خيارات البحث
النتائج 91 - 100 من 118
Use of powdered activated carbon for better removal of natural organic matter from groundwater by coagulation and flocculation
2003
Dalmacija, B. (Prirodno-matematicki fakultet, Novi Sad (Serbia and Montenegro). Departman za hemiju) | Klasnja, M. | Agbaba, J. | Ivancev-Tumbas, I. | Becelic, M.
The process of removal of natural organic matter from groundwater by adsorption on powdered activated carbon, coagulation and flocculation was investigated. It was found that the combination of these processes yielded a decrease of KMnO4 values, which allowed the reduction of the coagulant concentration, needed to achieve the necessary quality of drinking water, up to 50%. Also, it was established that the sequence of adding powdered activated carbon and coagulant is one of the essential factors determining the efficiency of NOM removal from water, and which is primarily conditioned by the nature of the organic matter present in the investigated water.
اظهر المزيد [+] اقل [-]Quality parameters of canal sediments
2003
Savic, R. (Poljoprivredni fakultet, Novi Sad (Serbia and Montenegro). Departman za uredjenje voda) | Belic, A. | Pantelic, S. | Bozinovic, M.
Importance of sediments quantity and quality problems addressing to land reclamation canal network in Vojvodina (Serbia, Serbia&Montenegro) are pointed out in this paper. Necessity for sediments monitoring and criteria definition for environmental discharge are drown. Special attention is paid to agricultural land as recipient of these sediments.
اظهر المزيد [+] اقل [-]The importance of protection of the belt of stoneworts for the surviving of the benthic macroinvertebrate communities from Lake Ohrid
2003
Trajanovski, S. | Trajanovska, S. | Budzakoska, B. (Hidrobioloski zavod, Ohrid (The Former Yugoslav Republic of Macedonia))
The most extended and deepest belt of macrophytic vegetation, the belt which almost without exceptions define the lower limit of littoral region of Lake Ohrid, consists algae from the family Characeae. Permanent presence of sunlight, well oxygen saturation, their density which decreases the waves action, together with the facts that these algae are food and shelter for the numerous endemorelic species from the very rich fauna of macro invertebrates, make the stonworts the most attractive life habitat in Lake Ohrid. Our results are found on researching of three types facies from four different localities in Lake Ohrid: sandy-muddy facies without of stoneworts, facies covered by stoneworts and facies covered by Gastropod and Bivalvia shells, also without of stoneworts. Without exceptions, in all four localities we approved the mentioned affirmation about the great importance of the stoneworms as life habitats, both by the number of present taxa and the density of the macro invertebrate communities.
اظهر المزيد [+] اقل [-]Phosphatase activity of water of the Lake Gruza [Serbia, Serbia&Montenegro]
2003
Nedovic, M. (Gradski vodovod, Kragujevac (Serbia and Montenegro)) | Raicevic, V. | Kikovic, D. | Lalevic, B.
The basic purpose of Gruza accumulation is to supply the town of Kragujevac and its vinicity with drinking water. The accumulation occupies large area, comparing with its relatively shallow water and low water mass, which is essential for water eutrophication. The aim of this research is to determine water quality, through index of phosphatase activity at five locations in one year period. According to the results obtained for index of phosphatase activity, water of Gruza lake belongs to 3rd A category. The maximum obtained value (19.60 micromol/s/cubic dm) was determined in the shallow part, at mouth of the river Gruza in July, 2000, and the minimum one (0.39 micromol/s/cubic dm) in the deepest part of accumulation, at location Brana in March, 2001.
اظهر المزيد [+] اقل [-]Microbiologial aspect of water quality of reservoir Bocac and its tributaries [Bosnia&Herzegovina]
2003
Bobic, M. (Institut za vode d.o.o., Bijeljina, Republika Srpska (Bosnia and Herzegovina))
In the scope of complex physical-chemical and biological water examination of Bocac water reservoir, the river Vrbas and trbutaries Ugar and Crna Rijeka, examination of standard microbiological indexes of water quality (aerobic organotrophs at 22-26 deg C and 37 deg C, total colliforms and colliforms of fecal origin) was performed during 2002 (March-November). Number of examined microbiological parameters was mainly in the scope of the 2nd water category (beta-mesosaprobic water) with worse water quality in upstream part of the reservoir. Ugar tributary had the best water quality, while Crna Rijeka had the worst status with obvious anthropogenic influence.
