Water Particles Research Articles

Impact of nuclear fragmentation on the stopping power ratio of12C ion beams.

Nuclear fragmentation generates a diverse dosimetric environment in the path of 12C ion beams. Concise parametrization of the beam's composition is paramount for determining key correction factors in clinical dosimetry. This study sets out to provide such a parametrization based on detailed Monte Carlo simulations of clinically relevant 12C beams. Special attention was paid to the products of nuclear fragmentations and their importance in determining the stopping power ratios. Using the Monte Carlo simulation package GATE, the spectral fluence of all primary and secondary particles in water were computed at different depths for selected clinically relevant incident energies. Collision-stopping power data was taken from the ICRU90, SRIM and MSTAR database, as well as from previous publications. The choice of stopping power data was shown to have a bigger impact on the resulting stopping power ratio than the choice of physics lists for the simulations. A comprehensive analysis of the relationship between fragmentation and dosimetric data has been provided. This study compared different methods for determining spectral fluence-based stopping power ratios, which is essential for accurate ion beam dosimetry.

A highly branched glucomannan from the fruiting body of Schizophyllum commune: Structural characteristics and antitumor properties analysis

In this study, a highly branched glucomannan (SCP-1) from Schizophyllum commune fruiting body with good solubility was isolated, and its structural characteristics and antitumor properties were analyzed. The monosaccharides of SCP-1 were fucose, glucosamine hydrochloride, galactose, glucose and mannose with a relative molar ratio of 14:6:210:593:177, and the molecular weight (Mw) of SCP-1 was 15.1 kDa. SCP-1 showed a rough and dense surface, and it was aggregated to particles in distilled water, though it might have triple-helix conformation. The main backbone chain of SCP-1 was →[3)-β-D-Glcp-(1]3→3)-β-D-Glcp-(1→2)-α-D-Manp-(1→2)-α-D-Manp-(1→3)-α-D-Glcp-(1→ and three sides chains including α-D-Glcp-(1→[6)-β-D-Glcp-(1]2→, α-D-Glcp-(1→3)-α-D-Manp-(1→ and α-D-Glcp-(1→[6)-α-D-Galp-(1]3→ were linked with 1,6-glycosidic bond, which was significantly different with the schizophyllan isolated from the mycelia of S. commune. SCP-1 could significantly inhibit the growth of A549 cells, the inhibition rate reached 41.62 % and the percentage of cells in S phase increased from 27.17 % to 56.40 % (400 μg/mL, 48 h). Moreover, SCP-1 could induce cell apoptosis and the total apoptosis rate reached 28.13 %. SCP-1 exerted apoptosis inducing effect probably by reducing the expression ratio of Bcl-2/Bax and the p-PI3K, p-Akt and p-mTOR expression level. The results showed that SCP-1 might have the potential to act as an antitumor agent for lung cancer therapy.

Preparation of Physalis alkekengi L. calyx total flavonoids-chitosan composite film and its effect on preservation of chilled beef.

In the present study, Physalis alkekengi L. calyx total flavonoids (PCTF) were extracted using the ultrasound-assisted ethanol method and separated and purified using macroporous resin AB-8. Physalis alkekengi L. calyx total flavonoid-chitosan (PCTF-CS) composite films containing 0.05 %, 0.10 % and 0.15 % PCTF were prepared using the purified PCTF laminated with chitosan (CS) and compared with single CS films, respectively, to investigate their mechanical properties, barrier properties, optical properties, microstructure, crystallography, thermal stability, water contact angle, particle size and zeta potential, antioxidant property, antimicrobial property, and preservation effect on chilled beef. The PCTF-CS films with PCTF additions had darker colors and higher mechanical and barrier properties than the CS films. In addition, the addition of PCTF improved the antioxidant and antimicrobial properties of the CS films. It enhances the freshness retention of fresh beef, and effectively inhibits the rise of weight loss, pH, total bacteria, total volatile basic nitrogen, and thiobarbituric acid reactive substances in beef, prolonging the shelf life of beef. These results indicate that the addition of PCTF can provide CS films with superior functional properties and bioactivities and that PCTF-CS composite films are a potential and promising packaging material for food preservation.

