In this paper the Basic Water Quality Model (BWQM) for the central part of River Neckar is used to analyse the oxygen budget and to assess the potentials of various measures to prevent or mitigate critical dissolved oxygen (DO) declines. It is shown that the oxygen budget is mainly governed by phytoplankton dynamics. The excessive growth of algae and the sudden break down of the resulting algal blooms may cause episodic DO depressions. Therefore, to stabilise the oxygen budget in a sustainable way, eutrophication has to be controlled within the central part of River Neckar and the upstream regions. The only feasible way to reach this goal appears to be a further drastic reduction of phosphorus emissions. In addition, it is indispensable to hold the very high standards of biochemical oxygen demand and ammonium retention at the wastewater treatment plants. A worse performance of the treatment plants would dramatically aggravate critical DO declines which may be caused by algae dynamics. As long as the oxygen budget is not completely stabilised, weir and turbine aeration can be used to mitigate DO depressions. It could be shown that the potentials of these measures suffice to keep DO at a tolerable level. However, due to the long travel times in River Neckar, it is important to start aeration up to several days before the DO minimum is reached.
{"title":"A Basic Water Quality Model for the River Neckar: Part 2 -model-based analysis of the oxygen budget and scenarios","authors":"I. Haag","doi":"10.1002/AHEH.200400653","DOIUrl":"https://doi.org/10.1002/AHEH.200400653","url":null,"abstract":"In this paper the Basic Water Quality Model (BWQM) for the central part of River Neckar is used to analyse the oxygen budget and to assess the potentials of various measures to prevent or mitigate critical dissolved oxygen (DO) declines. It is shown that the oxygen budget is mainly governed by phytoplankton dynamics. The excessive growth of algae and the sudden break down of the resulting algal blooms may cause episodic DO depressions. Therefore, to stabilise the oxygen budget in a sustainable way, eutrophication has to be controlled within the central part of River Neckar and the upstream regions. The only feasible way to reach this goal appears to be a further drastic reduction of phosphorus emissions. In addition, it is indispensable to hold the very high standards of biochemical oxygen demand and ammonium retention at the wastewater treatment plants. A worse performance of the treatment plants would dramatically aggravate critical DO declines which may be caused by algae dynamics. As long as the oxygen budget is not completely stabilised, weir and turbine aeration can be used to mitigate DO depressions. It could be shown that the potentials of these measures suffice to keep DO at a tolerable level. However, due to the long travel times in River Neckar, it is important to start aeration up to several days before the DO minimum is reached.","PeriodicalId":7010,"journal":{"name":"Acta Hydrochimica Et Hydrobiologica","volume":"62 1","pages":"549-559"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80680558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Most antibiotics are only partially metabolised by patients before being discharged into the municipal sewage system along with patient excreta. Studies have shown that the majority of antibiotics pass through sewage treatment and are then released into the environment. Accordingly, investigations conducted in various countries have detected a number of antibiotics in the low μg or ng per litre range in different environmental compartments. Studies connecting mass balances of use on a local scale and of input and analysis of the antibiotic concentrations present in municipal sewage treatment plants are scarce. Data on local use of antibiotics and their relation to nationwide consumption are not available. This study investigated the use, input, and fate of antibiotics on a local scale and this data were compared with the German nationwide consumption. 42 antibiotics and 15 antimycotics were used in the mass balance consideration over a period of one year. It was found that the local pattern of usage differed only little from that found nationwide. Seasonal changes were minor and the concentrations actually measured were found to be in the expected range. Differences in both the identified occurrence and the concentrations of the target compounds were observed within and between the three sampling periods.
