EVALUATION OF WATER AND SEDIMENT QUALITIES AT RIVER MOUTHS IN THE HAIHE RIVER SYSTEM

Water and sediment qualities are studied by analyzing samples taking from the mouths of the Haihe, Duliujian, New Ziya and Beipai rivers in the Haihe river basin in north China in 2005 and 2001, in order to find the changes of water and sediment pollutions. The concentrations of heavy metals, arsenic, total nitrogen (TN) and total phosphorus (TP) are analyzed and results have been compared for the two times. The in-situ measurement for Dissolved Oxygen (DO) and Sediment Oxygen Demand (SOD) rates were carried at the Haihe and Duliujian river mouths in 2006. The results show that the waters of the 4 river mouths are still seriously polluted, though much improved in the case of the Haihe and Duliujian rivers. The main pollutants are TP and TN in the New Ziya and Beipai rivers and mercury (Hg) at all 4 river mouths. Compared with those in 2001, the concentrations of almost all metals and arsenic in the 4 river mouths have decreased. Water quality at Haihe and Duliujian shows an improving trend, while the water quality at Beipai is similar to that of 2001. In contrast, water at the New Ziya river mouth is more severely polluted. The sediments in the 4 river mouths are not seriously polluted by heavy metals but are polluted by nitrogen and phosphorus. Most of the pollutant contents in the sediments show little change between 2001 and 2005. The in-situ DO and SOD measurement shows that the waters at the Haihe river mouth is in the state of oxygen depletion, and SOD is important consumer of DO at the river mouths. The overall analysis shows that increasing water pollution and eutrophication in waters far from cities are ongoing causes of concern.     

Concentrations,coexisting forms,and features of silicon distribution and migration in surface waters of Ukraine

The results of studying silicon concentrations and coexisting forms in surface water bodies of Ukraine with different hydrological regime, hydrophysical and hydrochemical characteristics are presented. Silicon distribution between its dissolved and suspended forms, as well as the relationship between the concentration of suspended silicon and the weight of suspended matter and its nature are discussed. The dominating form of silicon migration is shown to be its dissolved form (70.1–99.4% of its total content), while suspended form of silicon dominates in river waters with higher concentration of suspended matter of mineral origin, (56.1–81.5%). The results of studying silicon distribution between abiotic and biotic components of suspended matter, as well as between its dissolved forms with different charge signs are given. Dissolved silicon in the water bodies under study is shown to account for 93.0–99.0% of neutral fraction, where its compounds with molecular weight <0.2 kDa dominate.     

非稳沉采煤沉陷区沉积物-水体界面的氮、磷分布及迁移转化特征

以淮南后湖非稳沉采煤沉陷区沉积物-水体界面为研究对象,分析该湖未开发区(A区)、水产养殖区(B区)和水生蔬菜种植区(C区)3个功能区上覆水-间隙水-沉积物体系中氮、磷分布及其迁移特征.结果表明,氮、磷在不同水体界面的分布差异较大.其中上覆水中氮、磷浓度表现为A区B区C区;间隙水中氮、磷分布差异不显著,然而各功能区间隙水的氮、磷浓度明显高于上覆水,氮、磷主要由间隙水向上覆水中移动;沉积物中氮、磷含量以C区最高.后湖采煤沉陷区水体表现出氮污染、磷限制的现象.     

State of heterotrophic bacterioplankton of Yenisei estuary and the zone of Ob–Yenisei discharge in autumn in relation with environmental factors

In September 2011, variations of the total abundance of bacteria were studied, including, for the first time, the abundance of bacteria with intact membranes and active electron transport chains, as well as chlorophyll a concentrations and some hydrological and hydrochemical characteristics of water in Yenisei estuary and the zone of Ob–Yenisei river discharge. The study found abundant, viable, and actively functioning bacterioplankton to exist in the region. The absolute values of all microbiological characteristics were found to decrease with the distance from the freshened waters of Yenisei estuary toward the seawater of the Ob–Yenisei river discharge, while the percentage of bacteria with intact membranes and actively functioning microorganisms in bacterioplankton increased in the same direction. Positive correlations were found to exist between the values of all examined microbiological characteristics and the concentration in water of chlorophyll a, silicium, organic nitrogen, and oxygen, as well as water temperature. The same biological characteristics showed negative correlations with water salinity and phosphates. The spatial distribution of bacteria in the examined water body was supposed to be due mostly to the intensity of hydrodynamic processes, rather than the biogenic matter content of water.     

