The objective of this study was to examine the chemistry of trace elements in coalbed methane (CBM) discharge water reacting with semi-arid ephemeral stream channels in Powder River Basin, Wyoming. The study area consisted of two ephemeral streams, Burger Draw and Sue Draw. These streams are tributaries to the perennial Powder River, Wyoming. Samples were collected bimonthly from three CBM discharge points and seven channel locations in Burger Draw and Sue Draw. Samples were also collected bimonthly from the Powder River above and below the confluence of Burger Draw. Before sample collection, pH, temperature, dissolved oxygen (DO), and turbidity were measured in the field. Samples were transported to the laboratory and analyzed for dissolved trace elements including iron (Fe), manganese (Mn), boron (B), arsenic (As), selenium (Se), and fluoride (F). Results suggest pH of discharge water was 7.1 and increased significantly in the downstream channel of Burger Draw to 8.84 before joined with the Powder River. Temperature of CBM produced water at discharge points ranged between 20.3 and 22.7 [composite function (small circle)]C. Before discharge, DO concentrations of CBM produced water were between 1.42 and 1.5 mg/L. No significant differences in temperature, DO, and turbidity were found between Burger Draw flow and Powder River flow. However, significant differences were found within the sampling period in temperature and turbidity in flow of Burger Draw. The temperature, DO, and turbidity were all significantly different in Powder River within the sampling period. The CBM discharge water consisted of higher concentrations of F, Fe and B compared to other components. Significant changes were observed for Fe, Mn, and As; and seasonally for B. Dissolved Fe and Mn decreased, while As and Se increased in downstream channel flow. These findings will be useful in proper management of CBM produced water in semi-arid environments.

Hydrochemistry of an alluvial river was investigated employing the chemometric techniques such as cluster analysis (CA), principal component analysis (PCA), discriminant analysis (DA) and partial least square (PLS) with a view to extract information about the variables responsible for spatial and temporal variations in river hydrochemistry and water quality, the hidden factors explaining the structure of the hydro-chemical database of the river, factors/processes influencing the river hydro-chemistry. Analysis of spearman's correlation coefficient revealed non-significant correlation of the pollution indicator (BOD, COD, SO₄, F, NH₄-N, NO₃-N) variables with season and significant correlation with site, indicating contribution of the site-specific anthropogenic sources in the catchments. Spatial CA clustered the monitoring sites (10nos.) into three groups of relatively non-polluted sites, moderately polluted sites, and highly polluted sites. Temporal CA differentiated among the samples of monsoon and non-monsoon months. PCA rendered considerable data reduction, in terms of eight parameters explaining about 71% of the total variance and evolved six PCs. PCA grouped samples belonging to different seasons and sites distinctly correlating them with natural and anthropogenic variables. Temporal and spatial DA rendered 97 and 92% correct assignations of the samples, respectively, and revealed that temperature, pH, BOD, DO, alkalinity and Ca are the most significant variables to discriminate between the different seasons and account for most of the expected temporal variations in hydrochemistry of the river, whereas, hardness, DO, BOD, COD, Ca and Mg were the most significant discriminating variables in space. Spatial and temporal groupings of the samples were successfully achieved through PLS modeling. PLS showed that the summer season samples are dominated by PO₄, TDS, F, K, COD, BOD, Na, Cl, hardness and alkalinity, whereas, samples of winter season by DO, pH, NH₄-N and coliforms. Furthermore, PLS indicated site-specific dominance of anthropogenic contaminants suggesting for their pollution sources in the corresponding catchments of these sites.

The Erzgebirge, part of the so-called former “Black Triangle”, used to represent the strongest regional air pollution of Central Europe. To test the hypothesis of deposition enhancement with height, an altitudinal gradient along a N-S transect from the Elbe river lowlands to the Erzgebirge summit was chosen to investigate chemical composition, elevation-related variability, temporal changes, and seasonal patterns of ion concentrations from 1993 to 2002. The following questions were to be answered: (1) Which role does orography play on the composition of precipitation?, (2) Does fog occurrence overrule the orographic influence?, (3) Are there changes in the past 10 years, and if so, why?, (4) Do relevant seasonal changes occur and why? Air streams from westerly and to a lesser degree south-easterly directions prevail. The average precipitation was ion-poor (23 μS cm-¹ and acidic (pH 4.5). Sulphate still was the dominant anion (52.3-59.9 μeq L-¹, while NH⁺ ₄ determined the cations (41.9-62.2 μeq L-¹. Ion concentrations decreased with altitude to about 735 m a.s.l. and subsequently increased. The seeder-feeder effect largely explains the chemical composition of precipitation; enhanced in winter through snow crystals. Sub-cloud scavenging does not explain the observed patterns. Fog occurrence enhanced the observed effects at higher altitudes. Deposition amounts doubled from the lowlands to the Erzgebirge summit. From 1993 to 2002, acidity decreased by about 50%, mainly due to reduced SO₂ -emissions.

