Abstract Magnetite-diatomite nanocomposite was synthesized through co-precipitation methods as an effective Cr(VI) removal adsorbent. The properties of diatomite (DM), thermochemically modified diatomite (TMD), and magnetic-diatomite nanocomposite (MDN) were investigated using FTIR, X-ray diffraction analysis (XRD), BET, and complete silicate chemical analysis. The MDN shows 98.89% adsorption removal at optimized conditions using the response surface methodology (RSM) of Box–Behnken Design (BBD). The kinetic data for Cr(VI) sorption on MDN were well described by pseudo-second order, which indicates the Cr(VI) adsorption was mainly due to chemisorption. The isotherm data show that the Langmuir and Freundlich models better described Cr(VI) ion sorption data. The thermodynamic parameters ΔG°, ΔH°, and ΔS° were estimated, and the results indicate Cr(VI) sorption on MDN was a spontaneous (ΔG° < 0) and exothermic process (ΔH° < 0). The proper Fe3O4 loading into TMD improves the gram susceptibility (Xg) of MND for magnet separation. The regeneration of nanocomposite material revealed over 80% Cr(VI) removal efficiency after five consecutive adsorption–desorption cycles. The produced MDN was tested for the removal of Cr(VI) from real tannery wastewater. The obtained results suggest the possibility of using this nanocomposite as an effective, efficient adsorbent to remove Cr(VI) laden wastewater.
{"title":"Adsorptive removal of Cr (VI) from wastewater using magnetite–diatomite nanocomposite","authors":"Gemechu Lemessa, Yonas Chebude, Esayas Alemeyahu","doi":"10.2166/aqua.2023.132","DOIUrl":"https://doi.org/10.2166/aqua.2023.132","url":null,"abstract":"Abstract Magnetite-diatomite nanocomposite was synthesized through co-precipitation methods as an effective Cr(VI) removal adsorbent. The properties of diatomite (DM), thermochemically modified diatomite (TMD), and magnetic-diatomite nanocomposite (MDN) were investigated using FTIR, X-ray diffraction analysis (XRD), BET, and complete silicate chemical analysis. The MDN shows 98.89% adsorption removal at optimized conditions using the response surface methodology (RSM) of Box–Behnken Design (BBD). The kinetic data for Cr(VI) sorption on MDN were well described by pseudo-second order, which indicates the Cr(VI) adsorption was mainly due to chemisorption. The isotherm data show that the Langmuir and Freundlich models better described Cr(VI) ion sorption data. The thermodynamic parameters ΔG°, ΔH°, and ΔS° were estimated, and the results indicate Cr(VI) sorption on MDN was a spontaneous (ΔG° &lt; 0) and exothermic process (ΔH° &lt; 0). The proper Fe3O4 loading into TMD improves the gram susceptibility (Xg) of MND for magnet separation. The regeneration of nanocomposite material revealed over 80% Cr(VI) removal efficiency after five consecutive adsorption–desorption cycles. The produced MDN was tested for the removal of Cr(VI) from real tannery wastewater. The obtained results suggest the possibility of using this nanocomposite as an effective, efficient adsorbent to remove Cr(VI) laden wastewater.","PeriodicalId":34693,"journal":{"name":"AQUA-Water Infrastructure Ecosystems and Society","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135432512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohsen Hajibabaei, Azadeh Yousefi, Sina Hesarkazzazi, Amin Minaei, Oswald Jenewein, Mohsen Shahandashti, Robert Sitzenfrei
Abstract The resilience of water distribution networks (WDNs) should be proactively evaluated to reduce the potential impacts of disruptive events. This study proposes a novel hydraulically inspired complex network approach (HCNA) to assess and enhance WDN resilience in the case of single-pipe failure. Unlike conventional hydraulic-based models, HCNA requires no hydraulic simulations for resilience analysis. Instead, it quantifies the failure consequences of edges (pipes) on the WDN graph by incorporating topological attributes with flow redistribution triggered by failures. This HCNA procedure leads to the identification of critical edges (pipes), as well as impacted ones, representing edges more susceptible to the failure of others. The impacted edges are then systematically resized by integrating HCNA with a graph-based design approach, obtaining a wide range of resilience enhancement solutions. A comparative study between HCNA and a hydraulic-based model for three WDNs confirms HCNA's effectiveness in identifying the most critical pipes in various network sizes. Furthermore, HCNA provides comparable resilience enhancement solutions with a hydraulic-based evolutionary optimization but with significantly lower computational effort (1,400 times faster). Thus, it can efficiently be used for resilience enhancement of large-scale WDNs, where the application of conventional optimizations is limited due to the intensive computational workload.
