Integrated disinfection process flow scheme in the public water supply system of Budapest

Summary

The biggest in European Union UV water disinfection complex has been successfully operated at Kmegier, the Budapest water treatment plant with a capacity of 600,000 m3/day in Hungary. The municipal water supply system uses surface waters as a water source (The Danube River). The water body is not protected from possible input of various pathogens that can cause serious infectious disease outbreaks among the population. In addition viruses and cysts of pathogenic protozoa are highly resistant to traditional chlorination. The experts of Budapest water supply system Fvrosi VZMVEK Zrt. in cooperation with Russian LIT Scientific-Production Association carried out a series of tests at the pilot unit as a part of serial DUV 150/21 UV-system with low pressure lamps; and then industrial tests at DUV 36А/120 UV-systems. Blending the infiltrate water fed to the UV-system with river water abstracted directly from the Danube in the amount of 3% of the total flow rate was provided. Water quality analytical studies were carried out before and after disinfection by VZM-VEK Laboratory. In the process of studies the efficient UV-irradiation dosage of 60 mlJ/cm2 was determined for underflow (infiltrate) river water in definite operation conditions. The use of advanced combined water disinfection technology (chlorination + UV-irradiation) ensures minimizing the level of chlorination, reducing the risk of byproducts formation and improving the water safety.

Key words

surface water source , ultra-violet irradiation , drinking water supply , laboratory tests , efficient UV-irradiation dosage

Estimation of possible increasing the barrier function of natural water treatment facilities during periods of extraordinary situations

Summary

The need of increasing the barrier functions of water treatment process schemes and facilities during the periods of extraordinary pollution of water bodies is considered. The causes of extraordinary situations at water sources are as follows: industrial and transport accidents, manmade disasters, seasonal floods and even waterless seasons. The differences between extraordinary situations and their consequences in the water treatment practice from ordinary cases are given. Rules have been developed for preparing clean water of standard quality in emergency situations. Laboratory tests of water purification from the sources of various climatic zones using powdered activated carbons were conducted with water from Yakutsk, Astrakhan, Ryazan and Simferopol water utilities. The main sorption characteristics of the tested sorbents for methylene blue and iodine were determined. The results of testing powdered sorbents for four water sources showed that, compared with the traditional two-stage water purification scheme, the use of powdered activated carbon in the headworks of the process flow scheme provided for achieving the standard values for the permanganate index and total iron concentration. Also, unpleasant odors of water are almost completely eliminated, while no increase in coagulant doses was required compared to the operating facilities. It is shown that the efficiency of using powdered carbon practically does not depend on the climatic conditions of the regions. A generalized chart for the use of powdered carbon at the facilities with a two-stage treatment process flow scheme is proposed.

Key words

water treatment , natural water treatment , laboratory tests , extraordinary situations , powdered activated carbon