This research aims to investigate the near-bed turbulent flow characteristics in a meandering channel with both mobile bed and immobile bed conditions. Experiments were performed in a prismatic rectangular meandering channel with a non-uniform sand bed of size d50 = 0.523mm. The three-dimensional instantaneous fluid velocity was collected using the Acoustic Doppler velocimeter which will provide important results related to the flow turbulence such as mean flow velocity, turbulence intensity, Reynolds shear stress, turbulent kinetic energy, skewness, kurtosis and turbulent anisotropy. The secondary current flow and the exchange of momentum in the form of turbulence kinetic energy, Reynolds shear stress and turbulent intensity at the inner layer of the flow are identified more in a mobile bed condition as compared to an immobile condition, which causes sediment transport. For the inner layer of the flow, turbulence intensity and turbulent kinetic energy are decreased in magnitude and gradually increase in the outer layer of flow for both the bed conditions. Higher turbulence anisotropy is noticed in the mobile bed condition than in the immobile bed condition, which shows more nonuniformities near the bed level for the mobile bed condition. This study may help in understanding the effect of sediment transport due to a turbulent flow structure in a sinuous alluvial channel.
{"title":"Turbulent flow mechanisms in meandering channels with sediment transport","authors":"S. Sahoo, Anurag Sharma","doi":"10.2166/wpt.2023.035","DOIUrl":"https://doi.org/10.2166/wpt.2023.035","url":null,"abstract":"\u0000 This research aims to investigate the near-bed turbulent flow characteristics in a meandering channel with both mobile bed and immobile bed conditions. Experiments were performed in a prismatic rectangular meandering channel with a non-uniform sand bed of size d50 = 0.523mm. The three-dimensional instantaneous fluid velocity was collected using the Acoustic Doppler velocimeter which will provide important results related to the flow turbulence such as mean flow velocity, turbulence intensity, Reynolds shear stress, turbulent kinetic energy, skewness, kurtosis and turbulent anisotropy. The secondary current flow and the exchange of momentum in the form of turbulence kinetic energy, Reynolds shear stress and turbulent intensity at the inner layer of the flow are identified more in a mobile bed condition as compared to an immobile condition, which causes sediment transport. For the inner layer of the flow, turbulence intensity and turbulent kinetic energy are decreased in magnitude and gradually increase in the outer layer of flow for both the bed conditions. Higher turbulence anisotropy is noticed in the mobile bed condition than in the immobile bed condition, which shows more nonuniformities near the bed level for the mobile bed condition. This study may help in understanding the effect of sediment transport due to a turbulent flow structure in a sinuous alluvial channel.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49061174","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}
Chandima J Narangoda, Deeptha Amarathunga, C. Dangalle
Kelani River is the principal consumable water source for 80% of the population in the Colombo district and an important ecosystem complex for the freshwater fish biota of Sri Lanka. However, it is the most polluted river in the country. The present study was conducted to determine the water quality parameters and pollution of the upper and lower catchments of the river and select the most suitable parameters for predicting the pollution of each catchment. Thirteen locations of each catchment were selected for the study, and 14 water quality parameters were recorded by standard techniques. Measurements were compared with the standard values permissible for drinking purposes and aquatic life and subjected to principal component analysis. The study revealed that the most polluted catchment of the Kelani River was the lower catchment, and the chemical oxygen demand (COD) and water pH were selected as the most suitable parameters to predict the pollution levels of the lower catchment. The nitrate concentration and COD were selected as the most suitable water quality parameters to predict the pollution of the upper catchment. The present study indicates an accelerating trend in water pollution of the Kelani River when compared with studies conducted two decades ago.
