Water Flow Research Articles

Microplastics and dye removal from textile wastewater using MIL-53 (Fe) metal-organic framework-based ultrafiltration membranes

Microplastics (MPs) and other organic matters in textile wastewater have posed a formidable challenge for treatment processes, particularly in the primary stages such as ultrafiltration (UF). UF plays a crucial role in preventing the entry of pollutants into subsequent treatment steps. However, the performance efficiency of UF membranes is compromised by the potential fouling of membrane pores by MPs, dyes and other organic pollutants such as bovine serum albumin (BSA). This study focuses on enhancing UF membrane performance, specifically its antifouling properties, through the development of high-performance membranes using MIL-53(Fe) metal-organic framework (MOF) particles (noted as MIL-53 here). Various concentrations of the MIL-53 (0.05, 0.1, 0.2, and 0.5 wt%) were integrated into the membrane structure through phase inversion process. Streaming zeta potential results confirmed the negatively charged surface of the membranes and their high hydrophilicity was validated through contact angle analysis. FTIR, SEM, EDS, and XRD confirmed the presence of MIL-53 particles on the surface of membranes. The developed membranes were tested for 24 h to assess their antifouling properties, with a subsequent 30-min hydraulic flush to measure their flux recovery ratios. Methylene Blue (MB) dye was used as a cationic dye present in textile wastewater to evaluate the efficiency of the developed membranes in dye removal and the synergistic effects of dye rejection in the presence of organic matters (i.e., MPs and BSA). Since previous studies have not fully addressed the combination of dyes and organic matter, this study thoroughly investigated the effect of particle-type foulants (MPs) and their interactions with dye (MB), as well as water soluble protein-type foulants (BSA) and their interaction with MB. The results indicated that the developed membranes exhibited higher MB rejection when the dye was present with either MP or BSA, along with improved antifouling properties. The optimised UF membrane integrated with 0.1 wt% MIL-53 demonstrated nearly 96% BSA rejection and around 86% MB rejection in the mixed foulant case (BSA-MB). The modified membrane exhibited a substantial increase in water flux from 176 L m−2.h−1 to 327 L m−2.h−1. The findings of this research show the potential of iron-based MOFs in improving the performance of UF membranes and provide a platform for future studies on significant areas such as long-term stability studies and testing with other pollutants found in textile wastewater.

Impacts of forest canopy heterogeneity on plot-scale hydrometeorological variables - Insights from an experiment in the humid boreal forest with the Canadian Land Surface Scheme

High latitude regions, including the circumpolar boreal biome, are experiencing important changes in the availability of usable surface water because of climate change. In this context, an adequate representation of the land-atmosphere interaction is critical to ensure optimal management of current and future water resources, forest management, and climate prediction. However, the task is particularly intricate in high-latitude boreal forest, as land surface model faces several challenges due to the unique environmental conditions and ecological characteristics. The objective of this study is to quantify the impact of forest landscape heterogeneity, specifically stand leaf-area index (LAI), soil texture, and drainage regime, on surface water and energy balance in a small boreal high-latitude sub-catchment. To this end, hydrometeorological conditions at seventeen 20×20 m plots in a 1-km2 boreal forest sub-basin are simulated using the Canadian Land Surface Scheme (CLASS), a land surface model, at the point scale. The subplot-scale soil texture, drainage regime, and vegetation characteristics and type are based as closely as possible on field measurements and observations for the 17 plots. The model-driven experiment comprises two sets of simulations using CLASS, each employing the same model setup and run for the 17 experimental plots. The main set employs meteorological forcing from a local micrometeorological tower within the sub-basin to investigate the plot-to-plot variability of albedo, energy fluxes, and soil state variables. A second set of simulations is conducted using meteorological forcing from the ERA5-Land reanalysis, which spans from 1986 to 2022. This data provides a longer time series, enabling a more accurate representation of the interannual climatic variability in the sub-basin. The results of the main and secondary sets of CLASS simulations are used to assess the plot-to-plot and temporal variability of several key hydrometeorological variables by calculating a monthly spread. In brief, the following conclusions and broader implications can be drawn from the findings: i) The simulated total annual evapotranspiration remains relatively uniform between plots despite notable variation in its partitioning from plot to plot. ii) In the presence of a full snowpack, the albedo exhibits substantial heterogeneity at the subplot scale, linked to the canopy's LAI. iii) Local soil properties, drainage regime, and vegetation structure and type exhibit substantial influence on the plot-to-plot variability in soil water content. iv) When parameterized with localized observations and measurements, CLASS can represent and be responsive to the complex dynamics of energy and water fluxes at the plot scale within the heterogeneous surface of boreal forests.

