Per- and polyfluorinated alkyl substances (PFAS) have gained significant attention due to their persistence in the environment and potential bioaccumulative effects on ecosystems and human health. Specifically, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) have been widely detected in European rivers, leading to restrictions on their use. A 2015 study of the Danube River reported PFOA concentrations of 5-40 ng/L and PFOS concentrations of 5-30 ng/L. To evaluate the impact of these restrictions, this study measured the concentrations of PFOA and PFOS using UHPLC-QTOF systems, revealing a decreasing trend in their levels compared to earlier data.

Simultaneously, the growing demand for new organofluorine chemicals, particularly in lithium-ion battery production and the agrochemical and pharmaceutical industries, poses additional challenges. Municipal wastewater treatment plants are generally ineffective at removing these resistant fluorine-containing contaminants. To assess the fluorine content in riverine environments, the inorganic fluoride and total organofluorine concentrations in the dissolved water phase must be determined.

This study was focused on the analysis of PFAS compounds in water samples collected monthly from July to December 2023 at twelve sampling sites along the Hungarian section of the Danube River. Inorganic fluoride concentrations ranged from 28-106 µg/L, with a median of 45.3 µg/L, while total organofluorine concentrations ranged from 0.22-12.5 µg/L, with a median of 2.43 µg/L. The findings highlight the ongoing presence of fluorine-containing contaminants in the Danube River, despite regulatory efforts to reduce PFAS levels. These results underscore the need for continued monitoring and the development of more effective wastewater treatment technologies to address emerging environmental challenges.

The increasing abundance of microplastics in the water bodies poses a huge threat to the survival of marine organisms and to the health of people. Presently, a bay is one kind of surface water that has been contaminated by microplastics. One of the recently developed treatment techniques for eliminating microplastics from water is anodic oxidation. This study examined the potential of anodic oxidation with a lead dioxide (PbO₂) anode to remove microplastics from real water samples collected from Bacoor Bay, Philippines. Microplastics are broken down into nontoxic molecules like CO2 and H2O by hydroxyl (•OH) radicals produced during anodic oxidation, which eliminates the need for additional chemicals that could cause pollution of another form. Two factors, reaction time and current intensity, were investigated for their effects on removal efficiency. The concentration of microplastics in Bacoor Bay was discovered to be 49.56 mg/L. The water samples contained a variety of microplastics types, the bulk of which were fragment-shaped and ranged in size from less than 1 mm to 5 mm. The study's findings demonstrated that anodic oxidation resulted in a 42.53% microplastics removal efficiency and a 55.64% turbidity removal efficiency. Considering the results of this study, anodic oxidation using PbO₂ anode is a promising treatment method for microplastics, which can help alleviate the problem regarding microplastics.

Olive mill wastewaters is one of the most difficult wastewaters to treat in the agricultural industry due to its chemical composition, especially its phenolic content. In this study, Rhodotorula yeast strains were examined for their ability to reduce the phenolic content of the influent but also for their ability to produce glucans. Rhodotorula diobovatum EXF-6843, Rhodotorula kratochvilovae Hamam. 1988 EXF-3471, Rhodotorula mucilaginosa EXF-8984 and Rhodotorula toruloides NRRL Y-27012 were cultivated in sterile shake flask fermentations under nitro-limited conditions (C/N=120, glucose equivalents) in wastewater from olive mills with a phenol content of ph0= 3.2 g/L including a blank fermentation in distilled water by Rhodotorula toruloides NRRL Y-27012. The results showed the maximum total glucan production: Rhodotorula toruloides NRRL Y-27012 (blank) - 1.75 g/L at after 96 hours, Rhodotorula toruloides NRRL Y-27012 (OMW) - 0.97 g/L (44.81% phenol reduction) after 76 hours, Rhodotorula kratochvilovae Hamam. 1988 EXF-3471 - 1.19 g/L (46.71% phenol reduction) after 48 hours, Rhodotorula mucilaginosa EXF-8984 - 0.77 (66.02% phenol reduction) after 96 hours and Rhodotorula diobovatum EXF-8984 – 1. 15 g/L (62.93% phenol reduction) after 72 hours. In summary, the results suggested that glucan production by Rhodotorula yeasts, can be optimized by fermentation conditions (carbon/nitrogen source, C/N, pH, temperature, etc.), and the phenol reduction were at a very satisfactory level, making them suitable to develop potential biological recovery technologies for phenols from olive mill wastewater.