{"title":"Resilience enhancement of water distribution networks under pipe failures: a hydraulically inspired complex network approach","authors":"Mohsen Hajibabaei, Azadeh Yousefi, Sina Hesarkazzazi, Amin Minaei, Oswald Jenewein, Mohsen Shahandashti, Robert Sitzenfrei","doi":"10.2166/aqua.2023.180","DOIUrl":"https://doi.org/10.2166/aqua.2023.180","url":null,"abstract":"Abstract The resilience of water distribution networks (WDNs) should be proactively evaluated to reduce the potential impacts of disruptive events. This study proposes a novel hydraulically inspired complex network approach (HCNA) to assess and enhance WDN resilience in the case of single-pipe failure. Unlike conventional hydraulic-based models, HCNA requires no hydraulic simulations for resilience analysis. Instead, it quantifies the failure consequences of edges (pipes) on the WDN graph by incorporating topological attributes with flow redistribution triggered by failures. This HCNA procedure leads to the identification of critical edges (pipes), as well as impacted ones, representing edges more susceptible to the failure of others. The impacted edges are then systematically resized by integrating HCNA with a graph-based design approach, obtaining a wide range of resilience enhancement solutions. A comparative study between HCNA and a hydraulic-based model for three WDNs confirms HCNA's effectiveness in identifying the most critical pipes in various network sizes. Furthermore, HCNA provides comparable resilience enhancement solutions with a hydraulic-based evolutionary optimization but with significantly lower computational effort (1,400 times faster). Thus, it can efficiently be used for resilience enhancement of large-scale WDNs, where the application of conventional optimizations is limited due to the intensive computational workload.","PeriodicalId":34693,"journal":{"name":"AQUA-Water Infrastructure Ecosystems and Society","volume":"24 1-2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135271662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Real-time information on water supply and quality is a crucial asset for planning and managing water resources, infrastructure, and scientific research for sustainable development. In this direction, the innovative concept of smart water infrastructure is progressing. The present paper reports a case study on the demonstration of a `smart graded-water supply grid' on the campus of the Indian Institute of Technology Jodhpur, India. The paper describes the transformation of ∼13 km long water distribution network that supplies drinking water to ∼5,000 inhabitants into smart supply grid by deploying sensors and establishing an IoT-enabled real-time monitoring platform. The data sets of water flow and pressure collected from sensor nodes are analyzed to understand the characteristic diurnal water usage profiles unique to student hostels on the campus. The data show a distinctive consumption profile of student hostels over the weekdays with a maximum peak consumption of 16.38 m3/h. Monitoring of vital quality parameters such as chlorine, pH, and temperature demonstrate acceptable levels thereby ensuring compliance with safety standards. The purpose of the paper is to provide insights from a real-world case and close the knowledge gap between general awareness and the potential of smart water grid in sustainable management of graded-water services.
