Sewage Treatment Research Articles

Effects of degradable and non-degradable microplastics on SPNEDPR-AGS system: Sludge characteristics, nutrient transformation, key enzyme, and microbial community

The environmental risk of microplastics (MPs) in aerobic granular sludge (AGS) system is unclear. This study evaluates the effects of non-biodegradable polyvinyl chloride microplastics (PVC-MPs) and biodegradable polylactic acid microplastics (PLA-MPs) on AGS systems. The results showed that both destroyed the performance of AGS systems, with PVC-MPs achieving this by disrupting the AGS structure, while PLA-MPs mainly by causing the expansion of filamentous bacteria induced through the stimulation by lactic acid metabolite (R0: 5.52 ± 0.49 μg/L; RPLA5: 11.67 ± 0.56 μg/L). Moreover, both MPs inhibited nitrogen removal by disrupting partial nitrification and endogenous denitrification and suppressed key microbes such as Candidatus Competibacter and Nitrosomonas. Metabolic pathway analysis and molecular docking have further confirmed the mechanisms by which MPs affect critical metabolic pathways and key enzymes. Consequently, the hazards of biodegradable MPs to the stable operation of sewage treatment plants should also be of concern.

Flow regime mechanisms in sequencing batch reactor (SBR) configurations on aerobic granular sludge formation using particle image velocimetry (PIV)

Indah Water Konsortium (IWK) consistently encounters challenges in managing over 7000 sewage treatment plants (STPs) due to inadequate infrastructure for centralized treatment. In addressing the challenge of land acquisition during STP upgrades, aerobic granular sludge (AGS) technology is worth exploring. The AGS systems are designed in sequencing batch reactors (SBRs) as a superior alternative to reduce land requirements. Research trends on AGS formation by flow regime mechanism are not yet fully comprehended for different SBR configurations (column and rectangular-type) as sufficient adjusted aeration rates in producing high-quality effluent. In this study, mature AGS of about 2736 μm was achieved at 57 days of formation in rectangular-type SBR by laminar flow with an aeration rate of 4 L/min. Due to transitional flow dynamics, there was a delay of about 54 % of mature AGS (2505 μm) on day 88 in column-type SBR at an aeration rate of 6 L/min. Microbial growth indicated that effective mixing was essential in wastewater treatment to ensure uniform distribution of oxygen, nutrients, and microorganisms, while excessive agitation must be avoided to maintain granular integrity. Thus, this research offers insights into the novelty of AGS for full-scale application.

Thermal treatment of sewage sludge: Impact of the sludge type and origin on the formation of recalcitrant compounds

In a municipal wastewater treatment plant, the thermal treatment of sludge can be an efficient way of increasing the final sludge cake dryness and boosting anaerobic digestion performances. However, such treatments generate refractory compounds which, once returned to headworks, can affect the quality compliance of effluent discharges, particularly concerning organic nitrogen. This study explores the effects of thermal hydrolysis (TH) and hydrothermal carbonization (HTC) of municipal sludge on the refractory organic compound production. A novel approach using ultra-performance liquid chromatography with size-exclusion chromatography and UV/fluorescence detection (UPLC-SEC-UV/Fluo) was employed to characterise recalcitrant dissolved organic matter (rDOM), which typically consists of Maillard reaction products (MRP). Specifically, UPLC-SEC-UV/Fluo was combined with principal component analysis (PCA) to enable a more thorough examination of the chemical diversity of MRPs produced. Greater temperatures during the thermal treatment step lead to increased production of rDOM and rDON. Protein-rich sludge with a great AS:PS ratio yields the greatest rDOM levels. MRP characteristics, such as molecular weight distribution and aromaticity, are primarily influenced by temperature and plant origin. UPLC-SEC-UV/Fluo provides information on the structures of MRPs useful to optimize the thermal treatment process and in understanding their fate in subsequent processes (chemical oxidation, biodegradation).These insights have practical implications for sludge treatment processes, including optimizing TH and HTC conditions to control rDOM production and adapt the sludge treatment line of a water resource recovery facility.