Advanced technology in fruit preservation: Effects of nanoscale charged water particles on storage quality and reactive oxygen species in blueberries

During the postharvest period, blueberries with a short shelf life due to microbial activity and an overload of reactive oxygen species (ROS) were still a major unresolved problem. In this study, the effect of nanoscale charged water particles (NCWP) treatment on the postharvest characteristics and ROS metabolism in blueberries (Vaccinium ashei Reade) were investigated. The results showed that NCWP treatment significantly inhibited microbial growth, maintained high firmness and commercial acceptability, and extended the storage period of blueberries. The nutrient of blueberries was retained and elevated after NCWP treatment, especially in the 6 d of NCWP-9 h treatment, the total phenol and anthocyanin content reached the peak at 565.1 mg/L and 5.26 mg/g, which contribute to the total antioxidant capacity of blueberries increased. SEM showed that NCWP-9 h treatment maintained the integrity of the cuticular wax of the blueberry peel, which indirectly decelerated the decline of blueberry firmness. The NCWP treatment significantly enhanced the antioxidant enzyme system of blueberry peel. On days 2, 4 and 6 after NCWP-9 h treatment, the CAT, SOD and APX activities were significantly different from the control group (P < 0. 05), with 585.09 ΔA/min/g, 79.34 U/g and 3.32 umol/min/g, respectively, which effectively scavenged the oxidative stress markers (H2O2, O2−) accumulated in the blueberry peels, and slowed down the aging and deteriorated of the blueberry process. This finding demonstrates that NCWP is an effective postharvest preservation method for blueberries and provides a viable strategy for quality maintenance in the postharvest fruit and vegetable sector.

Cascaded frameworks in underwater optical image restoration

Optical imaging and vision technology have become crucial research topics in the field of underwater and ocean scenes. These technologies play a vital role in advancing underwater exploration, scientific research, and smart aquaculture. Despite their importance, optical systems face substantial challenges in complex water environments, especially in turbid conditions where light absorption and scattering by water and suspended particles drastically reduce the quality of captured images. This degradation highlights the need for sophisticated image restoration algorithms that can effectively recover the quality of images impaired by turbid water conditions. Cascaded frameworks, which incorporate multiple modules, including that of color correction, detail enhancement, and information fusion, have emerged as particularly efficacious, offering significant improvements over traditional direct or end-to-end restoration methods. This review elaborates on the comparative benefits of various cascading structures — serial, parallel, and hybrid — and examines different restoration algorithms that utilize intrinsic image features, physical models, prior knowledge, and deep learning technologies. Furthermore, it provides a comprehensive overview of publicly available datasets and evaluation metrics, both referential and non-referential, which are crucial for developing, validating, and optimizing underwater image restoration algorithms. Additionally, by conducting experimental comparative studies of several open restoration algorithms, the effectiveness and applicability of different methods are validated. Finally, the review proposes potential research directions, aiming to deliver valuable insights to scholars in underwater application and computer vision, thereby inspiring innovative research initiatives that could further enhance the capabilities of underwater optical imaging.

Self-floating Janus hydrovoltaics for sustainable electricity generation

Water is widely available in nature that attracts increasing interesting in simulating transpiration effect to induce the electricity. However, it faces great challenges in establishing continues moisture gradient rather than periodic wetting behaviors. Here, we propose a self-floating Janus generator containing the hydrophilic and hydrophobic regions to induce the continues electricity. The self-floating and hydrophilic behavior ensures a continuous water supply. The asymmetric Janus structure forms a distinct wet/dry interface to create a significant water gradient with evaporation equilibrium state. At wetting region, the electric double layer (EDL) is formed due to the interaction of water and carbon black particles. Attributed to the large water gradient and fast contact line evaporation, proton accumulates across the capillary front that induces a potential difference. As a result, the Janus generator achieves 0.46 V open circuit voltage lasting for 40 h. It also demonstrates the potential applications of Janus generator in power supply, moisture detection and sweat monitoring et al. The proposed Janus generators show great potential in ocean energy development and be of great significance to the sensing of rescue signals in the sea.