Danish rivers carry >50% of the phosphorus (P) transport as particulate P (PP). In five of six rivers sampled in November 1998 iron-bound P made up > 59% of PP and loosely adsorbed P ranged between 2% and 13%. This fraction could potentially be released in 14[per thousand] seawater. The behaviour of dissolved and particulate P fractions was studied during seven month in a 2 km long estuary with low freshwater retention time and low tidal range. The river carried ~10% of PP as loosely adsorbed P but increased concentrations of dissolved inorganic P (DIP) relative to the estuarine mixing line was only observed in the summer month with low freshwater flow and was more likely due to DIP release from the bottom sediment. Instead estuarine particles were always enriched with oxidized iron (ox.Fe) and iron-bound P as well as loosely adsorbed P and during May-September this coincided with increasing concentration of PP in estuary. We suggest that flocculation of ox.Fe and adsorption of DIP onto the particles with subsequent transport seawards is a major loss process for P during the summer month. During winter month where 85% of the run-off occurs the dominant process in the estuary is sedimentation of larger particles, however, a comparison of river particles with surface sediment clearly reveals that most PP is mobilized again from the bottom sediments.

Recent surveys of river Tisza (Serbia) have shown that class Oligochaeta is commonly present as dominant member of benthic macroinvertebrate community. Knowing the fact that this class is very good indicator of organic upload in aquatic ecosystem, in this paper it is used for saprobiological water quality assessment of middle and lower stream of river Tisza in summer of 2002, 2004 and 2005. Results presented as saprobiological indices, showed that water quality of river Tisza (Serbia) was alfa-mesosaprobioc (the third class) during research period.

Microbiological and saprobiological characteristics of river Moraca and Skadar lake for period of 2004/2005 are done at localities: Pernica, Moraca estuary and Vranjina (Skadar Lake). The objective of the research is to establish quality of water of these aquatic ecosystems based on microbiological and saprobiological analyses, as well as, to show need for protection of these water ecosystems from permanent contaminations, mainly by sewage should be pointed out. Saprobiological index is determined based on Gulyas Pal, and Pantle Buck is used to determine saprobiological level.

In this paper the results of the application of WQI method on Vojvodina main rivers and canals are shown. There were investigated 41 localities, from April 2002 to May 2003. There was observed high degree of correlation between the WQI values and the qualitative composition of the desmid community. Exceptions to that rule were noticed, since that WQI is not sufficient parameter of the water quality.

In the course of implementation of project Ecological Significance Evaluation of River Moravica Basin with Pollutants Identification, supported by REC and DRP, chemical and physical water analysis were done, as well as slime analysis. Heavy metals presence in water, herb Mentha aquatica and slime was analysed at six relevant locations downstream river Moravica. Heavy metals test results in slime and herb Mentha aquatica points out the presence of Zn, Cu, Fe, Mn, with heavy metals concentration rise from spring to mouth of river Moravica to river Juzna Morava. Chemical and physical analysis of water content, and detection of heavy metals presence in herb Mentha aquatica - as bioindicator and in slime, shows on water contamination with heavy metals as the inflow result of waste waters from numerous polluters.

The paper deals with quality of water and deposits in the Nadela stream (in Banat, Serbia). This stream is outline of regional multipurpose hydrosystem within the same name. Analyses are carried out according to water usability for irrigation and properties of settled sediments from stream bottom. Their potential influence, and effect of their application to surrounding arable soil were investigated.

This paper presents the results of the examinations of phytoplankton community of the Tamis river from March 2003 till December 2004. During the investigation it was determined 136 algal taxa from 6 divisions: Cyanophyta (10 taxa), Chrysophyta (1 taxa), Bacillariophyta (66 taxa), Pyrhophyta (4 taxa), Euglenophyta (14 taxa) and Chlorophyta (41 taxa). The contents and the structure analysis of phytoplankton as well as saprobiological valorization of water quality, has been carried out in the Republic Hydrometeorological Service of Serbia. Results of quality and quantitative analysis point to domination of Bacillariophyta and Chlorophyta. The index of saprobity given on the basis of Pantle-Buck method indicated that the quality of water of Tamis river on Jasa Tomic border locality belonged to beta and beta-alfa mesosaprobic category.