Hidrológiai Közlöny 2006 (86. évfolyam)

3. szám - Kaposvári Kázmér: Effect of the intervening ozonizing and Biologie Activated Carbon treatmant to drinking water produced by water supply intake at the River Tisza Szolnok

24 HIDROLÓGIAI KÖZLÖNY 2006. 86. ÉVF. 3. SZ. be related to the cooling and the consequential destruction and bacterial decomposition of algae masses and other orga­nic matters. The ammonia content reduced the efficiency of the chlorine sterilization applied in the water plant. The ste­rilization effect of the resulting mono-chlorine amine is ab­out 1/20 of the nascent chlorine (OCT /HOCI mixture) whe­reas the THM formation remained active. (Bermann D., 1988, Kreft P., 1985, Kárpáti Z. - Palicska J., 1981 ) The occurrence of iron and manganese in the treated water was typical in every case when the whole surface of the river was frozen. In January 1985 the Mn 2 + ion concentration was 0,7 mg/1 in the distribution network for a couple of days which created damages in the laundries of the medical insti­tutions and in many households. Table 1: The variation of the frequently complained water quality parameters after the technology developments (* Restricted to the duration of solid freezing, ** On the edge of the biological stability) In 10 % of the monitored cases the oxidizable organic content of the potable water did not meet the criteria contai­ned in the relevant standards, by default. The consequences of the higher organic matter content resulted in bacterial stability. According to the results of a few informative tests the absorbable carbon (AOC) is around 100 - 120 |ig/L. The regrowth and the aftergrowht contamination could be pre­vented only by applying 0,8-1,2 mg/1 chlorine with continu­ous dosing. This has resulted in the approximately c x > 80 Hg/I THM and c x> 50 ng/1 AOX. In relation with the residual organic matter the presence of toxic organic micro contaminants must also be mentio­ned. In 1988, the regular GC-MS measurements carried out by the Technology Institution of the University of Debrecen provided factual proof for the presence of biological com­pounds resulting from the manufacturing of insecticides and their agricultural utilization, from the production of dye stuff, plastics and pharmaceutical materials as well as from oil and lubricant contaminations. [10.] The group indication Daphnia tests showed xenobiotical infections in 10% of the monitored cases. 2.2. Quality of raw water entering into the water plant The catchment area of the Tisza river is 154039 km 2, from which 70% falls outside the boundaries of Hungary. This is a river of moods both in respect of hydrological be­havior and water quality. The greatest gauge difference is AH-13,36 m. The flow varies between Q mi n = 65,6 m 3/sec and Q nla x = 2610 mVsec. (Makiéit S. - Dinya Z„ 1988, Ka­posvári K., 2000). In the water quality of the Tisza river, the following specific water quality stages can be identified: A) „Standard, typical water quality", which is set by the origin of the water, by the natural components, the steady and regular emissions and the self cleaning processes. A co­uple of the parameters even of this stage provide ground for the complaints on the water quality. The strange taste and o­dor effects in the raw water are practically continuous, but their nature varies. The turbidity - apart from a couple of weeks in the summer — is steadily between 20-40 NTU. The amount of oxidizable organic matter (chemical oxygen de­mand) is 5-10 mg/1, but the absorbable carbon content (AOC) of the chemical oxygen demand always exceeds 100 Hg C/L with using simple treatment - flocculation +filtering - processes. In the evaluation of the raw Tisza water the ex­ternal primary contaminants can not be ignored. The pre­sence of a few compounds, like nicotine, benzpyrene, penta chlorine phenol, etc. shows the importance of these groups. (,Palicska J. - Csépay F. - Káda GY„ 1983) B) The intermediate water quality statuses are the re­sults of the seasonal processes coming regularly in the life of the river. While the cooling at the end of autumn, the to­tal freezing during winter, the melting and flood waves in springtime and the warming in August-September (26 C°) cause extreme overproduction due to transillumination, the­se effects result predictable changes in the quality of the raw water - Table 2. However, the processes of a simple treatment technology are not effective enough to reduce the concerned water quality parameters to the acceptable level. Table 2: Regular, seasonal raw water quality stages Event Period Tem­pera­ture (°C) Odor (Ball) Turbi­dity (NTU) Alga numb.+ Num­ber/L Zoo­plankt. Numb. IL Specific factors Cooling at the end of Autumn October­Novem ber 18­4 Vege­tative 30-40 1 -3 x 10 5 ­NHV NHJ, Taste Total free­zing at Winter­time January­February 0,2­0,4 Strong chemi­cal, mud 6-20 <2 x 10 s ­Fe 2 +, Mn 2 +, Oil Spring flood April 4-5 Mud >600 <2 x 10 5 ­Toxic com­pounds Summer biological overpro­duction August­Sep­tember 22­26 musty, fish < 10 5 x 10 6 Aleo­soma sp. Alga, Zoo­Plank­ton C) The emergency and catastrophic situations create unforeseeable type and extent of water quality problems. Unfortunately the occurrence of these cases is factual in the life of the Tisza river. From 1980, 14 foreign originated e­mergency situations have been occurred which were not re­ceiving even a similar publicity as the one did in 2000 when a foreign cyanide and toxic metal contamination has happe­ned. These emergency quality parameters and situations are typically created by industrial accidents, where usually a few type, but significant amount of material reaches the wa­ter and creates a catastrophic situation in the river itself. Component Tisza­water Potable water Component Tisza­water Original process Enhanced process Component Tisza­water Value of the component Com­plaints (%) Value of the component Com­plaints (%) Odor (Ball) P 3 P 2 P 3 >30 0 0 Taste (dilution) h J 3 (reagent) >25 0 0 Chemical Oxy­gen Demandps (mg/1) 5-15 2,5 - 4,0 10 0,65-1,15 0 TOC (mg/1) 6-8 3-5 ­1,1 - 1,4 ­Iron (mg/1) 0,1-0,7 0,1 -0,4 < 10 Not detect. 0 Manganese (mg/1) 0,1-0,6 0,05 - 0,3 * Not detec­table 0 Turbidity (NTU) 8-600 <2,0 >5 <2,0 0 Alga (number/L) 0,8- 5 x 10 6 1 x 10" - 1 x 10 5 >70 100-500 0 Zooplankton (number/L) 5 x 10' 1 x io 4 0-1,1 X 10 5 ­0- 1 x 10 2 0 Dapphnia complaint (%) 45 18 ­0 0 Actual chlorine demand (mg/1) 1,5-3,0 0,8-1,2 ­<0,25 ­AOC (Mg/1) ­80 ­25-30 ** AOX (/ig/l) ­40-50 ­25-30 **

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