Water Science and Engineering - 开云电竞网

Strengthening efficient usage, protection, and restoration of Yangtze River shoreline

Da Chen, Li-jun Hou, Ying-di Liao — 2021-10-15

Da Chen, Li-jun Hou, Ying-di Liao With the steady progress of the Yangtze River Protection Strategy, more and more attention has been paid to the protection and restoration of the Yangtze River shoreline. In the last five years, a large number of unreasonable and illegal uses of shoreline have been halted, and thus the Yangtze River ecosystem has been gradually restored. Both a shoreline protection system and a highly efficient utilization mode are urgently required. In combination with the Yangtze River Protection Law as well as relevant regulations and studies, this article provides a series of suggestions concerning protection, utilization, restoration, and management of the Yangtze River shoreline. Water Science and Engineering. 2021 14(4): 257-259.

Optimal reservoir operation using Nash bargaining solution and evolutionary algorithms

2021-10-15

Salman Sharifazari, Mahmood Sadat-Noori, Habibeh Rahimi, Danial Khojasteh, William Glamore Optimizing reservoir operation is critical to ongoing sustainable water resources management. However, different stakeholders in reservoir management often have different interests and resource competition may provoke conflicts. Resource competition warrants the use of bargaining solution approaches to develop an optimal operational scheme. In this study, the Nash bargaining solution method was used to formulate an objective function for water allocation in a reservoir. Additionally, the genetic and ant colony optimization algorithms were used to achieve optimal solutions of the objective function. The Mahabad Dam in West Azerbaijan, Iran, was used as a case study site due to its complex water allocation requirements for multiple stakeholders, including agricultural, domestic, industrial, and environmental sectors. The relative weights of different sectors in the objective function were determined using a discrete kernel based on the priorities stipulated by the government (the Lake Urmia National Restoration Program). According to the policies for the agricultural sector, water allocation optimization for different sectors was carried out using three scenarios: (1) the current situation, (2) optimization of the cultivation pattern, and (3) changes to the irrigation system. The results showed that the objective function and the Nash bargaining solution method led to a water utility for all stakeholders of 98%. Furthermore, the two optimization algorithms were used to achieve the global optimal solution of the objective function, and reduced the failure of the domestic sector by 10% while meeting the required objective in water-limited periods. As the conflicts among stakeholders may become more common with a changing climate and an increase in water demand, these results have implications for reservoir operation and associated policies. Water Science and Engineering. 2021 14(4): 260-268.

Estimation of aquitard hydraulic conductivity and skeletal specific storage considering non-Darcy flow

Chao Zhuang, Long Yan, Zhi-fang Zhou, Jin-guo Wang, Zhi Dou — 2021-10-04

Chao Zhuang, Long Yan, Zhi-fang Zhou, Jin-guo Wang, Zhi Dou Darcy's law has been widely used to study the groundwater drainage process within an aquitard. However, non-Darcy flow is frequently encountered in laboratory and in situ investigations. With consideration of a sudden drop in boundary hydraulic heads, aquitard compaction characteristics and their sensitivities to the non-Darcy flow control variables were analyzed. The non-Darcy flow was found to retard groundwater drainage, and the retardation effects were much more significant at early-to-intermediate time points. Under this specific boundary condition, the time-compaction curve in a log-log graph at early time points was found to be close to a straight line, whose slope can be used to indirectly evaluate the extent of the non-Darcy effect. A non-Darcy flow-based type curve method was developed for estimating aquitard hydraulic conductivity (K) and skeletal specific storage (S_s), and this method was used to interpret the time-compaction data recorded in a laboratory experiment. The tested aquitard was determined to be associated with non-Darcy flow due to the fact that the time-compaction curve deviated from the Darcy's law-based theoretical curve. Darcy's law resulted in an underestimated K. In contrast, the estimated S_s was almost unaffected by the flow state, if the observation lasted long enough to reach final steady compaction. Water Science and Engineering. 2021 14(4): 269-276.