The vertical transport and fate of MPs–oil composite pollutants in nearshore environment

MPs-oil composite pollutants interact with particles to form MPs-oil-particles aggregates (MOPAs) in nearshore environment. In this study, we investigated vertical transport and fate of MPs-oil composite pollutants mediated by particles under various time scales, proposed and elucidated associated mechanisms. Majority of MPs with -CH2 suspended in water columns and particles with Si-O and O-H adsorbed MPs-oil composite pollutants in sediment phase, which caused differences in morphology structure and composition. The MOPAs with spherical or irregular three-dimensional in water columns can transport to sediment phase, resulting in more than 79 % lamellar MOPAs and more than 63 % oil in sediment phase. Besides, we demonstrated that degraded small-sized MPs-oil composite pollutants can resuspend into water columns. The mass of n-alkanes in sediment phase (< 45 μg) was lower than in water columns (< 120 μg) during degradation process. More importantly, during the intermediate stage of degradation, the size of oil droplets on surface of MPs decreased and particles trapped them to sediment phase, resulting in a V-shaped curve of mass changes of C14-C35 in water columns. Our research fills the gap in the field of MPs-oil composite pollutants in water columns and sediment phase, which can provide theoretical support for their disposal.

Permeability–selectivity trade-off for a universal leaky channel inspired by mobula filters

Mobula rays have evolved leaf-shaped filter structures to separate food particles from seawater, which function similarly to industrial cross-flow filters. Unlike cross-flow filtration, where permeability and selectivity are rationally designed following trade-off analyses, the driving forces underlying the evolution of mobula filter geometry have remained elusive. To bridge the principles of cross-flow and mobula filtration, we establish a universal framework for the permeability–selectivity trade-off in a leaky channel inspired by mobula filters, where permeability and selectivity are characterized by the pore-scale leaking rate and the cut-off particle size, respectively. Beyond the classic pore-flow regime in cross-flow filtration, we reveal transition and vortex regimes pertinent to mobula filtration. Combining theory, physical experiments, and simulations, we present distinct features of water permeability and particle selectivity across the three regimes. In particular, we identify an unreported 1/2-scaling law for the leaking rate in the vortex regime. We conclude by demonstrating that mobula filters strike an elegant balance between permeability and selectivity, which enables mobula rays to simultaneously satisfy biological requirements for breathing and filter feeding. By integrating cross-flow and mobula filtration into a universal framework, our findings provide fundamental insights into the physical constraints and evolutionary pressures associated with biological filtration geometries and lay the foundation for developing mobula-inspired filtration in industry.

Analysis of the Existing Air Emissions Detection Methods for Stationary Pollution Sources Monitoring

The application of coal technologies for energy generation leads to high pollutant emissions. Thus, governmental and international organizations have created new programs and laws for monitoring emissions. Recently, the government of Kazakhstan has introduced regulations for the measurement of emissions produced by factories and power plants. However, the requirements and Corecommendations for the monitoring methods have not been defined. Therefore, this article addresses the problem and focuses on determining the measurement errors made by optical SGK510 and electrochemical POLAR devices used for coal power plants. The hypothesis is based on the fact that there are currently no systems for monitoring probe drying, and its implementation is expensive. The main methods are analyzed, namely their operation, taking into account the presence of water particles in samples, and the possibility of using adjustment coefficients is considered. The main pollutants chosen for analysis are CO, NO, NO2, NOx, SO2, and O2. Using the Broich–Pagan test, homoscedasticity was determined, and the Fisher test showed the possibility of using tuning coefficients. The data for the optical method were compared to measurements taken using Inspector 500. The error for SO2 determination was 7.19% for NO, 44.0985% for NO2, 733.26% for NOx, 7.39% for O2, 2.75% for CO, 60.81%. The comparison between SGK510 and POLAR demonstrated the following errors: for CO—1.5%, for NOx—82.4405%, for SO2—41.17%, for O2—11.61%. According to the Fisher criteria analysis of the optical method, only SO2 and CO values measured by SGK510 in comparison to Inspector 500 had close similarity, while others demonstrated high deviations. The significance tests were carried out by Fisher’s, t-test, and ANOVA methods. For the electrochemical measurement, only CO values had close similarity. In the future, methods will be proposed to improve the accuracy of the system while reducing maintenance costs, as well as cleaning sampling systems. The multicomponent analysis application for accuracy improvement with the exhaust gas humidity, temperature, and flow consideration was recommended as a possible solution.

