Environmental Science and Pollution Research最新文献

This study investigates the effects of ultraviolet (UV) aging on the physicochemical properties and adsorption capacity of three plastics commonly detected in the environment: polyethylene (PE), polypropylene (PP), and polystyrene (PS). One set of plastic samples was exposed to Xe-based simulated sunlight for up to 5 days and another set to outdoor conditions for up to 69 days. The physicochemical properties and ability of the pristine and aged plastic particles to adsorb pyrene, a representative polycyclic aromatic hydrocarbon (PAH), are evaluated. For the outdoor-exposed PP and PS samples, distinct Fourier transform infrared peaks related to carbonyl groups are detected. The adsorption coefficients of pyrene after 72 h of agitation in PE and PP samples aged via 69 days of outdoor exposure are 2.9 and 3.5 times higher compared with that in the respective pristine samples. This increase in adsorption capacity is probably attributed to these plastics undergoing changes in surface properties, including embrittlement. The findings indicate that the accumulation of PAHs on microplastics is accelerated on aged material surfaces, emphasizing the need for further studies under conditions that simulate natural sunlight exposure.

This study proposed a simple process-based model to predict total phosphorus (TP) inputs and dynamics in a large tropical semiarid basin in Brazil (19,015 km²), where the Castanhão dam, the largest non-hydropower reservoir in Latin America, is located. The model solved on a monthly basis the water balance and TP dynamics along the river system, considering complete mixing at the cross-section, steady-state regime, and a piston-type transport with first-order decay. Both primary and secondary data were used to validate the model, with deviations of up to about 20%. A linear increase in the flow rate along the river was observed, indicating that transmission gains were dominant. TP concentration increased with river flow rate and a consistent decay along the system was observed. TP from point sources (PS) was assumed constant. TP from non-point sources (NPS) decreased with time (R² = 0.90) due to the continuous wash-off process. NPS was the dominant load, decreasing respectively from 99 to 61% of the total load from high to low flows. TP load varied from 1 to 141 ton/month, with an average of 34 ton/month. This resulted in an average TP yield of 21.2 kg km^-2 year^-1, which is significantly lower than the national average due to the peculiarities of the region: lower precipitation, intermittent rivers, and high-density reservoir network. All the simulated TP values were above the mandatory limit of 0.05 mg/L. PS reduction was only effective for relatively low flows, while NPS reduction was the most relevant remediation measure for both high and low flows. The impact of climate change on TP concentration also yielded TP > 0.05 mg/L for all the projected scenarios, with the input loads to the Castanhão reservoir spanning from 23 to 266 ton/month. The proposed model can also be applied to other regions with different hydroclimatic conditions and land uses.

With the growth of the metalworking industry, effective control of wastewater with phosphate has become a global concern. This study took advantage of the abundant supply of natural soybean hulls as an adsorbent for the direct treatment of wastewater, aiming to remove Ni, Zn, and Mn from real wastewater produced during the phosphating stage of the metalworking industry to address this issue. Soybean hulls presented a specific surface area of 0.31 m² g^-1, average diameter of 0.2705 mm, and a pH value for PCZ of 6.43 at 25 °C. Real wastewater was acidic (pH 3.68) with COD of 1270 mg L^-1 and highly concentrated in Ni, Mn, and Zn (343.45 mg L^-1, 818.6 mg L^-1, and 953.85 mg L^-1, respectively). It was observed that the process depended on the adsorbent dosage, which can be linked to the low surface area of the material. The optimized pH value was found to be the natural pH of the effluent, which varied between 3 and 4. The average removal rates were 24.5% for Ni, 28.6% for Zn, and 16.5% for Mn, corresponding to the respective removal of 84.15, 135.07, and 272.80 mg L^-1 in a ternary system. The maximum adsorption capacities were observed at 50 °C, estimated as 3.125 mg g^-1 for Ni, 14.128 mg g^-1 for Zn, and 7.8 mg g^-1 for Mn. When evaluating the process kinetics, it was observed that adsorption capacity increased significantly during the initial 60 min, followed by a slower rate until saturation. The pseudo-first-order model provided the best fit for Ni adsorption, while Zn and Mn demonstrated the best fit with the pseudo-second-order model. This trend possibly occurred due to the different initial concentrations of each metal, which has shown to be a key factor in mass-driven adsorption mechanisms. Thus, using raw soybean hulls can be considered a viable alternative for coupling adsorption as a low-cost step to other treatment methods for metalworking wastewater.