A synergetic self-sealing model for cement-based composite using granular expansive agent and crystalline admixture

The autogenous self-sealing model has been researched in previous work, which could help to characterize the self-sealing process with crystalline products. The model outcome was presented in the form of leakage water flow, which demonstrates the self-sealing capacity or the recovery of watertightness. While in the research area of cement-based material self-sealing, the expansive agent cannot be neglectable, for example the superabsorbent polymer (SAP). Especially for the building components exposed to free water, an efficient water flow blockage after cracking is crucial to ensure stable service. Hence in this study, the self-sealing process of a granular expansive agent inside the crack of cement-based material was simulated. The model outputs were compared with experimental results to verify the reliability. Additionally, the autogenous self-sealing model was incorporated into this model to simulate the “crystallization-expansion” synergetic self-sealing. The contribution of crystalline product and expanded EA to water flow blockage were compared during the crystallizing process. Overall, this model is of great use to evaluate the role of expansive agent on water flow blockage after the cement-based material cracking in hydraulic engineering or engineering components exposed to water.

Data-based models to investigate protective piles effects on the scour depth about oblong-shaped bridge pier

The primary objective of this study is to examine the suitability of employing a machine learning models (MLMs) comprising Support Vector Machine (SVM), Gene Expression Programming (GEP), and Artificial Neural Network (ANN) algorithms to emulate the influence of geometric and geotechnical parameters of the piles on the scour depth reduction about the oblong-shaped bridge pier. A dataset consisting of 90 laboratory observations was utilized, allocating 70 % of the data for the training and 30 % for the testing the MLMs. An oblong-shaped bridge pier of diameter D, was positioned and subjected to a rectangular flume featuring an erodible bed comprising sand sediment particles of D50 = 1.7 mm under clear water and subcritical flow conditions. The spacing between the piles, LD, the angle of pile orientation with respect to the flow, θ, and the Froude number, Fr, were identified as independent parameters through the dimensional analysis and Buckingham-Π theory. The MLMs’ performance were assessed employing root mean square error (RMSE), mean absolute error (MAE), coefficient of determination (R2), and developed discrepancy ratio (DDR). The outcomes, affirming the predictive capacity of all MLMs included, revealed that the GEP model employing a three-gene configuration exhibited superior accuracy compared to the other two MLMs. Specifically, the performance indicators (RMSE, MAE, R2, DDR) during the training and testing phases were (0.0433, 0.033, 0.981, 6.8) and (0.054, 0.045, 0.958, 4.81) respectively. The sensitivity analysis elucidated the hierarchy of influential variables as follows: Fr, LD and θ.

