This study describes the impact of septic tanks on the groundwater quality of the shallow Pleistocene aquifer in Jericho area, Westbank, Palestine. Septic tanks are widely used for storage and disposal of sewage in the populated and agricultural city of Jericho. Routine hydrochemical tests for groundwater quality performed for several years identified the problem of a gradual nitrate increase, without pinpointing its definite sources. The geological formations of the Jericho area and the shallow nature of the Pleistocene aquifer, together with the mechanism of recharge, make the groundwater in this aquifer highly susceptible to contamination, particularly along sewers. The lithology of the Samara (high hydraulic conductivity) and the Lisan formation (low conductivity but increased infiltration along fractures) promote easy seepage of agricultural and anthropogenic inputs into the groundwater. Nitrate concentrations are elevated near septic tanks and animal farms, with nitrate values exceeding 74 mg/L. δ 15 N nitrate and δ 18 O nitrate signatures suggest sewage and manure as the main sources of high nitrate concentration in the groundwater. Samples taken during the end of the dry season indicate that a slight denitrification in the aquifer.
From 1998 to 2002 investigations were carried out to estimate both the quantity and quality (heavy metal contents) of suspended matter loads discharged into a floodplain area measuring approx. 5 km(2) of the Central German river Wei beta e Elster, a tributary of the river Saale in the Elbe river basin. Flood sediments, suspended particulate matter, and floodplain soils were investigated especially for the main pollutants Cd, Zn, Cu, Pb, Cr, and Hg. Supplementary gamma spectroscopy examinations were performed to help to identify the age of deposits in order to estimate sedimentation rates for last decades. The recent flood sediments are contaminated by up to 33 times the geogenic background (Cd). Up to 55% of the total annual SPM load of the river Weige Elster is relocated into the investigated retention area in the flood-stricken year 2002. The sedimentation rates for the last 50 years vary between 0.5 mm/a and 1 mm/a in far away and rarely flooded parts and between 1 mm/a and 2 mm/a in the frequently flooded parts of the inflow of the retention area.
Acta hydrochimica et hydrobiologicaVolume 34, Issue 6 p. 519-521 Editorial Editorial: Acta hydrochim. hydrobiol. 6/2006 Fritz H. Frimmel, Fritz H. FrimmelSearch for more papers by this authorBirgit C. Gordalla, Birgit C. GordallaSearch for more papers by this author Fritz H. Frimmel, Fritz H. FrimmelSearch for more papers by this authorBirgit C. Gordalla, Birgit C. GordallaSearch for more papers by this author First published: 25 January 2007 https://doi.org/10.1002/aheh.200790001AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume34, Issue6December 2006Pages 519-521 RelatedInformation
A preparative method was developed to sample dissolved organic carbon (DOC) and heavy metals (Ni, Mn) from polluted surface waters. Main focus was set on the preparative production of freeze-dried samples mainly composed of organic ligands from heavy metal complexes. First characterizations were done in the aqueous phase. Finally, freeze-dried samples provide stable organic matter for multiple characterizations. Acid mine drainage of the former mining area of Ronneburg (Germany) hold elevated concentrations of heavy metals and low concentrations of DOC. Municipal wastewater, passing the spoil pile, held elevated concentrations of DOC and low concentrations of heavy metals. Dissolved components smaller than 0.45 μm and larger than 1 nm were concentrated by nanofiltration. Organic heavy metal complexes were isolated from this solution by size-exclusion chromatography (SEC). Different size classes of molecules were collected from the column effluent, depending on their elution time, and were characterized by UV spectroscopy, ICP-OES, and DOC measurements. All samples held organic heavy metal compounds with different retention times. The organic heavy metal complexes in acid mine drainage had higher retention times than complexes from municipal wastewater. Most interestingly, we found different affinities of heavy metals to different size classes of DOC. This affinity of the heavy metals differs with size and origin of the DOC.
The sediment of Lagoa dos Patos-MS, Brazil, was investigated to verify the influence of metal sulfides and oxyhydroxides of Mn and Fe on the heavy metal availability. The spectrophotometric method of methylene blue was used, with 8 interlinked tubes containing the samples with SnCl2, where N-2 was introduced to release the H2S extracted with 6.0 mol L-1 HCl, and trapped in 0.05 M NaOH solution. The influence of SO42-, Mn(IV) and Fe(III) oxyhydroxides was investigated with samples constituted by a mixture of MnO2; Na2SO4; FeCl3, and sediments. The presence of SnCl2 was very important to avoid the interferences of iron and manganese oxyhydroxides. The method of standard addition was applied and the efficiency was (100.8 +/- 9.4)%. The ratio among the quantities of metals potentially available and the acid volatile sulfide (AVS) indicate that the system presents small metals availability to the benthic community, by the existence of sulfide capable to immobilize the metal as insoluble sulfide.