{"title":"Evaluation of water quality in the upper and lower catchments of the Kelani River Basin, Sri Lanka","authors":"Chandima J Narangoda, Deeptha Amarathunga, C. Dangalle","doi":"10.2166/wpt.2023.034","DOIUrl":"https://doi.org/10.2166/wpt.2023.034","url":null,"abstract":"\u0000 Kelani River is the principal consumable water source for 80% of the population in the Colombo district and an important ecosystem complex for the freshwater fish biota of Sri Lanka. However, it is the most polluted river in the country. The present study was conducted to determine the water quality parameters and pollution of the upper and lower catchments of the river and select the most suitable parameters for predicting the pollution of each catchment. Thirteen locations of each catchment were selected for the study, and 14 water quality parameters were recorded by standard techniques. Measurements were compared with the standard values permissible for drinking purposes and aquatic life and subjected to principal component analysis. The study revealed that the most polluted catchment of the Kelani River was the lower catchment, and the chemical oxygen demand (COD) and water pH were selected as the most suitable parameters to predict the pollution levels of the lower catchment. The nitrate concentration and COD were selected as the most suitable water quality parameters to predict the pollution of the upper catchment. The present study indicates an accelerating trend in water pollution of the Kelani River when compared with studies conducted two decades ago.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48548731","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}
Fifty vertical electrical soundings were carried out in the Adamawa region of Cameroon. The interpretation was done using inverse slope method (ISM) and curve matching methods. The aim was to employ the applicability and suitability of the ISM in deciphering the vertical electrical sounding (VES) data for groundwater and hydrogeophysical purposes in the Pan-African aquifers. The ISM can be used to interpret VES data collected with any electrodes array. The results obtained by the ISM geo-electrical interpretation correlate/agree well with the available lithological logs used in constraining the interpretation. The resistivity values obtained through this method are in the range of 20–900 Ω m with a mean of 241 Ω m and a standard deviation of 228 Ω m. The aquifer thickness is in the range of 2–90 m, with an average of 33 m and a standard deviation of 21 m. Resistivity, thickness and depth of the Pan-African aquifer in the Adamawa region, Central Africa have been determined and characterized using both the ISM and an integrated protocol of interpolation technique. The ISM can therefore be recommended for the interpretation of VES measurements in the similar Pan-African context worldwide.
{"title":"Hydraulic characterization of the Adamawa-Cameroon aquifer using inverse slope method","authors":"J. Asfahani, Z. Aretouyap, N. George","doi":"10.2166/wpt.2023.033","DOIUrl":"https://doi.org/10.2166/wpt.2023.033","url":null,"abstract":"\u0000 Fifty vertical electrical soundings were carried out in the Adamawa region of Cameroon. The interpretation was done using inverse slope method (ISM) and curve matching methods. The aim was to employ the applicability and suitability of the ISM in deciphering the vertical electrical sounding (VES) data for groundwater and hydrogeophysical purposes in the Pan-African aquifers. The ISM can be used to interpret VES data collected with any electrodes array. The results obtained by the ISM geo-electrical interpretation correlate/agree well with the available lithological logs used in constraining the interpretation. The resistivity values obtained through this method are in the range of 20–900 Ω m with a mean of 241 Ω m and a standard deviation of 228 Ω m. The aquifer thickness is in the range of 2–90 m, with an average of 33 m and a standard deviation of 21 m. Resistivity, thickness and depth of the Pan-African aquifer in the Adamawa region, Central Africa have been determined and characterized using both the ISM and an integrated protocol of interpolation technique. The ISM can therefore be recommended for the interpretation of VES measurements in the similar Pan-African context worldwide.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41968191","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}
Nepali Jayasinghe, Dilini Chandima Herath, Lalith Indranath Weerasekara, Sujithra Kaushalya Weragoda, Gayan Darshana Amarasooriya
This study was conducted to investigate the effect of different in-house practices on trihalomethane (THM) level fluctuations in pipe-borne water. Common in-house practices such as boiling, unboiling, boiling water with headspace/non-headspace, storage vessels materials, storage practices, and storage time were investigated to study residual THM and their percentage. Vessels made of plastic (P), clay (C), stainless steel (SS), glass (G), and aluminium (Al) were used for the study. Prime trihalomethanes of CHCl3, CHBrCl2, CHBr2Cl, CHBr3, and total of those four THMs (TTHMs) were measured, and removal/formation percentages were calculated. Results revealed that the percent change of TTHM varies based on the boiling practice as follows: open boiling TTHM > close boiling with headspace TTHM > close boiling without headspace (CBWH) TTHM. The following order was observed for residual TTHM for 6 h storage in the vessels; for CBWH water storage in open vessels C < G < P < SS < Al and close vessels C < G < P < SS < Al; and for un-boiled water storage in open vessels SS < C < Al < P < G and close vessels C < P < Al < SS < G. In conclusion, the lowest concentration of residual TTHM was found in the boiled water stored in a clay pot and recommended as an in-house practice to reduce TTHM.
