An Integration of Water Physicochemistry,Algal Bioassays,Phytoplankton, and Zooplankton for Ecotoxicological Assessment in a Highly Polluted Lowland River

Results of different approaches potentially useful for the evaluation of water ambient quality were analysed and compared in a small temperate lowland river with mixed diffuse and multiple-point source pollution. The Reconquista River (Buenos Aires Province, Argentina), one of the most polluted watercourses of Latin America, receives agrochemicals as well as domestic and industrial (mostly untreated) effluents. Physical and chemical water variables were determined; unispecies algal bioassays (with Chlorella pyrenoidosa and Scenedesmus acutus) were carried out in laboratory; and density and structure of phyto- and zooplankton were analysed at three sites in four dates (representing a range of likely conditions in the river). A general scheme of association among plankton, bioassays and physical/chemical variables was elaborated, that helped to infer possible control factors in this multi-stressed system. Some empirical methods, but mainly mathematical ones including multivariate techniques (as PCA, cluster analysis), were applied for evaluation of samples. A preliminary selection of indices and attributes as potential indicators of the water river quality was made, and then applied for assay a tentative integrative ordination of samples. The relative best water quality was recorded when-where dissolved oxygen concentration, algal diversity and planktonic crustacean density were higher. The worst water quality corresponded to the lack of cladocerans and lowest crustacean density, and higher: organic and industrial pollution, major nutrients (ammonium and orthophosphates), BOD, hardness, conductivity, algal biomass in bioassays, phytoplankton density (>10 000 ind. mL^-1), dominance of a single algal species (>90%), and rotifer proportion in zooplankton (>85%).     

沣河水污染特征及非点源污染负荷估算分析

沣河流域的主要污染指标为COD、BOD5、NH4+-N等,非点源污染负荷的定量化对流域水污染控制和水环境综合治理意义重大。结合沣河1986-2009年水量、含沙量及水质状况监测数据进行有机污染综合指数及相关分析,并采用平均浓度法对流域的非点源污染负荷和点源污染负荷进行了研究。结果表明:(1)有机污染综合指数(A值)呈抛物线趋势,径流量与沣河水质呈负相关性,含沙量与沣河水质呈正相关性。通过产业结构调整等措施,近年来沣河水质有明显改善;(2)沣河的污染负荷大部分来自降雨径流引起的非点源污染,在沣河水污染中TN的非点源污染负荷比例在56%以上,TP的非点源污染负荷比例在68%以上,NH4+-N的非点源污染负荷比例在63%以上,比重较大,非点源污染对沣河水质的影响不容忽视,而且TP受到的影响相对最大,可通过合理配置水土保持措施,有效防治非点源污染。     

Characteristics of bacterial community in the water and surface sediment of the Yellow River,China, the largest turbid river in the world

Purpose

Few studies have described the bacterial community structures of turbid rivers. In this paper, the characteristics of the bacterial community in the water and surface sediment of the Yellow River, China, the largest turbid river in the world, were studied.

Materials and methods

Water and sediment samples were collected from six sites along the river. Bacterial community composition was determined using the 16S ribosomal RNA (rRNA) gene clone library technique. The relationship between environmental parameters and bacterial diversity was analyzed.

Results and discussion

A total of 1,131 gene sequences were obtained and clustered into 639 operational taxonomic units (at the 97 % identity level), with Proteobacteria as the predominant phylum. The Shannon index for water samples ranged from 3.39 to 4.40 and was generally higher than that in other rivers; this was probably due to the high suspended particulate sediment (SPS) concentration in the Yellow River, which can provide more habitats for both aerobic and anaerobic bacteria. Also, the bacterial diversity of the water samples was slightly higher than that of the surface sediment samples. The bacterial diversity of water increased along the river in the downstream direction, while there was no trend for the sediment. Redundancy analysis indicated that pH, dissolved organic carbon (DOC), and SPS were the main factors controlling the water bacterial community in the Yellow River, and pH, nitrate–nitrogen, and water content were the main factors for the surface sediment bacterial community.

Conclusions

This study indicated that the bacterial diversity of the Yellow River is generally higher than that in other rivers, suggesting that SPS plays an important role in regulating bacterial diversity and community structure in aquatic environments.     