It has been demonstrated that the mathematical model of variable declining rate filters developed by Di Bernardo may be described by (z + 1) non-linear equations, where z is the number of filters in a bank. Three approximate solutions to this system of equations have been developed and then verified by comparison with numerical solution and published experimental data. Two of these solutions appeared to be very accurate, while the third showed higher, but still acceptable errors of calculation. According to this approximation, flow rates through filters are elements of a geometric progression.
A number of publications show relationships between impairment of vitality and reproduction as well as excessive shares of aged individuals within populations of Unio crassus with nitrate concentrations in the field. Our own examination of available data on nitrate concentrations in selected rivers of Brandenburg with known remainder populations of Unio crassus and of rivers without that species confirmed that above 2 mg L-1 NO3--N Unio crassus populations are impaired. Current toxicity data on nitrate do not indicate any mechanism by which the observations can be explained. Probably high NO3--N concentrations and the impaired production and vitality of Unio crassus populations share the same causes. These need to be identified.
The breach in the dam of a tailing pond in the processing plant of a gold mine in Baia Mare (NW Romania) in January 2000 lead to an ecological disaster in the rivers Szamos and Tisza. It was mainly caused by the released slurries containing cyanides and heavy metals. The investigation of surface sediment samples and depth profiles of the years 2000 and 2001 documented the pollution of the rivers Szamos and Tisza on Hungarian territory. In the Szamos and large areas of the Tisza floodplains a significant enrichment with the heavy metals Pb, Cd, Cu, and Zn is existent. The identification of the binding forms with sequential extraction showed that Cd and Zn exist in an easily available form. Therefore the remobilization is possible and an environmental hazard in the downstream areas must be considered. The anthropogenically caused portions of heavy metal concentrations decrease considerably with increasing distance to the mining region. The comparison of the concentrations of heavy metals in both years shows that the pollution is not only caused by the accident in January 2000. The increase of concentrations is based on the permanent input of pollutants into the rivers. The pollution is mainly caused by the erosion of exposed tailing dumps and the poor maintenance of the treatment plants.
The quality of the river Chienti (eastern-central Apennines, Italy) has been evaluated according to the Water Framework Directive 2000/60/EC, taking into consideration both biotic (animal and vegetable) and chemical parameters. In studying the biotic component, two indices were used: the E.B.I, Extended Biotic Index (version adapted to the Italian rivers), based on macroinvertebrates, and the EPI-D, the Eutrophication and/or Pollution Index, based on diatoms. For both macroinvertebrates and diatoms, two samplings were conducted, one in June and the other in October 2003. Instead, according to the Italian Law 152/99 the chemical and bacteriological analyses were conducted monthly for the entire year. The results of biomonitoring and chemical-bacteriological analyses unanimously demonstrated a good ecological situation for the upper section of the Chienti, though the situation tends to worsen as the river continues its descent and undergoes increased anthropogenic pressure. Data obtained were correlated with Spearman's coefficients and principal component analysis. Both statistical calculations showed clear, direct correlation between the two biotic indices and an inverse correlation between these and the chemical and bacteriological parameters. However, a few differences of judgement that emerged among the various indices highlight the importance of using them simultaneously in order to obtain a more accurate diagnosis of the ecological status of the watercourses.
Under laboratory conditions, the potential influence of diatom diets on reproduction of zoo-plankton Calanus sinicus was studied. Four diatom diet ingredients: Skeletonema costatum (SC), Chaetoceros muelleri (CM), Phaeodactylum tricornutum (PT), diatom mixture (MIX) and a control diet: the flagellate Platymonas subordiformis (PS), were used at the same carbon concentrations of 2.0 mu g mL(-1) C. In a period of 17-day laboratory experiment, the effects of these algae diets on egg production and hatching success of the copepod Calanus sinicus were examined. The diets were analyzed for fatty acid content as an indicator of food quality. The results showed that the female survival of all treatments reached more than 80% except PT. Comparing to the initial value, egg production of Calanus sinicus was reduced in diatom diets (PT, CM), but remained in normal level in SC and MIX, indicating that some single diatom diets had a negative effect on the egg production of Calanus sinicus. Feeding with mixed food however can eliminate this negative effect. Among all the treatments, hatching success in filtered seawater was significantly higher than in algal exudates, indicating that not only diatoms but also other phytoplankton in certain concentration can release extracelluar substance that may inhibit eggs from hatching. Fatty acid analysis showed that both egg production rate and hatching success were negatively correlated to the ratio of 20:5 omega 3 and 14:0 in fatty acid composition.