本研究旨在探讨不同的室内操作对管道水中三卤甲烷(THM)水平波动的影响。调查了常见的内部操作，如煮沸、未煮沸、沸水顶空/非顶空、存储容器材料、存储操作和存储时间，以研究残余THM及其百分比。研究中使用了塑料(P)、粘土(C)、不锈钢(SS)、玻璃(G)和铝(Al)制成的容器。测定CHCl3、CHBrCl2、CHBr2Cl、CHBr3及其四种THMs (TTHMs)的质数三卤甲烷，并计算其去除率/成形率。结果表明，不同沸腾方式下，TTHM的百分比变化如下:开煮TTHM >带顶空闭煮TTHM >无顶空(CBWH)闭煮TTHM。剩余TTHM在容器中储存6小时的顺序如下:开放容器C < G < P < SS < Al，封闭容器C < G < P < SS < Al;对于未煮沸的水，开放容器中SS < C < Al < P < G，封闭容器中C < P < Al < SS < G。综上所述，在陶罐中储存的沸水中，TTHM残留浓度最低，建议作为室内实践来减少TTHM。
{"title":"Variations of residual trihalomethane concentration in pipe-borne water during different in-house practices","authors":"Nepali Jayasinghe, Dilini Chandima Herath, Lalith Indranath Weerasekara, Sujithra Kaushalya Weragoda, Gayan Darshana Amarasooriya","doi":"10.2166/wpt.2023.032","DOIUrl":"https://doi.org/10.2166/wpt.2023.032","url":null,"abstract":"\u0000 This study was conducted to investigate the effect of different in-house practices on trihalomethane (THM) level fluctuations in pipe-borne water. Common in-house practices such as boiling, unboiling, boiling water with headspace/non-headspace, storage vessels materials, storage practices, and storage time were investigated to study residual THM and their percentage. Vessels made of plastic (P), clay (C), stainless steel (SS), glass (G), and aluminium (Al) were used for the study. Prime trihalomethanes of CHCl3, CHBrCl2, CHBr2Cl, CHBr3, and total of those four THMs (TTHMs) were measured, and removal/formation percentages were calculated. Results revealed that the percent change of TTHM varies based on the boiling practice as follows: open boiling TTHM > close boiling with headspace TTHM > close boiling without headspace (CBWH) TTHM. The following order was observed for residual TTHM for 6 h storage in the vessels; for CBWH water storage in open vessels C < G < P < SS < Al and close vessels C < G < P < SS < Al; and for un-boiled water storage in open vessels SS < C < Al < P < G and close vessels C < P < Al < SS < G. In conclusion, the lowest concentration of residual TTHM was found in the boiled water stored in a clay pot and recommended as an in-house practice to reduce TTHM.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44911607","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}
Combined adsorption and photocatalysis synergy was explored in this research because the porosity of activated carbon and hydroxyl radicals' generation are the main drivers of the adsorption and photodecomposition efficiency of dyes. In this study, periwinkle shell ash (PSA) activated at 800 °C was used for the adsorption of toxic crystal violet (CRV) dyes. The PSA was characterized by scanning electron microscope, Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller surface area analysis, and X-ray diffraction. Findings showed that CRV adsorption was dependent on the dosage, pH, contact time, and initial concentration. The adsorption capacity was 46.82 at pH (9) for CRV, dosage amount of 0.2 g/L, and an adsorbate concentration of 70 mg/L. Pseudo-second order gave a perfect fitting-chemisorption mechanism with values >0.98 (R2). Maximum photodegradation (93–98%) was achieved when the catalyst dosage increased to 0.75 g. Thermodynamics confirmed a spontaneous/exothermic process. The photocatalysis process confirmed that the combined process was effective and determined to be the rate-determining step by Langmuir–Hinshelwood. The study concluded that PSA was an efficient adsorbent, and TiO2 was a key factor in the reaction mechanism and recommended for potential synthesis of membrane substrates, high performance, efficiency, and cost reduction.