Biological and ecological consequences of combined biofilm, shellfish and phytoremediation along a wastewater treatment system from shrimp aquafarm

Biological treatments have been widely applied to remove wastewater nutrients, while single biological treatment is insufficient to achieve desired efficiency. Moving beyond removal of nutrient, equivalent focus on ecological consequences and biotic pollutants (e.g., pathogens) along the decontamination procedures is lacking. Herein, we established an efficient biological treatment system by integrating biofilm, shellfish and Spartina, which efficiently reduced the levels of wastewater nutrients (> 62.7 %) and sediment antibiotics (> 84.6 %) before discharge, with unsatisfied removal of total phosphorus and diversified potential pathogens. Our biological treatments potentiated C storage and ammoxidation process, and mitigated CH4 emission, of which are conjointly governed by the direct effect of nutrient pollutions and the indirect effect of antibiotics. In contrast, denitrification potential in wastewater and sediment was divergent, resulting in an uncertainty on net N2O emission. We identified diverse ammonia-oxidizing bacteria assistors that were candidates for improving ammoxidation. Intriguingly, bacterial biomakers could quantitatively and accurately diagnose wastewater entropy water quality index and sediment multi-nutrient cycling index, with overall 81.9 % and 91.1 % accuracy, respectively. The combined biological treatments can be a double-edged sword between water quality improvement and mitigating pathogenicity. These findings greatly deepen our understanding of the biological and ecological consequences of a biofilm-shellfish-phytoremediation system, and accordingly some strategies are informed for improving decontamination efficiency.

Occurrence of selected Covid-19 drugs in surface water resources: a review of their sources, pathways, receptors, fate, ecotoxicity, and possible interactions with heavy metals in aquatic ecosystems

The outbreak of the coronavirus disease 2019 (Covid-19) led to the high consumption of antibiotics such as azithromycin as well as corticosteroids such as prednisone, prednisolone, and dexamethasone used to treat the disease. Seemingly, the concentrations of these four Covid-19 drugs increased in wastewater effluents and surface water resources. This is due to the failure of traditional wastewater treatment facilities (WWTFs) to eliminate pharmaceuticals from wastewater. Therefore, the objective of the current research was to review the present state of literature on the occurrence of four Covid-19 drugs in water resources, the associated risks and toxicity, their fate, as well as the emergence of combined pollutants of Covid-19 drugs and heavy metals. From late 2019 to date, azithromycin was observed at concentrations of 935 ng/L, prednisone at 433 ng/L, prednisolone at 0.66 ng/L, and dexamethasone at 360 ng/L, respectively, in surface water resources. These concentrations had increased substantially in water resources and were all attributed to pollution by wastewater effluents and the rise in Covid-?19 infections. This phenomenon was also exacerbated by the observation of the pseudo-persistence of Covid-19 drugs, long half-life periods, as well as the excretion of Covid-19 drugs from the human body with about 30?90% of the parent drug. Nonetheless, the aquatic and human health toxicity and risks of Covid-19 drugs in water resources are unknown as the concentrations are deemed too low; thus, neglecting the possible long-term effects. Also, the accumulation of Covid-19 drugs in water resources presents the possible development of combined pollutants of Covid-19 drugs and heavy metals that are yet to be investigated. The risks and toxicity of the combined pollutants, including the fate of the Covid-19 drugs in water resources remains a research gap that undoubtably needs to be investigated.

Potential of two floating aquatic macrophytes in improving water quality: A case study in two tropical streams

The expansion of urbanization has led to significant adverse environmental effects, including the disposal of domestic sewage without treatment in water bodies. This impact contributes to the deterioration of water quality and poses serious risks to human health and the environment. In this context, effective and sustainable methods to mitigate the impacts should be explored, such as the use of plants capable of removing or degrading contaminants from water. The present study aimed to assess the phytoremediation potential of two free-floating aquatic macrophytes (Eichhornia crassipes and Pistia stratiotes) systems for enhancing the water quality collected from two polluted urban streams. The trials were performed in 25-L experimental units for seven days under ambient conditions. The water quality variables after the exposure period were compared to those at the beginning of the experiment to assess the potential improvements due to the presence of macrophytes. The systems with E. crassipes exhibited good performance in water samples from both streams, with reductions reaching 29.2% in dissolved solids, 36.8% in electrical conductivity, 44% in biochemical oxygen demand, 57% in nitrogen, and 45% in phosphorus. The systems with P. stratiotes also exhibited satisfactory outcomes, including 90 and 76.2% reductions in phosphorus levels of Santa Rita Stream and Galinha Stream, respectively, and 54% turbidity, and 38% biochemical oxygen demand in both streams. These findings highlight the potential of the two plant species for phytoremediation of polluted waters, considering their performance on short-term exposure. Therefore, this approach consists of a sustainable alternative by utilizing natural elements for environmental restoration, and the outcomes can contribute to future applications of phytoremediation techniques in developing countries.