Satellite altimetry for Indian reservoirs

2021-09-16

Kaushlendra Verma, Akhilesh S. Nair, Indu Jayaluxmi, Subhankar Karmakar, Stephane Calmant Satellite radar altimetry has immense potential for monitoring fresh surface water resources and predicting the intra-seasonal, seasonal, and inter-annual variability of inundated surface water over large river basins. As part of the Preparation for the Surface Water and Ocean Topography mission scheduled for launch in mid-2022, the present study aimed to evaluate the performance of radar altimetry over the inland water bodies of India. The Joint Altimetry Satellite Oceanography Network (Jason) and Satellite with ARgos and ALtiKa (SARAL/AltiKa) data were used to derive the water levels of 18 major reservoirs in India by incorporating the geophysical and propagation corrections into the radar range. In situ gauge data were used to evaluate the performance of the altimetry-derived water level time series from 2008 to 2019. The results showed a strong correlation between Jason-2 and in situ data with the determination coefficient (R²) and root mean squared error (RMSE) ranging from 0.96 to 0.99 and from 0.28 m to 1.62 m, respectively. The Jason-3 data had the highest correlation with the in situ observation (R² = 0.99) and the lowest correlation (R² = 0.82), with RMSE values ranging from 0.11 m to 1.18 m. With an R² range of 0.93-0.99 and an RMSE range of 0.20-1.05 m, the SARAL/AltiKa mission presented greater accuracy than the Jason altimetry mission. The estimated water levels can be utilized in remote, inaccessible, or ungauged areas and in international transboundary rivers for water storage and river discharge estimations. However, the accuracy of remotely sensed data depends on such factors as along-track distance, water body area, and geographical and terrain conditions near water bodies. Water Science and Engineering. 2021 14(4): 277-285.

Removal of copper(II) from aqueous solution using chemically modified fruit peels as efficient low-cost biosorbents

2021-08-24

Pongthipun Phuengphai, Thapanee Singjanusong, Napaporn Kheangkhun, Amnuay Wattanakornsiri Fruit peels, which are common agricultural byproducts, have been extensively used as abandoned or low-cost biosorbents to remove heavy metals. In this study, dragon fruit peel (DFP), rambutan peel (RP), and passion fruit peel (PFP) were used to remove Cu(II) ions from an aqueous solution. Concentrations of the adsorbed metal ions were determined using the atomic absorption spectroscopic method. Adsorption experiments were performed with different adsorbent dosages, pH values, contact times, and initial copper concentrations. The optimum set of conditions for biosorption of Cu(II) ions was found to be an adsorbent dosage of 0.25 g, a contact time of 180 min, an initial concentration of 100 mg/L, a pH value of 4 for RP and PFP, and a pH value of 5 for DFP. The adsorption conformed with the pseudo-second-order kinetic model. The adsorption data were consistent with the Langmuir and Freundlich isotherm models, but the best fit was with the Langmuir model. The Langmuir monolayer adsorption capacity values of DFP, RP, and PFP were calculated to be 92.593, 192.308, and 121.951 mg/g, respectively. RP showed a higher adsorption capacity of Cu(II) ions than PFP and DFP for all parameters. The results indicate that these biosorbents might be used to effectively adsorb Cu(II) ions from wastewater treatment plants. Water Science and Engineering. 2021 14(4): 286-294.

Effect of coagulation treatment on antifouling properties of PVC nanocomposite membrane in a submerged membrane system for water treatment