{"title":"Demonstration of real-time monitoring in smart graded-water supply grid: an institutional case study","authors":"Shobhana Singh, Manoj Chaudhary, Kim Sørensen","doi":"10.2166/aqua.2023.297","DOIUrl":"https://doi.org/10.2166/aqua.2023.297","url":null,"abstract":"Abstract Real-time information on water supply and quality is a crucial asset for planning and managing water resources, infrastructure, and scientific research for sustainable development. In this direction, the innovative concept of smart water infrastructure is progressing. The present paper reports a case study on the demonstration of a `smart graded-water supply grid' on the campus of the Indian Institute of Technology Jodhpur, India. The paper describes the transformation of ∼13 km long water distribution network that supplies drinking water to ∼5,000 inhabitants into smart supply grid by deploying sensors and establishing an IoT-enabled real-time monitoring platform. The data sets of water flow and pressure collected from sensor nodes are analyzed to understand the characteristic diurnal water usage profiles unique to student hostels on the campus. The data show a distinctive consumption profile of student hostels over the weekdays with a maximum peak consumption of 16.38 m3/h. Monitoring of vital quality parameters such as chlorine, pH, and temperature demonstrate acceptable levels thereby ensuring compliance with safety standards. The purpose of the paper is to provide insights from a real-world case and close the knowledge gap between general awareness and the potential of smart water grid in sustainable management of graded-water services.","PeriodicalId":34693,"journal":{"name":"AQUA-Water Infrastructure Ecosystems and Society","volume":"63 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135870021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Recent studies have proved that the utilization of polyethylene (PE) short-section or penstock is a promising water hammer control tool. However, the interplay between the magnitude attenuation and the phase offset of pressure-wave oscillations remains challenging. This study aimed at inspecting the capacity of a dual PE penstock/short-section-based control technique, with regard to the aforementioned interplay. In this technique, a PE penstock was lumped to the transient initiating zone of the main pipe and a short-section of the counter extremity of the pipe was replaced with PE. The transient pressure-wave behavior in a gravitational viscoelastic pipe involving cavitation was described by the extended 1D water hammer equations embedding the Vitkovsky and Kelvin–Voigt add-ons. The numerical solution was performed by the fixed grid method of characteristics. The high- (HDPE) and low-density (LDPE) were demonstrated in this study. Analysis revealed that upgrading techniques based on LDPE enabled a desirable tradeoff between the magnitude attenuation and the phase offset of pressure-wave oscillations. Particularly, the dual penstock/short-section specific upgrading technique allowed a more important attenuation magnitude of pressure peak (or crest), and led to a similar expansion of the wave oscillation period. Furthermore, results evidenced that the proposed technique outperformed the renewal of the original piping system.
{"title":"Tackling of hydraulic cavitation in pressurized pipe flow using high- or low-density polyethylene penstock and short-section","authors":"Dalila Kraiem, Ali Triki","doi":"10.2166/aqua.2023.189","DOIUrl":"https://doi.org/10.2166/aqua.2023.189","url":null,"abstract":"Abstract Recent studies have proved that the utilization of polyethylene (PE) short-section or penstock is a promising water hammer control tool. However, the interplay between the magnitude attenuation and the phase offset of pressure-wave oscillations remains challenging. This study aimed at inspecting the capacity of a dual PE penstock/short-section-based control technique, with regard to the aforementioned interplay. In this technique, a PE penstock was lumped to the transient initiating zone of the main pipe and a short-section of the counter extremity of the pipe was replaced with PE. The transient pressure-wave behavior in a gravitational viscoelastic pipe involving cavitation was described by the extended 1D water hammer equations embedding the Vitkovsky and Kelvin–Voigt add-ons. The numerical solution was performed by the fixed grid method of characteristics. The high- (HDPE) and low-density (LDPE) were demonstrated in this study. Analysis revealed that upgrading techniques based on LDPE enabled a desirable tradeoff between the magnitude attenuation and the phase offset of pressure-wave oscillations. Particularly, the dual penstock/short-section specific upgrading technique allowed a more important attenuation magnitude of pressure peak (or crest), and led to a similar expansion of the wave oscillation period. Furthermore, results evidenced that the proposed technique outperformed the renewal of the original piping system.","PeriodicalId":34693,"journal":{"name":"AQUA-Water Infrastructure Ecosystems and Society","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135870720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenlong Zhao, Xiaodong Yu, Ronglian Tang, Lin Shi, Nan Chen, Jian Zhang, Chang Du
Abstract The protection of negative pressures generated by the hydraulic transient process in the water supply system is crucial to safe and stable operation. In this study, a mathematical model of a pipeline hydraulic transient system with multi-undulating terrain was established based on the method of characteristics (MOC). The generation and development of water hammer negative pressures were analyzed, and double one-way surge tank protection schemes were proposed. It proved that the first surge tank should be located at the initial negative pressure point, and the second surge tank should be located at the second-highest point rather than the highest point. Additionally, compared with the theoretical minimum height, there was an optimization margin for the total surge tank height, which was reduced by 21% in this study. Meanwhile, the applicability of protection schemes and the influence of the one-way surge tank number on the total height were analyzed. The total height reduced with the increase of one-way surge tank number and tended to a minimum value. By comprehensively considering the engineering investment and negative pressure protection effect, the optimal surge tank number could be determined. This research represents an advance in negative pressure protection in multi-undulating terrain and provides support for further engineering studies.