Multivariate correlation of water quality,sediment and benthic bio-community components in Ell-Ren river system,Taiwan

The distribution and correlation of benthic bio-community, water and sediment pollutants were evaluated with multivariate analysis from data collected over six samplings at 12 sites in the Ell-Ren river system, Taiwan. A total of 41 benthic algae species, 8 aquatic insect species and 2 annelid species were collected. On the basis of both principal component and correlation matrix analyses, we defined six water and sediment pollutant components to reveal common behaviour. Metrioenemus sp., Tubifex sp., Bacillariophyceae and Cyanophyceae could tolerate the environment at highly polluted sites. Caenis sp., Rhithrogena sp. and Baetis sp. preferred sites that were aerobic, and their populations were negatively correlated (52–56%) with detrital heavy metals in sediment. The population of benthic algae was positively variated with lead of the “bound to organic matters and sulphides” fraction, but negatively with copper in the detrital pattern. Results suggested that benthic bio-community demonstrated measurable relationships with water and sediment pollutants in Ell-Ren river system, and could be used as indicators to assess the water quality of river over a longer period.     

Accumulation and Distribution of Metals in Bolboschoenus maritimus (Cyperaceae), from a South African River

The Diep River is a major freshwater ecosystem in the Western Cape, South Africa. Although it is surrounded by many sources of metal pollution, the actual metal levels in this river system are unknown. Wetland plants are known to accumulate metals and may possibly be used as biomonitors of metal contamination in a river system. One such species, the sedge Bolboschoenus maritimus, is found in abundance along the banks of this river. The aim of this study was to investigate and monitor the degree of metal contamination in the water and sediments of the lower Diep River, as well as to study the seasonal accumulation and distribution of metals in B. maritimus, and the use thereof as biomonitor species. Two sampling sites were used: one site above the wetland section of the river, receiving runoff mainly from agricultural lands (site 1), and one site close to the river mouth (site 2), exposed to several possible pollution sources. Water, sediment, and plant (root, leaf and stem) samples were collected seasonally for 1 year and analyzed for Al, Zn, Cu, and Fe. There was greater bioaccumulation of metals by plants at site 2, due to greater bioavailability of metals. B. maritimus was shown to be a root accumulator of metals. Seasonal fluctuations in root, stem, and leaf metal concentrations did not follow seasonal sediment concentration patterns. However, using B. maritimus as test species did provide valuable additional information to sediment and water analyses. More extensive research is needed to conclude whether this species is an effective biomonitor in the lower Diep River environment.     

Measuring fluctuating asymmetry of the terrestrial isopod Trachelipus rathkii (Crustacea: Isopoda, Oniscidea)

Studies on fluctuating asymmetry (FA) in soil invertebrates, particularly in isopods, are almost absent so far. As a result, methodology of measuring FA in isopods is little known. However, the ecological importance of these animals in decomposition processes and the fact that FA in soil invertebrates might serve as an indicator of environmental stress, e.g. soil pollution, make the topic worth for investigation. Our results revealed that woodlice are potentially able to signal environmental stresses via FA. We compared six traits (length of three segments of antennae, two segments of the seventh legs and the number of ocelli) between two populations (Hungary: Hajós, Blaskovics-puszta) and genders of the species Trachelipus rathkii living under different environmental stresses (i.e. changing humidity). Asymmetry was significantly higher in the Hajós population, where the soil moisture has changed dramatically for the last years. Asymmetry was lower in Blaskovics-puszta, where the habitat has remained constant during the last centuries and the population had time to adapt to seasonally changing environments. Gender did not have an effect on FA. Traits differed significantly from each other, thus it is advisable to use several traits simultaneously to detect FA. FA was higher in the a1 segment of the antennal flagellae than in the ischium of the pereiopod and ocelli. We also studied the effect of regeneration of lost body parts on the FA values. Asymmetry in the treated groups was significantly higher than in the control ones. This calls the attention to the problem of outliers, which may be caused by physical harm and can lead to artificial results.     