{"title":"Photoadsorption and reaction mechanism of periwinkle shell ash in the removal of hazardous dye","authors":"A. Nkwoada, G. Onyedika, E. Oguzie, M. Ogwuegbu","doi":"10.2166/wpt.2023.029","DOIUrl":"https://doi.org/10.2166/wpt.2023.029","url":null,"abstract":"\u0000 Combined adsorption and photocatalysis synergy was explored in this research because the porosity of activated carbon and hydroxyl radicals' generation are the main drivers of the adsorption and photodecomposition efficiency of dyes. In this study, periwinkle shell ash (PSA) activated at 800 °C was used for the adsorption of toxic crystal violet (CRV) dyes. The PSA was characterized by scanning electron microscope, Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller surface area analysis, and X-ray diffraction. Findings showed that CRV adsorption was dependent on the dosage, pH, contact time, and initial concentration. The adsorption capacity was 46.82 at pH (9) for CRV, dosage amount of 0.2 g/L, and an adsorbate concentration of 70 mg/L. Pseudo-second order gave a perfect fitting-chemisorption mechanism with values >0.98 (R2). Maximum photodegradation (93–98%) was achieved when the catalyst dosage increased to 0.75 g. Thermodynamics confirmed a spontaneous/exothermic process. The photocatalysis process confirmed that the combined process was effective and determined to be the rate-determining step by Langmuir–Hinshelwood. The study concluded that PSA was an efficient adsorbent, and TiO2 was a key factor in the reaction mechanism and recommended for potential synthesis of membrane substrates, high performance, efficiency, and cost reduction.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45672052","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}
This study aims to evaluate the water quality and reuse potential of groundwater combined with a saline solution for irrigation. The brine dilution process was done by adding groundwater by determining the total dissolved salts (TDS) value according to the irrigation criteria and then by calculating the amount of groundwater to be added using the law of concentrations to obtain the water mixture, as the TDS value decreased from 4922 and 3810 mg/l to 2587 and 2200 mg/l, respectively. The assessment aimed to determine the suitability of the water for irrigation, and the quality indices used were sodium adsorption ratio, magnesium hazard ratio percentage, sodium percentage, residual sodium carbonate, permeability index, Kelly index, and irrigation water quality index. The results indicated that the water after mixing is suitable for irrigation. The USSL diagram was used to evaluate the post-mixing water at two stations, Touggourt and El-Oued, and the results showed that the post-mixing water at Touggourt falls in the C4–S1 group (extremely high salinity with low sodium), and the post-mixing water at El-Oued falls in the C4–S2 group (very high salinity with medium sodium).
{"title":"Water quality assessment and reuse potential of groundwater combined saline solution for irrigation","authors":"Ammari Abdessattar, S. Kateb","doi":"10.2166/wpt.2023.030","DOIUrl":"https://doi.org/10.2166/wpt.2023.030","url":null,"abstract":"\u0000 This study aims to evaluate the water quality and reuse potential of groundwater combined with a saline solution for irrigation. The brine dilution process was done by adding groundwater by determining the total dissolved salts (TDS) value according to the irrigation criteria and then by calculating the amount of groundwater to be added using the law of concentrations to obtain the water mixture, as the TDS value decreased from 4922 and 3810 mg/l to 2587 and 2200 mg/l, respectively. The assessment aimed to determine the suitability of the water for irrigation, and the quality indices used were sodium adsorption ratio, magnesium hazard ratio percentage, sodium percentage, residual sodium carbonate, permeability index, Kelly index, and irrigation water quality index. The results indicated that the water after mixing is suitable for irrigation. The USSL diagram was used to evaluate the post-mixing water at two stations, Touggourt and El-Oued, and the results showed that the post-mixing water at Touggourt falls in the C4–S1 group (extremely high salinity with low sodium), and the post-mixing water at El-Oued falls in the C4–S2 group (very high salinity with medium sodium).","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42490518","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}
Recently, some areas are exposed to water scarcity and floods, and rainwater harvesting (RWH) is a practical solution, particularly in arid and semi-arid regions. The Wadi Watier basin located in South Sinai, Egypt was selected to identify the appropriate RWH techniques. Five alternatives were proposed: a dam with a reservoir, a storage pond, an underground tank, wadi bed cultivation, or a Jessor system. The hydrological model was built using the WMS software to determine the runoff volume at the proposed RWH sites. Multiple criteria were identified and classified based on their suitability degree. Then, an Analytic Hierarchy Process (AHP) was used to assign the effective weight of each evaluation criterion. The AHP revealed that the wadi slope and initial cost have the highest evaluation influence of 20%, followed by the wadi width of 15%. The rainfall volume, social acceptance, and cost revenue have moderate influences with weights from 8 to 11%. Finally, the storage ponds and underground tanks recorded the highest suitability evaluations at the selected RWH sites, at 65.4 and 62.7%, respectively. The dam with a reservoir recorded 49.3%, which is considered medium suitability, while wadi bed cultivation and Jessor systems were classified as low suitability evaluations with 42.7 and 41.7%, respectively.
