos—Páter: A homokszűrő baktériumvisszatartó képessége B uejiíix pa3pa6oTKH MeTOfla iicnbiTaHutt np0B0flHjiocb h npedeapumeAbHoe ucnbimamie. Ilo xo/iy 3Toro HcnbiTaHHH Mepe3 Ka>Kflbie «Ba naca npoaejiajiiicb cjieflyioinHe onepaunn : а) nyTeM oöieMHoro MeTOfla onpeAejimicH pacxoA BOAbi, npoxoAHBinefl Mepe3 ij)HJibTp (cfiue. 3). б) 3aMepaJiocb BpeMH $HJibTpanHH boám npii ee 10-n cm-om cjioe Ha (jmjibTpe (<pm. 4). e) b uejiflx onpesejieHHH KOJiHMecTBa GaKTepHÍi Coli B3HJiacb npoöa boám H3 pe3epByapa-CMeumBaTejifl (OOTO 1), H3 BOAbi, HaXOAHmeííCH HaA $HJIbTpOM (Ooto 2), H3 cepeAHHbi necHaHoro (})HJibTpa b 30 cm-om rjiyöHHe (O0T0 4 5), M 113 npO(j)HJIbTpOBaHHOH BOAbi (Ooto 6). e) 3aMepHJiacb TeMnepaTypa boau b pe3epByape h BHyTpii necMaHoro (jwjibTpa. noApoÖHoe HccJieAOBaHiie npoBOAHJiocb b paMi<ax 24-x AneBHoro iicnbiTaHHíi. 3aTonneFine ocymecTBUHJiocb c BbicoTofl boahoh noAyuiKH He b 10, a b 5 cm. B TeneHHe nepBbix 54-x nacoB HenpepbiBHO 3aTonjiíJjicji boaoh c rjiyöiiHOH b 5 cm, 3to CAejiajiocb TorAa, KorAa BOAa npo(JiHJibTpOBajiacb. Hamman c 3Toro, 3aTonjieHiie iiobtopsijiocb Mepe3 KawAbie 2 Maca ao 120-ro naca ncnbiTaHHH, a n0T0M qepe3 Mac. 3to CAenajiocb a->iíi oöecneHeHHH BeHthjihuhh (j)HJibTpa. HHTerpajibHan KpHBaji pacxoAa BOAbi, npoxoAHBiueíi iepe3 ijmjibTp npHBeAeHa Ha <pueype 6. B uenHx onpeAejieHHH MHCJia 6aKTepHH Coli B3HTHe npoö boám cHOBa noBTopjuiocb b MeTbipex MecTax : а) H3 npO(})HJlbTpyeMOH BOAbi HaA <j)HJIbTpOM ((j)OTO 7). б) H3 npcAnojiOJKeHHOÍi ÖHOAOrHiecKOH njieHKH c rjiyŐHHM 1,0—1,5 cm ot noBepxHoc™ (J

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3 ctJiopMHpoBajiacb othochTeJIbHO ÖblCTpO H pe3yjIbTaTHBH0. 2. Ko3(J)nuHeHT noJie3Horo aghctbhji necHaHoro (})HJibTpa npM oniicaHHbix ycjioBHHX BcerAa 6bin okojio 90% n Bbinie. 3. BepxHHii cjioíí neciaHoro 4>HJibTpa c tojhahhoíí 50% 3a BpeMH HcnbiTaHim HacTOJibKO HacbnuHJicíi 6anTepHHMH, MT0 OH paÖOTajI C OTJlHMHblM K03(j)HUHeHT0M nojie3Horo a£hctbhh h nocjie oÖMeHa BepxHiix cJioeB h yAajieHHH npeAnojio>KeHHOÍi ÖHOAOrHMecKOtt njieHKH. C(J)OpMJieHHe H0B0H ÖHOJIOrHMeCKOH njieHKH OCymeCTBHjiocb 3a 10—12 qacoB. 4. BjiaroAapn HarpyweHHio c SaKTepnoíJiaroM, npeAn0Ji0>KeHH0H ŐHOAorHHecKOíí njieHKoil h aACopimiBHOií cn0C06H0CTbi0 necnaHoro (JiHJibTpa CAejiaeTCH BepoHThmm 3aAep>KaHHe h -SaKTepiio^ara. flpaKTHMecKHM 3HaweHHeM SToro MOweT ciHTaTboi to, hto ko3(J>hi;hcht nojie3Horo AeöcTBHH necMaHoro (JtH^bTpa ÖHOJiorHHecKH MOMceT cTaTb SoAee MHorocTopoHHHM b cjiynae Hacbimehhh necnaHHoro (JiHJibTpa 6aKTepH0(J>ar0M. 5. MoAeAHpoBaHHH noi<a3ajiH, mto c tohkh 3peHHH ycjiOBHH BOAonpoHHuaeMOCTH, BeHTHJiímHH necnaHoro (J)HJibTpa HMeeT Sojibmoe 3HaneHne. Investigation into the Bacteria-Retaining: Ability of Sand Filters By A. Dobos and J. Páter, Candidate of. Medical Sciences Experiments aiming at the determination of the bacteria-retaining ability of sand filters were carried out at the I. Institute for Hydraulics, Technical University, Budapest. The problems to be answered by these experiments were : the time required for the development of the biological film, the time required for the redevelopment of the film after a break-through, variation in the bacteria retaining ability, i. e., efficiency of the filter with time. Bacteria of the Escherichia Coli aerogenes species was introduced into the water to be passed through the filter, this species being harmless to humán