{"title":"Negative pressure protection of water supply systems with multi-undulating terrain by one-way surge tanks","authors":"Wenlong Zhao, Xiaodong Yu, Ronglian Tang, Lin Shi, Nan Chen, Jian Zhang, Chang Du","doi":"10.2166/aqua.2023.293","DOIUrl":"https://doi.org/10.2166/aqua.2023.293","url":null,"abstract":"Abstract The protection of negative pressures generated by the hydraulic transient process in the water supply system is crucial to safe and stable operation. In this study, a mathematical model of a pipeline hydraulic transient system with multi-undulating terrain was established based on the method of characteristics (MOC). The generation and development of water hammer negative pressures were analyzed, and double one-way surge tank protection schemes were proposed. It proved that the first surge tank should be located at the initial negative pressure point, and the second surge tank should be located at the second-highest point rather than the highest point. Additionally, compared with the theoretical minimum height, there was an optimization margin for the total surge tank height, which was reduced by 21% in this study. Meanwhile, the applicability of protection schemes and the influence of the one-way surge tank number on the total height were analyzed. The total height reduced with the increase of one-way surge tank number and tended to a minimum value. By comprehensively considering the engineering investment and negative pressure protection effect, the optimal surge tank number could be determined. This research represents an advance in negative pressure protection in multi-undulating terrain and provides support for further engineering studies.","PeriodicalId":34693,"journal":{"name":"AQUA-Water Infrastructure Ecosystems and Society","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136232197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Water environments of urban constructed water quality treatment (WQT) wetland waterscapes are strongly related to water quality, whereas scenic beauty values help achieve better aquatic environments. However, correlations between several water quality indicators (WQIs) and scenic beauty indexes (SBIs) have not been thoroughly revealed in the existing studies. In this research, an analytic hierarchy process (AHP)-based on scenic beauty estimation (SBE) per site in two WQT wetlands has been developed. The weights of indicators were determined by the AHP voting, which includes three main criteria, i.e., conditions of vegetation, physical geographical conditions, and human geographical conditions. SBIs are voted and calculated from the professional group and the unprofessional group. WQIs of typical pollutants (i.e., dissolved oxygen (DO), CODCr, NH3-N, pH, and total phosphorus) were sampled in situ simultaneously. Inter-relationships among SBIs and WQIs are indicated by correlative analysis and a regression model, which highlights that DO increase, CODCr removal, and NH3-N removal can explain 68.8% of changes in the SBI. Accordingly, applications for WQT wetland eco-engineered landscaping (EEL) were suggested to be conducted on quantitative estimations in three aspects, i.e., following strategies of EEL, improving WQT techniques, and applying the attention restoration theory.