Activation of PAA at the Fe-Nx Sites by Boron Nitride Quantum Dots Enhanced Charge Transfer Generates High-Valent Metal-Oxo Species for Antibiotics Degradation.

Advanced oxidation processes (AOPs) based on peracetic acid (PAA) offer a promising strategy to address antibiotic wastewater pollution. In this study, Fe-doped graphitic carbon nitride (g-C3N4) nanomaterials were used to construct Fe-Nx sites, and the electronic structure was tuned by boron nitride quantum dots (BNQDs), thereby optimizing PAA activation for the degradation of antibiotics. The BNQDs-modified Fe-doped g-C3N4 catalyst (BNQDs-FCN) achieved an excellent reaction rate constant of 0.0843 min-1, marking a 21.6-fold improvement over the carbon nitride (CN)-based PAA system. DFT calculations further corroborate the superior adsorption capacity of the Fe-Nx sites for PAA, facilitating its activation. Charge transfer mechanisms, with PAA serving as an electron acceptor, were identified as the source of high-valent iron-oxo species. Moreover, the BNQDs-FCN system preferentially targets oxygen-containing functional groups in antibiotic structures, elucidating the selective attack patterns of these highly electrophilic species. This research not only elucidates the pivotal role of high-valent iron-oxo species in pollutant degradation within the PAA-AOPs framework but also pioneers a wastewater treatment system characterized by excellent degradation efficiency coupled with low ecological risk, thereby laying the groundwork for applications in wastewater management and beyond.

Plastic-Degrading Microbial Consortia from a Wastewater Treatment Plant

Plastic waste pollution has become a global crisis, with millions of tons of plastic expected to accumulate in landfills and in natural environments, posing a serious threat to wildlife and human health. As current recycling methods remain inefficient, there is an urgent need for innovative enzymatic solutions to break down plastics and enable a circular economy approach. In this study, we explore the plastic-degrading potential of microorganisms enriched from activated sludge (AS) sourced from a municipal wastewater treatment plant (WWTP)—a known microplastic-contaminated industrial niche. Five microbial consortia (i.e., microbiomes) were enriched under selective pressure using low-carbon conditions and high concentrations of polyester polymers, including post-consumer PET, post-consumer PLA, and virgin PLA. Enrichment was performed for 100 days at 37 °C and 50 °C, followed by microbiomes isolation and metagenomic analysis to identify plastic-active bacteria and their enzymes. The results revealed that PLA polymers, but not post-consumer PET, were effectively degraded by the microbiomes, as confirmed by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC), showing significant molecular weight reduction compared to the abiotic controls. Microbial community analysis highlighted a distinct enrichment profile driven by the polymer composition and the temperature. At 50 °C, the Bacillales order became the predominant population, whereas at 37 °C, a more diverse community within the Proteobacteria and Actinobacteria phyla were selected. Nonetheless, the enriched microbial communities at both temperatures included phyla with members known for polyester degradation. Moreover, at 50 °C, enrichment of putative PET/PLA hydrolases was also observed. These findings suggest that AS microorganisms are a reservoir of polyester-active enzymes, particularly PLA-depolymerases, and hold promise for advancing biotechnological strategies to mitigate plastic pollution through re- and up-cycling.