Implications of landscape changes for ecosystem services and biodiversity: A national assessment in Ecuador

Ecuadorian ecosystems experience high pressure due to anthropogenic activities and climate change. Despite the need of regular monitoring of biodiversity and ecosystem services (BES), attempts to assess the current and future interdependencies of BES and landscape changes are still lacking. This study suggests a spatial assessment of the capacity of ecosystems/land use types to provide BES as status quo and its future development under scenarios of deforestation and climate change. To address data scarcity and improve legitimacy, spatial modeling was combined with participatory approaches. Specifically, changes in landscape pattern were simulated using a modeling platform that combines Geographic Information System (GIS) and Cellular Automaton (CA) modules. Experts in ecosystem conservation and management participated through surveys and workshops. Food, drinking water, service water, soil erosion control, water flow regulation, pollination/seed dispersal, regulation of macro climate, and landscape aesthetic/amenity were identified as the most relevant ES. Among the forest ecosystems, Páramo-related ecosystems were regarded to provide multiple ES with high capacities. Compared to the current status, the deforestation scenario showed to decrease most BES by 20–25 %, while increasing food provision by 5 %, as a trade-off. Regarding the climate change scenarios, the “Representative Concentration Pathways” (RCP) by 2070 were simulated with an increase in temperature of 2 °C (RCP 2.6) and of 4 °C (RCP 6.0). RCP 6.0 showed more noticeable impact than RCP 2.6, which caused a decrease in most BES whereas an increase in food provision due to the possible expansion of arable land into higher altitudes. The results of the spatial assessment also indicated high and low potential areas for BES provision. Such information can support decision-making for BES management e.g., priority areas for actions. Furthermore, the applied spatially explicit assessment could be a starting point for a regular assessment of BES, which has not yet been implemented in Ecuador.

Environment DNA Reveals Fish Diversity in a Canyon River within the Upper Pearl River Drainage.

Investigating fish diversity in canyon rivers through conventional fish surveys is challenging due to precipitous conditions, including steep slopes, rapid water flow, and complex habitats. Additionally, intensive construction of dams has further complicated the understanding of contemporary fish diversity in these rivers. In this study, we used the environmental DNA (eDNA) technique to assess fish diversity and examine the effects of dams on fish diversity in the Mabiehe River, a canyon river in the upper reaches of the Pearl River drainage. Water samples from 15 sampling sites were collected, yielding 9,356,148 valid sequences. Utilizing the NCBI public database, a total of 60 freshwater fish species were identified, with Carassius auratus, Cyprinus carpio, and Pelteobagrus fulvidraco being the most dominant species in the Mabiehe River. We also detected one nationally protected fish species, three provincially protected fish species, and six exotic species in this river. Furthermore, eDNA analyses demonstrated that the lotic river sections harbor more species and greater diversity than dammed sections, suggesting that dams might exert significant impacts on local fish diversity. Overall, this study supports the effectiveness of the eDNA technique as a complementary tool to traditional field surveys for monitoring fish biodiversity in canyon rivers.

Revealing the mechanisms of water permeability enhancement of urban loess subgrades due to vibration application

Urban loess subgrades are affected by considerable vibrations from traffic, especially when the underground pipelines leak, and seepage under vibrations often causes road damage. However, the influence of vibrations on the water permeability of loess subgrades remains elusive. Here we address this issue by performing vibration-assisted permeability tests and scanning electron microscopy, mercury intrusion porosimetry, and suction–nuclear magnetic resonance measurements. This allowed the evolution of the saturated hydraulic conductivity (Ks), water-air migration, soil microstructure, and pore water forms to be evaluated. The water permeability of the loess subgrade is promoted by vibrations due to the increase in Ks, the acceleration of wet front migration, and the escape of entrapped air. Moreover, the value of Ks under vibration is 3–14 times greater than that without vibration, and the maximum increase occurs at a vibration frequency near the natural frequency of the loess. Furthermore, a theoretical framework of loess vibration permeability is proposed, and the mechanisms by which vibration accelerates the permeability behavior of the loess subgrade are revealed. Vibration promotes the expansion of soil pores, a decrease in the binding capacity of pore water, the mobilization of fine particles, and the formation of local low-permeability layer. Moreover, it accelerates the opening of entrapped air bubbles and the displacement of water-air, the reduction in seepage resistance. Thus, seepage water flows rapidly along infiltration channels. These findings are highly important for the road safety performance and the sustainable development of the traffic environment in loess regions.

