Pub Date : 2022-06-22DOI: 10.1080/23249676.2022.2087774
U. Lundin, P. Jonsson, L. Facciolo
Spillways are very important dam safety devices that can discharge large amounts of water to prevent over-topping a dam. However, spillways are expensive to build and have operational issues. This paper is a report from a test of a system capable of discharging the full turbine flow even in the absence of an external power grid absorbing the electrical power. Instead the power is dissipated in a local load. The scope of the tests is to verify the use of the discharge capacity of the turbine under continuous operation as spillway flow for emergency discharge from a Hydropower reservoir. A dumpload consisting of a hot water electrode boiler cooled by water taken from the turbine spiral case was used as a local load. The results show long-term stability of using a local load and turbine discharge as an electrical alternative to building additional traditional spillways to increase spillway capacity from a hydropower reservoir.
{"title":"Using hydropower turbine discharge as a complementary spillway","authors":"U. Lundin, P. Jonsson, L. Facciolo","doi":"10.1080/23249676.2022.2087774","DOIUrl":"https://doi.org/10.1080/23249676.2022.2087774","url":null,"abstract":"Spillways are very important dam safety devices that can discharge large amounts of water to prevent over-topping a dam. However, spillways are expensive to build and have operational issues. This paper is a report from a test of a system capable of discharging the full turbine flow even in the absence of an external power grid absorbing the electrical power. Instead the power is dissipated in a local load. The scope of the tests is to verify the use of the discharge capacity of the turbine under continuous operation as spillway flow for emergency discharge from a Hydropower reservoir. A dumpload consisting of a hot water electrode boiler cooled by water taken from the turbine spiral case was used as a local load. The results show long-term stability of using a local load and turbine discharge as an electrical alternative to building additional traditional spillways to increase spillway capacity from a hydropower reservoir.","PeriodicalId":51911,"journal":{"name":"Journal of Applied Water Engineering and Research","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45819627","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}
Pub Date : 2022-06-22DOI: 10.1080/23249676.2022.2082566
Shakir Ali, P. Ojasvi, A. Islam
Artificial recharging of the abandoned and/or functional dug wells through a recharge filter is an efficient and economical method for mitigating and maintaining depleting water tables. An optimum sizing of the recharge filter is necessary to avoid its over-design or under-design and has a minimum cost. Optimum sizing of the recharge filter for the dug well recharging has received very little attention, especially in India. In this paper, analytical expressions for designing the recharge filter were derived based on the concept of maximization of the hydrological water balance equation. Optimum sizing of the recharge filter based on the minimum cost was formulated using the optimization model. The optimization model was solved using the Snopt non-linear programming optimization model of the AMPL software. The results of the optimization model were also compared with the analytical framework. Sensitivity analyses using an analytical framework indicated that size, time of filling and empty time for the recharge filter were more sensitive to the changes in watershed area and watershed condition as compared to the diameter of the discharge pipe, the porosity of the filter material and depth of the recharge filter. It could be concluded that the derived optimization model incorporating the derived analytical expressions can successfully be used for optimum sizing and evaluation of the effectiveness of the recharge filter of any shape and locations in different hydro-climatic regions.