Space and time regularities in variations of nitrogen compound concentrations in watercourses of the Republic of Bashkortostan

The dynamics of anthropogenic activity and anthropogenic sources of nutrients in the Republic of Bashkortostan have been analyzed. Statistical analysis of many-year data of hydrochemical monitoring have been used to establish the year-to-year and annual regularities in the variations of N compound concentrations in watercourses. Maps of the mean annual N concentration in its forms (ammonium, nitrites, and nitrates) have been constructed. The fitness of river water to different types of water use have been assessed. Probability distributions of the concentrations of hydrochemical components have been constructed for different phases of stream water regimes. The exceedance probabilities have been evaluated for MAC values of N compounds in watercourses.     

WATER POLLUTION IN THE RIVER MOUTHS AROUND BOHAI BAY

Twelve water samples were collected and analyzed. The samples were taken from the river mouths around Bohai Bay including the Jiyun. New Yongding, Haihe, Dagu, Duliujian, Qingjinghuang, Qikou, Dakou, and Yellow Rivers, and tested for concentrations of heavy metals, arsenic, total nitrogen (TN) and total phosphorus (TP). The results show that the river mouths are polluted and the water quality exceeds Class V of the Environmental Quality Standard for Surface Water (EQSSW). The main pollutants are Hg, nitrogen (N) and phosphorus (P). The concentrations of the other pollutants are within Class II of the Standard. The Hg content in the Haihe River mouth is now 10 times higher than it was 20 years ago, indicating that the accelerating water pollution has reached an alarming level. The high concentrations of N and P cause eutrophication of the waters. Analysis indicates that the terrestrial pollutants and nutrients are the main cause of frequently occurring red tides in the Bohai Sea.     

Copper in natural waters in Transbaikalia

Cu concentrations in surface (river and lake) and subsurface waters are determined. The geographic pattern of Cu distribution in natural water is identified. This pattern is controlled by the difference between its concentrations in drained rocks and soils and the geochemical redox conditions of its migration. Territories with low, medium, and elevated Cu concentrations in natural waters are identified. The concentrations of Cu in natural waters of the region are found to be generally lower than the Clarke values.     

Spatial and Temporal Variability of Biogenic Elements Flow and Water Quality in a Small River

Regularities of the formation of biogenic elements flow and water quality in the Istra River (downstream of the Istrinskoye Reservoir) and its tributaries are revealed. Temporal variability in water quality parameters is shown to be closely related to fluctuations in the river water abundance, whereas spatial variability is determined by different intensity of anthropogenic load on river watersheds. It was found that the mean annual (for the period of 1991–1995) concentrations of nitrogen and phosphorus mineral compounds do not always meet the requirements of drinking water supply. A method of estimating the environmental state of the main river, taking into account biogenic elements input from its basin is suggested.     

Migration of dissolved matter at Serebryanka R. Mouth,the basin of the Sea of Japan (Sikhote Alin Reserve)

Ions of major salt composition and dissolved forms of some microelements (F, B, Sr, Rb, Cs, V, As, Mo, U) at the mouth of the Serebryanka R. (Sikhote Alin Reserve) are shown to feature conservative behavior in July 2009. The distribution of dissolved mineral phosphorus is shown to be controlled mostly by chemical processes (desorption from river suspension), even during vegetation period, while the role of biological consumption is secondary. The behavior of dissolved organic phosphorus and silicon is nearly conservative. A considerable amount of barium (up to 46% of its concentration in river water) is shown to be removed from solution, maybe because of its sorption on particulate matter of continental runoff. Ittrium and rare-earth elements (La, Ce, Pr, Nd, Dy, Ho) show an abrupt decrease in the concentrations of their dissolved forms at the initial stages of river water penetration into the sea. This decrease is supposedly due to coagulation and flocculation of organic and organic-mineral colloids.     