Carbon dioxide stripping from acidic wastewater through a vortex venturi tubular microbubble generator

Microbubble generation technology can improve CO2 stripping efficiency while consuming less sweeping gas. In this paper, a vortex venturi tubular microbubble generator is developed based on the concept of “Initial bubble generation with a thin plate type static mixing element” and “Bubble collapse with a venturi channel”. Microbubble characteristics were tested, followed by post-processing of the focused beam reflectance measurement (FBRM) to obtain a multidimensional dataset. The test results indicated that the microbubble quality generated by the vortex venturi tubular microbubble generator was higher than that of the SV-type static mixer. When the gas-liquid volume ratio was 1, the average bubble diameter was 107.05 μm, and microbubbles accounted for 93.29 %. The average bubble diameter of the SV-type static mixer was 473.55 μm, and the proportion of microbubbles was 23.81 % under identical conditions. Furthermore, the CO2 removal efficiency and pH enhancement rate were greatly affected by the gas-liquid volume ratio and the inlet water flow rate, and both fitted an exponential equation correlation. Accordingly, when the gas-liquid volume ratio increased, the quantity of bubbles generated significantly influenced the CO2 stripping efficiency. The stripping efficiency based on the tubular microbubble generator is significantly higher than that of the SV-type static mixer. When the gas-liquid volume ratio was 1, the CO2 removal efficiency was equivalent to that of the SV-type static mixer at a gas-liquid volume ratio of 3.5. When achieving equal CO2 removal efficiency, the gaseous nitrogen consumption of the tubular microbubble generator was 48.61 %-63.30 % lower than that of the SV-type static mixer, and the corresponding energy consumption of the gas compressor was reduced by 38.24 %-55.83 %. The CO2 stripping process based on the vortex venturi tubular microbubble generator offers an environmentally and economically viable treatment option for acid wastewater.

Experimental study of dam-break-like tsunami loads on vertical structures with overhanging horizontal slabs: Slab with air chamber

Tsunamis pose a significant threat to coastal engineering. A comprehensive physical experiment was conducted to examine the effect of air chambers on vertical structures with overhanging horizontal slabs under tsunami bores. This paper, serving as the second part of the series, contrasts with conditions without air chambers (flat slab as Part I) to underscore the chamber's effects. The experiment employed dam-break waves to simulate tsunamis, and the collected pressure data and experimental images were analyzed. Results show that the chambers restrict water flow, thereby enhancing the impact on the slab. This focusing effect greatly increases both maximum uplift and horizontal pressure (by almost 1.3 times). The uplift pressure rises with increasing chamber volume, while horizontal pressure escalates with greater beam volume. However, both pressures diminish as slab height increases. Water flowing into the chambers disperses air, generating numerous bubbles that accumulate above, forming an air layer that reduces pressure signal fluctuations. This phenomenon of entrained and trapped air is compared and analyzed with existing literature. The maximum pressure of the nearshore air chamber is greater than that of the offshore air chamber by 13% (3.68 kPa vs. 3.27 kPa), while the quasi-steady pressures of the two are almost equal. Differences in pressure between chambers result from the sequence of water flow impacts and reflections. New design envelope equations and conversion coefficients are proposed based on experimental data. The focusing coefficient, considering bore height, slab height, and chamber parameters, is summarized. Novel equations for estimating pressure on a flat slab with specific chambers are proposed, with validation results indicating high accuracy.