{"title":"Multi-criteria decision support system for selecting the rainwater harvesting technique in wadi systems, Sinai, Egypt","authors":"M. Abdelkader, U. Mahmoud, A. Mobasher, M. Reda","doi":"10.2166/wpt.2023.031","DOIUrl":"https://doi.org/10.2166/wpt.2023.031","url":null,"abstract":"\u0000 Recently, some areas are exposed to water scarcity and floods, and rainwater harvesting (RWH) is a practical solution, particularly in arid and semi-arid regions. The Wadi Watier basin located in South Sinai, Egypt was selected to identify the appropriate RWH techniques. Five alternatives were proposed: a dam with a reservoir, a storage pond, an underground tank, wadi bed cultivation, or a Jessor system. The hydrological model was built using the WMS software to determine the runoff volume at the proposed RWH sites. Multiple criteria were identified and classified based on their suitability degree. Then, an Analytic Hierarchy Process (AHP) was used to assign the effective weight of each evaluation criterion. The AHP revealed that the wadi slope and initial cost have the highest evaluation influence of 20%, followed by the wadi width of 15%. The rainfall volume, social acceptance, and cost revenue have moderate influences with weights from 8 to 11%. Finally, the storage ponds and underground tanks recorded the highest suitability evaluations at the selected RWH sites, at 65.4 and 62.7%, respectively. The dam with a reservoir recorded 49.3%, which is considered medium suitability, while wadi bed cultivation and Jessor systems were classified as low suitability evaluations with 42.7 and 41.7%, respectively.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49412519","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}
This paper investigates the performance of five supervised machine learning algorithms, including support vector machine (SVM), logistic regression (LogR), decision tree (DT), multiple perceptron neural network (MLP-NN), and K-nearest neighbours (KNN) for predicting the water quality index (WQI) and water quality class (WQC) in the coastal aquifer of the Gaza Strip. A total of 2,448 samples of groundwater were collected from the coastal aquifer of the Gaza Strip, and various physical and chemical parameters were measured to calculate the WQI based on weight. The prediction accuracy was evaluated using five error measures. The results showed that MLP-NN outperformed other models in terms of accuracy with an R value of 0.9945–0.9948, compared with 0.9897–0.9880 for SVM, 0.9784–0.9800 for LogR, 0.9464–0.9247 for KNN, and 0.9301–0.9064 for DT. SVM classification showed that 78.32% of the study area fell under poor to unsuitable water categories, while the north part of the region had good to excellent water quality. TDS was the most important parameter in WQI predictions while and were the least important. MLP-NN and SVM were the most accurate models for the WQI prediction and classification in the Gaza coastal aquifer.
{"title":"Prediction of groundwater quality index in the Gaza coastal aquifer using supervised machine learning techniques","authors":"A. Aish, H. A. Zaqoot, W. Sethar, Diana A. Aish","doi":"10.2166/wpt.2023.028","DOIUrl":"https://doi.org/10.2166/wpt.2023.028","url":null,"abstract":"\u0000 This paper investigates the performance of five supervised machine learning algorithms, including support vector machine (SVM), logistic regression (LogR), decision tree (DT), multiple perceptron neural network (MLP-NN), and K-nearest neighbours (KNN) for predicting the water quality index (WQI) and water quality class (WQC) in the coastal aquifer of the Gaza Strip. A total of 2,448 samples of groundwater were collected from the coastal aquifer of the Gaza Strip, and various physical and chemical parameters were measured to calculate the WQI based on weight. The prediction accuracy was evaluated using five error measures. The results showed that MLP-NN outperformed other models in terms of accuracy with an R value of 0.9945–0.9948, compared with 0.9897–0.9880 for SVM, 0.9784–0.9800 for LogR, 0.9464–0.9247 for KNN, and 0.9301–0.9064 for DT. SVM classification showed that 78.32% of the study area fell under poor to unsuitable water categories, while the north part of the region had good to excellent water quality. TDS was the most important parameter in WQI predictions while and were the least important. MLP-NN and SVM were the most accurate models for the WQI prediction and classification in the Gaza coastal aquifer.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45699886","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}
The harmonious coexistence of humans and nature has reached a broad consensus in the world. Maintaining the health of the ecological environment is the foundation of the existence and development of human civilization, and is also the inevitable choice for human beings to deal with the global ecological environment crisis. As an important factor affecting ecological stability, rural domestic wastewater has been neglected and not treated effectively for a long time because of its special geographical location and development limitations. In this paper, an integrated process of an MBR was applied to rural domestic wastewater treatment, inside which the modified PVDF@ZrO2 membrane was used to replace the traditional PVDF membrane. A series of membrane analyses and project follow-ups have proven that the hydrophilicity, anti-fouling performance of the membrane, and the treated water quality were improved. Meanwhile, this research enlightens us to pay attention to the overall planning, the maintenance of the pipe network, and the stable investment of funds in the treatment of rural domestic wastewater.