{"title":"Optimum design of a recharge filter for recharging the dug wells: a field application","authors":"Shakir Ali, P. Ojasvi, A. Islam","doi":"10.1080/23249676.2022.2082566","DOIUrl":"https://doi.org/10.1080/23249676.2022.2082566","url":null,"abstract":"Artificial recharging of the abandoned and/or functional dug wells through a recharge filter is an efficient and economical method for mitigating and maintaining depleting water tables. An optimum sizing of the recharge filter is necessary to avoid its over-design or under-design and has a minimum cost. Optimum sizing of the recharge filter for the dug well recharging has received very little attention, especially in India. In this paper, analytical expressions for designing the recharge filter were derived based on the concept of maximization of the hydrological water balance equation. Optimum sizing of the recharge filter based on the minimum cost was formulated using the optimization model. The optimization model was solved using the Snopt non-linear programming optimization model of the AMPL software. The results of the optimization model were also compared with the analytical framework. Sensitivity analyses using an analytical framework indicated that size, time of filling and empty time for the recharge filter were more sensitive to the changes in watershed area and watershed condition as compared to the diameter of the discharge pipe, the porosity of the filter material and depth of the recharge filter. It could be concluded that the derived optimization model incorporating the derived analytical expressions can successfully be used for optimum sizing and evaluation of the effectiveness of the recharge filter of any shape and locations in different hydro-climatic regions.","PeriodicalId":51911,"journal":{"name":"Journal of Applied Water Engineering and Research","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59990551","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}
Pub Date : 2022-06-20DOI: 10.1080/23249676.2022.2088631
A. B. Dariane, Mohamadreza M. Behbahani
In this paper, using a neural network-based streamflow simulation model (NNSSM), we simulate the runoff of the Ajichai River. The selection of suitable inputs is an essential step toward developing NNSSM. For this aim, we investigate a novel application of the Genetic Classification Algorithm (GCA) as an input variable selection (IVS) method in comparison with the Self-Organizing Map (SOM) and Binary Fully Informed Particle Swarm Optimization (BFIPSO). In another innovative application, we establish Social Choice (SC) for the final ranking of selected data using SOM. Next, the model was improved by adding seasonality indexes. The results indicate the superiority of GCA. The average (maximum) Nash-Sutcliffe index for GCA was found to be 0.63(0.84), while it was 0.55(0.71) and 0.58(0.77) for SOM-SC and BFIPSO, respectively. Moreover, GCA took less than 30 min for each run, while for SOM-SC and BFIPSO at least 3 and 48 h were needed under the same circumstances.
{"title":"Development of an efficient input selection method for NN based streamflow model","authors":"A. B. Dariane, Mohamadreza M. Behbahani","doi":"10.1080/23249676.2022.2088631","DOIUrl":"https://doi.org/10.1080/23249676.2022.2088631","url":null,"abstract":"In this paper, using a neural network-based streamflow simulation model (NNSSM), we simulate the runoff of the Ajichai River. The selection of suitable inputs is an essential step toward developing NNSSM. For this aim, we investigate a novel application of the Genetic Classification Algorithm (GCA) as an input variable selection (IVS) method in comparison with the Self-Organizing Map (SOM) and Binary Fully Informed Particle Swarm Optimization (BFIPSO). In another innovative application, we establish Social Choice (SC) for the final ranking of selected data using SOM. Next, the model was improved by adding seasonality indexes. The results indicate the superiority of GCA. The average (maximum) Nash-Sutcliffe index for GCA was found to be 0.63(0.84), while it was 0.55(0.71) and 0.58(0.77) for SOM-SC and BFIPSO, respectively. Moreover, GCA took less than 30 min for each run, while for SOM-SC and BFIPSO at least 3 and 48 h were needed under the same circumstances.","PeriodicalId":51911,"journal":{"name":"Journal of Applied Water Engineering and Research","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48255734","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}
Pub Date : 2022-05-23DOI: 10.1080/23249676.2022.2074899
Mouna Jaouadi, N. Amdouni
Dissolved organic matter (DOM) is abundant in groundwater in Tunisia. In this study, the organic matter from groundwater was examined using elemental analysis, fluorescence and FTIR spectroscopies. In addition, total organic carbon (TOC), chemical oxygen demand (COD) and UV-absorbance at wavelength 254 nm (UV254) were measured. Elemental analysis indicated that groundwater contained a high amount of oxygen but a low amount of carbon. FTIR analyses revealed that polysaccharides were the main compounds present in the groundwater. The removal of DOM was studied by adsorbing activated carbon-supported aluminum. The characterization of DOM and activated carbon after adsorption confirms the removal of organic matter. The decrease in the BET surface of adsorbent after adsorption confirms that the pores are occupied by organic matter. TOC was removed by adsorption, and activated carbon-supported aluminum was superior (∼80%) to raw-activated carbon (∼52%), and may be explored to remove contaminants from wastewater.