Habib Etemadi, Hamidreza Qazvini, Elham Shokri — 2021-08-24

Habib Etemadi, Hamidreza Qazvini, Elham Shokri A submerged membrane system was used in this work to investigate the effect of the polyaluminum chloride (PAC) coagulant on the antifouling performance of the polyvinyl chloride/alumina (PVC/Al₂O₃) nanocomposite membrane. The prepared nanocomposite membranes were characterized with field emission scanning electron microscopy (FE-SEM), atomic force microscopy, contact angle, porosity measurement, and pure water flux. The results revealed that the membrane containing Al₂O₃ nanoparticles (the mass ratio of PVC to Al₂O₃ was 98.5/1.5) had a higher hydrophilicity, porosity, and pure water flux than other membranes. The FE-SEM images showed that when Al₂O₃ nanoparticles were present in the PVC membrane, large pores and macrovoids formed on the surface and cross-section of the membrane. The fouling behavior of membranes was investigated through the filtration of humic acid (HA) solution with and without the PAC coagulant. Without PAC addition, the PVC/Al₂O₃ membrane significantly decreased the irreversible fouling ratio from 60.7% to 19.4% and showed a high HA removal efficiency of approximately 90.5%. The Hermia model confirmed that the cake formation mechanism best described the experimental data for the neat PVC and nanocomposite membranes with the presence and absence of the PAC coagulant. This confirms that the PAC coagulant can significantly mitigate fouling and improve HA removal in the submerged membrane system. Water Science and Engineering. 2021 14(4): 295-303.

Utilization of soda residue and ground granulated blast furnace slag to stabilize/solidify sewage sludge in leachate soaking environment

Jun He, Xiao-ying Feng, Li-rong Zhou, Lei Zhang — 2021-08-24

Jun He, Xiao-ying Feng, Li-rong Zhou, Lei Zhang This study investigated sewage sludge stabilized/solidified with soda residue (SR) and ground granulated blast furnace slag (GGBS) after being dewatered with quicklime. The soaking durability test was conducted on the solidified sludge in tap water or landfill leachate. The toxicity and mineralogical characteristics of the solidified sludge were evaluated. The results showed that the unconfined compressive strength (UCS) of the solidified sludge met the strength requirement for use as a temporary cover material (≥50 kPa) for a short time (< 7 d). The solidified sludge had considerable soaking durability because UCS increased with the soaking time. The increase in the GGBS dosage improved the soaking durability of the solidified sludge. The UCS values of sludge solidified with 50% SR and 30% GGBS (sample S5G3) and with 80% SR (sample S8G0) after soaking in leachate for 60 d were 712.9 and 82.6 kPa, respectively. The X-ray diffraction (XRD) analysis indicated that hydration products, such as ettringite, Friedel's salt, gismondine, brushite, and hydrocalumite, contributed to the strength, soaking durability, and leach-ability performance of the solidified sludge. The inhibition of some hydration reactions and precipitation of ettringite and calcite on the surface of the specimens soaked in leachate led to a lower strength than that soaked in tap water. Sample S5G3 has the potential to be used as a filling or construction material, and sample S8G0 is suitable to be used as a temporary cover material in landfill. Water Science and Engineering. 2021 14(4): 304-313.

Groundwater contamination risks with manure-borne microorganisms under different land-application options

2021-11-06

Farhana Haque Ananna, M. G. Mostofa Amin, Deen Islam, Tanvir Ahmed, Md. Ashrafuzzaman, Mohammad Gulzarul Aziz There is a huge potential for recycling animal manure in agricultural farms, but fecal microorganisms from land-applied animal manure can join shallow groundwater through leaching especially in alluvial formations. Thus, this study investigated the leaching rate of total viable count (TVC) below a 1.1-m soil depth in a field lysimeter planted with rice-maize-rice rotation, where the rotation received different treatments, i.e., chemical fertilizer, dry manure, fresh manure, alternate wetting and drying (AWD) irrigation, and traditional irrigation. Leachate samples of six major irrigation/rainfall events were collected and analyzed for TVC concentration. In the Aman rice season, manure application had a significantly higher TVC leaching (5.5×10⁶ colony forming units (CFU) per milliliter) than the no-manure treatment (8.2×10⁴ CFU/mL). In the maize season, manure application increased more than one log-scale of TVC leaching concentration. A higher concentration of TVC leaching (3×10⁵ CFU/mL) was observed even after 93 d of fresh manure application. The fresh manure had a higher TVC load, and it possibly helped microorganisms survive longer by providing a more manure-like environment in the soil. In the Boro rice season, manure application increased the TVC leaching up to 3-4 log-scale compared with the control treatment. The AWD irrigation increased TVC leaching compared with the continuous irrigation because the desiccation fractures developed in the AWD irrigation helped TVC bypass the organic-rich topsoil. The Boro rice fields had higher TVC leaching than the maize fields with higher manure doses. The study suggests that there is scope to improve manure management to protect the groundwater quality. Water Science and Engineering. 2021 14(4): 314-322.