{"title":"Countermeasures for rural domestic wastewater based on ecological environment security: a case study of an MBR-integrated process based on the PVDF@ZrO2 flat membrane, China","authors":"Na Zhong, Fan Kai, Liankui Xu","doi":"10.2166/wpt.2023.027","DOIUrl":"https://doi.org/10.2166/wpt.2023.027","url":null,"abstract":"\u0000 The harmonious coexistence of humans and nature has reached a broad consensus in the world. Maintaining the health of the ecological environment is the foundation of the existence and development of human civilization, and is also the inevitable choice for human beings to deal with the global ecological environment crisis. As an important factor affecting ecological stability, rural domestic wastewater has been neglected and not treated effectively for a long time because of its special geographical location and development limitations. In this paper, an integrated process of an MBR was applied to rural domestic wastewater treatment, inside which the modified PVDF@ZrO2 membrane was used to replace the traditional PVDF membrane. A series of membrane analyses and project follow-ups have proven that the hydrophilicity, anti-fouling performance of the membrane, and the treated water quality were improved. Meanwhile, this research enlightens us to pay attention to the overall planning, the maintenance of the pipe network, and the stable investment of funds in the treatment of rural domestic wastewater.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49334309","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}
Matheus Proença, A. Paschoalini, Daniel H. S. Obata
The water loss rates in Brazil are still very concerning and cause huge financial, social, and environmental damages. Although great advances have been made in acoustic leak detection methods, some of them are intrusive or at least demand convenient access points to the pipe's surface. Furthermore, some methods are expensive and require a highly experienced and qualified operator. Thus, the goal of this paper is to establish a benchmark using a simplistic analytical model for the ground surface analysis for leaks location, simplifying the search process carried out in water networks, and requiring minimal system interference. For leak location prediction, the proposed method considered two seismic wave paths – the compressional body waves and the Rayleigh superficial waves. The traveltime curves of the compressional waves are calculated as a function of the surface wave's experimental information. Monte Carlo Simulations were carried out to test each model's precision considering uncertainties related to the input parameters of the problem. At last, through a parametric study, the two seismic events were combined to obtain better accuracy in predicting the leakage epicenter location. In the results, the maximum absolute error found was 15 cm, and the minimum improvement obtained with the parametric study was 27.4%.
{"title":"Prediction of the probabilistic water leak location in underground pipelines using Monte Carlo simulation","authors":"Matheus Proença, A. Paschoalini, Daniel H. S. Obata","doi":"10.2166/wpt.2023.026","DOIUrl":"https://doi.org/10.2166/wpt.2023.026","url":null,"abstract":"\u0000 The water loss rates in Brazil are still very concerning and cause huge financial, social, and environmental damages. Although great advances have been made in acoustic leak detection methods, some of them are intrusive or at least demand convenient access points to the pipe's surface. Furthermore, some methods are expensive and require a highly experienced and qualified operator. Thus, the goal of this paper is to establish a benchmark using a simplistic analytical model for the ground surface analysis for leaks location, simplifying the search process carried out in water networks, and requiring minimal system interference. For leak location prediction, the proposed method considered two seismic wave paths – the compressional body waves and the Rayleigh superficial waves. The traveltime curves of the compressional waves are calculated as a function of the surface wave's experimental information. Monte Carlo Simulations were carried out to test each model's precision considering uncertainties related to the input parameters of the problem. At last, through a parametric study, the two seismic events were combined to obtain better accuracy in predicting the leakage epicenter location. In the results, the maximum absolute error found was 15 cm, and the minimum improvement obtained with the parametric study was 27.4%.","PeriodicalId":23794,"journal":{"name":"Water Practice and Technology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45805032","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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