鄱阳湖区水体氮、磷污染状况分析

通过系统测定鄱阳湖湖水、主要入湖口河水及部分农田水、地下水及城市污水氮磷含量,对其氮、磷污染状况进行了分析,同时对湖水及河水的氮、磷来源进行了初步讨论.结果表明,鄱阳湖区水体已达到一定程度的氮、磷污染,特别是饶河段氮含量较高(0.89-3.15mg/L),信江磷含量较高(0.098-0.22mg/L),而湖体的总氮、总磷含量也分别达到1.06±0.28mg/L和0.067±0.042mg/L,已具备富营养化的条件.     

Pollutant Migration in Water Bodies in Mining Regions (Based on Data on Apatite Deposits)

Variations in the key indices of the chemical composition of surface waters are studied in a region where these waters are polluted by mining plant wastes. The forms of metals migration and their distribution in the bottom deposits of watercourses are examined. The possible steps for reducing the pollution of water in a watercourse are discussed.     

Zur Bewertung der Analytik und Interpretation des Gruppenparameters “Extrahierbares organisch gebundenes Halogen” von Wässern

Organohalogen compounds are gaining in importance in the control of surface and drinking water due to their unwholesome properties. An accumulation of the organohalogen compounds, occurring mostly at low concentrations, is possible in different ways. The author discusses the possibility and problems of the extractability from waters with the aid of organic solvents. The group parameter EOX that can be determined does not allow any statement concerning components of individual substances, but gives some clues to the state of surface and drinking waters which are mostly anthropogenically polluted. Results of practical examples as well as theoretical considerations indicate the importance of the different distribution coefficients in the solvent/water extraction system. The degree of extraction can be considerably increased by the application of suitable mixtures of solvents. In waters with a known composition, the probably detectable EOX-quantity can be calculated by means of theoretical degrees of extraction.     

A review of pollutants in the sea-surface microlayer (SML): a unique habitat for marine organisms

Boundary layers between different environmental compartments represent critical interfaces for biological, chemical and physical processes. The sea-surface microlayer (uppermost 1-1000 microm layer) forms the boundary layer interface between the atmosphere and ocean. Environmental processes are controlled by the SML, and it is known to play a key role in the global distribution of anthropogenic pollutants. Due to its unique chemical composition, the upper organic film of the SML represents both a sink and a source for a range of pollutants including chlorinated hydrocarbons, organotin compounds, petroleum hydrocarbons, polycyclic aromatic hydrocarbons (PAH) and heavy metals. These pollutants can be enriched in the SML by up to 500 times relative to concentrations occurring in the underlying bulk water column. The SML is also a unique ecosystem, serving as an important habitat for fish eggs and larvae. Concentration ranges and enrichment factors of pollutants in the SML in different areas of the world's oceans have been critically reviewed, together with available toxicity data for marine biota found within the SML. Overall, the SML is highly contaminated in many urban and industrialized areas of the world, resulting in severe ecotoxicological impacts. Such impacts may lead to drastic effects on the marine food web and to fishery recruitment in coastal waters. Studies of the toxicity of fish eggs and larvae exposed to the SML contaminants have shown that the SML in polluted areas leads to significantly higher rates of mortality and abnormality of fish embryos and larvae.     