Virus Removal from Real Wastewater as an Environmental Management Approach

The increased presence of resistant microorganisms in water promotes the need for supplementary measures to mitigate the water source’s contamination. Traditional treatments are inefficient in wastewater management at removing some emerging contaminants. Corbicula fluminea, an invasive species, can be used in the treatment due to their resistance and biofiltration capacity, working as a pest management strategy. In this study, this bivalve was used to promote the virus disinfection from the municipal wastewater treatment plant (MWTP) that enters (influent) and after the secondary treatment (effluent leaving the plant). JC virus, norovirus (GI, GII), and hepatitis A (HAV) were identified. C. fluminea promoted norovirus GI and GII removal after 72 h and a slight decrease in the JC virus concentration. These results prove the potential of this pest management approach to be used in virus removal. Furthermore, infectivity assays using mengovirus confirmed the correlation between the presence of the genome detected by PCR and the infectious virus particles. This highlights the potential of PCR as a reliable indicator of the infectious virus’s presence. However, such an infectivity assay proved that even when PCR results are undetectable, a reduced number of viruses may remain viable and able to infect susceptible cells in culture.

Fluorescence spectrometric analysis for diagnosing compositional variations in effluent organic matter by chlorination and ozonation

Analyzing the reactivity of organic matter to oxidants such as chlorination and ozonation is crucial for evaluating the effectiveness of water treatment systems and their potential impacts on environmental safety and human health. This study explored the changes in organic substances, specifically bovine serum albumin (BSA), humic acid sodium salt (HA), and effluent organic matter (EfOM) from a wastewater treatment facility during chlorination and ozonation. Four spectrometric techniques were employed: ultraviolet absorbance at 254 nm (UVA254), fluorescent excitation-emission matrix (EEM), synchronous fluorescence two-dimensional correlation spectroscopy (SF-2DCOS), and EEM-parallel factor integrated 2DCOS (EEM-PARAFAC-2DCOS). The findings revealed that ozone possesses superior oxidizing properties compared to chlorine, as evidenced by UVA254 and EEM analyses, resulting in more diverse structural modifications in EfOM. SF-2DCOS and EEM-PARAFAC-2DCOS provided comprehensive details on the direction and sequence of these changes, with EEM-PARAFAC-2DCOS delivering clear and intuitive insights. Protein-like and fulvic-like substances were susceptible to chlorination and ozonation, exhibiting different reaction sequences with each oxidant. Furthermore, variations in protein-like and humic-like components in actual EfOM samples may not align precisely with those in model substances, emphasizing the importance of considering specific organic matter variations in real EfOM samples compared to model substances. This research offered a deeper understanding of the reactivity and transformation of organic matter in wastewater treatment processes through simple and rapid spectroscopic methods, potentially improving the management and mitigation of undesired byproducts.

Development of cost functions for wastewater treatment by sequential batch reactor

Sequential batch reactor is widely used for industrial wastewater treatment. To consider sequential batch reactor for biological treatment of wastewater at a specific site, it is essential to ensure economy and sustainability. An approach for scrutiny of economic aspects may be based upon use of cost functions to compare sequential batch reactor and other technologies. Such approach will enable to conduct prudent analysis and select the most economic treatment scheme for a particular project. In most of published studies, the cost functions for conventional wastewater treatment systems are described with historic or some other data available to the investigators. No detailed engineering exercise related to cost functions for sequential batch reactor is cited in earlier research studies. In this document the novel and appropriate methodology has been presented to develop cost functions based on engineering, estimation and statistical approach to forecast cost for sequential batch reactor based wastewater treatment system.

Modelling and set-point definition for the development of a joint control system of two interconnected wastewater treatment plants and its application in practice

ABSTRACT The use of activated sludge models (ASMs) is a common way in the field of wastewater engineering in terms of plant design, development, optimization, and testing of stand-alone treatment plants. The focus of this study was the development of a joint control system (JCS) for a municipal wastewater treatment plant (mWWTP) and an upstream industrial wastewater treatment plant (iWWTP) to create synergies for saving aeration energy. Therefore, an ASM3 + BioP model of the mWWTP was developed to test different scenarios and to find the best set-points for the novel JCS. A predictive equation for the total nitrogen load (TN) coming from the iWWTP was developed based on real-time data. The predictive TN equation together with an optimized aeration strategy, based on the modelling results, was implemented as JCS. First results of the implementation of the JCS in the real environment showed an increase in energy efficiency for TN removal.