Mobilization Potential of Heavy Metals: A Comparison Between River and Lake Sediments

Toxic metals introduced into aquatic environments by human activities accumulation in sediments. A common notion is that the association of metals with acid volatile sulfides (AVS) affords a mechanism for partitioning metals from water to solid phase, thereby reducing biological availability. However, variation in environmental conditions can mobilize the sediment-bound metal and result in adverse environmental impacts. The AVS levels and the effect of AVS on the fate of Cu, Cd, Zn, Ni in sediments in the the Changjiang River, a suboxic river with sandy bottom sediment and the Donghu Lake, a anoxic lake with muddy sediment in China, were compared through aeration, static adsorption and release experiments in laboratory. Sips isotherm equation, kinetic equation and grade ion exchange theory were used to describe the heavy metal adsorb and release process. The results showed that AVS level in the lake sediment are higher than that of the river. Heavy metals in the overlying water can transfer to sediments incessantly as long as the sediment remains undisturbed. The metal release process is mainly related to AVS oxidation in lake sediment while also related to Org-C and Fe–Mn oxyhydroxide oxidation in river sediment. The effect of sulfides on Zn and Ni is high, followed by Cd, and Cu is easy bound to Org-C. AVS plays a major role in controlling metals activity in lake sediment and its presence increase the adsorption capacity both of the lake and river sediments.     

Determining the Validity of using Summer Monitoring to Estimate Annual Deposition of Acidic Pollutants in Southern Ontario,Canada

We tested the hypothesis that compensatory fertilization of Scots pine (Pinus sylvestris L.) stands polluted by theHarjavalta copper-nickel smelter in SW Finland alleviates thestress imposed by metal-contaminated soils. The treatments inthe experiment consisted of control, liming, slow-release mineral mixture and stand-specific fertilization, which comprised at least methylene urea and ammonium nitrate. Stresswas assessed by needle fluctuating asymmetry (FA) which increases with an increase in developmental instability. Sevenyears after the treatments, we found pronounced variation inboth FA and needle length among study sites (0.5, 2, 4 and 8 km from the smelter) and among treatments. FA increased and needlelength decreased with proximity to the pollution source. Variation in FA was independent of tree size (used as index ofgrowth rate in even-age stand); the effects of the treatmentson needle length, on the other hand, were expressed only inmedium-sized and large trees. Liming best alleviated pollutionstress, while the application of a slow-release mineral mixtureincreased FA by 30%. In pollution-stressed stands FA correlatedpositively with constitutive resin flow but was independent of volume growth. Our findings suggest that physiological stress (indicated by increase in developmental instability) and tree growth or stand productivity are not directly linked to one another, and that some increase in productivity can be achievedwithout the alleviation of pollution-induced stress.     

Estimation of Source of Heavy Metal Contamination in Sediments of Gomti River (India) using Principal Component Analysis

This study explores the extent and possible sources of heavy metal (Cd, Cr, Cu, Fe, Mn, Pb, Zn and Ni) contamination in the bed sediments of the Gomti River performing principal component analysis on the five years (Jan. 1994–Dec. 1998) data set obtained through continuous monitoring of the river water and bed sediments at eight selected sites and water/wastewater of its tributaries/drains. Influence of anthropogenic activities on metal contamination of the bed sediments was evaluated through computing the geoaccumulation index for various metals at studied sites. PCA performed on combined (river bed sediment, water, suspended solids, water/wastewater from tributaries/drains) data set extracted two significant factors explaining more than 58% of total variance. Factor loadings suggested the presence of both natural as well as anthropogenic sources for all these metals in the river bed sediments. Among all the sites, the sites 4 and 5 are more contaminated with Cd, Cu, Cr and Pb, which was supported by the geoaccumulation indices computed for metals. Factor scores revealed presence of seasonal (monsoon-related) differences in metals profiles for river water and suspended solids and absence of seasonal differences for bed sediment and wastewater. Further, the metal contamination of the bed sediment was also evaluated using biological thresholds. Results suggested that the river bed sediments are contaminated with heavy metals, which may contribute to sediment toxicity to the freshwater ecosystem of the Gomti River.     