{"title":"Characterizations of activated carbons and groundwater organic matter adsorption","authors":"Mouna Jaouadi, N. Amdouni","doi":"10.1080/23249676.2022.2074899","DOIUrl":"https://doi.org/10.1080/23249676.2022.2074899","url":null,"abstract":"Dissolved organic matter (DOM) is abundant in groundwater in Tunisia. In this study, the organic matter from groundwater was examined using elemental analysis, fluorescence and FTIR spectroscopies. In addition, total organic carbon (TOC), chemical oxygen demand (COD) and UV-absorbance at wavelength 254 nm (UV254) were measured. Elemental analysis indicated that groundwater contained a high amount of oxygen but a low amount of carbon. FTIR analyses revealed that polysaccharides were the main compounds present in the groundwater. The removal of DOM was studied by adsorbing activated carbon-supported aluminum. The characterization of DOM and activated carbon after adsorption confirms the removal of organic matter. The decrease in the BET surface of adsorbent after adsorption confirms that the pores are occupied by organic matter. TOC was removed by adsorption, and activated carbon-supported aluminum was superior (∼80%) to raw-activated carbon (∼52%), and may be explored to remove contaminants from wastewater.","PeriodicalId":51911,"journal":{"name":"Journal of Applied Water Engineering and Research","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41328736","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}
Pub Date : 2022-04-03DOI: 10.1080/23249676.2021.1947399
Selma Laguel, M. H. Samar
In this study, the elimination of Uranyl from aqueous solution is studied using an advanced technique of extraction; emulsion liquid membrane (ELM). Experimental results for the extraction of Uranyl are presented. The membrane phase consists of Kerosene as a diluent, Cyanex 302 as a carrier and sorbiton monooleate (Span 80) as a surfactant. Sulfuric acid solution as an internal aqueous phase. At the optimum conditions, the main variables studied which influenced the ELM extraction of Uranyl were the concentration of surfactant (3%), carrier (0.3%), internal phase (1 N H2SO4), types of internal phase (H2SO4 sulfuric acid), diluent (Kerosene), stirring speed (200 rpm), and the effect of volume ratios of the internal phase to the organic phase 1:1 (A/O) and of the emulsion to the feed solution 20/200 (Vemul/Vext). The results indicate that the removal percentage was obtained 100% in less than 20 min.This study also evaluated the effect of H2SO4 concentration in the internal aqueous phase on the stripping of Uranyl. The ELM treatment process represents a very interesting advanced separation process for the removal of Uranyl from aqueous solutions.
本研究采用先进的萃取技术对水溶液中铀酰的去除进行了研究；乳液液膜（ELM）。介绍了萃取铀酰的实验结果。膜相由作为稀释剂的煤油、作为载体的Cyanex 302和作为表面活性剂的山梨醇单油酸酯（Span 80）组成。作为内部水相的硫酸溶液。在最佳条件下，表面活性剂（3%）、载体（0.3%）、内相（1 N H2SO4）、内相类型（H2SO4-硫酸）、稀释剂（煤油）、搅拌速度（200 rpm）以及内相与有机相的体积比为1:1（A/O）和乳液与进料溶液的体积比20/200（Vemul/Vext）的影响。结果表明，在不到20分钟的时间内，去除率达到100% min。本研究还评估了内部水相中H2SO4浓度对铀酰汽提的影响。ELM处理工艺代表了一种非常有趣的从水溶液中去除铀酰的高级分离工艺。
{"title":"Uranyl extraction from aqueous solution by emulsion liquid membrane process","authors":"Selma Laguel, M. H. Samar","doi":"10.1080/23249676.2021.1947399","DOIUrl":"https://doi.org/10.1080/23249676.2021.1947399","url":null,"abstract":"In this study, the elimination of Uranyl from aqueous solution is studied using an advanced technique of extraction; emulsion liquid membrane (ELM). Experimental results for the extraction of Uranyl are presented. The membrane phase consists of Kerosene as a diluent, Cyanex 302 as a carrier and sorbiton monooleate (Span 80) as a surfactant. Sulfuric acid solution as an internal aqueous phase. At the optimum conditions, the main variables studied which influenced the ELM extraction of Uranyl were the concentration of surfactant (3%), carrier (0.3%), internal phase (1 N H2SO4), types of internal phase (H2SO4 sulfuric acid), diluent (Kerosene), stirring speed (200 rpm), and the effect of volume ratios of the internal phase to the organic phase 1:1 (A/O) and of the emulsion to the feed solution 20/200 (Vemul/Vext). The results indicate that the removal percentage was obtained 100% in less than 20 min.This study also evaluated the effect of H2SO4 concentration in the internal aqueous phase on the stripping of Uranyl. The ELM treatment process represents a very interesting advanced separation process for the removal of Uranyl from aqueous solutions.","PeriodicalId":51911,"journal":{"name":"Journal of Applied Water Engineering and Research","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46289712","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}
Pub Date : 2022-03-16DOI: 10.1080/23249676.2022.2030253
Ouardia Gueciouer Teffah, M. S. Guettouche, Ayoub Zerouel, Salima Charifi Bellabas
The aim of this research is the modelling and mapping of flood risk zones in the M’zab valley of Ghardaia city by combining the hazard map and the flood vulnerability map. The undertaken research utilizes the hydrologic engineering centre-hydrologic modelling system as the modelling tool to simulate the runoff in the watershed and hydrologic engineering centre – river analysis system to model the water levels of different river locations based on steady flow analysis and to define flood-prone areas. The flood risk map allows the identification of five classes ranging from a low to a very high risk of flooding. Thus, the low to very low-risk areas extend over roughly 70.58% of the total surface area of Ghardaia city. These areas, which are located in the southern part of the alluvial plain, are considered as low vulnerability regions, while areas with high-risk cover more than 20% of the city.
{"title":"Flooding study in the desert climate zone: case study of M’zab valley (Algeria)","authors":"Ouardia Gueciouer Teffah, M. S. Guettouche, Ayoub Zerouel, Salima Charifi Bellabas","doi":"10.1080/23249676.2022.2030253","DOIUrl":"https://doi.org/10.1080/23249676.2022.2030253","url":null,"abstract":"The aim of this research is the modelling and mapping of flood risk zones in the M’zab valley of Ghardaia city by combining the hazard map and the flood vulnerability map. The undertaken research utilizes the hydrologic engineering centre-hydrologic modelling system as the modelling tool to simulate the runoff in the watershed and hydrologic engineering centre – river analysis system to model the water levels of different river locations based on steady flow analysis and to define flood-prone areas. The flood risk map allows the identification of five classes ranging from a low to a very high risk of flooding. Thus, the low to very low-risk areas extend over roughly 70.58% of the total surface area of Ghardaia city. These areas, which are located in the southern part of the alluvial plain, are considered as low vulnerability regions, while areas with high-risk cover more than 20% of the city.","PeriodicalId":51911,"journal":{"name":"Journal of Applied Water Engineering and Research","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48420365","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}
Pub Date : 2022-03-14DOI: 10.1080/23249676.2022.2050312
Harith Hamad Mhmood, Meric Yilmaz, S. Sulaiman
In this research, the flood wave resulting from the hypothetical overtopping failure of the Haditha Dam on the Euphrates River, Iraq, was simulated, utilizing the ArcMap 10.2 and HEC-RAS 5.0.7 software and the observed field data from the Iraqi Ministry of Water Resources. Flooding parameters were calculated, for the study reach from the Haditha Dam to Heet city and major cities in between. The Manning coefficient of the study reach was calibrated to 0.035 and 0.07 for the main river and the floodplain, respectively. The results showed the flood wave propagation along the study reach, the flood hydrograph and time to the peak discharge/time to the maximum water surface elevation, maximum velocity, and width of the inundated area at the selected cities. The analysis outputs and the inundation maps can be used to provide an emergency action plan for the flooded regions.