Multidrug-resistant ESBL-producing Klebsiella pneumoniae complex in Czech hospitals, wastewaters and surface waters

BackgroundMultidrug-resistant (MDR) bacteria pose a significant challenge to the treatment of infectious diseases. Of particular concern are members of the Klebsiella pneumoniae species complex (KpSC), which are frequently associated with hospital-acquired infections and have the potential to spread outside hospitals via wastewaters. In this study, we aimed to investigate the occurrence and phylogenetic relatedness of MDR KpSC from patients with urinary tract infections (UTIs), hospital sewage, municipal wastewater treatment plants (mWWTPs) and surface waters and to evaluate the clinical relevance of the KpSC subspecies.MethodsA total of 372 KpSC isolates resistant to third-generation cephalosporins and/or meropenem were collected from patients (n = 130), hospital sewage (n = 95), inflow (n = 54) and outflow from the mWWTPs (n = 63), river upstream (n = 13) and downstream mWWTPs (n = 17) from three cities in the Czech Republic. The isolates were characterized by antimicrobial susceptibility testing and whole-genome sequencing (Illumina). The presence of antibiotic resistance genes, plasmid replicons and virulence-associated factors was determined. A phylogenetic tree and single nucleotide polymorphism matrix were created to reveal the relatedness between isolates.ResultsThe presence of MDR KpSC isolates (95%) was identified in all water sources and locations. Most isolates (99.7%) produced extended-spectrum beta-lactamases encoded by blaCTX−M−15. Resistance to carbapenems (5%) was observed mostly in wastewaters, but carbapenemase genes, such as blaGES−51 (n = 10), blaOXA−48 (n = 4), blaNDM−1 (n = 4) and blaKPC−3 (n = 1), were found in isolates from all tested locations and different sources except rivers. Among the 73 different sequence types (STs), phylogenetically related isolates were observed only among the ST307 lineage. Phylogenetic analysis revealed the transmission of this lineage from patients to the mWWTP and from the mWWTP to the adjacent river and the presence of the ST307 clone in the mWWTP over eight months. We confirmed the frequent abundance of K. pneumoniae (K. pneumoniae sensu stricto and K. pneumoniae subsp. ozaenae) in patients suffering from UTIs. K. variicola isolates formed only a minor proportion of UTIs, and K. quasipneumoniae was not found among UTIs isolates; however, these subspecies were frequently observed in hospital sewage communities during the first sampling period.ConclusionThis study provides evidence of the transmission and persistence of the ST307 lineage from UTIs isolates via mWWTPs to surface waters. Isolates from UTIs consisted mostly of K. pneumoniae. Other isolates of KpSC were observed in hospital wastewaters, which implies the impact of sources other than UTIs. This study highlights the influence of urban wastewaters on the spread of MDR KpSC to receiving environments.

Are irbesartan and losartan ecotoxic for free-living marine nematodes? Response elements from taxonomic and functional features

The Angiotensin II receptor antagonists (ARA II) are primarily eliminated in domestic effluent and commonly observed in conventional wastewater from sewage plants and rivers that receive run-off from treatment facilities. Nevertheless, ARA II medications show low elimination efficiencies in municipal wastewater treatment facilities, suggesting possible harmful effects for aquatic life. In the current study, individual and combined treatments (187.5–900 ng/L) of two ARA II, losartan and irbesartan, were applied for one month to marine nematodes. The results highlighted significant decreases in the relative abundance of epistratum feeding groups, characterized by a spiral amphid shape, elongated/filiform tail shape, and c-p3 life history type, especially in the assemblages exposed to the highest concentrations and mixtures. The results also emphasized that losartan is more toxic compared to irbesartan, with antagonism interactions between both drugs. Another conclusion was that Longicyatholaimus longicaudatus and Marylynnia puncticaudata were sensitive to ARA II contamination, whereas the genera Theristus, Halalaimus, and Sabatieria species were tolerant.

Balancing Surface Chemistry and Flake Size of MXene-Based Electrodes for Bioelectrochemical Reactors.

