Phytoplankton community of the drinking water supply reservoir Borovitsa (South Bulgaria) with an emphasis on cyanotoxins and water quality

AbstractThe phytoplankton diversity, algal biomass, and selected physicochemical parameters were investigated in the drinking water reservoir (Borovitsa) located in the Kardzhali region, Bulgaria. Particular attention was given to Cyanoprokaryota and presence of cyanotoxins in the water samples. Twenty-nine species belonging to six divisions (Cyanoprokaryota, Chlorophyta, Zygnemophyta, Dinophyta, Euglenophyta and Bacillariophyta) were identified. The microscopic examination of the phytoplankton samples showed the dominance of Ankyra judayi, Oocystis lacustris (Chlorophyta) and Aphanizomenon flos-aquae (Cyanoprokaryota) in July 2006, and Microcystis pulverea, Synechococcus elongatus (Cyanoprokaryota), Radiococcus planktonicus (Chlorophyta) and Melosira varians (Bacillariophyta) in September 2006. A blooming event due to Aphanizomenon flos-aquae was observed in July 2006. The reservoir exhibits a tendency to shift from an oligotrophic environment to a state of mesotrophy. Presence of cyanotoxins such as anatoxin-a, microcystins and saxitoxins were analyzed by HPLC and ELISA methods. Our results demonstrated the presence of anatoxin-a and microcystins (0.09 µg/L) in the raw water samples from July 2006, and saxitoxins (2.5 µg/L) and microcystins (0.18 µg/L) in the raw water samples from September 2006. The study underlines that permanent monitoring programs of Cyanoprokaryota in the reservoirs used as sources of drinking water and toxicity assessments should be implemented. Indirect exposure and transfer of cyanotoxins through food chains must also be considered.

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Temperature and nutrients are significant drivers of seasonal shift in phytoplankton community from a drinking water reservoir, subtropical China

Environmental Science and Pollution Research ◽

10.1007/s11356-014-2534-3 ◽

2014 ◽

Vol 21 (9) ◽

pp. 5917-5928 ◽

Cited By ~ 50

Author(s):

Hong Lv ◽

Jun Yang ◽

Lemian Liu ◽

Xiaoqing Yu ◽

Zheng Yu ◽

...

Keyword(s):

Drinking Water ◽

Phytoplankton Community ◽

Water Reservoir ◽

Subtropical China ◽

Drinking Water Reservoir ◽

Seasonal Shift

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Community Compositions of Phytoplankton and Eukaryotes during the Mixing Periods of a Drinking Water Reservoir: Dynamics and Interactions

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17041128 ◽

2020 ◽

Vol 17 (4) ◽

pp. 1128 ◽

Cited By ~ 23

Author(s):

Miaomiao Yan ◽

Shengnan Chen ◽

Tinglin Huang ◽

Baoqin Li ◽

Nan Li ◽

...

Keyword(s):

Drinking Water ◽

Phytoplankton Community ◽

Morphological Characteristics ◽

Water Reservoir ◽

Shaanxi Province ◽

Heihe River ◽

Algal Density ◽

Eukaryotic Community ◽

Drinking Water Reservoir ◽

Eukaryotic Microorganisms

In deep drinking water reservoir ecosystems, the dynamics and interactions of community compositions of phytoplankton and eukaryotes during the mixing periods are still unclear. Here, morphological characteristics combined with high-throughput DNA sequencing (HTS) were used to investigate the variations of phytoplankton and the eukaryotic community in a large canyon-shaped, stratified reservoir located at the Heihe River in Shaanxi Province for three months. The results showed that Bacillariophyta and Chlorophyta were the dominant taxa of the phytoplankton community, accounting for more than 97% of total phytoplankton abundance, which mainly consisted of Melosira sp., Cyclotella sp., and Chlorella sp., respectively. Illumina Miseq sequencing suggested that the biodiversity of eukaryotes increased over time and that species distribution was more even. Arthropoda (6.63% to 79.19%), Ochrophyta (5.60% to 35.16%), Ciliophora (1.81% to 10.93%) and Cryptomonadales (0.25% to 11.48%) were the keystone taxa in common, contributing over 50% of the total eukaryotic community. Cryptomycota as a unique fungus was observed to possess significant synchronization with algal density, reaching a maximum of 10.70% in December (when the algal density distinctly decreased) and suggesting that it might affect the growth of algae through parasitism. Co-occurrence network patterns revealed the complicated and diverse interactions between eukaryotes and phytoplankton, suggesting that eukaryotes respond to variations in dynamic structure of the phytoplankton community, although there might be antagonistic or mutualistic interactions between them. Redundancy analysis (RDA) results showed that environmental variables collectively explained a 96.7% variance of phytoplankton and 96.3% variance of eukaryotic microorganisms, indicating that the temporal variations of phytoplankton and eukaryotic microorganisms were significantly affected by environmental conditions. This study shows that potential interactions exist between phytoplankton and eukaryotic microorganism communities, andcould improve our understanding of the ecological roles of phytoplankton and eukaryotic microorganisms in changing aquatic ecosystems. However, long-term investigations are necessary in order to obtain comprehensive understandings of their complicated associations.

