Applied Water Science最新文献

Soil moisture movement reveals the hydrological environment and irrigation characteristics of plants, which is very important and basic hydrological problem. A soil moisture movement algorithm based on cellular automata suitable for greenhouse was proposed to simulate the lateral flow and vertical penetration of soil water in different soil layers. Artemisia annua was used as an experimental plant, and two numerical simulations were set up to determine the minimum water replenishment and the degree of upward soil modification. To verify the performance of the model, corn was used as an experimental plant for application simulation. The numerical simulation results show that the effect of only water for plant cells is superior to soil cells, and the disturbance behavior of the underlying soil layer should be minimized during the cultivation process. The average MAE/RMSE of all soil layers is 0.86/1.06 and in deep layer (50 cm and 60 cm) is 0.53/0.64. It shows the model has a certain prediction and simulation ability, especially in deep soil layers. The proposed algorithm can simply calculate soil flow, set the minimum water replenishment, and evaluate the water replenishment efficiency, which can provide a theoretical reference for the water replenishment and soil replacement scheme.

Herein, a 3D sponge-like polypyrrole/TiO₂ (Ppy-TiO₂) composite aerogel was developed for the first time to remove hydroxybenzotriazole (HOBt) from water. Mesoporous TiO₂ was prepared via a sol–gel method, and then the Ppy-TiO₂ composite hydrogel was prepared by oxidative polymerization and converted to aerogel by freeze-drying. The morphological, compositional, and surface characteristics of the prepared materials were detailly characterized. The characterization studies revealed that pure anatase mesoporous TiO₂ nanoparticles were successfully prepared and incorporated into amorphous 3D Ppy with a porous chain-like network structure. Coupling Ppy and TiO₂ extended the light absorption to the visible region and decreased the electron/hole recombination rate. The performance studies revealed that the Ppy-TiO₂ composite has higher adsorption and photocatalytic activities than the sum of the individual components. Optimum performance was obtained at pH 5.3 using 0.25 g/L of the Ppy-TiO₂ composite with a Ppy: TiO₂ mass ratio of 1:1. The intermolecular hydrogen bonding was pivotal in the adsorption process which was multilayer. The degradation of HOBt occurs primarily by holes, then superoxide anion radicals. The total organic carbon (TOC) analysis showed a 90% reduction in carbon content after 30 min of treatment. The toxicity study indicated that the photocatalytic process decreased the toxicity of the HOBt solution. The synergism between adsorption and photocatalysis, easy separation, and reusability promote the application of Ppy-TiO₂ composite aerogel for water treatment.

Biographene was prepared through the pyrolysis of Acacia nilotica waste using diverse temperatures and time spans. The obtained materials were characterized using scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDX), X-ray diffraction analysis (XRD), and Fourier transform infrared spectroscopy (FTIR) methods. The data obtained indicated that when the temperature and time increased, the texture of the biographene became more porous with greater carbon content. The effect of various variables on Cd(II) adsorption, using the optimized biographene product, was investigated, and the results revealed that the optimum pH was 4 and the maximum adsorption capacity was 118.9 mg/g. The Langmuir isotherm model and pseudo-second-order kinetic model best fit the equilibrium data, indicating the adsorptive behavior of the as-prepared biographene implying a homogenous monolayer surface. The recyclability investigation elucidates the remarkable potentiality of up to five consecutive cycles. As such, the biographene-based Acacia nilotica could be considered a sustainable candidate for cadmium removal from polluted water.