{"title":"Local use of antibiotics and their input and fate in a small sewage treatment plant – significance of balancing and analysis on a local scale vs. nationwide scale","authors":"R. Alexy, A. Sommer, F. Lange, K. Kümmerer","doi":"10.1002/AHEH.200400657","DOIUrl":"https://doi.org/10.1002/AHEH.200400657","url":null,"abstract":"Most antibiotics are only partially metabolised by patients before being discharged into the municipal sewage system along with patient excreta. Studies have shown that the majority of antibiotics pass through sewage treatment and are then released into the environment. Accordingly, investigations conducted in various countries have detected a number of antibiotics in the low μg or ng per litre range in different environmental compartments. Studies connecting mass balances of use on a local scale and of input and analysis of the antibiotic concentrations present in municipal sewage treatment plants are scarce. Data on local use of antibiotics and their relation to nationwide consumption are not available. This study investigated the use, input, and fate of antibiotics on a local scale and this data were compared with the German nationwide consumption. 42 antibiotics and 15 antimycotics were used in the mass balance consideration over a period of one year. It was found that the local pattern of usage differed only little from that found nationwide. Seasonal changes were minor and the concentrations actually measured were found to be in the expected range. Differences in both the identified occurrence and the concentrations of the target compounds were observed within and between the three sampling periods.","PeriodicalId":7010,"journal":{"name":"Acta Hydrochimica Et Hydrobiologica","volume":"33 1","pages":"587-592"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85030718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to simulate and forecast dissolved oxygen (DO) in the central part of River Neckar, we developed a Basic Water Quality Model (BWQM). The present paper gives a comprehensive description of model development, model structure along with the governing equations, sensitivity and identifiability analyses as well as calibration and validation. The development of BWQM was guided by two major restrictions: it has to account for all relevant processes affecting DO, and it should only be based on readily available data and system knowledge. These restrictions led to a model, calculating nine state variables, including DO, phytoplankton, nutrients, and biochemical oxygen demand. However, due to limited data, the representation of phytoplankton is quite simple. A local sensitivity analysis led to a subset of five parameters, which are much more sensitive than the 22 other parameters. These five parameters are all closely connected with phytoplankton dynamics, highlighting the importance of phytoplankton for the DO budget. On the basis of an a priori identifiability analysis, four out of the five most sensitive parameters were chosen for model calibration. The calibrated model performed well in simulating DO and phytoplankton. Given the data availability and the present state of system knowledge, BWQM comes close to representing the optimal model with respect to predicting DO and phytoplankton.
{"title":"A Basic Water Quality Model for the River Neckar: Part 1 – model development, parameter sensitivity and identifiability, calibration and validation","authors":"I. Haag","doi":"10.1002/AHEH.200400652","DOIUrl":"https://doi.org/10.1002/AHEH.200400652","url":null,"abstract":"In order to simulate and forecast dissolved oxygen (DO) in the central part of River Neckar, we developed a Basic Water Quality Model (BWQM). The present paper gives a comprehensive description of model development, model structure along with the governing equations, sensitivity and identifiability analyses as well as calibration and validation. The development of BWQM was guided by two major restrictions: it has to account for all relevant processes affecting DO, and it should only be based on readily available data and system knowledge. These restrictions led to a model, calculating nine state variables, including DO, phytoplankton, nutrients, and biochemical oxygen demand. However, due to limited data, the representation of phytoplankton is quite simple. A local sensitivity analysis led to a subset of five parameters, which are much more sensitive than the 22 other parameters. These five parameters are all closely connected with phytoplankton dynamics, highlighting the importance of phytoplankton for the DO budget. On the basis of an a priori identifiability analysis, four out of the five most sensitive parameters were chosen for model calibration. The calibrated model performed well in simulating DO and phytoplankton. Given the data availability and the present state of system knowledge, BWQM comes close to representing the optimal model with respect to predicting DO and phytoplankton.","PeriodicalId":7010,"journal":{"name":"Acta Hydrochimica Et Hydrobiologica","volume":"16 1","pages":"533-548"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88656017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Herzsprung, E. Bozau, O. Büttner, A. Duffek, K. Friese, M. Koschorreck, M. Schultze, W. Tümpling, K. Wendt‐Potthoff
Pore water of sediments plays an important role in aquatic systems as mediator and as the reactive zone between the sediment and surface water. Sediment pore waters with high ionic strength from acidified pit lakes were investigated to obtain information about the influence on the lake water quality. The analysis of soluble reactive phosphorus, nitrate, ammonium, silica, dissolved organic carbon, ferrous iron, sulfate, chloride, sodium, potassium, calcium, magnesium, manganese, and total dissolved iron was predetermined as the dataset required for evaluation of water quality. The data collection procedure was optimised by designing a methodology for stabilisation, dilution of pore water samples and adaptation of analytical methods. The developed methodology was evaluated with respect to the effort required in the laboratory under routine conditions. In the first round of analyses, 72% of 638 individual analyses from a random selection of pore water profiles were found to be within the calibration ranges. Remedial actions to handle the remaining 28% of invalid analytical results are exemplified. Differences between comparative analyses of some ions by continuous flow analysis, ion chromatography, and atomic emission spectroscopy were evaluated. The majority of results measured by ion chromatography differed on a highly significant level from results measured by atomic emission spectroscopy. Possible reasons, originating from the extreme sample matrix, are discussed. Finally, the designed methodology and the results of the method comparison are used to recommend the selection of analytical methods under specific conditions.