At standard atmospheric pressure and temperature, the main components of liquefied petroleum gas (LPG)—propane and butane—exist in gaseous form. Moderate pressurization converts LPG into liquid form, which is suitable for storage in cylinders and tanks. When gas is required for consumption, the valve at the top of the tank opens, pressure drops, and the liquid LPG vaporizes. This natural vaporization process relies on ambient heat from the surroundings, which is transferred through the walls of the LPG tank. The natural vaporization rate depends on several factors, such as the ambient temperature, the surface area of the tank in contact with the liquid (i.e., the filling percentage), the exact composition of LPG, and the design and positioning of the LPG tank. When natural vaporization rates cannot meet the gas demand, as in the case of colder climates and large commercial applications, an additional LPG vaporizer is necessary. The literature's data on natural vaporization in LPG tanks are incomplete and ambiguous, often limited to the most prevalent conditions. This leaves engineers and designers in doubt on whether an LPG vaporizer is actually required. Therefore, the aim of this study is to provide an exact calculation procedure for the natural vaporization in LPG tanks that is capable of taking into consideration different ambient conditions, propane–butane mixtures, LPG tank designs, and the system's working conditions. Aboveground and underground installations, as well as horizontally and vertically positioned LPG tanks, are also accounted for in the present study. The analysis reveals that LPG vaporizers are necessary in situations of high demand, low-temperature environments, limited tank size, and when using butane-heavy LPG mixtures.

Carbon dioxide (CO₂) represents more than 70% of the greenhouse gases (GHG), which are responsible for the greenhouse effect, a natural phenomenon that directly affects and allows life on the Earth. However, over the last half-century, the CO₂ atmospheric concentration has rapidly increased to about 400 ppm due to human-related emissions, causing the well-known climate change. Of these emissions, 21% are originated from industry, in which the cement production has the largest impact.

In this scenario, many solutions using either CO₂ capture storage (CCS) or CO₂ capture and utilization (CCU) in cement industries have been investigated, including the synthesis of chemicals, polymers, fuels, and nanomaterials.

In this work, one functional unit with 2 Mtons of cement/year was adopted to compare the conversion of the captured CO₂ to carbon nanotubes (CNT) and methanol. Along with emission factors and economic evaluations, the proposed analyses were employed using material and energy balances.

The results showed that, currently, methanol seems more attractive since it can increase profits per functional unit up to 322 M€/year and allows a reduction of 8% of the total CO₂ emissions inside the cement industry, while for CNTs the values are respectively 90 M€/year and 0.01%.

Nevertheless, CO₂ conversion to CNT has the potential to increase its attractiveness in the cement sector according to the CNT market expansion in the future (carbon nanotubes would replace the large markets of iron and aluminum).

Cement-based materials are preferred in constructing various infrastructures including wastewater treatment plants (WWTPs) due to their durability, low processing cost, and watertightness. However, the increasingly reported maintenance in many cement-based WWTP facilities is raising concerns about their performance in aggressive environments such as WWTPs. Wastewater contains different chemical substances (e.g., sulfates, organic compounds, and nitrates) which have known deterioration effects on cement performance. Still, less is known about the deterioration process occurring on cement-based materials exposed above sewage line and submerged in sewage liquid.

This study aimed to understand the difference in cement deterioration between submerged and above sewage structures in WWTP facilities. This was an in-situ experiment that involved 23 specimens of ordinary Portland cement. The specimens were exposed to above sewage in the pumping station and below sewage in sand-trap structures. The specimens were exposed for different durations:30, 75, and 24 days. After exposure, specimens were analyzed. The analysis involved material physical observation (using stereo microscopy), morphology (SEM), and mineralogical analysis (using XRD).

The results of our study show that (a) specimens exposed to sewage gases had a notable physical change compared to those submerged in sewage liquid in sandtrap locations. (b) SEM-SE images show that specimens from sewage gases had massive spongy and prismatic needle crystals, whereas, in sewage liquid, specimens showed little or no such morphologies. (c) These crystals observed in samples from sewage gases in the pumping station were confirmed by XRD to gypsum (CaSO₄.2H₂O), ettringite (3CaO·Al₂O₃·3CaSO₄·32H₂O), and thaumasite (CaSiO₃·CaCO₃·CaSO₄·15H₂O) minerals. These minerals are secondary minerals in cement and are characterized by high volume expansion and their presence in hydrated concrete results in volume expansion crack formation. These results suggest that cement-based concrete above sewage line are more prone to deterioration than those submerged in sewage liquid.