اظهر المزيد [+] اقل [-]Change in biodiversity of ichthyofauna from the Lake Ohrid [The Former Yugoslav Republic of Macedonia]
2003
Taleski, T. (Hidrobioloski zavod, Ohrid (The Former Yugoslav Republic of Macedonia))
Every country must to concern the biodiversity of flora and fauna, especially in ecosystems rich with endemic and relict species. Such ecosystem is the Lake Ohrid.
اظهر المزيد [+] اقل [-]Changes in the composition of gastropod fauna of the profile HBZ-Radozda from Lake Ohrid
2003
Budzakoska, B. | Trajanovski, S. (Hidrobioloski zavod, Ohrid (The Former Yugoslav Republic of Macedonia))
In this paper, we present the results from both quantitative and qualitative composition of the Gastropod fauna from Lake Ohrid (profile HBZ-Radozda) with their vertical distribution in littoral and sublittoral region of the lake. The results of our investigations shows some changes in biodiversity and the density of gastropod communities that settle this profile, compared with the investigations made 30 years ago.
اظهر المزيد [+] اقل [-]Effects of preozonation on natural organic matter removal from groundwater by coagulation and flocculation processes
2003
Agbaba, J. (Prirodno-matematicki fakultet, Novi Sad (Serbia and Montenegro). Departman za hemiju) | Dalmacija, B. | Klasnja, M. | Ivancev-Tumbas, I.
The paper deals with pilot-scale investigations of the effect of preozonation on NOM removal from groundwater by coagulation and flocculation processes. It was found that the preozonation increased the efficiency of organic matter removal by coagulation and flocculation from 23.6 to 47.2% as judged on the basis of KMnO4 values. From the aspect of the change of content of trihalomethanes precursors preozonation exhibits both the positive and negative effects if their content in the water after coagulation is considered in dependence of the applied ozone dose. The obtained values siggest the necessity of careful optimization of the processes of preozonation, coagulation, and flocculation, especially from the aspect of the change in content of the precursors of disinfection byproducts.
اظهر المزيد [+] اقل [-]The presence of heavy metals in some fish species from the Medjuvrsje [water] reservoir [Serbia, Serbia&Montenegro]
2003
Lazic, T. (Regionalni centar za talente, Cacak (Serbia and Montenegro)) | Markovic, G. | Nikolic, D. | Cupic, S.
Heavy metals contamination of the muscular tussue of nase (Chondrostoma nasus), bream (Alburnus brama) and bleak (Alburnus alburnus) fish species from the Medjuvrsje water reservoir (the Zapadna Mora river), was examined. With the expection of the nase muscular tissue where cadmium (Cd) and mercury (Hg) concentrations above and slightly below MPC, respectively, were detected, the rest of the samples were safe. With the aim of conducting more thorough monitoring of these pollutants, a greater number of elements and a larger number of organisms should be included in the analyses.
اظهر المزيد [+] اقل [-]The hydrophilic flora of the Grosnica [water] reservoir [Serbia, Serbia&Montenegro]
2003
Topuzovic, M. | Pavlovic, D. (Prirodno-matematicki fakultet, Kragujevac (Serbia and Montenegro). Institut za biologiju)
The paper presents results of research on hydrophilic flora of the Grosnica reservoir in the Kragujevac basin (Serbia, Serbia&Montenegro). The obtained results confirm that the development of hydrophilic vegetation is dependent on the time, manner, and place of reservoir formation, as well as on the extent of human influence. Analysis of floristic composition of hydrophilic plants of this reservoir indicates presence of 30 species belonging to 20 families. Floristic composition of the hydrophilic flora with flora elements, life forms and ecological factors are presents.
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