{"title":"Routine analysis of sediment pore water of high ionic strength","authors":"P. Herzsprung, E. Bozau, O. Büttner, A. Duffek, K. Friese, M. Koschorreck, M. Schultze, W. Tümpling, K. Wendt‐Potthoff","doi":"10.1002/AHEH.200500656","DOIUrl":"https://doi.org/10.1002/AHEH.200500656","url":null,"abstract":"Pore water of sediments plays an important role in aquatic systems as mediator and as the reactive zone between the sediment and surface water. Sediment pore waters with high ionic strength from acidified pit lakes were investigated to obtain information about the influence on the lake water quality. The analysis of soluble reactive phosphorus, nitrate, ammonium, silica, dissolved organic carbon, ferrous iron, sulfate, chloride, sodium, potassium, calcium, magnesium, manganese, and total dissolved iron was predetermined as the dataset required for evaluation of water quality. The data collection procedure was optimised by designing a methodology for stabilisation, dilution of pore water samples and adaptation of analytical methods. The developed methodology was evaluated with respect to the effort required in the laboratory under routine conditions. In the first round of analyses, 72% of 638 individual analyses from a random selection of pore water profiles were found to be within the calibration ranges. Remedial actions to handle the remaining 28% of invalid analytical results are exemplified. Differences between comparative analyses of some ions by continuous flow analysis, ion chromatography, and atomic emission spectroscopy were evaluated. The majority of results measured by ion chromatography differed on a highly significant level from results measured by atomic emission spectroscopy. Possible reasons, originating from the extreme sample matrix, are discussed. Finally, the designed methodology and the results of the method comparison are used to recommend the selection of analytical methods under specific conditions.","PeriodicalId":7010,"journal":{"name":"Acta Hydrochimica Et Hydrobiologica","volume":"46 5 1","pages":"593-607"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82757467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"Preparative isolation and characterization of heavy metal complexes from acid mine drainage and surface wastewater","authors":"M. Wengel, G. Gleixner","doi":"10.1002/AHEH.200400655","DOIUrl":"https://doi.org/10.1002/AHEH.200400655","url":null,"abstract":"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.","PeriodicalId":7010,"journal":{"name":"Acta Hydrochimica Et Hydrobiologica","volume":"35 1","pages":"568-578"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86609386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eleven selected species of vegetative bacteria, bacteria spores and mold spores were irradiated with different doses of UV radiation of a 222 nm krypton-chloride excimer lamp and a 254 nm mercury lamp under laboratory conditions. Then the inactivation curves were determined. The necessary UV fluences for a respective reduction were higher for the excimer lamp for the tested vegetative bacteria of Bacillus cereus, Arthrobacter nicotinovorans, Staphylococcus aureus and Pseudomonas aeruginosa and slightly higher for the spores of Streptomyces griseus and Clostridium pasteurianum. However, less than 250 Jm 2 UV fluence with 222 nm was sufficient for a 4-log reduction, depending on the species. On the other hand, the UV fluences for the 254 nm mercury lamp were much higher for the bacterial spores of Bacillus cereus, Thermoactinomyces griseus and the bacteria of Deinococcus radiodurans and slightly higher for the mold spores of Aspergillus niger and Penicillium expansum. The results show that especially the germs with a higher UV resistance and those with more effective repair mechanisms can be inactivated more efficiently by the 222 nm excimer lamp. This may be due to the fact that low UV fluence mainly affects radiation sensitive microorganisms by DNA damage whereas at higher UV fluence (various) mechanisms of protein damage can presumably be held responsible for inactivation.