Characteristics of sediment discharge in the subarctic Yukon River, Alaska

The characteristics of sediment discharge in the Yukon River, Alaska were investigated by monitoring water discharge, water turbidity and water temperature. The river-transported sediment, 90 wt.% or more, consists of silt and clay (grain size62.5 μm), which probably originated in the glacier-covered mountains mostly in the Alaska Range. For early June to late August 1999, we continuously measured water turbidity and temperature near the estuary and in the middle of Yukon River by using self-recording turbidimeters and temperature data loggers. The water turbidity (ppm) was converted to suspended sediment concentration (SSC; mg/l) of river water, using a relation between simultaneous turbidity and SSC at each of the two sites, and then, the suspended sediment discharge, approximately equal to water discharge times SSC, was numerically obtained every 1 or 2 h. It should be noted that the sediment discharge in the Yukon River is controlled by SSC rather than water discharge. As a result, a peak sediment discharge occurred in mid or late August by local sediment runoffs due to glacier-melt (or glacier-melt plus rainfall), while a peak water discharge was produced by snowmelt in late June or early July. Application of the “extended Shields diagram” indicates that almost all the river-transported sediments are under complete suspension.     

金沙江流域输沙特性分析

金沙江是长江上游河流泥沙的主要来源。通过对金沙江流域主要控制水站径流泥沙资料的统计分析，论述了金沙江河流泥沙的来源和沿程分配、输沙量的年内分配和年际变化、径流量和输沙量的关系，以及泥沙形成的原因。为研究金沙江流域的水土流失和泥沙输移规律，合理地开发和利用其水土资源提供了科学依据。     

论黄河干流内蒙古段泥沙危害及其防治

分析了黄河干流北端产生泥沙淤堵的原因,认为该段支流的水土流失严重是其根源,上游来水量减少加剧了干流的淤堵。阐述了泥沙淤堵对国民经济和社会可持续的重大影响,通过对２条支流治理与未治理的实例对比分析,提出多泥沙河流治理对策;变被动防守为主动治理,从水土流失防治着手;按市场经济机制,全社会共同出力进行治理;采用综合,系统的防治措施,治理开发水沙资源,变害为利,全流域统筹考虑,水沙统一调控。     

巢湖十五里河不同河段沉积物古菌群落结构特征研究

[目的]为了探究城市河流沉积物古菌群落结构特征及其环境指示意义,[方法]应用高通量测序技术获取巢湖十五里河不同河段表层沉积物古菌群落组成,用冗余分析(RDA)和相关性分析等方法探究古菌群落结构特征与沉积物环境因子间的联系.[结果]十五里河表层沉积物古菌的优势菌门和次优势菌门分别是广古菌和奇古菌与深古菌,其相对丰度分别为...     

Distribution of Zn in a Northwestern Mediterranean River

Determination of Zn in the aqueous, suspended and sedimentary phases of the Rhone River was carried out by differential pulse anodic stripping voltammetry with static mercury drop electrode. For total desorbable Zn (operationally defined as that measured on unfiltered water at pH 1.5 to 2) the concentration was 2.0 ± 0.6 μg L^?1 in unfiltered upstream water (8 stations) and in the unfiltered delta water (2 stations) was 1.05 ± 0.25 μg L^?1. The delta values are slightly higher than values found recently for estuaries of other rivers such as the Amazon and Yangtse, but non-delta values correspond mainly with those from relatively unpolluted areas. Overall, in non-delta water about 35% of the Zn was in true solution, 25% adsorbed on suspended material and 40% was in the suspended material but not desorbable. The calculatedK _d for Zn on the suspended material was about 2.5E4. The Zn content in suspended matter including adsorbed Zn was 69 ± 33 mg kg^?1, much lower than other literature values, and is approximately equivalent to the concentration in fine sediment fractions. The Zn in Rhone river sediment was on average 40 times the amount from nearby non-industrialized areas such as the Roya river.     

黄河上游内蒙古河段塑槽输沙需水量分析

为了解冲积性河流塑槽输沙需水量,合理调配水资源,以内蒙古河段为例,依据挟沙水流能量平衡方程,研究了冲积性河流挟沙水流的能量耗散原理及水流塑槽和输沙能量的分配模式,给出了反应冲积性河流冲淤状态的塑槽输沙需水量计算方法,由平滩流量、河道来沙量和冲淤量三者组成的关系确定塑槽输沙需水量。利用内蒙古河段1960-2013年实测资料,计算得到内蒙古河段塑槽输沙水量,汛期来沙量0.7～1.1亿t,塑造2 000～3 000 m~3/s的中水河槽、淤积水平控制30%以下,需要的汛期塑槽输沙水量为94.6～141.2亿m~3;分析了不同条件下汛期塑槽输沙水量变化规律:来沙量一定,同样的中水河槽规模,控制淤积水平越低,需要的塑槽输沙水量越大;来沙量一定,同样的淤积水平,塑造中水河槽规模越大,需要的塑槽输沙水量越大;控制同样淤积水平,塑造同样中水河槽规模,汛期来沙量越大,需要的塑槽输沙水量越大。内蒙古河段塑槽输沙需水量计算结果和结果变化规律可为黄河上游内蒙古河段水资源配置提供参考。     