According to spider patterns five different types of thermal groundwater are distinguishable in Jordan. Each spider diagram comprises groups of elements which characterise soluble minerals of the aquifer such as halite, calcite, and gypsum, and leachable fractions of trace elements such as B, Ba, Br, Y, Cs, Rb, and U. In Jordan, mineralization of groundwater is largely controlled by dissolution of halite, carbonates, gypsum, and leaching diverse K-bearing minerals. Caused by interaction with Neogene basalts, limestones are silicified and mineralogically altered. Groundwater from these aquifers significantly differs in composition from those of the unaltered limestone aquifers. The benefit of spider patterns is that they visualise (i) chemical differences in groundwater from essentially similar aquifer rock such as young, old or thermally altered limestones and (ii) chemical similarities of groundwater produced from different geological formations. In contrast to spider patterns, ionic ratios widely overlap and do not unequivocally allow grouping of groundwater. delta S-34(sulfate) varies between -4 and +29 parts per thousand. Low values prove the presence of oxidised sulfides either of igneous origin or from sedimentary rocks. The spread of delta S-34 is caused by mixing with marine sulfate. All analysed water from Paleozoic rocks is replenished from younger aquifers. Considerable transaquifer flow exists more or less all over the Jordan territory. Salinization of sandstone-bound water along the rift escarpment is caused by a Na+-K+-SO42-HCO3- brine, whereas the wells Al Umari 1 and Wadi Araba 5 are affected by the presence of a Ca2+-Cl- brine.
This paper describes the geochemistry of sediment samples placed in floodplains and alluvial terraces downstream from gold mines in the Carmo River basin, Quadrildtero Ferrifero, Minas Gerais, Brazil. The geochemistry signature Na2O, K2O, SiO2, CaO, MgO, Al2O3, Fe2O3, TiO2, P2O5, Mn, As, Cu, Zn, Ba, Ni, Cr, S, Co were analyzed in different facies from stratigraphic profiles. As, Cu, Zn, and Mn anomalies are mainly associated with the clayed facies deposited in floodplains and oxbow lakes, and with coarse-sediment facies deposited in the channel. The facies were accumulated by the gold exploitation activity in the region. The contamination of As, Cu, and Zn was controlled by minerals such as iron oxides and hydroxides (hematite, magnetite, and mainly goethite), manganese oxides, and sulfide-rich minerals. The As-bearing sediments of the region characterize one of the most As contaminated area of Brazil. Their main source is associated with gold exploration in the last three centuries.
The relationships between cyanobacterial abundance and the physical and chemical characteristics of waters were studied to identify the environmental variables responsible for the changes in species composition observed in a river characterized by variations in water quality. Principal component analysis showed that some communities had significantly different species composition and relationships with environmental variables than others. These analyses allowed us to identify indicator species with contrasting responses to nutrient conditions. One of the four cyanobacterial groups distinguished in the analysis was negatively correlated with variables related to aspects of water disturbance, including nutrients. The results indicate that the eutrophication gradient structured species composition and affected cyanobacterial community distribution. Since organisms have an integrating response to their environment, the use of cyanobacterial assemblages to indicate eutrophication gradients could help in the assessment of water quality in aquatic ecosystems.
Biological treatment of heavy metals is an effective technology for the treatment of low concentration industrial wastewater. The purpose of this study was to evaluate the zinc and cadmium removal capacities through absorption (active) and adsorption (passive) by free and alginate-immobilized cells of Scenedesmus quadricauda. Immobilized cells have high capacities for uptake of both the heavy metal tested and the kinetics under the conditions studied were relatively fast. About 90% of the biosorption (adsorption) occurred within 10 min and equilibrium was reached within 30 minutes in both free and immobilized cells. However, a different pattern was observed for absorption. Maximum absorption by immobilized cells was found to be around 6.6 mmol Zn2+ and 8.0 mmol Cd2+ per mg protein, these values being approximately 1.4 and 1.6 fold higher than those of the free cells. Statistical analysis (ANOVA) confirmed the superiority of immobilized cells for metal absorption but not for adsorption. Free cells were equally good for adsorption. The results obtained on the patterns of metal/metal interactions showed either antagonistic, or non-interaction type of behaviour for both adsorption and absorption. However, no synergistic type of behaviour was observed during treatment.
The objective of this case study was to calibrate and verify a detailed sediment transport model in a 4-kilometre stretch of the middle Elbe floodplains in Germany. The hydraulic RMA-2 model and the SED2d-WES sediment transport model were used. The sediment transport model was verified with a flood event by detailed measurements of surface water levels, flow velocities at six profiles, suspended sediment concentration and sediment deposition (by means of 10 sediment traps). Discharge was modelled for three steady-state conditions. Surface water levels could be calculated to an accuracy of less than 5 cm compared to measurements. The differences between calculated and measured velocities were with one exception smaller than 0.2 m/s (measured range 0.1...1.0 m/s). Simulated average sediment input amount to 35 g/(m(2) d) for the given flood event. The highest calculated sedimentation rates of 700 g/(m(2) d) (dry density 90 kg/m(2)) took place in backwaters and abandoned channels. Twenty-five percent of the deposited sediment settled in the backwaters (which only account for 13 percent of the area). The most sensitive parameters of the sediment transport model were the settling velocity and critical shear stress. The modelling approach allowed a realistic spatial distributed calculation of sediment inputs into the floodplain of the Elbe River.