Coupled 1D–3D hydrodynamic modelling,with application to the Pearl River Delta

Within the hydrodynamic modelling community, it is common practice to apply different modelling systems for coastal waters and river systems. Whereas for coastal waters 3D finite difference or finite element grids are commonly used, river systems are generally modelled using 1D networks. Each of these systems is tailored towards specific applications. Three-dimensional coastal water models are designed to model the horizontal and vertical variability in coastal waters and are less well suited for representing the complex geometry and cross-sectional areas of river networks. On the other hand, 1D river network models are designed to accurately represent complex river network geometries and complex structures like weirs, barrages and dams. A disadvantage, however, is that they are unable to resolve complex spatial flow variability. In real life, however, coastal oceans and rivers interact. In deltaic estuaries, both tidal intrusion of seawater into the upstream river network and river discharge into open waters play a role. This is frequently approached by modelling the systems independently, with off-line coupling of the lateral boundary forcing. This implies that the river and the coastal model run sequentially, providing lateral discharge (1D) and water level (3D) forcing to each other without the possibility of direct feedback or interaction between these processes. An additional disadvantage is that due to the time aggregation usually applied to exchanged quantities, mass conservation is difficult to ensure. In this paper, we propose an approach that couples a 3D hydrodynamic modelling system for coastal waters (Delft3D) with a 1D modelling system for river hydraulics (SOBEK) online. This implies that contrary to off-line coupling, the hydrodynamic quantities are exchanged between the 1D and 3D domains during runtime to resolve the real-time exchange and interaction between the coastal waters and river network. This allows for accurate and mass conserving modelling of complex coastal waters and river network systems, whilst the advantages of both systems are maintained and used in an optimal and computationally efficient way. The coupled 1D–3D system is used to model the flows in the Pearl River Delta (Guangdong, China), which are determined by the interaction of the upstream network of the Pearl River and the open waters of the South China Sea. The highly complex upstream river network is modelled in 1D, simulating river discharges for the dry and wet monsoon periods. The 3D coastal model simulates the flow due to the external (ocean) periodic tidal forcing, the salinity distribution for both dry and wet seasons, as well as residual water levels (sea level anomalies) originating from the South China Sea. The model is calibrated and its performance extensively assessed against field measurements, resulting in a mean root mean square (RMS) error of below 6% for water levels over the entire Pearl River Delta. The model also represents both the discharge distribution over the river network and salinity transport processes with good accuracy, resolving the discharge distribution over the main branches of the river network within 5% of reported annual mean values and RMS errors for salinity in the range of 2 ppt (dry season) to 5 ppt (wet season).     

Distribution,characteristics and potential impacts of chromophoric dissolved organic matter (CDOM) in Hudson Strait and Hudson Bay,Canada

The characteristics of chromophoric dissolved organic matter (CDOM) were studied in Hudson Bay and Hudson Strait in the Canadian Arctic. Hudson Bay receives a disproportionately large influx of river runoff. With high dissolved organic matter (DOM) concentrations in Arctic rivers the influence of CDOM on coastal and ocean systems can be significant, yet the distribution, characteristics and potential consequences of CDOM in these waters remain unknown. We collected 470 discrete water samples in offshore, coastal, estuarine and river waters in the region during September and October 2005. Mixing of CDOM appeared conservative with salinity, although regional differences exist due to variable DOM composition in the rivers discharging to the Bay and the presence of sea-ice melt, which has low CDOM concentrations and low salinity. There were higher concentrations of CDOM in Hudson Bay, especially in coastal waters with salinities <28$<28$, due to river runoff. Using CDOM composition of water masses as a tracer for the freshwater components revealed that river runoff is largely constrained to nearshore waters in Hudson Bay, while sea-ice melt is distributed more evenly in the Bay. Strong inshore–offshore gradients in the bio-optical properties of the surface waters in the Hudson Bay cause large variation in penetration of ultraviolet radiation and the photic depth within the bay, potentially controlling the vertical distribution of biomass and occurrence of deep chlorophyll maxima which are prevalent only in the more transparent offshore waters of the bay. The CDOM distribution and associated photoprocesses may influence the thermodynamics and stratification of the coastal waters, through trapping of radiant heating within the top few meters of the water column. Photoproduction of biologically labile substrates from CDOM could potentially stimulate the growth of biomass in Hudson Bay coastal waters. Further studies are needed to investigate the importance of terrestrial DOM in the Hudson Bay region, and the impact of hydroelectric development and climate change on these processes.     