{"title":"Correlations among AHP-based scenic beauty estimation and water quality indicators of typical urban constructed WQT wetland park landscaping","authors":"Yan Huang, Tianjie Li, Yang Jin, Wenting Wu","doi":"10.2166/aqua.2023.071","DOIUrl":"https://doi.org/10.2166/aqua.2023.071","url":null,"abstract":"Abstract Water environments of urban constructed water quality treatment (WQT) wetland waterscapes are strongly related to water quality, whereas scenic beauty values help achieve better aquatic environments. However, correlations between several water quality indicators (WQIs) and scenic beauty indexes (SBIs) have not been thoroughly revealed in the existing studies. In this research, an analytic hierarchy process (AHP)-based on scenic beauty estimation (SBE) per site in two WQT wetlands has been developed. The weights of indicators were determined by the AHP voting, which includes three main criteria, i.e., conditions of vegetation, physical geographical conditions, and human geographical conditions. SBIs are voted and calculated from the professional group and the unprofessional group. WQIs of typical pollutants (i.e., dissolved oxygen (DO), CODCr, NH3-N, pH, and total phosphorus) were sampled in situ simultaneously. Inter-relationships among SBIs and WQIs are indicated by correlative analysis and a regression model, which highlights that DO increase, CODCr removal, and NH3-N removal can explain 68.8% of changes in the SBI. Accordingly, applications for WQT wetland eco-engineered landscaping (EEL) were suggested to be conducted on quantitative estimations in three aspects, i.e., following strategies of EEL, improving WQT techniques, and applying the attention restoration theory.","PeriodicalId":34693,"journal":{"name":"AQUA-Water Infrastructure Ecosystems and Society","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136235603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nor Zida Rosly, Abdul Halim Abdullah, Mazliana Ahmad Kamarudin, Siti Efliza Ashari, Shahrul Alang Ahmad
Abstract The present study reports the adsorptive potential of an alternative and regenerative adsorbent, lead sulphide (PbS) modified with calix[4]arene towards a methyl orange (MO) dye solution. The chemical and morphological aspects of synthesised PbS nanoparticles and calix[4]arene-modified PbS were analysed by FESEM, EDX and FTIR, which indicated successful immobilisation of calix[4]arene on the PbS surface. The response surface methodology (RSM), based on central composite design (CCD), was conducted to evaluate the significant factors and to optimise the influence of various factors (adsorbent dosage, contact time and pH) on the adsorption of MO. Under optimal conditions (pH of 4, a dosage of 89.70 mg and a contact time of 129.76 min), the maximum adsorption of MO by calix[4]arene-modified PbS was observed. The MO uptake behaviour was well described by the Freundlich model and the pseudo-second-order kinetic model, indicating a multilayer chemical adsorption with a maximum adsorption capacity (qmax) of 3.268 mg/g. The adsorption mechanism of MO dye on the surface of calix[4]arene-modified PbS can be attributed to various interactions such as dipole–dipole hydrogen bonding interactions, Yoshida hydrogen bonding, π–π interactions and electrostatic interaction. The results strongly demonstrated the use of novel adsorbents, calix[4]arene-modified PbS and a reusability strategy as an alternative adsorbent in MO dye removal.
{"title":"Adsorptive removal of methyl orange dye in aqueous solutions using calix[4]arene-modified lead sulphide: insight into response surface methodology, isotherm and kinetic studies","authors":"Nor Zida Rosly, Abdul Halim Abdullah, Mazliana Ahmad Kamarudin, Siti Efliza Ashari, Shahrul Alang Ahmad","doi":"10.2166/aqua.2023.153","DOIUrl":"https://doi.org/10.2166/aqua.2023.153","url":null,"abstract":"Abstract The present study reports the adsorptive potential of an alternative and regenerative adsorbent, lead sulphide (PbS) modified with calix[4]arene towards a methyl orange (MO) dye solution. The chemical and morphological aspects of synthesised PbS nanoparticles and calix[4]arene-modified PbS were analysed by FESEM, EDX and FTIR, which indicated successful immobilisation of calix[4]arene on the PbS surface. The response surface methodology (RSM), based on central composite design (CCD), was conducted to evaluate the significant factors and to optimise the influence of various factors (adsorbent dosage, contact time and pH) on the adsorption of MO. Under optimal conditions (pH of 4, a dosage of 89.70 mg and a contact time of 129.76 min), the maximum adsorption of MO by calix[4]arene-modified PbS was observed. The MO uptake behaviour was well described by the Freundlich model and the pseudo-second-order kinetic model, indicating a multilayer chemical adsorption with a maximum adsorption capacity (qmax) of 3.268 mg/g. The adsorption mechanism of MO dye on the surface of calix[4]arene-modified PbS can be attributed to various interactions such as dipole–dipole hydrogen bonding interactions, Yoshida hydrogen bonding, π–π interactions and electrostatic interaction. The results strongly demonstrated the use of novel adsorbents, calix[4]arene-modified PbS and a reusability strategy as an alternative adsorbent in MO dye removal.","PeriodicalId":34693,"journal":{"name":"AQUA-Water Infrastructure Ecosystems and Society","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136235402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The aim of the present research is to develop a new, fast, and easily applicable adsorption method for the removal of hazardous Cr(VI) and Cu(II) ions from the polluted industrial wastewater by using Racomitrium ericoides (Brid.) Brid. (REB), a type of moss. Although there are studies in the literature in which different moss species were used for the removal of heavy metals (HMs), REB was used for the first time in this study. Adsorption experiments were carried out through a batch system. The impact of significant experimental parameters showed that the optimum values of initial pH were 2.0 for Cr(VI) retention and 5.0 for Cu(II), and 360 min was selected as the optimum contact time for both HMs. An artificial neural network (ANN) model was applied to create a predictive model for the uptake efficiency of HMs. Adsorption kinetics of Cr(VI) and Cu(II) ions followed the pseudo-second order model. The maximum adsorption capacities of REB identified through the Langmuir model were 41.2 mg g−1 for Cr(VI) and 22.7 mg g−1 for Cu(II) ions. The results of the study demonstrated that REB can be utilized as an abundant, low-cost, and effective adsorbent in removal of HMs from aqueous solutions.
