Joanna Szczykowska

SYMPTOMS OF WATER EUTROPHICATION IN THE BACHMATY RESERVOIR

When analyzing the symptoms of eutrophication and water quality in a small retention reservoir Bachmaty, an attempt to assess changes in its trophic condition before and after modernization, was undertaken. The study upon changes in water trophic level was carried out on a small retention reservoir Bachmaty located in Podlasie region on the Orlanka river in the municipality of Dubicze Cerkiewne. Tests of water samples collected from the surface layer of the coastal zone were performed once a month, and the time of the research was divided into two periods. The first period was conducted since April 2007 to March 2008 and since April 2009 to March 2010. The second research period included the time immediately after the reservoir reclamation, which ended in May 2011. The study was conducted since May 2011 to March 2012 and since April 2013 to March 2014. The trophic level of Bachmaty reservoir was also assessed according to the concentration criteria and based on the trophic status indices (TSI) calculated after Carlson’s as well as Kratzer and Brezonik’s. Reclamation of the reservoir, which consisted mainly in removing the sediments, caused a reduction in all TSI values. Analysing the overall trophic level index, i.e. the average of TSI (TP), TSI (TN), and TSI (Chl), water of the Bachmaty reservoir may be classified as eutrophic in individual years of the research, although a gradual decline in the TSI value could be observed directly after the reservoir modernizing. After testing it was found that the formation of the trophic level of Bachmaty reservoir was largely affected by the amount of total phosphorus supplied to the water. Water quality in the reservoirs, and also the content of phosphorus compounds is largely determined by external supply.

TROPHIC STATE OF SMALL RETENTION RESERVOIRS IN PODLASIE VOIVODESHIP

The study was carried out using water samples from two small retention reservoirs located in the communes: Czarna Białostocka and Turośń Kościelna in Podlaskie Voivodeship. The main tasks of both reservoirs are to improve the water balance by means of regulating the levels and water outflow. Three characteristic measurement and control points were selected on both reservoirs in accordance to the water flow in the longitudinal section. The first and third points were located near the inflow and outflow of water, while the second in the middle of the reservoirs. Samples of water for the study were collected from the surface layer of the shore zone of the reservoirs once a month from March 2015 to February 2017 (water from two hydrological years was analyzed). Water samples were subject to determination of total phosphorus, total nitrogen, and chlorophyll “a” concentrations, as well as turbidity. Contamination of the water reservoirs with biogenic compounds is a common problem and at the same time difficult to eliminate due to the scattered nature of external sources of pollution, especially in the case of agricultural catchments, as well as the inflow of untreated sewage from areas directly adjacent to the reservoirs. Based on achieved results, high values of TSI (TN), TSI (TP), TSI (Chl), and overall TSI, clearly indicate the progressive degradation of water quality in analyzed reservoirs. Appearing water blooms due to the mass development of phytoplankton adversely affect the quality of water in the reservoirs and biochemical processes occurring both in water and bottom sediments, are conditioned by progressive eutrophication.

DYNAMICS OF NITROGEN AND PHOSPHORUS FORMS CONTENT IN DOJLIDY RETENTION RESERVOIRE

The Dojlidy Ponds, which include Dojlidy water dam, are located within Bialystok city limits in Podlasie area, Poland. The reservoir with a water surface of 34 ha and average depth of 1.75 m was constructed in 1962 as a result of Biala River damming. The researches were conducted in July, October and December 2014 as well as in March 2015. Each time five test samples were collected from spots located along the reservoir. Water samples were tested for the presence of ammonia nitrogen, nitrite nitrogen, organic nitrogen, phosphates and organic phosphorus. The values of nutrient indicators exhibited high variability during the study period. The highest concentration of nitrite and nitrate nitrogen were observed in July, while the lowest in October – nitrite nitrogen, and in December – nitrate nitrogen. Different situation was observed after the analysis of phosphorus forms – the highest concentrations of organic phosphorus and phosphates were observed in December and the lowest in July. Relatively high concentrations of nitrogen and phosphorus forms identified in water samples were most likely caused by tributaries, due to the pollution from the reservoir catchment. Technical parameters of the object and location of the reservoir have undoubtedly an impact on the tested parameters contents.

EUTROPHICATION AS A PRIORITY ISSUE OF WATER QUALITY IN SMALL RETENTION RESERVOIRS

The study aimed at comparing changes in the trophic status of waters in two small retention reservoirs “Otapy-Kiersnówek” and “Jasionówka”, located in the Podlasie region, which have a similar way of management and the similarity of catchments, using the TSI trophy indicators. The obtained results show that total phosphorus is the limiting factor in both reservoirs. Analyzing the average annual value of TSI in the tested waters, it was found that both reservoirs can be classified as hypertrophic. Trophic state of the tested waters is strictly dependent on the processes taking place in their vicinity. The reservoirs revealed a clear effect of a surface runoff on water quality. Factors that favor the poor quality of water in both reservoirs are unfavorable morphometric conditions of reservoirs due to their small depth, which allows continuous mixing and strong heating of water in spring and summer. Additional causes can include an open space around the reservoirs and the lack of high vegetation that would shield the edges against the wind, which facilitates often mixing of waters to the bottom and resuspension of bottom sediments, which in turn increases the concentration of phosphorus in water.

