Environmental Science: Water Research & Technology最新文献

Water quality prediction is a highly important task for the anticipation and management of a polluted environment. Accurate prediction can assist in making better decisions in the area of environmental water quality. The WQI (water quality index) is the best method of measuring water quality. However, previous research has suffered from limitations, such as ambiguity and eclipsing. Machine learning algorithms are considered effective methods to rectify the limitations of conventional WQIs. The proposed model aims to detect the main water quality parameters, which include biochemical and physical features. It is also used to determine the usability of water for irrigation purposes. The proposed model uses federated learning to train optimized RPART (recursive partitioning) on water quality data such as pH, turbidity, dissolved oxygen and temperature. These data are distributed across different geographical or organizational locations without transferring raw data to a central server. The proposed algorithm demonstrates a shorter search time compared to RPART, achieving O(1) in the best case and O(log N·2^d) in the worst case for completing the search operation. The dataset partitioning of 15% for testing, 70% for training, and 15% for validation indicates the robust classification and prediction performance of the WQI model for Indian reservoirs. ORPART gives 92% data accuracy, requires less search time for keys, and has high data capability with a lower error rate. The integration of the federated learning and optimized RPART techniques can lead to more efficient, sustainable, and data-driven management of irrigation water quality, benefiting agriculture, the environment, and local communities.

Fluoxetine (FLX), a widely prescribed antidepressant and one of the most prevalent pharmaceuticals detected in the environment, has piqued significant interest recently due to its persistence and potential ecological effects. Despite its widespread detection, no comprehensive review currently exists that focuses specifically on FLX's environmental behaviour. As a polyfluorinated synthetic organic compound, FLX serves as an ideal model for understanding the broader challenges faced by fluorinated pharmaceuticals. This review presents a critical and integrative assessment of FLX, beginning with its molecular structure and the role of the C–F bond in enhancing the chemical stability and recalcitrance. The review then explores its environmental fate, including its behaviour towards hydrolysis, photolysis, partitioning, susceptibility to microbial attack, potential for bioaccumulation, and interactions and joint toxicity with other co-existing pollutants. This is followed by a comprehensive and critical discussion of existing advanced removal techniques currently investigated for FLX removal. Despite some promising approaches, challenges remain due to the inherent stability of the C–F bond, the toxicity of by-products, and the complexity of the matrix. The review proposes treatment chains, such as adsorption (AC, biochar, nano-adsorbents), followed by chemical (AOPs, electro-Fenton, UVC/solar irradiation) and biological (MBBR, biofilters) as recommendations for future studies. In addition, the review also aims to highlight the need for environmental management of FLX, not only to mitigate its ecological footprint but also to offer broader insights into the class of polyfluorinated pharmaceuticals.

This review aims to provide a comprehensive overview of the electrochemical advanced oxidation processes (EAOPs) for the removal of underwater microplastics. First, we analyze the sources of various microplastic contaminants, such as personal hygiene products, synthetic textiles, industrial processes, plastic waste, fishing nets, and road wear, and the complexity of underwater microplastic distribution, including spatial, vertical, and temporal distributions. Then, the types, principles and reaction mechanisms of EAOPs for underwater microplastic removal are described in detail, and their applications to microplastic removal are discussed, including electrode materials and parameter optimization. The unique contribution of this review lies in its critical synthesis that bridges the gap between fundamental electrochemistry and applied water treatment, offering a dedicated focus on the operational parameters and implementation challenges specific to microplastic degradation, which have not been comprehensively addressed in the literature. In addition, the advantages and limitations of EAOPs are analyzed, such as their efficient decomposition ability, low risk of secondary pollution and easy control, along with the problems such as high energy consumption, high electrode cost and complicated operation. Finally, to promote the sustainable application of EAOPs in wastewater treatment, ways to overcome these limitations, including the development of new electrode materials, optimization of operating parameters, integration of other technologies, and resource and energy recovery, are suggested.

As the world's largest coal producer and consumer, China actively promotes efficient clean coal use to achieve its “dual carbon” goal. Semicoke, a high-value product from low-temperature pyrolysis of low-rank coal, effectively replaces loose coal and industrial coke. This enables clean low-rank coal utilization while reducing terminal carbon emissions. However, production generates high-concentration organic wastewater with complex components where oil forms highly stable emulsions using micron/nanometer carbon powder as emulsification cores. Emulsified oil typically exceeds 1 g L⁻¹, making it unsuitable for traditional physical separation. Persistent emulsified oil clogs phenol ammonia recovery equipment, causing pipeline scaling and process interruptions that lead to frequent cleaning and maintenance shutdowns. It also significantly inhibits downstream biological treatment, becoming a key near-zero emissions bottleneck. Existing reviews only discuss traditional processes like air flotation and gravity sedimentation. They lack a systematic review of emulsified oil stability mechanisms or removal strategies, nor do they summarize recent applications of advanced functional materials. This review examines current status and development trends of emulsified oil removal from semi-coking wastewater while exploring main sources and distinct formation mechanisms. It comprehensively evaluates novel adsorption materials, membrane separation technologies, and efficient reverse-phase demulsifiers, focusing on removal mechanisms, recent breakthroughs, and key challenges. Ultimately, the analysis aims to facilitate emulsified oil removal technology innovation. Further, this work supports the development of cost-effective treatment systems. Such advancements are vital to promote the industry's green transformation and to aid China's environmental and carbon neutrality objectives.