{"title":"Higher effectiveness of photoinactivation of bacterial spores, UV resistant vegetative bacteria and mold spores with 222 nm compared to 254 nm wavelength","authors":"M. Clauss","doi":"10.1002/AHEH.200600650","DOIUrl":"https://doi.org/10.1002/AHEH.200600650","url":null,"abstract":"Eleven selected species of vegetative bacteria, bacteria spores and mold spores were irradiated with different doses of UV radiation of a 222 nm krypton-chloride excimer lamp and a 254 nm mercury lamp under laboratory conditions. Then the inactivation curves were determined. The necessary UV fluences for a respective reduction were higher for the excimer lamp for the tested vegetative bacteria of Bacillus cereus, Arthrobacter nicotinovorans, Staphylococcus aureus and Pseudomonas aeruginosa and slightly higher for the spores of Streptomyces griseus and Clostridium pasteurianum. However, less than 250 Jm 2 UV fluence with 222 nm was sufficient for a 4-log reduction, depending on the species. On the other hand, the UV fluences for the 254 nm mercury lamp were much higher for the bacterial spores of Bacillus cereus, Thermoactinomyces griseus and the bacteria of Deinococcus radiodurans and slightly higher for the mold spores of Aspergillus niger and Penicillium expansum. The results show that especially the germs with a higher UV resistance and those with more effective repair mechanisms can be inactivated more efficiently by the 222 nm excimer lamp. This may be due to the fact that low UV fluence mainly affects radiation sensitive microorganisms by DNA damage whereas at higher UV fluence (various) mechanisms of protein damage can presumably be held responsible for inactivation.","PeriodicalId":7010,"journal":{"name":"Acta Hydrochimica Et Hydrobiologica","volume":"111 3 1","pages":"525-532"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78005519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Department of Geology, Vienna University, Vienna, Austria Metal mobility at contaminated sites can be assessed by soil water investigations or by leaching tests. Leaching tests are usually carried out in open contact with the atmosphere disregarding possible changes of redox conditions. This can affect the original metal speciation and distribution, particularly when anoxic samples are investigated. In this study, the applicability of common leaching tests (the German S4 test (S4), ammonium nitrate extraction (AmmN), and saturation soil extraction (SSE)) is tested for the assessment of zinc release from sulfide-bearing flotation residues of a former ore mine. Results are compared to soil solution samples obtained by centrifugation and suction cups. The influence of sample storage on S4 leaching test results is investigated in a long-term study to assess oxidation kinetics. Within the first 200 days the release of zinc increases with a slope of 0.1 mmol kg -1 d -1 or 6.0 mg kg -1 d -1 , respectively. Since oxidation of the sulfide-bearing samples leads to a significant overestimation of metal release, a feasible modification for the conduction of leaching tests for anoxic material is proposed where oxidation is prevented efficiently. The modified SSE is found to be the only of the tested leaching procedures, which can be recommended for the assessment of current soil water concentrations at anoxic sites if direct investigation of the soil water is impossible due to technical reasons.
可通过土壤水调查或浸出试验来评估受污染场址的金属流动性。浸出试验通常在与大气开放接触的情况下进行，不考虑氧化还原条件可能发生的变化。这可能会影响原始金属的形态和分布，特别是在研究缺氧样品时。在本研究中，测试了常用浸出试验(德国S4试验(S4)、硝酸铵浸出(AmmN)和饱和土浸出(SSE))在评价某原矿含硫化物浮选渣中锌释放的适用性。结果与离心法和吸盘法得到的土壤溶液样品进行了比较。在一项评估氧化动力学的长期研究中，研究了样品储存对S4浸出试验结果的影响。在前200天内，锌的释放量分别以0.1 mmol kg -1 d -1或6.0 mg kg -1 d -1的斜率增加。由于含硫化物样品的氧化导致对金属释放量的显著高估，因此提出了一种可行的改进方法，用于有效防止氧化的缺氧材料的浸出试验。改进的SSE被发现是测试的浸出程序中唯一的，如果由于技术原因无法直接调查土壤水，则可以推荐用于评估缺氧场地当前土壤水浓度。
{"title":"Methods of metal release assessment in soil water at anoxic sites","authors":"N. Schuwirth, T. Hofmann","doi":"10.1002/AHEH.200500651","DOIUrl":"https://doi.org/10.1002/AHEH.200500651","url":null,"abstract":"Department of Geology, Vienna University, Vienna, Austria Metal mobility at contaminated sites can be assessed by soil water investigations or by leaching tests. Leaching tests are usually carried out in open contact with the atmosphere disregarding possible changes of redox conditions. This can affect the original metal speciation and distribution, particularly when anoxic samples are investigated. In this study, the applicability of common leaching tests (the German S4 test (S4), ammonium nitrate extraction (AmmN), and saturation soil extraction (SSE)) is tested for the assessment of zinc release from sulfide-bearing flotation residues of a former ore mine. Results are compared to soil solution samples obtained by centrifugation and suction cups. The influence of sample storage on S4 leaching test results is investigated in a long-term study to assess oxidation