Changes in lotic benthic macroinvertebrate assemblages along the transboundary Axios-Vardar River (Greece – Former Yugoslavian Republic of Macedonia) were examined in order to identify major anthropogenic impacts correlated to the benthic community composition during the low flow season. Macrozoobenthos and water samples were collected from 21 sites during summer 2000 and beginning of autumn 2001. Parallel to sampling, the recording of the physical structure of the sites took place using the River Habitat Survey (RHS) method. The multivariate techniques of FUZZY and Canonical Correspondence Analysis (CCA), as well as the Hellenic biotic score (HES) and the habitat quality scores (HMS, HQA) were applied to the data. Total dissolved solids and total suspended solids were found to be the primary factors affecting the structure of the observed communities. Additionally, species composition responded to anthropogenic activities, e. g. untreated sewage effluents, industrial discharges, agricultural runoff, intense water abstraction and impoundment. As expected, macrozoobenthos community composition shifted from sensitive to tolerant taxa where human impacts were most evident.
Tracer experiments were carried out in groyne fields (GF) of the river Elbe near Havelberg (Germany) in order to estimate the hydraulic connectivity with the river channel. The characteristic times of the five groyne fields, which were estimated from the exponentially declining tracer curves in 43 runs, ranged between 15 min and 69 min and did not correlate with the water level. Methodological investigations show that single point injection and two measurements (in the outflowing water and in the dominant region) are sufficient to provide robust in-situ tracer curves. Using simplified mathematical simulations with connected stirred tanks, the conditions are investigated for the development of breaks in tracer curves and for the occurrence of significant errors in the estimation of intrinsic residence times. It was shown that an initial uniform dye distribution is not mandatory for the estimation during steady states. In special cases, point injections are more advisable. Moreover, the mean hydraulic residence time was found to be not equivalent to the estimated characteristic time. In fact, it is mostly overestimated by tracer experiments. The degree of overestimation depends on mixing and the volumetric proportions between the different parts of the GF and can be calculated from measured dye concentration differences. For example, an overestimation of 32% was calculated for a groyne field with a commonly found circulation flow pattern.
A subaquatic sediment core was taken from the Rhine River to determine substance specific concentration profiles in correlation to time and depth. Based on these data emission histories were related for selected contaminants. Significant emission sources and emission pathways were compiled. In correlation to investigations of national and international monitoring programmes a significant reduction of environmental emissions up to a tenth of previous values were found since 1998. Some selected compounds, discharged by municipal and industrial activities, for example disinfectants (methyltriclosan), flame retardants (tris(chloropropyl)phosphate), chlorinated benzenes, anilines and naphthalenes, can be classified as significant synthetic substances in the scope of the Water Framework Directive. Because of their chemical characters, their persistence, bioaccumulation and ecotoxicity, as well as their occurrence within the sediment core, these compounds create a significant potential risk for water quality, but a reduction of these synthetic compounds to zero cannot be expected for the next future. In summary, this study provides a comprehensive reconstruction of the pollution history of anthropogenic contaminants, their fate and behaviour in the fluvial system. In addition, an estimation of the time period required for environmental measurements and monitoring programmes to improve, achieve and save a good status of the river systems are given.
The effect of different organic and inorganic aqueous matrices on the photocatalytical degradation of dissolved atrazine and dichloroacetic acid (DCA) with immobilized TiO2 was investigated. Two series of experiments were carried out at pH values around 7.1 for the degradation of atrazine and around 5.3 for the degradation of DCA. It is shown that the effects of the water constituents are completely different for the various substances and pH ranges. In pure deionized water 95% of the initial amount p = 1 mg/L of atrazine were degraded within 24 hours. Tap water as matrix led to a distinct lower degradation rate (factor 3). The single additives chloride, sulfate, phosphate, carbonate and DOC showed no decrease in the degradation rate. Especially in the case of phosphate and carbonate there was even a significant promoting effect. DEDIA, the doubly desalkylated and not dechlorinated product, occurred in higher concentrations than in the experiment without additives. In pure deionized water rho(0)(DCA) = 1 mg/L was completely degraded within 330 min. By addition of any tested substance, organic or inorganic, the degradation rate of DCA, which is strongly dependent on the adsorption on the TiO2 surface, decreased clearly. In the case of tap water the degradation rate decreased by a factor of 7.5. From the checked inorganic ions phosphate showed the strongest effect followed by sulfate, chloride and carbonate. Added DOC also had a significant influence on the degradation rate.
