Arkadiusz Nędzarek, Agnieszka Tórz and Jacek Kubiak
Oxygen conditions and trophic state of Lake Głębokie (Szczecin, Poland) in the years 2008-2010
The research in Lake Głębokie was conducted in the years 2008-2010. Sampling from three selected sites was designed in such a way that vertical profiles of the characteristics of interest were obtained. Measurements were performed to determine the content of dissolved oxygen, oxygen saturation expressed as a percentage, water temperature, total phosphorus, chlorophyll a, dry seston mass, and Secchi disk depth. During the course of a year, water temperature varied from 0.58°C to 24.72°C. However, a permanent thermal stratification was not observed in the summer season due to complete water mixing. Dissolved oxygen concentrations in the water varied within a range that started at hard-to-measure insignificant values and reached up to 9.63 mg O2 l-1, while oxygen saturation reached a maximum of 116% O2. At the same time, it was observed that oxygen conditions gradually worsened as the depth became greater. The largest oxygen deficits occurred in the winter season of 2009-2010. The oxygen conditions were typical for an eutrophic lake. Its high trophic state was confirmed by an analysis performed using the method proposed by Carlson (1977) as well as by an analysis performed according to the directives of the OECD (1982). The trophic state of this lake is borderline eutrophic and hypertrophic. The oxygen conditions found in this lake ought to be seen as not beneficial to fish.
The aim of the study was to analyze and assess the possibility of using a two-stage filtration system with ceramic membranes: a 3-tube module with 1.0 kDa cut-off (1st stage) and a one-tube module with 0.45 kDa cut-off (2nd stage) for treating effluent water from a juvenile African catfish aquaculture. The study revealed that during the 1st filtration stage of the effluent water, the highest degrees of retention were obtained with respect to: suspended solids SS (rejection coefficient RI=100%), turbidity (RI=99.40%), total iron (RI=89.20%), BOD5 (RI=76.0%), nitrite nitrogen (RI=62.30%), and CODCr (RI=41.74%). The 2nd filtration stage resulted in a lower reduction degree of the tested indicators in comparison to the 1st filtration stage. At the 2nd stage, the highest values of the rejection coefficient were noted in for the total iron content (RIV=100%), CODCr (RIV=59.52%; RV=64.28%, RVI=63.49%) and turbidity (RIV and RV = 45.0%, RVI=50.0%). The obtained results indicate that ceramic membranes (with 1.0 and 0.45 kDa cut-offs) may be used in recirculation aquaculture systems as one of the stages of effluent water treatment.
Małgorzata Bonisławska, Adam Tański, Arkadiusz Nędzarek and Agnieszka Tórz
The study examined the development of pike (Esox lucius L.) roe in water containing variously concentrated coagulants PIX®113 and PAX®18, which are increasingly being used in Poland as a method of lake reclamation. The genital products came from spawners caught from a natural water body (Lake Przybiernów). The eggs were incubated in water taken from the same lake, and subjected to the process of phosphorus and iron precipitation with coagulants. Based on the results, it was found that the coagulants used in the experiment inhibit the embryogenesis of pike by the formation of aggregates falling to the bottom, reducing the percentage of live embryos and affecting the size and malformation of the hatching larvae.
Grażyna Adler, Arkadiusz Nędzarek and Agnieszka Tórz
The health benefits and detrimental effects of coffee consumption may be linked to chemical compounds contained in coffee beans. The aim of our study was to evaluate the concentration of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), zinc (Zn), aluminum (Al), nickel (Ni), lead (Pb) and cadmium (Cd) in green and roasted samples of coffee beans purchased in Bosnia and Herzegovina, and to determine the potential health implications at current consumption level.
The concentrations were determined using a microwave high-pressure mineralization and atomic absorption spectrometer that measures total metal (ionic and non-ionic) content.
The average metal concentrations (μg element/g coffee) in the green coffee beans were; Na: 18.6, K: 19898, Ca: 789, Mg: 1758, Fe: 60, Cu: 14, Zn: 3.6, Al: 4.2, Ni: 0.415, Pb: 0.076, and Cd: 0.015, while, in the roasted; Na: 23, K: 23817, Ca: 869, Mg: 1992, Fe: 41.1, Cu: 11.4, Zn: 5.41, Al: 4.19, Ni: 0.88, Pb: 0.0169, and Cd: 0.0140.
The level of investigated metals at the present level of consumption of coffee in Bosnia falls within the limits recommended as safe for health.
Adam Tański, Małgorzata Bonisławska, Agnieszka Tórz, Krzysztof Formicki, Arkadiusz Nędzarek, Arkadiusz Drost and Agnieszka Rybczyk
The study focused on the effect of iron and aluminium coagulants (PIX®113, PAX®18) commonly used for purification of open waters on key stages of embryonic development of pike (Esox lucius L.). Fertilized pike roe was incubated in lake water and in water with the admixture of coagulants, applied in the concentration of 50.0 mg dm-3 at selected stages of embryogenesis: blastopore closure, inoculation, and the hatching of larvae. In the course of the experiment, live embryos were observed and total lengths of the larvae were measured. Simultaneously, selected hydrochemical indicators were gauged. It was discovered that coagulants had the strongest effect at the first stage of embryogenesis (the end of the process of gastrulation). At that stage the survival rate of embryos was the lowest (73.5- 75.0%) and the percentage of deformities in the hatched larvae was the highest (9.7-10.0%).
Małgorzata Bonisławska, Adam Tański, Małgorzata Mokrzycka, Adam Brysiewicz, Arkadiusz Nędzarek and Agnieszka Tórz
Fish farming and especially rearing and breeding of rainbow trout and carp is one of potential sources of surface water pollution. The study was aimed at assessing the effect of a rainbow trout farm on water quality in the Gowienica River in winter. Temperature, pH, electrolytic conductivity, total suspended solids, dissolved oxygen, BOD5, CODCr, alkalinity, water hardness, calcium, magnesium, ammonium-nitrogen, nitrate-nitrogen (III and V) and total phosphorus were determined according to Polish Norms and APHA  in water samples collected in winter up- and downstream the study object. The increment of pollutant concentrations in rainbow trout farm effluents was referred to the requirements in Rozporządzenie MŚ . Performed studies and literature review show that effluents from the assessed fish farm did not worsen water quality of the river. Increased concentrations of total suspended solids and CODCr in effluents were noted only in March. According to data from the report on environmental status in zachodniopomorskie province in the years 2008-2011, poor water quality of the Gowienica River is recorded already upstream the rainbow trout farm. Pollution of this stretch of the river may originate from uncontrolled waste water management and from nutrient runoff from fields.