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UDC 628.166:628.179.2
Khasanova D. I., Shilin S. O., Garifutdinov M. K., Kovrizhnykh E. A.
Biocidal properties of OPTS-600 – a new nonoxidizing agent inhibiting microbial flora in water recycling systems
Summary
Corrosion processes in water recycling systems are often caused by different microorganisms, i. e. bacteria, algae, micromycetes. To eliminate them special substances – biocides are used. Biocidal agents have been continuously improved and at present they are complex multicomponent chemical systems. These complexes must be both broad spectrum, i. e. be equally efficient in inhibiting all the microorganism groups, and long acting (up to several weeks). Thus, developing and testing new biocidal agents for water recycling systems has been a relevant objective. The results of studying the biocidal properties of OPTS-600 new complex nonoxidizing polyhexamethyleneguianidine hydrochloride-based biocide with synergistic additives are presented. The results of the laboratory and pilot studies showed that OPTS-600 biocide almost completely inhibited the growth of microbial flora by affecting equally efficiently not only different bacterial groups but also algae and micromycetes. OPTS-600 biocidal agent is long acting and provides for inhibiting the growth of microbial flora during two weeks after it has been added into the water recycling systems. It was determined that the optimal concentration of OPTS-600 biocide in circulating water was 30 mg/l, recommended treatment interval – 1–2 months.
Key words
algae , biocorrosion , biodeposits , aerobic and anaerobic bacteria , micromycetes , biocide , algaecide , fungicide
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UDC 628.113.8:504.064.4
Nitsak G. B., Nesterova A. R.
The causes of odor in drinking water during the summer period in Ekaterinburg
Summary
The results of studies carried out to determine the causes of odor of biological origin in public water supply of Ekaterinburg during the summer period are presented. The analysis was performed with water samples taken in accordance with the operating programs of in-process water quality monitoring in the public water supply systems during the 2001–2013 vegetative periods. The algae species directly inducing the odor in water were determined. The markers that provide for well-timed responding to the water quality changes were determined. Based on the results of the studies the order of actions during the summer period was introduced at the enterprise that provided for measuring the amount of Planktothrix agardhii with the standard procedure of raw water monitoring and reducing the sampling intervals in case of spotting the trends of the algae amount growing. In case the set marker value is reached the process flow pattern at the treatment facilities is changed to ensure guaranteed elimination of water odor.
Key words
potable water , phytoplankton , water quality monitoring , algae , odor of biological origin
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UDC 628.16.094.413.094.3
Vasil'eva A. I., Nasyrova M. R., Kantor L. I., Trukhanova N. V., Melnitsky I. A.
Role of algae in the formation of water chlorination byproducts
Summary
For many years the precursors and mechanisms of water chlorination byproducts formation in the process of water purification at the surface water intake of Ufa city have been investigated. The main task of the study was evaluating the contribution of the representatives of the three phytoplankton species typical for the Ufa River to the trihalomethanes formation: diatomic (Bacillariophyta), green (Chlorophyta) and blue-green algae (Сyanophyta). Initially phytoplankton cells were isolated from the river water samples by concentrating, then in laboratory conditions algae were cultured on substrata. The chlorination experiments were carried out both with water samples with algae biomass and with the sample filtrates. The model samples were chlorinated with 1; 2; 3 mg/l chlorine dosages, exposure time – 2 hours. The concentration of trihalomethanes was measured by gas chromatographic vapor-phase analysis with electron-capture detection. The results of the studies revealed the following specific features. The samples with high concentration of blue-green algal biomass (13.6 mg/l – 96%) after chlorination with 3 mg/l dosage showed significant increase of the total trihalomethane concentration– 131.6 µg/l. In the samples with dominant green algal mass (26.19 mg/l – 99.8%) or with green (0.07 mg/l – 53%) and diatomic algae (0.059 mg/l – 47%) only the lowest total trihalomethane concentrations were detected – 3.69 and 2.62 µg/l, respectively. The similar situation was observed in the process of chlorinating filtrates of these samples. This suggests that blue-green algal metabolites or products of the algal mass decay are most probable precursors of trihalomethanes.
Key words
chlorination , potable water quality , phytoplankton , total trihalomethanes , algae , Chlorophyta (green) , Bacillariophyta (diatomic) , Сyanophyta (blue-green)
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