An environmental flow method applied in small and medium-sized mountainous rivers

Xian-run Zhang, Dan-rong Zhang, Yuan Ding — 2021-10-22

Xian-run Zhang, Dan-rong Zhang, Yuan Ding In small and medium-sized mountainous rivers, there are usually hydropower stations in upper reaches as well as widened and heightened river sections in downstream reaches that are close to settlements. The environmental flow (EF) ensures river connectivity and the survival of aquatic organisms. The Tennant and wetted perimeter methods were used to calculate the minimum EF, and the R2CROSS criteria were used to evaluate the rationality of hydraulic parameters. The result shows that downstream areas with large cross-sections may suffer from shallow water depths, insufficient wetted perimeters, and poor overall connectivity of the water bodies, even under the standard EF discharges. A novel method was proposed to ensure EF and sustain suitable hydraulic conditions. The minimum EF calculated by the Tennant method is adopted as the design flow, and a small trapezoidal trough channel is excavated on the wide riverbed of an artificial river section. The width and depth of the small channel are calculated with Manning's equation. As a study case, this method was applied in the Fenglingang River in Zhejiang Province of China. A trapezoidal groove with a depth of 0.74 m and a bottom width of 0.52 m was excavated in the center of Fenglingang River to sustain EF and maintain river connectivity. This small channel not only prevents the river from cutoff, but also enables the water depth and wetted perimeter to meet the demand of aquatic organisms. Water Science and Engineering. 2021 14(4): 323-329.

A factor mining model with optimized random forest for concrete dam deformation monitoring

Hao Gu, Meng Yang, Chong-shi Gu, Xiao-fei Huang — 2021-10-30

Hao Gu, Meng Yang, Chong-shi Gu, Xiao-fei Huang The unique structure of a dam complicates safety monitoring. Deformation can provide important information about dam evolution. In contrast to model prediction, actual dam response monitoring data can be used for diagnosis and early warning. Given the poor data mining ability of the conventional methods, it is essential to develop a method for extracting the factors influencing a dam. In this study, a data mining method and a model for evaluation of concrete dam deformation were developed using the evidence theory and a random forest. The model has the advantages of being easily understood, visualization with low complexity of training time, and accurate prediction. The model was applied to an actual concrete dam. The results indicated that the proposed random forest model could be used in analysis of concrete dams. Water Science and Engineering. 2021 14(4): 330-336.

Energy and momentum correction coefficients within contraction zone in open-channel combining flows

Jie Zhou, Cheng Zeng, Zhou Zhou, Ling-ling Wang, Yu-ran Yin — 2021-09-16

Jie Zhou, Cheng Zeng, Zhou Zhou, Ling-ling Wang, Yu-ran Yin Flow dynamics associated with open-channel confluences are highly three-dimensional (3D) with significant velocity gradients in the contraction zone downstream of junctions. The main objective of the present study was to investigate the impact of discharge ratio and junction angle on the non-uniformity of the velocity distribution within the contraction zone. A one-dimensional (1D) theoretical model and a 3D numerical model were developed to establish the relationships of the maximum values of energy and momentum correction coefficients (α_m and β_m) with discharge ratio (q) and junction angle (θ). The expressions of α_m and β_m were determined in terms of q and cosθ with the 1D theoretical model, and the constants were determined through regression analysis with the computed results from the 3D numerical model. The expressions show that α_m and β_m increased with an increase in junction angle or a decrease in discharge ratio due to the improved three-dimensionality of the flow structure. The expressions of α_m and β_m determined from the present study are consistent with the existing findings with θ = 90°. Water Science and Engineering. 2021 14(4): 337-344.