PHOSPHORUS CONTAMINATION AS A BARRIER TO WATER QUALITY OF SMALL RETENTION RESERVOIRS IN PODLASIE REGION

The aim of study was to evaluate the quality of water flowing into small retention reservoirs in terms of the concentration of total phosphorus and phosphates. The study involved three small retention reservoirs located in the municipalities of: Bransk, Dubicze Cerkiewne and Kleszczele in Podlasie region. Selection of the research facilities was made due to the similarity in the soil management type within catchment of the flowing watercourse, retained water utilization ways, and a small surface of reservoirs. Watercourse reaching the reservoir provides biogens along with water, which directly affect the water quality resulting in high concentrations in water, either indirectly by initiating or accelerating the process of degradation of the reservoir and the loss of its usability. We found that total phosphorus only of 20.8% of water samples from Nurzec river feeding the Otapy-Kiersnówek reservoir, about 25% of water samples of Orlanka river feeding Bachmaty reservoir, and 17% of samples taken from the watercourse supplying Repczyce reservoir, corresponded to values specified for the second class in the current Regulation of the Minister of the Environment. It can be assumed that this situation is caused by a long-term fertilization using manure, which in consequence led to the oversaturation of soils and phosphorus compounds penetration into the river waters in areas used for agricultural purposes. Especially in the early spring periods, rising temperature together with rainfall caused soil thawing resulting in increasing concentrations of contaminants carried along with the washed soil particles during the surface and subsurface runoff. Values of TSI(TP) calculated for OtapyKiersnówek reservoir amounted to 112.4 in hydrological year 2012 and to 112.7 in 2013, for Bachmaty reservoir 73.04–75.71, and for Repczyce reservoir to 101.07–102.12, which allowed for qualifying them as hypertrophic. Kaywords: phosphorus compound, eutrophication, small retention reservoirs

DIVERSITY OF THE TSI INDICATORS OF THE MIDDLE-FOREST SMALL RETENTION RESERVOIR

Studies upon the trophic status were carried out using water samples from a small retention reservoir Topiło located in a particularly valuable natural forests of Puszcza Białowieska. In order to assess the degree of Topiło reservoir contamination, three measurement and control points were selected for testing, which were situated near the inflow (point No. 1) and outflow (point No. 3) of river Perebel, as well as in the middle part of the reservoir (point No. 2). The selection and placement of measurement and control points on the reservoir was dictated by the ability to capture changes in the study object. Tests of water samples collected from the surface layer of the coastal zone, were carried out once a month during the period from April 2007 to March 2014. The following determinations in collected water samples were performed: total nitrogen, total phosphorus, chlorophyll “a”, and turbidity. The trophic level of Topiło reservoir was also assessed according to the concentration criteria and based on the trophic status indices (TSI) calculated after Carlson’s as well as Kratzer and Brezonik’s. Given the annual average value of overall trophic level (Trophic Status Index), the dominant role of the TSI (TP) during all years of research attracts some attention. The TSI index values ranged within 78.3–80.26, which allowed to classify the water of Topiło reservoir as hypertrophic. The research indicates an advanced and constantly progressive degradation of water quality in Topiło reservoir. Values of TSI (Chl) were in the range of 49.2–77.35 and therefore water status in winter can be defined as eutrophic indicating the hypertrophy in remaining periods under study. Additional investments planned for advance reclamation treatments should be necessarily taken into consideration at the stage of planning and design of new small water retention reservoirs. Topiło reservoir requires modernization and reclamation, it is also necessary to clean it up, especially the bottom pond, out of the stocked wood residues, as well as to remove the excess of sludge.

Structural waveguide co-doped with Yb3+/Tm3+ for measurement of chlorophyll concentration

In the article a system for measuring the concentration of chlorophyll in methanol solution have been developed. Microstructural waveguide co- doped with Yb3+/Tm3+ ions was used as a sensing element. The waveguide consisted of thirty-seven glass capillaries arranged hexagonally was fabricated using the stacking and drawing method. Due to the excitation of the active core by laser diode (λ=980nm), an effective energy transfer between Yb3+ and Tm3+ ions occurs. As a result, two luminescence bands at 480 nm (1G4→3H6) and 650 nm (1G4→3F4) were obtained. Concentration of chlorophyll methanol solution in the range from 2.75 to 13.66 [mh/dms] was measured. Linear dependence of the decrease of luminescence intensity of thulium ions on its concentration was obtained. The sensitivity of the developed system was 0.005 [1/(mg/dm3)].

The present condition of small water retention and the prospects of its development using the example of the Podlaskie Voivodeship

The necessity and purposefulness of the investments related to water retention are justified mostly due to the preservation of the environment equilibrium as well as due to its farming, anti-flood, landscape and recreation aspects. Reasonable water manage ment where various forms of retention are used gives large chances for the mitigation of the effects of unfavorable phenomena related to its insufficient amount. The creation of plans regarding the formation of reservoirs accumulating water is not necessarily synonymous with their realization. The reason of problems connected with the implementation of plans regarding the formation of new reservoirs lies mainly in financial measures and in problems with obtaining them. Water deficit in Poland is the reason for which the principles of its national usage need to be complied with. Realization of plans at both Voivodeship and municipality level that are focused on small retention will contribute to considerable increase in the retention capacity and will enable considerable increase in available resources in hydrographic catchments of both the characterized area and the entire country. The paper presents the characteristics of the present state and assumes the perspective development of small water retention in the Podlaskie Voivodeship using the example of the Podlaskie Voivodeship.