Nitrification is the process by which reduced forms of nitrogen are oxidized to produce nitrite and nitrate. When chloramine is used in potable water systems for secondary disinfection, there is a serious potential issue. The usage of monochloramine as a secondary disinfectant is growing in place of free chlorine. Water is treated with ammonia to promote the creation or breakdown of monochloramines. Regulations may be broken as a result of nitrification's detrimental effects on water quality. A study was conducted to look into the quality of the water, the impact of pipe material on the beginning of nitrification, and the effects of nitrification on In-Premise Plumbing. Here, the impact of pipe material on nitrification in premise plumbing was investigated along with examining its effects on water quality. Empirical modeling approach using Artificial Neural Network (ANN) was taken to observe and predict these effects. Input variables of ANN modeling are copper dose concentration, pH level and number of days while output variables are nitrite and ammonia utilization. The best-fitted models are, for ammonia utilization, ANN model with Levenberg–Marquardt algorithm and 50 hidden neurons, which had a coefficient of determination of 0.738 and a mean squared error of 65.8, and, for nitrite utilization, ANN model also using Levenberg–Marquardt algorithm and 50 hidden neurons, which had a coefficient of determination of 0.601 and a mean squared error of 0.0063.

Coastal erosion is the degradation of shorelines caused by natural factors such as sea level rise, currents, and wave action, as well as human activities like construction, deforestation, and fisheries. This process leads to the loss of land and sediments. In Sri Lanka, this phenomenon has impacted 15 tourist attractions in Kalpitiya, altering coastal landforms, including beaches, cliffs, dunes, and barrier islands. Over time, a 50-meter stretch of beach has been destroyed, resulting in the loss of valuable coastal habitats and infrastructure. This study investigated shoreline changes and calculated erosional and depositional rates using Geographic Information Systems (GIS) and remote sensing techniques. The region of interest (ROI) covered the coastal area from Mannar to Puttalam on the northwest coast of Sri Lanka. To analyze shoreline changes, vector data were processed using the Digital Shoreline Analysis System (DSAS V5_0) integrated with ArcGIS 10.5. Secondary data sources included topographic maps, digitized shorelines, and satellite maps obtained from the Survey Department and the United States Geological Survey (USGS) website. Coastal slope and contour lines were created to understand coastal geomorphology and its characteristics. Moreover, the Topographic Wetness Index (TWI) and Normalized Difference Vegetation Index (NDVI) were examined for supportive analysis. Weighted linear regression rate analysis revealed that the Kalpitiya vulnerability region experienced approximately 69% erosion and 30% accretion. The Erosion Potential Rate (EPR) parameter was used to calculate erosional and depositional rates, showing a maximum erosional rate of 13.48 m/year and a maximum depositional rate of 25.36 m/year.

Pollution makes our environment endangered; the pollutants present in the air, such as N2O, S2O, CO, etc., affect living things and cause climatic changes in our environment. This leads to an increase in mortality rates and economic burdens. In order to address the above challenges, a new design of an IoT-powered air pollution monitoring system is introduced. This design utilizes an advanced sensor that monitors the harmful gases present in the air continuously. Furthermore, the proposed design incorporates a Kalman filter supported by an AI architecture that enhances the data accuracy and real-time processing by refining sensor data. The AI structure triggers the automatic response once it detects hazardous conditions; further, the automated response activates the instant alert and ventilation system that are placed in the proposed design. This increases safety and provides protection to the surroundings. The IoT system supports continuous data transmission from the sensor to the cloud; this enables seamless monitoring and time-to-time decision-making. Based on the predefined index, the proposed model predicts the air quality with three conditions: good, moderate, and danger. After air quality observation, the proposed system alerts the pollution control board for further action. The preliminary result obtained from the proposed model shows a significant improvement in the data accuracy and response time compared to conventional methods.

Battery-operated electric vehicles store energy during the charging from the grid. This stored battery energy is extensively used for driving the vehicle, known as the grid-to-vehicle (G2V) technology. However, the battery storage energy is not utilized when the vehicles are parked in the parking lot. To utilize this energy, vehicle-to-grid (V2G) technology is introduced, where the stored battery energy will supply the grid when the vehicles are not in drive. This can reduce the burden on the utility grid. During the power transition from G2V and V2G, the transient and switching losses are present in the system. This can affect the grid-side parameters (namely frequency, real power, reactive power, and inverter current) and converter-side parameters (namely converter output voltage, converter switching losses, and SOC of the battery). To overcome this problem and to improve the performance of the system, this paper proposes the integration of a DC/DC zeta converter. The effectiveness of this integration is verified under various test conditions and is compared with the results of the conventional buck-boost converter. From the simulation results, it is observed that when the system is operating in G2V mode, the output voltage and frequency are settled very quickly at 0.035 sec and 0.12 sec respectively and the ripple voltage is reduced by 120 V, with the proposed converter. Similarly, in V2G mode, the output ripple voltage is reduced by 10V and the response quickly settles compared to conventional converter. In the overall operation, the converter switching losses are minimized, thereby improving the entire system's performance. From all these findings, it is recommended that the DC/DC zeta converter integration in V2G and G2V systems leads to superior and fast charging/discharging of the energy.