A comparative study on UASB MF-OMBR and AnMF-OMBR treating slaughterhouse wastewater: Process performance, struvite precipitation, and economic evaluation

Up-flow anaerobic sludge blanket microfiltration osmotic membrane bioreactor (UASB MF-OMBR) is a cutting-edge technology derived from the anaerobic osmotic membrane bioreactor (AnOMBR). This study investigated long-term performance of an UASB MF-OMBR and an anaerobic microfiltration osmotic membrane bioreactor (AnMF-OMBR) comparatively focusing on process performance, membrane fouling, microbial community shift, struvite precipitation, and economic evaluation for the treatment of synthetic and real slaughterhouse wastewater (SSW and RSW). The UASB MF-OMBR achieved higher process performance regarding chemical oxygen demand (COD) removal (70 ± 1 %), methane yield (0.24 ± 0.03 L CH4 g−1 CODremoved) and NH4+-N rejection (85 ± 3 %). On the other hand, high COD and PO43−-P rejections were observed in both systems (>92 % and ∼98 %, respectively). The impact of the salinity build-up in the UASB MF-OMBR was the lower due to the bioreactor configuration. In addition, compared to the AnMF-OMBR, the better water fluxes were obtained in the UASB MF-OMBR, which can be attributed to the less membrane fouling. The results of precipitation modelling and Mg2+ measurement in the sludge of both bioreactors demonstrated that the struvite precipitation occurred during the forward osmosis (FO) operation was more often and in higher amounts in the AnMF-OMBR. The economic evaluation indicated that the specific produced permeate cost (SPC) with revenue was slightly lower for the UASB MF-OMBR than that of the AnMF-OMBR.

Effects of baffles and springs in shell and multi-tube heat exchangers: Comparative approach

Shell and multi-tube heat exchangers (SMTHX) are widely used in various industries such as power generation, chemical processing, and refrigeration due to their high efficiency and flexibility. Improving heat transfer within an SMTHX is critical for enhancing overall performance and efficiency. This study investigates the comparative effectiveness of using baffles versus spring wires to enhance heat transfer in SMTHXs. Both experimental and numerical analyses were conducted over a Reynolds number range of 8500–12500, focusing on key parameters such as the Nusselt number, pressure drop, and exergy efficiency. The experiments were performed with a variable cold water flow rate on the shell side and a constant flow rate on the tube side. The numerical model was validated against experimental results. The findings reveal that the Nusselt number increases to 62 with baffles and to 65.5 with spring inserts, representing improvements of 1.54 and 1.61 times, respectively, compared to a plain tube under identical conditions. While the pressure drop for baffles is significantly higher than for spring inserts, the springs show a pressure drop that is 87 % of that observed with baffles. Additionally, exergy efficiency is superior with spring inserts. These results demonstrate that spring inserts are more effective than segmental baffles in enhancing heat transfer in SMTHXs. The study provides valuable insights into the mechanisms of heat and fluid flow, supported by visualizations of velocity, temperature, and pressure contours and streamlines.

Climate change does not impact the water flow of barley at the vegetative stage, ameliorates at anthesis and worsens after subsequent drought episodes

Climate change will bring the interaction of stresses such as increased temperature and drought under high [CO2] conditions. This is likely to impact on crop growth and productivity. This study aimed to (i) determine the response of barley water relations to vegetative and anthesis drought periods under triple interaction conditions, (ii) test the possibility to prime barley plants for drought, and (iii) analyse the involvement of aquaporins in (i) and (ii). The water status of barley was not affected by drought at the vegetative stage, regardless of the environmental conditions. At the anthesis stage, when the water shortage period was more severe, barley plants growing under combined elevated CO2 and temperature conditions were able to maintain a better water status compared with plants grown under current conditions. Elevated CO2 and temperature conditions reduced the stomatal conductance and slowed down the plant water flow through a root-leaf hydraulic conductivity coordination. Leaf HvPIP2;1 and HvTIP1;1 aquaporins seemed to play a key role regulating barley's water flow, while leaf and root HvPIP2;5 provided basic level of water flow. At anthesis drought and under future combined conditions, plants showed a reduced cell dehydration and decrease in leaf relative water content compared with plants grown under current conditions. Exposure to a previous drought did not prime the water status of barley plants to a subsequent drought, but instead worsened the response under future conditions. This was due to an imbalance between the roots versus shoot development.