Runoff from glaciated catchments is an integrated process that includes glacier melt, snowmelt, rainfall and surface and subsurface runoff of meltwater from glacierized and non-glacierized areas. Monitoring and quantifying the contribution of the hydrologic components (snow, ice and rain) to river discharge in the Himalayan basins is essential for decision-making in the water sector, particularly in water resources management and flood risk reduction in the region. An attempt has been made to characterize and hydrologically model streamflow (Bhagirathi River) for the Gangotri Glacier (Central Himalaya, India). A semi-distributed conceptual hydrological model is used for the streamflow modelling and assessing the major streamflow components (snow melt, glacier melt and rainfall runoff). Initially, the model was calibrated using the available in situ hydro-meteorological records for the ablation seasons of 2013–14 to 2015–16 (3 years), and further validated for the ablation seasons of 2016–17 to 2018–19 (3 years). The model performed well for all the studied years except for some months, where abrupt changes in the contrasting weather parameters (precipitation and temperature) were recorded. In the Gangotri Glacier Valley (upper Bhagirathi River catchment), snowmelt contributed the largest portion (55.5%) to total streamflow followed by glacier melt (29.7%) and rainfall runoff components (14.7%).

This comprehensive study explored the removal of methylene blue (MB) from aqueous solutions as a model pollutant, utilizing solar-driven photocatalysis with nano-sized titanium dioxide (TiO₂) and composites with activated carbon (AC) and reduced graphene oxide (RGO). This research introduces continuous solar reactor instead of conventional batch experiments investigating its design configuration. Utilizing response surface methodology (RSM), the study determined the optimal process conditions (MB concentration at 30 mg/L, pH 8.82, irradiation time 138 min), under which TiO₂ achieved a 93.13% MB removal efficiency. The study further revealed that the integration of TiO₂ with AC and RGO (5% wt.) significantly enhanced the MB photocatalytic degradation. The TiO₂/AC composite achieved 98.3% MB degradation in 138 min of solar exposure, related to its large specific surface area of 146 m²/g and a pore volume of 0.439 cm³/g. Likewise, the TiO₂/RGO composite demonstrated 97% removal with a surface area of 102 m²/g and a pore volume of 0.476 cm³/g, significantly better than nano-TiO₂. Additionally, the research investigated the role of the solar reactor configuration on MB removal. Using 26 mm Pyrex tube diameter with 15 cm long on parabolic aluminum concentrator inclined at 30° optimally achieved the peak MB degradation efficiency. Recyclability tests shown a noticeable decrease in nano-TiO₂ efficiency to 56.03% without regeneration; however, after regeneration following the third cycle, the efficiency significantly recovered to 70.07%. Thereby, this paper introduces an innovative, continuous, and well-designed solar reactor system for dye removal, employing nano-TiO₂ and its composites with AC and RGO for improved photocatalytic efficiency under statistically optimized process conditions.

Bottlenecks inherent in batch and column adsorption configurations have impeded the implementation of the adsorption technique in large-scale wastewater treatment systems. This study mainly aimed to develop an innovative wastewater treatment prototype that integrates inclined plate settlers (IPS) and composite adsorbent coating (CAC). The objective is to enable the removal of Cd²⁺ from aqueous solutions in a continuous setup, thereby enhancing its practicality for large-scale applications. The combined IPS-CAC system was optimized at various angle of inclination (θ), influent flow rate (Q) and adsorbate initial concentration (C_o) using the Box–Behnken Design (BBD) of the Response Surface Methodology (RSM). At optimized operating parameters (θ = 45°, Q = 5 ml/min and C_i = 1.87 mg/L) the IPS-CAC Cd²⁺ predicted (R² = 0.9926) and experimental removal efficiencies were 75.8% and 69.7 ± 4.67%, respectively. The IPS-CAC breakthrough adsorption capacity was 9.6 mg/g. Comparing IPS-CAC performance with a tank without plates and IPS with plain plates, the Cd²⁺ removal efficiencies were 2.4 ± 0.1% and 4.6 ± 1.1%, respectively, confirming the synergistic effect of IPS and CAC. Additionally, breakthrough curves were acquired for various flow rates, cadmium influent concentrations, and plate inclination angles. Only a 10% decline in the removal effectiveness (from 69.7 to 59.7%) of the CAC after three adsorption–regeneration cycles was observed, indicating its stability for heavy metal removal. The results underpin the potential of using IPS-CAC for industrial wastewater treatment and enhancing the use of adsorption on a larger scale.