{"title":"Adsorptive removal of Cr(VI) and Cu(II) ions from aqueous solutions by a natural moss","authors":"Sengul Tugba Ozeken, Duygu Ozdes, Celal Duran","doi":"10.2166/aqua.2023.299","DOIUrl":"https://doi.org/10.2166/aqua.2023.299","url":null,"abstract":"Abstract The aim of the present research is to develop a new, fast, and easily applicable adsorption method for the removal of hazardous Cr(VI) and Cu(II) ions from the polluted industrial wastewater by using Racomitrium ericoides (Brid.) Brid. (REB), a type of moss. Although there are studies in the literature in which different moss species were used for the removal of heavy metals (HMs), REB was used for the first time in this study. Adsorption experiments were carried out through a batch system. The impact of significant experimental parameters showed that the optimum values of initial pH were 2.0 for Cr(VI) retention and 5.0 for Cu(II), and 360 min was selected as the optimum contact time for both HMs. An artificial neural network (ANN) model was applied to create a predictive model for the uptake efficiency of HMs. Adsorption kinetics of Cr(VI) and Cu(II) ions followed the pseudo-second order model. The maximum adsorption capacities of REB identified through the Langmuir model were 41.2 mg g−1 for Cr(VI) and 22.7 mg g−1 for Cu(II) ions. The results of the study demonstrated that REB can be utilized as an abundant, low-cost, and effective adsorbent in removal of HMs from aqueous solutions.","PeriodicalId":34693,"journal":{"name":"AQUA-Water Infrastructure Ecosystems and Society","volume":"21 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135219914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Waqas Zaffar, Ishtiaq Hassan, Zulfiqar Ali, Kaleem Sarwar, Muhammad Hassan, Muhammad Taimoor Mustafa, Faizan Ahmed Waris
Abstract The stilling basin of the Taunsa barrage is a modified form of the United States Bureau of Reclamation (USBR) Type-III basin, which consists of baffle and friction blocks. Studies revealed uprooting of baffle blocks due to their vertical face. Additionally, the literature highlighted issues of rectangular face baffle blocks: less drag, smaller wake area, and flow reattachment. In contrast, the use of wedge-shaped baffle blocks (WSBBs) is limited downstream of open-channel flows. Therefore, this study developed numerical models to investigate the effects of USBR and WSBB basins on the hydraulic jump (HJ) downstream of the Taunsa barrage under lower tailwater conditions. Surface profiles in WSBB and modified USBR basins showed agreement with previous studies, for which the coefficient of determination (R2) reached 0.980 and 0.970, respectively. The HJ efficiencies reached 57.9 and 58.6% in WSBB and modified USBR basins, respectively. The results of sequent depths, roller length, and velocity profiles in the WSBB basin were found more promising than the modified USBR basin, which further confirmed the suitability of the WSBB basin for barrages. Furthermore, WSBB improved flow behaviors in the basin, which showed no fluid reattachment on the sides of WSBB, increased wake regions, and decreased turbulent kinetic energies.