Microplastic distribution and risk assessment in estuarine systems influenced by traditional villages and artisanal fishery activities

Microplastics (MPs) are widespread in oceans worldwide, posing a significant threat to aquatic ecosystems. The abundance of these particles in water is related to population density and urban development, functioning as a sink for MPs. However, the pollution levels due to the accumulation of MPs in the estuarine in Amazonian mangrove areas remain unknown. Here, we show that population density and fishing activities influence the distribution of MP pollution in these waters. We found the highest abundance of MPs in the inner (1.03 items/m3) and outer (0.82 items/m3) portions of the estuary, corresponding to the areas with the highest population density and fishing activity, respectively. The main morphological characteristics of MPs are fibers (89.8%), blue color (55.2%), and size of 1000–2000 μm (31.7%). The risk analysis showed a low level of danger, suggesting that the potential impact on the ecosystem is still small. Our results demonstrate that the presence of human populations and their fishing activities significantly influence the accumulation of MPs in the estuarine waters on the Amazon coast. Based on our findings, more sophisticated analysis using MPs’ spatial distribution models can be associated with hydrodynamic processes, aiming to define pollution hotspots and support the mitigation of their emerging negative effects. In addition, monitoring and generating valuable information are the main targets for developing comprehensive strategies to preserve biodiversity and sustainability in the Amazon coastal zone.

Exploring the dynamic mechanical response and mesoscopic characteristics of typical frozen rock in Yulong Copper Mine

Dynamic mechanical characteristic testing at low temperatures was conducted for the typical porphyry and sandstone specimens of Yulong Copper Mine in Tibet, China. The stress and strain characteristics of the specimens at different temperatures were analyzed. A dynamic constitutive model was developed by considering the initial damage. Furthermore, microscopic damage characteristics during the water-saturated rock freezing process were investigated using the PFC3D software, revealing the mechanisms of frost heave damage to rocks. The results indicated that the water-ice phase transition either enhanced or deteriorated the specimen strength at low temperatures. Specifically, freezing at −10°C and −20°C enhanced the strength of sandstone. However, freezing at −10°C enhanced the porphyry specimens, and freezing at −20°C caused significant frost swelling injury. The new constitutive equation effectively fitted the dynamic stress and strain curves for both specimens, highlighting their differences. The maximum contact force and particle contact in the frozen rock PFC3D model were affected by rock and water particle deformations. The frost swelling deformation of water particles had a more pronounced impact on specimen damage and was related to the temperature. A specific freezing temperature existed at which the increase in saturated rock strength corresponded to the maximum specimen strength at that temperature.