{"title":"Simulation of the flood wave caused by hypothetical failure of the Haditha Dam","authors":"Harith Hamad Mhmood, Meric Yilmaz, S. Sulaiman","doi":"10.1080/23249676.2022.2050312","DOIUrl":"https://doi.org/10.1080/23249676.2022.2050312","url":null,"abstract":"In this research, the flood wave resulting from the hypothetical overtopping failure of the Haditha Dam on the Euphrates River, Iraq, was simulated, utilizing the ArcMap 10.2 and HEC-RAS 5.0.7 software and the observed field data from the Iraqi Ministry of Water Resources. Flooding parameters were calculated, for the study reach from the Haditha Dam to Heet city and major cities in between. The Manning coefficient of the study reach was calibrated to 0.035 and 0.07 for the main river and the floodplain, respectively. The results showed the flood wave propagation along the study reach, the flood hydrograph and time to the peak discharge/time to the maximum water surface elevation, maximum velocity, and width of the inundated area at the selected cities. The analysis outputs and the inundation maps can be used to provide an emergency action plan for the flooded regions.","PeriodicalId":51911,"journal":{"name":"Journal of Applied Water Engineering and Research","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47257694","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}
Pub Date : 2022-03-08DOI: 10.1080/23249676.2022.2031321
T. Karchiyappan, Rekha Pachaiappan
This study reports an effective method to explore the significant role of modified chitosan in recovering a protein from starch wastewater of sweet potato. Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray analysis (EDX), polarizing optical microscopy (POM), and scanning electron microscope analysis (SEM) are used to characterize modified chitosan. Parameters, such as agitation time, chitosan dose, initial pH, and settling time, are monitored over the protein recovery process. Also, the second-order polynomial model was developed with Box Behnken design (BBD). 3-D response surface contour graphs are plotted to learn about the interactive effects of process parameters on protein recovery. The optimum operating conditions are determined by using the desired function methodology. Under these optimal conditions, 95% of the protein was recovered. An artificial neural network (ANN)-based model was developed for simulating protein recovery. Electrophoresis analysis has shown that recovered protein can be used as livestock feed ingredients.
{"title":"Protein recovery from sweet potato starch wastewater using modified chitosan","authors":"T. Karchiyappan, Rekha Pachaiappan","doi":"10.1080/23249676.2022.2031321","DOIUrl":"https://doi.org/10.1080/23249676.2022.2031321","url":null,"abstract":"This study reports an effective method to explore the significant role of modified chitosan in recovering a protein from starch wastewater of sweet potato. Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray analysis (EDX), polarizing optical microscopy (POM), and scanning electron microscope analysis (SEM) are used to characterize modified chitosan. Parameters, such as agitation time, chitosan dose, initial pH, and settling time, are monitored over the protein recovery process. Also, the second-order polynomial model was developed with Box Behnken design (BBD). 3-D response surface contour graphs are plotted to learn about the interactive effects of process parameters on protein recovery. The optimum operating conditions are determined by using the desired function methodology. Under these optimal conditions, 95% of the protein was recovered. An artificial neural network (ANN)-based model was developed for simulating protein recovery. Electrophoresis analysis has shown that recovered protein can be used as livestock feed ingredients.","PeriodicalId":51911,"journal":{"name":"Journal of Applied Water Engineering and Research","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46193104","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}
Pub Date : 2022-01-29DOI: 10.1080/23249676.2022.2030254
Leandro José Isensee, D. H. M. Detzel, A. Pinheiro, G. A. Piazza
Trends can be detected in time series of extreme hydrological events. However, persistence and record length are often ignored in those analyses resulting in contradicting conclusions. The aim of this study is to evaluate their influence on trend detection in extreme streamflow time series. In this study, 108 time series of maximum and minimum streamflow in Brazil were analysed, with a minimum length of 60 years and an average of 76 years. Mann-Kendall (MK), Spearman’s rho, and Pettitt statistical tests were applied to assess trends. Portmanteau and Hurst’s autocorrelation tests were adopted to assess the persistence. Modifications of the MK test were used to remove the persistence effects. We found a strong persistence in the studied time series. Even after removing it, several time series remained non-stationary. Record length significantly affected the results of the analyses, with an increase in the number of trends according to the period analysed.