{"title":"Numerical investigation of hydraulic jumps with USBR and wedge-shaped baffle block basins for lower tailwater","authors":"Muhammad Waqas Zaffar, Ishtiaq Hassan, Zulfiqar Ali, Kaleem Sarwar, Muhammad Hassan, Muhammad Taimoor Mustafa, Faizan Ahmed Waris","doi":"10.2166/aqua.2023.261","DOIUrl":"https://doi.org/10.2166/aqua.2023.261","url":null,"abstract":"Abstract The stilling basin of the Taunsa barrage is a modified form of the United States Bureau of Reclamation (USBR) Type-III basin, which consists of baffle and friction blocks. Studies revealed uprooting of baffle blocks due to their vertical face. Additionally, the literature highlighted issues of rectangular face baffle blocks: less drag, smaller wake area, and flow reattachment. In contrast, the use of wedge-shaped baffle blocks (WSBBs) is limited downstream of open-channel flows. Therefore, this study developed numerical models to investigate the effects of USBR and WSBB basins on the hydraulic jump (HJ) downstream of the Taunsa barrage under lower tailwater conditions. Surface profiles in WSBB and modified USBR basins showed agreement with previous studies, for which the coefficient of determination (R2) reached 0.980 and 0.970, respectively. The HJ efficiencies reached 57.9 and 58.6% in WSBB and modified USBR basins, respectively. The results of sequent depths, roller length, and velocity profiles in the WSBB basin were found more promising than the modified USBR basin, which further confirmed the suitability of the WSBB basin for barrages. Furthermore, WSBB improved flow behaviors in the basin, which showed no fluid reattachment on the sides of WSBB, increased wake regions, and decreased turbulent kinetic energies.","PeriodicalId":34693,"journal":{"name":"AQUA-Water Infrastructure Ecosystems and Society","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136032930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alves Francisco Nhaurire, Tanya Wells-Brown, Rehana Capurchande
Abstract As part of the process of decentralization of water supply services in Mozambique, Water User Committees play a key role in the management of water systems. However, they struggle with sustainability issues, which affect the access to water in the communities. With this paper, we intend to understand the sustainability of water systems in Mozambique based on the socio-cultural dynamics, normative and institutional framework, and the interaction of social actors involved in the community management of water systems. This is a qualitative study based on phenomenology principles whose experiences were based on fieldwork carried out in Gaza Province, Mozambique. The study revealed that community management of water supply systems in Mozambique was a policy option for decentralization of water supply management, in response to the weak capacity (resources and technicians) for this purpose. The study shows that in practice, there has yet to be much success in achieving the objectives of the Water User Committee, as they have proven to be less effective in meeting water access needs. There are challenges affecting the sustainability of the Water User Committee, such as weak understanding of their roles, conflicts, transparency, accountability and, in turn, the sustainability of water sources.
{"title":"Water committees in the implementation of decentralization measures in the water sector in Gaza Province, Mozambique: ownership and resistance","authors":"Alves Francisco Nhaurire, Tanya Wells-Brown, Rehana Capurchande","doi":"10.2166/aqua.2023.059","DOIUrl":"https://doi.org/10.2166/aqua.2023.059","url":null,"abstract":"Abstract As part of the process of decentralization of water supply services in Mozambique, Water User Committees play a key role in the management of water systems. However, they struggle with sustainability issues, which affect the access to water in the communities. With this paper, we intend to understand the sustainability of water systems in Mozambique based on the socio-cultural dynamics, normative and institutional framework, and the interaction of social actors involved in the community management of water systems. This is a qualitative study based on phenomenology principles whose experiences were based on fieldwork carried out in Gaza Province, Mozambique. The study revealed that community management of water supply systems in Mozambique was a policy option for decentralization of water supply management, in response to the weak capacity (resources and technicians) for this purpose. The study shows that in practice, there has yet to be much success in achieving the objectives of the Water User Committee, as they have proven to be less effective in meeting water access needs. There are challenges affecting the sustainability of the Water User Committee, such as weak understanding of their roles, conflicts, transparency, accountability and, in turn, the sustainability of water sources.","PeriodicalId":34693,"journal":{"name":"AQUA-Water Infrastructure Ecosystems and Society","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135993869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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