Study on the Vertical Distribution Characteristics of Suspended Sediment Driven by Waves and Currents

Port coasts are affected by waves and tidal currents, and sediment continues to silt up, leading to a reduction in the depth of water in the channel, blocking the channel and seriously affecting the safe operation of ports. The main cause of sediment deposition in ports is suspended sediment transport, and the characteristics of the vertical distribution of suspended sediment concentrations are the embodiment of the suspended sediment transport law. This paper is divided into three parts to study the vertical distribution characteristics of suspended sediment concentrations. Firstly, the shortcomings of the traditional diffusion model were analysed by using the finite mixing theory (FMT); secondly, the sediment mixing length coefficient κs model was introduced and combined with the sediment group settling velocity model to establish the vertical distribution model of suspended sediment concentrations under wave–current; finally, the effects of various factors on the vertical distribution of the suspended sediment concentration were investigated. The results show that the model in this paper has the characteristics of “low variance and low bias”, which solves the problem that κs is difficult to determine. When the model κs &lt; κs′ (κs′ = 0.4), the concentration of suspended sediment predicted by κs′ is overestimated, and vice versa. As the sediment concentration increases, the interaction between particles increases and the vertical distribution of the suspended sediment concentration shows the pattern of “small top and large bottom”. The larger the particle size, the greater the sedimentation rate of the suspended sediment, and a large amount of sediment will be suspended near the bottom without mixing. The higher the wave height, the stronger the boundary layer turbulence and the movement of the water particles’ trajectory, and the smaller the difference in sediment concentration between the bottom and the sea surface.

Microplastic pollution unveiled: the consequences of small unregulated dumping in villages, spanning from soil to water.

Microplastic contamination in soil ecosystems is a major environmental concern in the world. The current study aims to explore the extent of microplastic pollution in unregulated village dumpsites in India, focusing on the movement of these pollutants from soil to aquatic environments. Soil samples from eight distinct sites (A to H) in six villages were analyzed for various properties, including pH, bulk density, porosity, water retention capacity, hydraulic conductivity, and particle size distribution. The attenuated total reflection-Fourier-transform infrared spectroscopy (ATR-FTIR) method was used to identify prevalent plastic types. The research classifies microplastics by their shape and color, identifying a wide range of particles such as sheets, fibers, foams, fragments, and films. The study also examines the presence and concentration of microplastics in both soil and sediment samples. It was found that PE and PP microplastics are significantly present across different size fractions. Sample A contains a variety of items in the 1-5mm size range, mainly PE, while the 0.3-1mm fraction is largely PP. Samples B to H are mostly composed of PE microplastics in different forms. Sample F is unique with a mix of PE, EPS, and a higher amount of red and blue foam particles in the 0.3-1mm fraction. Microplastics were quantified using stereomicroscopy, revealing concentrations between 80 and 840 numbers per kilogram in soil and 20 to 60 numbers per kilogram in sediments. The findings emphasize the widespread nature of microplastic pollution across ecosystems and the importance of developing effective strategies for monitoring and mitigating their impact on environmental health and human well-being.

You can bring plankton to fecal indicator organisms, but you cannot make the plankton graze: particle contribution to E. coli and MS2 inactivation in surface waters.

Organisms that are associated with feces ("fecal indicator organisms") are monitored to assess the potential for fecal contamination of surface water bodies in the United States. However, the effect of the complex mixtures of chemicals and the natural microbial community within surface water ("particles") on fecal indicator organism persistence is not well characterized. We aimed to better understand how particles, including biological (e.g., potential grazers) and inert (e.g., minerals) types, affect the fecal indicator organisms Escherichia coli K-12 ("E. coli") and bacteriophage MS2 in surface waters. A gradient of particles captured by a 0.2-µm-pore-size filter ("large particles") was generated, and the additional particles and dissolved constituents that passed through the filter were deemed "small particles." We measured the ratio of MS2 and E. coli that survived over a 24-h incubation period for each condition (0%-1,000% large-particle concentration in raw water) and completed a linear regression that included large- and small-particle coefficients. Particles were characterized by quantifying plankton, total bacterial cells, and total solids. E. coli and MS2 persistence was not significantly affected by large particles, but small particles had an effect in most waters. Small particles in higher-salinity waters had the largest, negative effect on E. coli and MS2 survival ratios: Significant small-particle coefficients ranged from -1.7 to -5.5 day-1 in the marine waters and -0.89 to -3.2 day-1 in the fresh and estuarine waters. This work will inform remediation efforts for impaired surface water bodies.IMPORTANCEMany surface water bodies in the United States have organisms associated with fecal contamination that exceed regulatory standards and prevent safe recreation. The process to remediate impaired water bodies is complicated because these fecal indicator organisms are affected by the local environmental conditions. For example, the effect of particles in surface water on fecal indicator concentrations are difficult to quantify in a way that is comparable between studies and water bodies. We applied a method that overcomes this limitation to assess the effects of large particles, including natural plankton that could consume the seeded fecal indicator organisms. Even in environmental water samples with diverse communities of plankton present, no effect of large particles on fecal indicator concentrations was observed. These findings have implications for the interpretation and design of future studies, including that particle characterization of surface water may be necessary to assess the fate of fecal indicators.