H2O2 oxidation – CaO precipitation pretreatment combining forward osmosis for electroless nickel spent tank liquid (ENSTL) reduction

ABSTRACT The electroless nickel spent tank liquid (ENSTL), as a typical hazardous waste, contains a variety of refractory organic substances as well as heavy metals and inorganic salts. Generally, ENSTL is delegated for disposing by qualified hazardous waste disposal departments in China. However, the temporary storage, transportation, and higher entrusted disposal expenses increase the burden on enterprises producing the hazardous ENSTL. This paper explored an oxidation/precipitation pretreatment and forward osmosis (FO) combined process for ENSTL reduction. 400 mmol/L Hydrogen peroxide and 5.0 wt% calcium oxide were selected as the optimal pretreatment in order to minimize the osmotic pressure of ENSTL, by which the conductivity was significantly reduced from 50.8 mS/cm to 26.8 mS/cm. As a result, the concentrating factor (N) could be dramatically increased from 2.45 by the direct FO to 8.71 by the combined system. Accordingly, the average water flux during the 24 h concentrating cycle increased from 2.47 L/(m2·h) to 4.56 L/(m2·h). TOC rejection rate decreased from 90.23% to 84.39% due to the transformation of organic matter forms by the chemical oxidation during the pretreatment. Meanwhile, TP, Ni and NH4 + rejection rates decreased to a certain extent, which may related to the mitigation of membrane fouling by the pretreatment.

Hydrology controls sulfuric acid-mediated weathering in an orogenic regime of southwestern Taiwan

Chemical weathering is a pivotal geochemical process that shapes the carbon cycling and climates in the critical zone. Among its critical drivers, river discharge holds a particular significance, especially in the orogenic landscapes. Here, we examined the impact of discharge on mineral weathering in southwestern (SW) Taiwan by analyzing river water chemistry across a wide discharge range. Current observations indicated that carbonate contributes significantly to total weathering (50–80 %), with sulfuric acid accounting for one-half to two-thirds of carbonate weathering. A statistically strong correlation between river discharge and sulfuric acid-mediated carbonate weathering was highlighted, while the silicate weathering remained constant. This relationship suggests an increased influx of fresh minerals, such as pyrite, into the weathering regime as water flow increases. Our model identifies a critical discharge threshold of 4.6 m3 s−1, determining whether mineral weathering acts as a net source or sink of CO2. Consequently, mineral weathering in SW Taiwan acts as a net CO2 sink during dry periods but turns into a net source during wet periods. Through analyzing a decade of daily discharge data, we found mineral weathering in SW Taiwan is a net CO2 source, with a 2.6-fold increase in annual mean discharge causing a 3.8-fold increase in net CO2 flux. This pattern is likely to be applicable to other similar minerals containing mountain-building regions, highlighting the significant role of hydrology in determining weathering sources and their potential impact on the carbon cycle balance.

Trajectory tracking control of vectored thruster autonomous underwater vehicles based on deep reinforcement learning

ABSTRACT Vectored thruster autonomous underwater vehicles (AUVs) offer superior manoeuvrability compared to traditional fin and rudder systems, especially at low or zero velocities. However, controlling these AUVs becomes challenging in the presence of unpredictable interference forces and external water flow velocities. This paper introduces a novel three-dimensional trajectory tracking method for vectored thruster AUVs using reinforcement learning, enabling the system to learn optimal control policies through environmental interaction. A 5-degree of freedom (5-DOF) model is developed from the kinematics and dynamics equations of the underactuated AUV. An extended state observer (ESO) is used to estimate the differential expansion state based on observed variables. A reinforcement learning-based trajectory tracking strategy is then implemented. Simulation experiments demonstrate the method’s effectiveness in precisely controlling AUVs under varying environmental conditions, achieving exceptional tracking accuracy even in the presence of random interference forces and external water flow velocities.