Per- and polyfluoroalkyl substances (PFAS) are increasingly recognized as persistent global contaminants with significant health implications. This study offers the first thorough assessment of 19 PFAS across 21 discharge points in Xi'an and Xianyang within the Wei River Basin, utilizing an advanced online solid-phase extraction with liquid chromatography–tandem mass spectrometry (SPE-LC-MS/MS). Notably, we observed distinct seasonal variations in ∑PFAS concentrations: dry water period (January 2024: 141.3–1930.7 ng L⁻¹, averaging 360.7 ng L⁻¹) > flat water period (May 2024: 7.9–2704.6 ng L⁻¹, averaging 245.4 ng L⁻¹) > abundant water period (September 2023: 22.0–637.4 ng L⁻¹, averaging 145.4 ng L⁻¹). Short-chain PFAS, especially perfluorobutanoic acid (PFBA) and perfluorobutanesulfonic acid (PFBS), were predominant, with over 90% detection frequencies in all water periods. Only one critical finding was the elevated PFOS level at the SW19 discharge point, reaching 1427.0 ng L⁻¹ during the flat water period—28 times higher than the US EPA's advisory limit for drinking water. Ecological risk assessments indicated SW19 exhibits high risks (RQ > 1) for PFOS during both flat and dry water periods, although the majority of PFAS discharge points are categorized as low or negligible risk. These results emphasize the urgent need for targeted source control in petrochemical and electronics industries, enhanced wastewater treatment technologies for short-chain PFAS, and long-term monitoring programs that account for hydrological changes. This study provides a methodological framework for monitoring multiple PFAS in complex watersheds and supports China's “New Pollutants Governance Action Plan”.

This study investigated the feasibility of tobacco wastewater treatment and simultaneously generating electricity using microbial fuel cells (MFCs) under aerobic conditions. A series of dual-chamber MFCs inoculated with tobacco wastewater were constructed, and the effects of an extra carbon source (glucose and acetate) and no additional carbon source in tobacco wastewater on MFC performance were compared. MFCs with extra carbon sources exhibited significantly superior electricity generation performance, achieving maximum voltages of 0.70 V (glucose) and 0.68 V (acetate) and maximum power densities of 605.79 mW m⁻² and 653.55 mW m⁻², respectively. The COD removal rates of tobacco wastewater in MFCs with glucose and acetate reached 72.75% and 74.71%, respectively, which were significantly higher than that of the MFC with raw tobacco wastewater (29.35%). Microbial community analysis revealed that the addition of carbon sources markedly increased the abundance of electroactive bacteria (e.g., Trichococcus and Enterococcus) while reducing anode microbial diversity, indicating the dominance of electrochemically active bacteria. This study validates the potential of aerobic MFCs for treating tobacco wastewater and provides theoretical insights for optimizing carbon source selection and microbial community regulation.

This research investigates the development of a mesoporous silica–Prussian blue (HOM-SiO₂-PB) composite adsorbent, created using a one-pot in situ sol–gel method. This technique integrates Prussian blue (PB) into the SiO₂ framework, enhancing its ability to capture cesium ions (Cs⁺) from contaminated water. The composite was thoroughly analyzed using various methods, including XRD, XPS, HR-TEM, SEM, and N₂ adsorption–desorption measurements. Results showed that HOM-SiO₂-PB has a high adsorption capacity of 92.5 mg g⁻¹ for Cs⁺ ions, with the adsorption process governed by ion exchange between Cs⁺ and K⁺ ions. Adsorption isotherms fit models such as the Langmuir model with R² values greater than 0.984, while kinetic data followed a pseudo-first-order model. The adsorbent demonstrated 98.3% removal efficiency, reducing Cs⁺ concentrations from 2.02 mg L⁻¹ to below 20 μg L⁻¹. The material also showed excellent selectivity for Cs⁺ over other ions like Na⁺, K⁺, Mg²⁺, and Ca²⁺, with a distribution coefficient (K_d) of 3.9 × 10³ L g⁻¹, and maintained high stability and reproducibility after seven regeneration cycles. This study underscores the potential of HOM-SiO₂-PB as an effective and sustainable solution for removing radioactive Cs⁺ ions from contaminated water.