Polarization optical properties of suspended particles measurement in water by a polarized Scheimpflug lidar system.

The polarization optical properties of suspended particles in water play a pivotal role in numerical simulation or real water medium detection. Polarized multi-wavelength oceanic lidar provides an effective method for characterizing the size, shape, and concentration of suspended particles. In this paper, we present a concise and effective optical approach to measure the information in the polarization of the lidar signal with 0°, 45°, 90°, and 135° polarization angles of suspended particles by laboratory experiments based on polarized Scheimpflug lidar system. This work uses typical suspended particles with different sizes and shapes as tracer particles to analyze particulate polarization information. Experiments with spherical or irregular silicon dioxide particles show that these particles can be effectively distinguished by analyzing the polarization optical properties of the backward scattering light. The laboratory system can classify suspended particles and may serve as a shipborne oceanic lidar or be used with submersibles.

Design of Scheduled Fog Irrigation System with ESP 32 in Mustard Seedbed (Brassica juncea L.)

Plants receive water from the fog irrigation system in the form of tiny, mist-like water particles. Currently, irrigation technology has advanced, nurseries can be automatically irrigated. In this research, the ESP32 microcontroller is used to create the electronic circuits for the automation of the fog irrigation control system in a mustard green nursery. This study's methodology combines direct field observation with an experimental or trial approach. Water flow (ml/minute), water use efficiency (%), plant height (cm), number of leaves, and scheduled fog irrigation system performance are among the measured parameters. In this investigation, four different treatments were used: manual irrigation using a watering can, two-time, three-time, and one-time irrigation. All is going according to plan with this mist watering system. With an average height of 4.58 cm and an average number of leaves of 3.24, the mist irrigation system had the highest water use efficiency of 77.35% during the test. It was also found that mist irrigation produced the highest amount of mustard leaves in the three-times-per-day treatment. Keywords: ESP32, Fog irrigation, Green mustard, Nurseries.

From Wet to Protective: Film Formation in Waterborne Coatings.

The importance of anticorrosive coatings cannot be overstated, as they play a vital role in safeguarding assets and infrastructure across various industries. Within this context, the emergence of waterborne (WB) coatings stands out for their paramount significance, offering a sustainable alternative to traditional solvent-based (SB) coatings and addressing pressing environmental concerns. Despite their eco-friendliness, the complexity of their film formation mechanism and the lack of understanding present challenges in enhancing the performance of waterborne coatings for corrosion protection. These coatings are created by dispersing polymers in water, which then form a protective film on a substrate. The process involves stages like water evaporation, particle packing, and polymer interdiffusion, often leading to films with defects and inferior protection against extremely corrosive environments compared to SB coatings. This Review scrutinizes the interplay of factors affecting film formation in application, including coalescing agents, environmental factors, and application conditions. A comparative analysis between SB and WB coatings is also featured to shed light on the performance gap under harsh conditions. This Review discusses analytical techniques for studying film formation, aiming to guide future research toward improving WB coatings' durability and effectiveness. In compiling this collective wisdom, this Review emphasizes the translation of theoretical understanding into practical knowledge, equipping formulators with actionable insights to optimize WB coatings for real-world application and performance.