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Pharmaceuticals Load in the Svihov Water Reservoir (Czech Republic) and Impacts on Quality of Treated Drinking Water

Water ◽

10.3390/w12051387 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1387

Author(s):

Josef V. Datel ◽

Anna Hrabankova

Keyword(s):

Drinking Water ◽

Water Retention ◽

Treatment Process ◽

Water Reservoir ◽

Raw Water ◽

Surrounding Area ◽

Drinking Water Reservoir ◽

Treated Drinking Water ◽

Positive Effect

An important component of micropollutants are PPCPs (pharmaceuticals and personal care products). This paper contains the results of the monitoring of surface water, groundwater and wastewater in the surrounding area of the Svihov drinking water reservoir. Over the period 2017–2019, over 21,000 water samples were taken and analyzed for 112 pharmaceuticals, their metabolites, and other chemicals. The results are discussed in detail for two streams with the highest observed concentration of PPCPs (Hnevkovice, Dolni Kralovice) and two streams with the highest water inflow into the reservoir, representing also the highest mass flow of PPCPs into the reservoir (Miletin, Kacerov). The overall analysis of the results shows that acesulfame, azithromycin, caffeine, gabapentin, hydrochlorothiazide, ibuprofen and its metabolites, oxypurinol, paraxanthine, and saccharin (on some profiles up to tens of thousands ng/dm3) attain the highest concentration and occur most frequently. The evaluation of raw water and treated drinking water quality showed the significant positive effect of water retention in the reservoir (retention time of 413 days) and also of the treatment process, so that the treated drinking water is of high quality and contains only negligible residues of few PPCPs near the detection limit of the analytical method used.

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Microbial Load of Drinking Water Reservoir Tributaries during Extreme Rainfall and Runoff

Applied and Environmental Microbiology ◽

10.1128/aem.68.5.2188-2197.2002 ◽

2002 ◽

Vol 68 (5) ◽

pp. 2188-2197 ◽

Cited By ~ 231

Author(s):

T. Kistemann ◽

T. Claßen ◽

C. Koch ◽

F. Dangendorf ◽

R. Fischeder ◽

...

Keyword(s):

Drinking Water ◽

Water Samples ◽

Microbial Contamination ◽

Water Reservoir ◽

Extreme Rainfall ◽

Water Reservoirs ◽

Drinking Water Reservoir ◽

Catchment Areas ◽

Parasitic Parameters ◽

Runoff Events

ABSTRACT Hygienic and microbiological examinations of watercourses are usually not carried out during heavy rainfall and runoff events. After rainfall or snowmelt, there are often massive increases in turbidity in flooding creeks in mountain ranges, which are frequently interpreted as an indication of microbial contamination. The aim of this study was to quantify the microbial loads of watercourses during such runoff events and to compare these loads with loads occurring during regular conditions. In a 14-month monitoring period we investigated the microbial loads of three tributaries of different drinking water reservoirs. A total of 99 water samples were taken under different runoff conditions and analyzed to determine physical, chemical, bacterial, and parasitic parameters. Thirty-two water samples were considered event samples during nine measuring series. The criteria for events, based on duration and intensity of precipitation, water depth gauge measurements, and dynamics, had been fixed before the investigation for each creek individually. Of the physical and chemical parameters examined, only the turbidity, pH, and nitrate values differed clearly from the values obtained for regular samples. Most of the bacteriological parameters investigated (colony, Escherichia coli, coliform, fecal streptococcal, and Clostridium perfringens counts) increased considerably during extreme runoff events. If relevant sources of parasitic contamination occurred in catchment areas, the concentrations of Giardia and Cryptosporidium rose significantly during events. The results show that substantial shares of the total microbial loads in watercourses and in drinking water reservoirs result from rainfall and extreme runoff events. Consequently, regular samples are considered inadequate for representing the microbial contamination of watercourse systems. The procedures for raw water surveillance in the context of multiple-barrier protection and risk assessment ought to include sampling during extreme runoff situations.

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Occurrence of 1,4-dioxane and MTBE in drinking water sources in Japan

Water Science & Technology Water Supply ◽

10.2166/ws.2006.049 ◽

2006 ◽

Vol 6 (2) ◽

pp. 47-53 ◽

Cited By ~ 5

Author(s):

D. Simazaki ◽

M. Asami ◽

T. Nishimura ◽

S. Kunikane ◽

T. Aizawa ◽

...

Keyword(s):

Drinking Water ◽

Surface Water ◽

Water Samples ◽

Quality Standards ◽

Raw Water ◽

Water Quality Standards ◽

Butyl Ether ◽

Water Treatment Plants ◽

Standard Value ◽

Surface Water Samples

Nationwide surveys of 1,4-dioxane and methyl-t-butyl ether (MTBE) levels in raw water used for the drinking water supply were conducted at 91 water treatment plants in Japan in 2001 and 2002, prior to the revision of the drinking water quality standards. 1,4-dioxane was widely and continuously detected in raw water samples and its occurrence was more frequent and its concentrations higher in groundwater than in surface water. However, its maximum concentration in raw water was much lower than its new standard value (50 μg/L), which was determined as a level of 10−5 excessive cancer risk to humans. Trace levels of MTBE were also detected in several surface water samples.

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