The effectiveness of boron-doped diamond (BDD) and titanium metal-mixed oxides (Ti/MMO: Ti/RuO₂-TiO₂ and Ti/RuO₂-IrO₂-Pt) anodes to treat cheese whey wastewater (CWW) by electrochemical oxidation (EO) was evaluated. The results show that EO with BDD is effective in the removal of organic compounds. Conversely, Ti/MMO anodes exhibit higher removals of nitrogenated compounds. After 8 h of EO treatment at an applied current density of 500 A m^-2, the biodegradability index increased from 0.55 to 0.81 with the BDD anode, while with Ti/MMO only reached 0.64. The acute toxicity of the CWW, before and after treatment, was assessed with the model organism Daphnia magna. The use of BDD showed favorable outcomes, leading to a reduction in ecotoxicity, which changed the CWW classification from "very toxic" to "toxic," very close to the "non-toxic" level. Contrarywise, the use of Ti/MMO anodes led to an escalation of potentially harmful substances in the treated effluent. Still, Ti/MMO anodes provide the most favorable energy consumption when operating at current densities equal to or below 100 A m^-2. While both Ti/RuO₂-TiO₂ and Ti/RuO₂-IrO₂-Pt exhibit similar performance, the effectiveness of Ti/RuO₂-TiO₂ is somewhat lower.

Antibiotic pollution has emerged as a critical concern due to the widespread use of antibiotics, their persistence in the environment, and their detrimental effects on aquatic ecosystems and human health. Therefore, developing and implementing effective strategies to eliminate these contaminants is essential. Metal-organic frameworks (MOFs) have garnered substantial interest in water purification due to their remarkable potential. This paper provides a comprehensive review of MOFs and related nanocomposites, with a particular emphasis on their effectiveness in removing antibiotics from water sources. MOFs stand out due to their unique characteristics, including high porosity, adjustable structures, and crystalline nature, making them exceptional in adsorbing contaminants and functioning as photocatalysts. The paper delves into the mechanisms of adsorption, which include electrostatic interactions, π-π bonding, van der Waals forces, hydrogen bonding, and surface complexation. It also examines the factors influencing adsorption and photodegradation, comparing these techniques to conventional adsorbents, and highlights the superior performance and cost-effectiveness of MOFs. Additionally, the study discusses the challenges, current trends, and future prospects in the field, offering insights that may inspire new researchers to further explore antibiotic removal using MOFs and develop innovative solutions to existing challenges.

This study addresses the impact of climate change (2021-2080) on the seasonal distribution of rainfall, temperature, and season lengths over Iran under three Shared Socioeconomic Pathways (SSPs) of the low (SSP1-1.9), moderate (SSP2-4.5), and high (SSP5-8.5) levels of global warming, based on the 29 model ensemble of the Coupled Model Inter-comparison Project Phase 6 (CMIP6). Results reveal that spring and autumn lengths are ~ 90 days during the baseline period (1980-2014), while summer (~ 97 days) is longer than winter (~ 87 days) by 10 days. However, global warming will result in longer summer and winter and shorter spring and autumn seasons in the future. The temperature will increase during all four seasons of spring and autumn (1.5-2.7 $_{}^{\circ }C$ ), winter (1.1-2.2 $_{}^{\circ }C$ ), and summer (2.0-3.2 $_{}^{\circ }C$ ) consistently with the level of global warming scenarios. Meanwhile, minimum and maximum temperature enhancement will occur during winter and summer, respectively, under a given climate change scenario. Rainfall over Iran will increase during all seasons (6-36%) under SSP1-1.9 but will reduce under warmer scenarios SSP2-4.5 (12-24%) and SSP5-8.5 (8-24%). The contributions of the spring, summer, autumn, and winter seasons to the annual rainfall are 32%, 5%, 20%, and 43%, respectively, implying winter and spring as wet seasons during the baseline period. However, climate change may shift the wet season from winter to spring or autumn, depending on the station and SSP, under climate change. Water managers and policymakers need to consider the highlighted issues for future sustainable management in Iran.