This research aimed to synthesize polyvinyl fluoride membranes and coat them with tannic acid (TA) nanoparticles and polyethylene glycol (PEG) additives so that the membrane’s removal efficacy for humic acid (HA) pollutant from agricultural wastewater was investigated. Thus, six membranes with PEG:TA ratios of 0:0, 1:0, 0:1, 1:1, 4:1, and 1:4 were synthesized. Then, the membranes’ characteristics were identified by FTIR-ATR, FESEM, and AFM analysis, and HA’s particle size and zeta potential were also investigated. Based on optimizing effective parameters, the operating pressure of 1.5 bar and HA concentration of 80 ppm were selected as optimal values. The membrane with PEG:TA = 4:1, as the optimally modified membrane, had a pure water flux of 446.03 L/m².h, effluent flux of 72.43 L/m².h, and pollutant removal rate of 86.62% at pH = 7 after 60 min had passed. These values for the pristine membrane (PEG:TA = 0:0) were 265.64 L/m².h, 89.39 L/m².h, and 75.59%, respectively. The results showed that although the effluent flux was lower in the optimized modified membrane than in the pristine membrane, HA removal percentage was increased.

Throughout history, many scientists considered time as the result of changing the world and believed that time is not true. Among those who say that time is not true, Einstein is the only one who was able to mathematically explain the relativity of time in the field of geometry (space time) and present his equations in relativistic physics. Although Einstein, like other scientists, did not provide a clear definition of time, he presented the relativity of time well. He showed that time is not independent of space and bends along with space. Also, Einstein used the speed of light to convert mass into energy to introduce the law of mass–energy equivalence. Currently, basic laws such as conservation of mass, conservation of energy and equivalence of mass and energy have been presented. Recently, due to the importance of time in the development of science, especially in the field of water and chemistry, “timemass equivalence law” has also been presented (by the author). In this research, with the aim of expanding the relativity of time in the flows of mass and energy (not the field of motion and geometry), while presenting new definitions of “phenomenon”, “time” and “specific speed of transformation”, in addition to the theory of “mass equivalence law” “Time” was completed, the general equations of equivalence of energy time—and timemass were introduced. Then, to check the results more accurately, the general masstime equation (in this study, absorption kinetics) by performing surface absorption experiments of heavy metals (Fe + 2, Pb + 2, Zn + 2, Ni + 2, Cd + 2, Cu + 2)) was investigated by the adsorbents of green walnut shell (GWH) and its biochar (GWHB), and the results are tested in different ways.

A study was conducted at Punjab Agricultural University, Ludhiana, Punjab, with the aim of monitoring soil loss and infiltration rate in loamy sand soil. The study focused on the effects of applying polyvinyl alcohol (PVA) and mulch under simulated rainfall conditions. The experimental setup involved testing three levels of PVA (0.5%, 0.75%, and 1.0%), one level of wheat-straw mulch (600 g/m²), and a Control treatment (untreated soil). Each of these treatments was replicated four times. The lowest soil loss (20.9 g/m²) was recorded under the 1.0% PVA treatment, while the highest (120.1 g/m²) was seen under the 0.5% PVA treatment. The 1.0% PVA treatment showed a significant reduction in soil loss compared to the 0.5% PVA, 0.75% PVA, mulch, and Control treatments, with reductions of approximately 82.6%, 45.1%, 81.2%, and 89.6%, respectively. Regarding infiltration rates, the Control treatment exhibited the lowest rate (2.4 cm/h), while the 1.0% PVA treatment displayed the highest rate (9.6 cm/h). Additionally, the use of mulch led to a 44.7% reduction in soil loss compared to the treatment without mulch, likely due to the mitigated impact of raindrops. The infiltration rate was significantly higher (4.8 cm/h) under the mulched treatment compared to the unmulched treatment (2.4 cm/h). Overall, the application of PVA and mulch resulted in a drastic reduction in soil loss, likely attributable to the enhanced stability of soil aggregates, improved infiltration rate, and reduced runoff.