MXenes have excellent properties as electrode materials in energy storage devices or fuel cells. In bioelectrochemical systems (for wastewater treatment and energy harvesting), MXenes can have antimicrobial characteristics in some conditions. Here, different intercalation and delamination approaches to obtain Ti3C2Tx MXene flakes with different terminal groups and lateral dimensions are comprehensively investigated. The effect of these properties on the energy harvesting performance from wastewater is then assessed. Regardless of the utilized intercalant molecules, MXene flakes obtained using soft delamination approaches are much larger (up to 10µm) than those obtained using mechanical delamination methods (<1.5nm), with a relatively higher content of ─O/─OH surface terminations. When employed in microbial fuel cells, electrodes made of these large MXene flakes have demonstrated a power density of over 400% higher than smaller MXene flakes, thanks to their lower charge transfer resistance (0.38Ω). These findings highlight the crucial role of selecting appropriate intercalation and delamination methods when synthesizing MXenes for bioelectrochemical applications.

Mutagenic drinking water and different levels of emerging micropollutants in Southern Brazil: A new challenge

This study investigated the presence of mutagenic compounds in raw and treated waters at four water treatment plants (WTP01 to WTP04), in southern Brazil. Samples were concentrated using Amberlite XAD4 resin and the acidic and neutral pH fractions tested by mutagenesis in Salmonella/microsome assay, using TA98, TA100 and YG7108 strains in presence and absence of metabolic activation (in vitro human S9). Mutagenesis in raw water was found only by strain TA98 at WTP03, with and without S9. In treated water, significant results were found for TA98 and TA100 strains, the latter being the most sensitive, with prevalence in acidic extract tests without S9. A chemical analysis was performed in the water samples, prioritizing the investigation of the presence and concentration of globally used Emerging Micropollutants (EMs). These compounds in water sources have the potential to contaminate drinking water due to the inefficiency of the conventional treatment employed and can generate disinfection by-products. WTP04 site had the highest total EMs in raw and treated waters, followed by WTP03 in treated water. These WTPs expressed an EMs removal capacity of 45% and only 23%, respectively. Some pharmaceuticals and caffeine showed the highest concentrations, and the latter was directly related to the disposal of domestic sewage in the aquatic ecosystem. The presence of EMs in water after treatment for all WTPs investigated suggests the importance of expanding guidelines that include EMs to establish better standards for the protection of aquatic life and better quality of the drinking water supplies.

Potential of different biobed–biopurification systems in the treatment of domestic sewage

ABSTRACT Four biobed–biopurification systems (BBPS1, BBPS2, BBPS3, and BBPS4) were constructed for the treatment of wastewater. These biobeds were filled with different materials such as rice husk, soil, vermicompost, gravel, and sand as substrates. A total of 5 L of primary treated effluent was provided to each setup and the effluents were analysed after different retention intervals, i.e., 0, 24, 48, and 72 h for different physio-chemical properties. The findings of the experiment showed that BBPS1, BBPS2, BBPS3, and BBPS4 were highly efficient in removing organic impurities but much less efficient in eliminating physical impurities. Much faster removal of the pollutants was achieved in BBPS1 and BBPS2 in comparison to BBPS3 and BBPS4. Both the BBPS1 and BBPS2 beds created favourable circumstances for organic contaminants to biodegrade as BOD removal efficiency was 55.35 and 56.44% and COD removal efficiency was 85.15 and 70.9%, respectively. Both the setups, i.e., BBPS1 and BBPS 2 are also much more efficient for the removal of biogenic contaminants, i.e., 85.7 and 73.2% for nitrate and 65.12249 and 76.99743% for phosphate, respectively. Overall, the performance of BBPS2 proved to be excellent in comparison to other setups, by calculation of its removal efficiency percent for different parameters.

Enhancing biomass fuel properties of municipal sewage sludge with carbon-rich and low ash energy crops common reed and miscanthus