The Effects of Montmorillonite–Humic Acid Composite Particles on the Photolysis of Tetracycline in Water

Suspended particulate matter (SPM) is an important component of natural water bodies and can significantly influence the photolytic behavior of water pollutants. A comprehensive understanding of the photochemical behavior of water pollutants in natural waters requires consideration of the presence of SPM. In this study, montmorillonite–humic acid (MMT-HA) composite particles were synthesized to simulate SPM in natural waters and their effects on the photolysis of tetracycline (TC) were investigated. The results demonstrated that the presence of MMT-HA composite particles in water significantly enhanced the photolysis of TC, with the photolytic kinetics following a pseudo-first-order model. Electron spin resonance spectra and free radical quenching experiments indicated that the photoactive components (MMT and humic acids) in the composite particles induced the generation of reactive oxygen species under light exposure, further contributing to the enhanced photolysis of TC. Comparative analysis of the free radical signals and adsorption experiments revealed that the accelerated photolysis of TC was also related to the interfacial interaction between the MMT in the composite particles and the TC molecules. The formation of surface complexes between TC molecules and the negatively charged sites on the MMT surface facilitated light absorption and electron transfer, thereby accelerating the photolysis of TC. Photoproduct analysis indicated that the primary degradation pathways of TC in the composite particle systems included the addition of hydroxyl radicals to the aromatic ring, as well as demethylation, deamination and dehydration in the side chains. This study shows that SPM in water bodies can affect the photochemical behavior of pollutants and should be taken into account when assessing the phototransformation of pollutants in natural waters.

Soil behavior near the PVD filter and interpretation of clogging during vacuum preloading

Clogging near the prefabricated vertical drain filter during vacuum preloading reduces the efficiency of ground treatment, and existing research has yet to agree on the cause. This study conducted a small model test to comprehensively examine the soil's water content and particle size distribution at different distances from the filter and tailwater for different preloading durations. The results showed that the particle size distribution of the soil at different selected points exhibited a slightly irregular difference. This indicates that no measurable migration of particles occurs, which was further confirmed by the particle size distribution of the soil after the one-dimensional consolidation test. The application of vacuum pressure did not significantly change the soil particle composition and, thus, its compressibility and permeability properties. The particle size distribution of tailwater revealed that a small number of fine particles with a mean size of 3–4 μm rapidly discharged with tailwater during the initial stage of vacuum preloading, which was much less than the mean size of the slurry and pore size of the filter. The decrease in water content and permeability indicates non-uniform consolidation, and the increase in the permeability coefficient ratio suggests the formation and development of the clogging zone.

The Influence of Aloe Vera Biocoagulant and Mixing Time in Reducing Biological Oxygen Demand, Chemical Oxygen Demand and Total Suspended Solids Levels

Aloe vera is a plant with complex composition of carbohydrates, sugars, and mucilage, enabling it to bind particles in water and serve as a coagulant in the coagulation-flocculation process. This study aims to assess the impact of varying doses and rapid stirring times on the reduction of biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total suspended solids (TSS) levels in liquid waste from pharmaceutical companies. The research involves two factors: (1) aloe vera concentration at three levels (20 mL/L, 40 mL/L, and 60 mL/L); (2) fast mixing time at three levels (20 minutes, 40 minutes, and 60 minutes), with each treatment repeated thrice. Levels of BOD, COD and TSS were measured post-treatment using a jar test tool. The results of the analysis showed that the optimal efficacy of the aloe vera coagulant occurred at a concentration of 40 mL/L for 40 minutes. At this optimal condition, the effectiveness of the aloe vera coagulant in reducing BOD, COD and TSS levels was 72.3%, 78.5%, and 65.3%, respectively. This indicates that the aloe vera coagulant can be effectively utilized in the treatment of pharmaceutical industrial wastewater to reduce BOD, COD and TSS levels