{"title":"Extreme streamflow time series analysis: trends, record length, and persistence","authors":"Leandro José Isensee, D. H. M. Detzel, A. Pinheiro, G. A. Piazza","doi":"10.1080/23249676.2022.2030254","DOIUrl":"https://doi.org/10.1080/23249676.2022.2030254","url":null,"abstract":"Trends can be detected in time series of extreme hydrological events. However, persistence and record length are often ignored in those analyses resulting in contradicting conclusions. The aim of this study is to evaluate their influence on trend detection in extreme streamflow time series. In this study, 108 time series of maximum and minimum streamflow in Brazil were analysed, with a minimum length of 60 years and an average of 76 years. Mann-Kendall (MK), Spearman’s rho, and Pettitt statistical tests were applied to assess trends. Portmanteau and Hurst’s autocorrelation tests were adopted to assess the persistence. Modifications of the MK test were used to remove the persistence effects. We found a strong persistence in the studied time series. Even after removing it, several time series remained non-stationary. Record length significantly affected the results of the analyses, with an increase in the number of trends according to the period analysed.","PeriodicalId":51911,"journal":{"name":"Journal of Applied Water Engineering and Research","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45789554","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}
Pub Date : 2022-01-13DOI: 10.1080/23249676.2021.2017805
Yasmin El-Dakrory, M. Sliem, Maha Abdelkreem, S. H. Hassab Elnaby, R. Rezk
This study investigates the comparison between magnetite nanoparticles loaded tea waste (MNLTW) and magnetite nanoparticles loaded reduced graphene oxide nanosheets (MNPs@rGO), as effective adsorbents for the removal of R6G dye from effluents. XRD, TEM, and SEM techniques were used to characterize the proposed adsorbents. The adsorption process was optimized under the parameters of initial concentration, contact time, pH, and the quantity of adsorbents. An amount of 0.15 g of both adsorbents removed about 87% of R6G by MNLTW and 65% by (MNPs@rGO) from 100 ml of a 23.95 mg/l concentrated solution in 40 and 60 min for MNLTW and (MNPs@rGO), respectively at pH 7. LIF measurements have developed better results than those of spectrophotometer. The isothermal analysis according to Langmuir isotherm was (R2 = 0.98) for (MNPs@rGO) and Temkin isotherm (R2 = 0.89) for MNLTW. The kinetic study is well described with a pseudo-second order model.
{"title":"Laser induced fluorescence detection of R6G dye adsorbed on Fe3O4 nanomaterials","authors":"Yasmin El-Dakrory, M. Sliem, Maha Abdelkreem, S. H. Hassab Elnaby, R. Rezk","doi":"10.1080/23249676.2021.2017805","DOIUrl":"https://doi.org/10.1080/23249676.2021.2017805","url":null,"abstract":"This study investigates the comparison between magnetite nanoparticles loaded tea waste (MNLTW) and magnetite nanoparticles loaded reduced graphene oxide nanosheets (MNPs@rGO), as effective adsorbents for the removal of R6G dye from effluents. XRD, TEM, and SEM techniques were used to characterize the proposed adsorbents. The adsorption process was optimized under the parameters of initial concentration, contact time, pH, and the quantity of adsorbents. An amount of 0.15 g of both adsorbents removed about 87% of R6G by MNLTW and 65% by (MNPs@rGO) from 100 ml of a 23.95 mg/l concentrated solution in 40 and 60 min for MNLTW and (MNPs@rGO), respectively at pH 7. LIF measurements have developed better results than those of spectrophotometer. The isothermal analysis according to Langmuir isotherm was (R2 = 0.98) for (MNPs@rGO) and Temkin isotherm (R2 = 0.89) for MNLTW. The kinetic study is well described with a pseudo-second order model.","PeriodicalId":51911,"journal":{"name":"Journal of Applied Water Engineering and Research","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42353811","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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