organism, and, because of the characteristic growth of cultures —, readily discernible from those of other polluting bacteria that may have entered during the experiment. The equipment used for these experiments and a section through the sand filter are shown in III. 1 and Fig. 1, respectively. It has been endeavoured to maintain the bacteria coneentration in water passed through the filter constant during the entire period of the experiment, for which purpose fresh cultures have been added from time to time. In order to establisli the most practical method a pilot test with a duration of 48 hours was alsó carried out. In the course of the latter the following steps were undertaken every second hour: a) measurement of the water quantity passing through the filter, by volumetric methods (Fig. 3) b) measurement of infiltration time of 10 cm deep water cover on the filter (Fig. 4) c) in order to de termi ne the Coli bacteria count, samples were taken from the mixing tank (III. 1), from the water covering the filter (III. 2), from the center of the filter, from a depth of 30 cm (Ills. 4 and 5) and from the filtered water, d) water temperatures in the mixing tank and within the filter were measured. Detailed investigations were carried out during an experiment of 24 days duration. The filter was flooded with a 5 cm deep cover instead of a 10 cm deep one. The 5 cm deep cover was maintained continuously during the first 54 hours, i. e., the 5 cm cover was reestablished whenever the previous dose seeped into the filter. From this time until the 120th hour flooding was repeated every second hour, and from then on hourly, to permit ventilation. The totál water quantity passing through the filter is plotted in Fig. 6. In order to determine the Coli-count, samples were again taken from four points : a) from the water cover above the filter (III. 7) b) from the assumed biological film, from a depth of 1,0 to 1,5 cm below the surface of the sand filter (III. 8) c) from the center of the sand filter, i. e., from a depth of 30 cm below the sand surface (III. 9), and d) from the filtered water (III. 10). Results obtained are compiled in Figs. 7 and 8. Conclusions can be summarized as follows : 1. The 24 days investigation of the bacteria retaining ability of the sand filter revealed that when filtering water which contains Coli bacteria in a coneentration of 1 million/cu. cm, the assumed biological film developed fairly readily and effectively. 2. Under conditions described the average filtering efficiency was not smaller than 90 per cent. 3. During the experiment at least the upper half of the sand filter became saturated with bacteria to an extent that the filter was capable of operating at an unchanged efficiency even after the exchange of upper layers and the removal of the assumed biological film. A new biological film developed in 10 to 12 hours. 4. On basis of test-loads containing a bacteriophag it may be assumed that the adsorptive capacity of the assumed bacteriological film and the sand filter may result in bacteriophage retention as well. This circumstance may be of practical significance, inasmuch as the biological effect of bacteriophage saturated sand filters may become more variegated. 5. As indicated by scale model tests, the ventilation of sand filters is of appreciable influence on permeability characteristics of the latter. /