Continuous monitoring of the water bodies is necessary for the hydrological and ecological systems of any region to remain viable. This study expands on existing approaches for the delineation and monitoring of changing dynamics of lakes using remote sensing. A hybrid index namely water index built-up index (WIBI) is derived by subtracting normalized difference water index (NDWI) from normalized difference built-up index (NDBI), and it is used for the detection and analysis of area and flow changes in the water body. NDWI is efficient in delineating the water bodies, even in vegetated areas, due to its reliance on the green band, while it may overestimate the results in regions with significant built-up areas. NDB index, which utilizes the short-wave infrared (SWIR) band, is highly effective for detecting built-up areas. The intuitive hybrid index integrates the key features of both NDWI and NDBI to enhance the accuracy of analysis. The application is investigated at Ashtamudi Lake, Kollam, India, and the results are compared with water body detection indices such as NDWI and SWIR1. This study further focused on assessing water quality by examining temperature, turbidity, and chlorophyll content using Google Earth Engine data. The other water quality parameters like pH, total dissolved solids (TDS), conductivity, and salinity was also determined by using water quality analyser as a field data. The proposed method successfully captured the water quality parameters and lake area in comparison with field measurements. These findings could aid in the development of strategies for the rejuvenation of Ashtamudi Lake.

Water pollution caused by the increasing concentration of toxic chemicals, such as heavy metal ions, pesticides, pharmaceutical waste, and plastic contaminants, has become a global issue. The rising levels of these pollutants pose significant health risks to humans and various species. Recently, adsorption has emerged as a promising method for removing these contaminants. This review focuses on metal-organic frameworks (MOFs) as adsorbents, highlighting their large surface areas and adjustable porosity, which optimize the adsorption process. The review analyzes the active sites within MOFs, their roles in adsorption mechanisms, and the underlying chemistry involved. It also discusses the structural chemistry of MOFs and its impact on pollutant removal efficiency. Furthermore, the review addresses stability, scalability, and economic feasibility challenges. Finally, it suggests future research directions for next-generation MOF materials to enhance their effectiveness in sustainable environmental remediation, ultimately improving our ability to combat contamination issues and protect healthy ecosystems.

Flow-electrode capacitive deionization (FCDI) is an innovative approach for removing charged ions from untreated water, utilizing the interaction between ions and flow carbon electrodes. A review of recent publications on FCDI reveals a predominant focus on salt removal from water (desalination) and electro-sorption processes. Though desalination is just one step in improving the water quality, it is worthwhile looking at the research in the context of FCDI techniques that involve other water treatment methods. This paper offers a detailed review of recent literature on FCDI applications in wastewater treatment. Given the broad scope of wastewater treatment, the specific areas where FCDI shows promise, including removal of heavy metal and radioactive elements, organic micropollutant elimination, halogen removal, and resource recovery, are addressed. Additionally, we assess the current research landscape and propose potential future directions in this evolving field.

This study aimed to optimize biodiesel production from waste cooking oil using ultrasonic-assisted transesterification and evaluate the combustion characteristics of a diesel engine powered by various biodiesel blends. The effects of transesterification parameters, including reaction time, alcohol-to-oil molar ratio, catalyst concentration, and ultrasonic amplitude, were experimentally investigated. The optimal conditions for achieving a biodiesel yield of 96.65% were found to be a reaction time of 6 min, an alcohol-to-oil molar ratio of 6:1, a catalyst concentration of 1.0 wt.%, and an ultrasonic amplitude of 75% with a duty cycle of 0.7. In the subsequent phase, engine performance and emissions were evaluated for biodiesel-diesel blends at volume ratios of 0:100 (B0), 10:90 (B10), 20:80 (B20), 30:70 (B30), 40:60 (B40), and 100:0 (B100) under varying load conditions at a constant speed of 1500 rpm. The results indicated that biodiesel blends exhibited similar engine performance to diesel, with a slight increase in brake-specific fuel consumption and a minor decrease in brake thermal efficiency. Emission analysis revealed significant improvements, with B100 reducing carbon monoxide (CO), unburned hydrocarbons (HC), and smoke opacity by 42.9%, 29.9%, and 42.1%, respectively, compared to B0. Notably, B40 showed the highest reduction in nitrogen oxide (NO_x) emissions, achieving a 4.94% decrease. These findings suggested that B40 can serve as a viable diesel substitute without requiring fuel system modifications, offering comparable mechanical performance and enhanced emission characteristics.