黄河流域泥沙配置状况及其资源化

 通过分析黄河流域水沙运动过程和水沙分布特点,给出了流域泥沙配置单元,指出流域泥沙配置单元的配置量随着流域治理工程实施、径流条件等不断变化;1950—1999年,流域水土保持滞沙、水库拦沙、河道滞沙、两岸引沙用沙、河口淤积与入海泥沙等配置单元年均配置沙量占流域产沙量(17.63亿t)的14.24%、14.05%、12.19%、10.56%和50.77%;阐述了水库拦沙多、河道淤积严重是黄河流域泥沙配置现状不合理的主要原因,指出流域水沙资源优化配置和泥沙资源化是维护黄河健康的重要途径;结合黄河下游长期泥沙处理与利用的经验和教训,总结了黄河下游泥沙资源化的主要途径,包括淤临淤背、河道治理与河槽维护、引洪淤灌与土壤改良、灌区堆沙高地农田化、建筑材料转化、河口泥沙造地和疏浚泥沙利用、湿地塑造等。     

环江流域90年代水沙变化研究及治理方略探讨

 根据实测水文资料,对泾河2级支流环江流域20世纪90年代水沙变化进行了较为深入的分析和研究,利用3种方法计算环江流域90年代综合治理的减洪减沙效益;分析了流域地下径流补给变化情况,估算了流域地表水资源利用率;对环江流域水资源开发利用及今后治理方略进行了探讨。研究结果表明:进入90年代后,环江流域最大24h降雨量明显增大,径流、泥沙大幅度增加,单位(mm)有效降雨产洪产沙量为4个阶段的最大值。流域综合治理措施减洪减沙作用减弱,地下径流补给情况有所好转,地表水资源利用率不高。据此提出了环江流域综合治理的总方略,可供环江流域水土保持生态工程建设参考。     

柳河流域径流、泥沙时变过程研究

柳河是东北地区泥沙问题最为严重的河流之一,具有河道泥沙淤积严重、大量沉积以及向辽河泥沙输出量高等特点。对柳河流域径流、泥沙要素从20世纪中叶到21世纪初的年内分配及年际变化进行了时变过程分析,并研究了径流量与泥沙输沙量的相关关联系数及关联度,结果表明,柳河流域径流量年内及年际分配都很不均匀,且有随时间的发展更不均匀的趋势。径流量与输沙量之间有着很密切的相关关系,各站的关联度由0.560～0.921不等,但总体上,关联度较大。     

上海市小城镇河流沉积物磷污染特征研究

磷是导致河流富营养化的重要元素,沉积物是河流富营养化的重要内源。目前小城镇的发展与环境监测不相适应。对上海市小城镇河流沉积物磷污染调查分析表明:镇级河流磷污染相对突出,朱家角镇镇级河流污染最为突出,枫泾区级河流磷污染相对突出,松江相对磷污染风险较小,但区域内差异较大,夏季是河流沉积物磷含量最高的季节,高温度和沉积物磷的高含量使得沉积物成为夏季上海市小城镇河流富营养化污染的重要内源。     

柳河流域径流、泥沙时变过程研究

柳河是东北地区泥沙问题最为严重的河流之一,具有河道泥沙淤积严重、大量沉积以及向辽河泥沙输出量高等特点。对柳河流域径流、泥沙要素从20世纪中叶到21世纪初的年内分配及年际变化进行时变过程分析,并研究径流量与泥沙输沙量的相关关联系数及关联度,结果表明,柳河流域径流量年内及年际分配都很不均匀,且有随时间的发展更不均匀的趋势。径流量与输沙量之间有着很密切的相关关系,各站的关联度由0.560～0.921不等,但总体上,关联度较大。