Wastewater treatment plant effluents, sewage sludge, and purified water are important resources for producing renewable energy and implementing a carbon-neutral green energy policy due to their richness in organic matter and nutrients for energy crops. In the present study, the biomass energy potential, fuel quality, and combustion emission characteristics of sewage sludge and the energy plants Arundo donax and Miscanthus×giganteus and their mixtures were investigated to improve the combustion properties of sewage sludge. The plant biomass is produced using sewage treatment plant effluent as a nutrient source. The proximate and ultimate analysis results showed that adding plant biomass shifted the fuel value of the mixtures, mainly reducing the ash content and increasing the volatile matter and carbon content in the solid biofuel. The regression analysis showed that heating values of 25, 50, and 75 % biomass in sewage sludge mixtures linearly increased HHV and LHV values. The increase in volatile matter significantly improved the ignitability index of sewage sludge, reaching the optimum value of 35 at 75 % biomass mixtures for both crops. The NOx and SO2 emissions of the mixtures were lower than those of sewage sludge. Overall, the results indicate a synergistic effect between the combustion of biomass from energy crops and sewage sludge. A comprehensive comparison of proximate, ultimate, heating value, fuel indices, and gaseous emissions shows that the mixed fuels of 50 % biomass and 50 % sewage sludge can promote combustion and reduce emissions. Arundo had better biofuel properties than Miscanthus.

Hydrothermal synthesis of tungsten oxide photo/electrocatalysts: precursor-driven morphological tailoring and electrochemical performance for hydrogen evolution and oxygen reduction reaction application.

A hydrothermal approach was adopted to synthesize tungsten oxide (WO3) nanocatalysts with tailored morphology, using oxalic acid (H2C2O4) and hydrochloric acid (HCl) as precursors. This precursor-driven method yielded two distinct WO3 catalysts with unique structural and functional properties, viz. rod-shaped WO3-ox and nanoflower-shaped WO3-h. Characterization by FESEM and XRD revealed variations in morphology and crystallite size, contributing to their specialized catalytic applications. UV-Vis spectroscopy confirmed strong UV absorption by WO3-ox at 283.57nm with an optical band gap of 2.86eV, making it ideal for photocatalytic activities. Electrochemical analysis demonstrated that WO3-ox effectively drives the hydrogen evolution reaction (HER), while WO3-h is more suitable for the oxygen reduction reaction (ORR), an essential process in microbial fuel cells (MFCs). In practical applications, WO3-ox achieved an 83.9% degradation efficiency of methylene blue (MB) within 3h, validating its high photocatalytic efficacy for wastewater treatment. Meanwhile, WO3-h, utilized as a cathode catalyst in MFCs, significantly enhanced system performance, elevating chemical oxygen demand (COD) removal efficiency to 78.7% and improving coulombic efficiency by 3%. These findings underscore the potential of precursor-driven hydrothermal synthesis for optimizing WO3 catalysts tailored for energy and environmental applications, specifically in hydrogen production and sustainable wastewater treatment systems.

Detection of human enteric viral genes in a non-native winter crane fly, Trichocera maculipennis (Diptera) in the sewage treatment facilities at Antarctic stations

BackgroundThe Antarctic environment is susceptible to the introduction of non-native species due to its unique ecosystem, which has evolved under geographical isolation and extreme climatic conditions over an extended period. The recent introduction of the non-native winter crane fly, Trichocera maculipennis, to maritime Antarctica may pose a potential threat to the Antarctic ecosystem. In this study, we evaluated the possibility of the mechanical transmission of viruses by T. maculipennis.MethodsWe assessed the potential for the mechanical transmission of viruses using next-generation sequencing (NGS), quantitative PCR (qPCR), and virus isolation methods from T. maculipennis (Tm)-related samples (Tm body-wash fluid and Tm body-ground samples) collected from habitats and sewage treatment facilities located at three research stations in Antarctica.ResultsVirome analysis detected the genomic fragments of human adenovirus (AdV) and human endogenous retrovirus (HERV) in Tm-related samples. These viruses are commonly found in human feces. In addition, plant viruses, such as pepper mild mottle virus (PMMoV) and cucumber green mottle mosaic virus (CGMMV), both known indicators of enteric viruses, were identified in all Tm-related samples, likely originating from wastewater. However, the low quantities of AdV and HERV genomes detected in Tm-related samples through qPCR, coupled with the non-viability of AdV in virus isolation tests, indicate that T. maculipennis has limited potential for mechanical transmission under the conditions in the studies.ConclusionsOur study represents the first evaluation of the potential risk of non-native species serving as vectors for viral pathogens in Antarctica. Although the viruses detected were in relatively low quantities and non-viable, this study highlights the importance of further evaluating the risks associated with non-native species, particularly as the likelihood of their introduction increases to Antarctica due to climate change and increased human activity.Graphical abstract