kinetics. Within the first 200 days the release of zinc increases with a slope of 0.1 mmol kg -1 d -1 or 6.0 mg kg -1 d -1 , respectively. Since oxidation of the sulfide-bearing samples leads to a significant overestimation of metal release, a feasible modification for the conduction of leaching tests for anoxic material is proposed where oxidation is prevented efficiently. The modified SSE is found to be the only of the tested leaching procedures, which can be recommended for the assessment of current soil water concentrations at anoxic sites if direct investigation of the soil water is impossible due to technical reasons.","PeriodicalId":7010,"journal":{"name":"Acta Hydrochimica Et Hydrobiologica","volume":"34 23","pages":"579-586"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91547401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"Longitudinal impacts of anthropogenic pressures on benthic macroinvertebrate assemblages in a large transboundary Mediterranean river during the low flow period","authors":"Y. Chatzinikolaou, V. Dakos, M. Lazaridou","doi":"10.1002/AHEH.200500644","DOIUrl":"https://doi.org/10.1002/AHEH.200500644","url":null,"abstract":"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.","PeriodicalId":7010,"journal":{"name":"Acta Hydrochimica Et Hydrobiologica","volume":"284 1","pages":"453-463"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76615623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"The progression of flow rates in variable declining rate filter systems","authors":"W. Dąbrowski","doi":"10.1002/AHEH.200500647","DOIUrl":"https://doi.org/10.1002/AHEH.200500647","url":null,"abstract":"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.","PeriodicalId":7010,"journal":{"name":"Acta Hydrochimica Et Hydrobiologica","volume":"100 1","pages":"442-452"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76990356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Environmental data are highly variable. They also include uncertainties resulting from all steps of the analytical process e. g. sampling, or sampling pre-treatment. However, a lot of information is unfortunately often lost because only univariate statistical methods are used for data evaluation and interpretation. This neglects correlation between different pollutants and relationships among various sampling points. It is therefore necessary to apply additional methods of analysis that can accommodate such relationships. This ability is provided by the established, and by the more modern, multivariate statistical methods because they can analyze complex sets of multidimensional data. These methods are used to visualize large amounts of data and to extract latent information (e. g. differently polluted areas, dischargers, or interactions between different environmental compartments). The goal of this paper is to present the use of established statistical techniques, like cluster or factor analysis, and the progress made in basic modern techniques (e. g. cluster imaging, multiway-partial least squares regression, projection pursuit, or information theory) and to demonstrate each with examples and illustrations.
{"title":"Modern chemometric data analysis – methods for the objective evaluation of load in river systems","authors":"C. Kowalik, J. Einax","doi":"10.1002/AHEH.200500649","DOIUrl":"https://doi.org/10.1002/AHEH.200500649","url":null,"abstract":"Environmental data are highly variable. They also include uncertainties resulting from all steps of the analytical process e. g. sampling, or sampling pre-treatment. However, a lot of information is unfortunately often lost because only univariate statistical methods are used for data evaluation and interpretation. This neglects correlation between different pollutants and relationships among various sampling points. It is therefore necessary to apply additional methods of analysis that can accommodate such relationships. This ability is provided by the established, and by the more modern, multivariate statistical methods because they can analyze complex sets of multidimensional data. These methods are used to visualize large amounts of data and to extract latent information (e. g. differently polluted areas, dischargers, or interactions between different environmental compartments). The goal of this paper is to present the use of established statistical techniques, like cluster or factor analysis, and the progress made in basic modern techniques (e. g. cluster imaging, multiway-partial least squares regression, projection pursuit, or information theory) and to demonstrate each with examples and illustrations.","PeriodicalId":7010,"journal":{"name":"Acta Hydrochimica Et Hydrobiologica","volume":"7 1","pages":"425-436"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74358811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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