The contamination issues posed by antibiotics in the environment and their impact on human health are well-documented. This review stresses how important it is to come up with removal techniques to remove antibiotics from waterways. Different kinds of waste that contains antibiotics, like ciprofloxacin, erythromycin, levofloxacin, metronidazole, sulfamethoxazole, and trimethoprim, are reviewed. The review further overviews different biological, physical, and chemical methods, as well as combined removal methods. Biological treatments include both aerobic and anaerobic processes. Physical treatments include membrane technologies such as reverse osmosis, microfiltration, ultrafiltration, and nanofiltration. Along with chemical solutions like coagulation–flocculation, adsorption methods utilizing activated carbon, man-made materials, and biomass materials are discussed. Advanced oxidation processes (AOPs) such as electrochemical oxidation, ozonation, the Fenton process, and UV/H₂O methods are important for breaking down and removing pharmaceutical products, particularly membrane technology. The ability of these technologies to remove antibiotics from different types of wastewater depends on the chemical composition of the compounds. This review stresses the importance of using integrated treatment methods and highlights the critical role of AOPs in enhancing the degradation and removal of antibiotics, contributing to the development of more effective wastewater treatment strategies.

Septic systems often exceed regional soil treatment capacity, leading to failures and high-load pollutant discharge into surface and groundwater. Consequently, cost-effective post-treatment solutions are needed to protect public health and environment. Biochar, a carbonaceous sorbent, effectively treats septic tank effluent. However, the few studies on this topic have focused on its role in enhancing constructed wetland performance overlooking its potential as a filter material especially for key design factors like filter clogging and particle size. Additionally, flow regime effects and effective models for contaminant removal are underexplored. To inform pilot scale biochar filter design, we assessed the effect of particle size and flow regime (intermittent, continuous) on filter performance and longevity. The biochar effectively removed nutrients and organics from septic tank effluent with fine-sized biochar achieving the highest removal (total nitrogen (TN) 50.47%, ammonium 69.25%, chemical oxygen demand (COD) 53.83%, total organic carbon 67.85%) but lowest filtration rates (0.051 ± 0.006 m h⁻¹) and higher clogging susceptibility. Large-sized biochar treated more than eight times the volume of wastewater than fine-sized biochar over the same period. The stepwise cluster inference model we developed accurately predicted COD and TN removal (R² > 0.80). Our findings suggest that effective biochar filter design should prioritize large-diameter filters to maximize surface area reducing pressure loss and use vegetation and geotextiles to extend service life. Future studies should focus on reducing clogging in fine biochar, understanding biofilm formation, and modifying biochar for better contaminant removal. This study provides valuable insights into optimizing biochar filters for septic effluent treatment.

Phosphorus (P) significantly influences watershed eutrophication, largely depending on its speciation and composition. In urban rivers, phosphorus pollution has become a critical and challenging issue for water environment management. However, most studies on urban pollution have predominantly focused on total phosphorus (TP), with relatively limited research on phosphorus species. To align with the increasingly stringent environmental standards, there is a pressing need for refined management of phosphorus pollution. Characterizing pollution sources is a prerequisite for the prevention and control of phosphorus pollution in urban rivers. This study examined sediment samples from a river in Chengdu, a megacity in Southwest China impacted by typical pollution sources, to investigate the speciation of phosphorus and the compositional characteristics of dissolved organic matter (DOM). This research reveals significant differences in phosphorus speciation among sediments from various pollution sources in urban rivers. During sewage transport from point sources to receiving water bodies, the proportion of labile organic phosphorus (LP_o) decreases, while the proportion of non-labile organic phosphorus (NLP_o) increases. Among the inorganic P species associated with typical river pollution sources, exchangeable inorganic phosphorus (Ex-P_i) accounts for up to 80%, and iron-bound inorganic phosphorus (Fe-P_i) accounts for as much as 97%. An analysis of the DOM characteristics indicates that the sedimentary DOM is predominantly of biogenic origin with low humification. Redundancy analysis reveals the response mechanisms between phosphorus speciation and DOM. Different types of DOM release nutrients through photodegradation and biodegradation, thereby influencing the phosphorus speciation in sediments subjected to various pollution sources. This study clarifies the impact of DOM from different pollution sources on phosphorus speciation, providing a qualitative linkage that distinguishes the contributions of point and non-point source pollutions to phosphorus speciation. This study offers technical guidance for the prevention and control of eutrophication in urban rivers.