Discharge of biogenic substances with river runoff in Selenga basin

Averaged many-year measurement data on the concentrations of mineral forms of biogenic elements are analyzed, and their total concentrations in the rivers of Selenga, Chikoi, Khilok, Uda, Dzhida, and Temnik are evaluated. The monthly variations of the concentrations of major biogenic substances are characterized, and their ratios within a year are determined. Characteristics of river water runoff and biogenic substance concentrations are used to evaluate their within-year discharge by rivers. Characteristic variations in the ratios between the total and mineral forms of biogenic elements discharged by rivers have been revealed. It is established that the share of mineral components in the total input into the Selenga delta N_tot and P_tot are 82 and 22%, respectively.     

Concentration dynamics of biogenic elements and phytoplankton at Selenga R. Mouth and in Selenga shallows (Lake Baikal)

The seasonal and year-to-year dynamics of the concentrations of biogenic elements and organic matter, as well as quantitative composition of phytoplankton in water of Selenga delta branches is studied. The distribution of those components from the mouth of the Kharauz branch (the main branch) to the water area of the Selenga shallows in different hydrological seasons is shown. The concentrations of nitrate nitrogen and phosphate phosphorus in the zone of mixing of river and lake waters have been found to drop by 30 and 50%, respectively, because of the consumption of those substances by phytoplankton.     

Seasonal Variations in the Forms of Heavy Metal Occurrence in the Kuibyshev Reservoir Waters and Bottom Deposits

Seasonal dynamics of total concentrations and the main forms of occurrence of heavy metals (HM) in the water mass and bottom deposits (BD) are studied in the Priplotinnyi (Near-dam) Pool of the Kuibyshev Reservoir. In the near-bottom and interstitial waters, heavy metals are mostly found in the form of complex compounds with organic and mineral ligands; the proportions of these complexes and the dominant form in the above media change from season to season. The hard skeleton of bottom deposits contains a large store of heavy metals that can be a source of the secondary pollution of water masses.     

Nitrogen compounds in the surface and subsurface waters of Karelia

Materials of long-term studies of the concentration and distribution of N forms (NH₄⁺, NO₃⁻, NO₂⁻, N_org) in precipitation, surface water and groundwater are generalized. Precipitation was found to be the main source of N compounds input into these waters. The effect of anthropogenic factors is local and does not influence the concentration and distribution of N forms in most water bodies that serve as wastewater recipients. The N forms dominating in precipitation are NO₃⁻ and N H₄⁺; N_org dominates in most surface water bodies, and NO₃⁻ dominates in groundwater. The median concentrations of N_tot in clear surface and subsurface waters are similar. The obtained characteristics of the concentrations and distribution of N forms in natural waters of Karelia can be used for other water bodies in the humid zone.     

Characteristic of Lower Don aquatic ecosystem in late autumn

Multidisciplinary studies were carried out in the Lower Don River in the low-water November of 2012. The studies showed relatively low concentrations of oil products (up to 2 MAC) and heavy metals (up to 1 MAC), which were likely due to the cessation of navigation in the river. However, copper concentration was found to be in excess of its MAC. The most polluted were found to be the port water areas of the cities of Volgodonsk, Ust’-Donetsk, and Semikarakorsk. The distribution of nutrients over streams is uneven: the Don water is poorer in nutrients than the waters of the Severskii Donets and the Manych are. Oxbows can serve as depots of organic matter, where it accumulates over longer periods than in the river. The residual manifestations of the summer–autumn blooming of blue-green algae, observed in shallows, the predominance of algae of divisions Cryptophyta and Bacillariophyta (typical representatives of winter planktonic algacenosis), and their low abundance suggest the transitional state of phytoplankton communities to autumn–winter season (pre-winter period). The species diversity and biomass of zooplankton were largest in the Don R. and lowest in the Severskii Donets R. The formation of zooplankton species composition shows the effect of the runoff from the Tsimlyanskoe Reservoir. An increase in the proportion of oligochaetes and invading species was recorded in the Don. The decrease in the diversity of benthos is attributed to natural factors, i.e., the decay of imago and thicket forms in autumn. The biomass of the soft (food) benthos is low because of the predominance of its small-size forms.