Simulating droplet distribution characteristics in sprinkler irrigation using a modified ballistic model under multifactor coupling

External factors affecting the processes of sprinkler irrigation water flow generation, flight, and landing have not been thoroughly considered in existing ballistic models. This result indicates that ballistic models with better prediction effects under specific conditions are not sufficient for extension to multi-factor coupled scenarios in large-scale farmlands. Therefore, wind, evaporation, surface slope, and tilted sprinkler riser factors were comprehensively considered in this study. Differential equations for jet and droplet motion under the influence of wind, differential equations of droplet evaporation, sprinkler riser deflection angle matrix, and surface slope angle matrix were constructed to establish a droplet distribution model for sprinkler irrigation considering multifactor coupling using MATLAB 2018a software. The results showed that, under different working conditions, the data points of the droplet landing diameter, velocity, and angle were distributed near the 1:1 line. The Nash efficiency coefficients (NSE) for the droplet landing diameter, velocity, and angle varied from 0.821 to 0.932, 0.616 to 0.931, and 0.770 to 0.911, respectively. The increase in slope resulted in droplets with diameters larger than 4.63 mm concentrating on the land in the reverse slope direction. When the ambient temperature increases from 10 to 45 °C and the total evaporation rate increases from 0.45 to 4.37 %, the larger droplets have a larger area of contact with the air, and the higher the temperature, the greater the energy loss to the larger droplet diameters. The higher the wind speed, the more droplets in the downwind direction fall to the ground at a smaller landing angle, which can easily increase the risk of soil shear damage. If the sprinkler riser was tilted east, the droplets on both the east and west sides tended to be distributed centrally; the maximum droplet landing velocity occurred on the east side (tilted side), and the maximum droplet landing angle occurred on the west side. This study considers various factors that may affect the motion of sprinkler irrigation water flow, extends the application scenarios of the theoretical model, and improves the applicability of the theoretical model for sprinkler irrigation droplet motion in more complex and practical agricultural environments.

Laboratory evaluation of wicking geotextile for moisture reduction in silty sands at different fines contents

The effect of fines content on the performance of the wicking geotextile is not clear. This study developed a simple moisture reduction test method to quantify the effectiveness of the wicking geotextile in reducing moisture in silty sands at four different fines contents and four different waiting periods. The sand was prepared at an initial moist condition based on its average field moisture capacity. A wicking or non-wicking woven geotextile was placed in the middle of a soil column. The effect of a geotextile on the moisture content of the sand was evaluated by measuring their gravimetric moisture contents at different distances from the geotextile at different times. Test results show that the amount of moisture reduced by the wicking geotextile decreased with the content of fines in the silty sand. On the contrary, the non-wicking geotextile obstructed water flow, hence moisture accumulated on it. The moisture content profile in the soil column indicated the influence zone by the wicking geotextile in the silty sand, which depended on the fines content. The percent of soil moisture content reduction by the wicking geotextile identified the limit of the fines content for the effectiveness of the wicking geotextile.

Incorporation of zeolitic imidazolate framework-8 (ZIF-8) in the polyamide and polysulfone layers of forward osmosis membranes for enhancing aquaculture wastewater recovery and PPCPs removal

Wastewater recovery is essential to alleviate water resource shortages, and this can be achieved through a high-energy-efficient forward osmosis (FO) process combined with an emerging material, zeolitic imidazolate framework-8 (ZIF-8). Here, we create thin-film composite FO membranes (TF-CFOMs) by incorporating ZIF-8 into the active polyamide (PA) and/or support polysulfone (PSf) layers to address the challenges of low water flux and loss of draw solutes during operation. Experimental factors included the dosage of ZIF-8 nanoparticles in PA preparation solutions and the dosages of 2-methylimidazole (2-Hmim) and zinc nitrate hexahydrate (ZNH) in n-methyl-2-pyrrolidone (NMP) to fabricate the PSf casting solutions with in-situ formed ZIF-8 nanoparticles. Successful ZIF-8 incorporation on the TF-CFOM surface was confirmed, and the ZIF-8 TF-CFOMs exhibited increased surface hydrophilicity and separation performance. Only modifying the PA layer by adding 0.025 wt% ZIF-8 nanoparticles in trimesoyl chloride (TMC) resulted in the membrane (PA0.025T-PSf0) with water flux 2.3 times higher than the pristine TF-CFOM (4.9 LMH). The pristine and modified TF-CFOMs were further applied for aquaculture wastewater (AWW) recovery and removal of pharmaceuticals and personal care products (PPCPs). Results of water recovery demonstrated that the recovery rate reached 89.1% in 3.5 days when using the dual-layer modified TF-CFOM. Results of PPCP removal indicated that both pristine and modified TF-CFOMs can achieve high PPCP rejection efficiency (>90%), with the modified TF-CFOM (PA0.025T-PSf2.0) performing the best. Overall, the PA0.025T-PSf2.0 TF-CFOM achieved high and stable separation efficiency in long-duration AWW recovery, making it well-suited for practical field applications.

Spatial Predictive Modeling of Liver Fluke Opisthorchis viverrine (OV) Infection under the Mathematical Models in Hexagonal Symmetrical Shapes Using Machine Learning-Based Forest Classification Regression

Infection with liver flukes (Opisthorchis viverrini) is partly due to their ability to thrive in habitats in sub-basin areas, causing the intermediate host to remain in the watershed system throughout the year. Spatial modeling is used to predict water source infections, which involves designing appropriate area units with hexagonal grids. This allows for the creation of a set of independent variables, which are then covered using machine learning techniques such as forest-based classification regression methods. The independent variable set was obtained from the local public health agency and used to establish a relationship with a mathematical model. The ordinary least (OLS) model approach was used to screen the variables, and the most consistent set was selected to create a new set of variables using the principal of component analysis (PCA) method. The results showed that the forest classification and regression (FCR) model was able to accurately predict the infection rates, with the PCA factor yielding a reliability value of 0.915. This was followed by values of 0.794, 0.741, and 0.632, respectively. This article provides detailed information on the factors related to water body infection, including the length and density of water flow lines in hexagonal form, and traces the depth of each process.

Evaluation of productivity and efficiency of a large-scale coupled or decoupled aquaponic system

Aquaponics, a sustainable agricultural method, is gaining attention for its closed-loop system's potential to address diverse environmental and economic challenges in traditional agriculture. The aim of this study was to fill knowledge gaps in scaling up lab-scale systems to larger-scale decoupled aquaponics, offering a comprehensive understanding of the system's productivity and water and fertiliser use efficiency. In coupled aquaponics (CAP), the aquaculture, and the hydroponic units are arranged in a single loop, and water flows continuously from the fish tanks to the plant unit and vice-versa. In decoupled aquaponics (DCAP), the aquaculture and hydroponics units are arranged in a multi-loop setup as separate functional units that can be controlled independently. This work compared coupled aquaponics, decoupled aquaponics and hydroponics (HP, in perlite slabs) under the same climatic conditions with a substrate grown crop in a pilot scale greenhouse. The evaluation of growth parameters, yield, water, and fertiliser use for basil, cucumber, parsley, and tomato cultivations co-cultivated with the tilapia recirculating aquaculture system (RAS) are presented. The highest yields were achieved by DCAP plants in all experiments (15% higher than HP and 19% than CAP for basil, 38% than CAP in cucumber, 17% and 72% than HP and CAP in parsley, and 8% and 55% for HP and CAP in tomato experiments). The CAP treatment that did not receive any fertilisers presented the highest water use efficiency compared to both HP and DCAP treatments. Also, compared to HP, the DCAP treatment presented higher water and fertilisers use efficiency. Consequently, the adoption of decoupled aquaponic systems is the key to aquaponic evolution in the future.