N-doped activated carbon (AC) was employed in a three-dimensional electrode system (3DES) to enhance the removal of sulfur-containing volatile organic compounds (S-VOC). The technical parameters for preparing N-doped AC were optimized based on CS2 removal and COS accumulation, where the mass ratio of AC to urea was 1:1.0, and the activation temperature and heat-treatment time were 400 °C and 120 min, respectively. When the mixing S-VOC were purified under an operating voltage of 8 V and peroxydisulfate concentration of 0.15 mol/L, CS2 removal in the 3DES system with N-doped AC reached 100% within 75 min, and was above 83% as purification time extended to 200 min. Additionally, the COS content in the outlet gas was usually undetectable within 120 min, and was lower than that in the other electrochemical systems. Modification of raw AC through urea impregnation and subsequent heat treatment significantly improved its surface structure and pore size distribution. Moreover, polar functional groups, such as C=O and pyridinic-N, increased noticeably, enhancing the S-VOC adsorption capacity and dielectric properties. Consequently, highly reactive substances were more efficiently activated in 3DES system with N-doped AC, and oxidizing species HO• and 1O2 had important contributions to S-VOC purification compared to SO4–• radicals. A pathway was proposed to elucidate the transformation of sulfur-containing components, such as CH3SH and CS2. This study provides an efficient approach for S-VOC purification.
The variation in pollutant concentrations among different water bodies poses a significant challenge for environmental surveillance. Traditional UV-Vis spectrometers, with fixed optical paths, face limitations in accurately determining Chemical Oxygen Demand (COD) and other water quality parameters. High concentrations surpass the detection limit, while low concentrations yield weak response signals, thereby compromising measurement accuracy. This study tackles these challenges by enhancing a UV-Vis spectrometer with a variable optical path. By utilizing a right-angle reflector for reflection and a stepping motor for control, measurements are conducted within the wavelength range of 190–700 nm. The instrument incorporates a spectral fusion algorithm to optimize spectral measurements within its operational range. Furthermore, a Partial Least Squares (PLS) model has been established for COD inversion by using laboratory standard solutions and field samples. The spectrometer has been tested in the nearshore waters of Shenzhen Bay, China, validating its applicability and the model’s accuracy. The utilization of a variable optical path UV-Vis spectrometer facilitates the acquisition of precise monitoring data with wide measuring range, thereby enabling the prompt detection of anomalies and subsequent reduction in reaction time.
Lead (Pb) exposure and vitamin D deficiency have been independently linked to adverse health outcomes, but the relationship between Pb toxicity and vitamin D remains unclear. Therefore, this retrospective study evaluated this relationship in childr,en and explored the potential mediating role of immune inflammation. 653 children were enrolled in this study. The multivariable-adjusted linear regression model was employed to evaluate the does-effect associations among Pb exposure on inflammatory biomarkers and serum vitamin D levels. Concomitantly, mediating effect models were applied to identify the potential role of inflammation in the relationships between Pb exposure and vitamin D malabsorption. Our findings revealed lower vitamin D levels and elevated inflammatory markers in children with Pb exposure. We observed a dose-dependent relationship between serum Pb levels and vitamin D status, mediated by inflammatory responses. Specifically, SII demonstrated a complete mediating effect on the association between serum Pb and vitamin D3 levels (effect value: −0.280; 95% CI: −0.774, −0.021). These findings suggest that Pb-induced chronic inflammation may contribute to vitamin D malabsorption in children, which subsequently facilitates the occurrence of immune diseases. This therefore highlights the need for interventions to reduce Pb exposure and protect children from immunological diseases and detrimental health outcomes.
Control of methane emissions has attracted widespread attention in the context of worldwide efforts to alleviate the greenhouse effect. Biofiltration, a green and cost-effective treatment process, has been widely used for the purification of methane. Currently, there is still a lack of comprehensive information on methane biofiltration. Herein, the state-of-the-art development trends of methane removal via biofiltration were comprehensively reviewed and commented on. First of all, this article reviewed the mechanisms of methane removal and the possible degradation pathways in biofilters. Secondly, the removal characteristics of single methane, methane mixed with volatile organic compounds or gaseous inorganic compounds by biofiltration, were summarized and discussed. Thirdly, the practical applications of methane biofiltration were summed up and some inspirations were proposed. Finally, the effective measures to improve the performance of methane biofiltration were put forward, and corresponding insights and future research directions for methane biofiltration were provided. This article can provide references for the practical applications of methane biofiltration and the mitigation of greenhouse effects.
The activation of oxygen by ferrous (Fe2+) to generate ·OH for contaminants degradation was inhibited due to the low utilization of oxygen, thus limiting its application in the practical environment. In this study, with the superior oxygenation capacity of micro-nano bubbles (MNBs) and the stronger O2 activation capacity of Fe2+-oxalate complexes, the MNBs/Fe2+/oxalate (Ox) system was constructed with 4,4′-sulfonyldiphenol (BPS) as the main target emerging contaminants (ECs), and to investigate the enhancement contribution and reinforcement mechanism of the involvement of MNBs to the removal efficiency of ECs in the Fe2+/Ox system. It was shown that the MNBs/Fe2+/Ox system could effectively degrade four structurally diverse ECs. In this case, with BPS as the main target contaminant, adding MNBs could increase the BPS removal efficiency by about 35%. In the MNBs/Fe2+/Ox system, the degradation rate of BPS depended on the concentration of FeII(Ox)22−, while the extent of degradation was mainly governed by FeII(Ox)22− and FeII(Ox)0. EPR and probe experiments showed that the reactive oxygen species (ROS) produced by the system and the iron hydroxide complexes produced by Fe3+ hydrolysis contributed to the degradation of BPS by oxidation and coagulation, respectively. In particular, ·OH and O2•− were the main reactive oxygen species produced by this system. Moreover, the involvement of MNBs significantly increased the formation of ROS and iron hydroxide complexes in the Fe2+/Ox system. The oxygenation process of MNBs used in this study enhanced the contaminants degradation performance of the Fe2+/Ox system and has broadened the application scope of MNBs.
As emerging organic contaminants (EOCs), azoles have been detected in various environments. However, comprehensive information on the impact of azoles on biological nitrogen removal (BNR) processes in wastewater treatment is limited, particularly regarding the denitrification process. This study aims to investigate the short-term (< 24 h) inhibitory potentials of ten azole compounds on major BNR processes, including nitrification, denitrification, and anaerobic ammonium oxidation (Anammox). At 6 mg/L, pyrazole (PA), triazole (TA), benzotriazole (BTA), and methyl-benzotriazole (MBTA) caused over 90% inhibition of nitrification activity. In comparison, denitrifiers exhibited greater resistance to these azoles, with calculated half-maximal inhibitory concentrations (IC50) of 126, 520, 412, and 152 mg/L, respectively. Regarding Anammox, the calculated IC50 was 20 mg/L for BTA and 18 mg/L for MBTA, while PA and TA showed no significant inhibition (< 20%) at concentrations up to 250 mg/L. The granular structure of Anammox sludge did not exhibit additional protection from the inhibition. The ammonium oxidizing process in nitrification showed the highest sensitivity to tested azoles. The results are expected to aid in evaluating the stability of BNR processes for treating azole-containing wastewater and in developing effective strategies to protect BNR systems from disruptions caused by azoles.
Aerobic granular sludge (AGS) is a neoteric wastewater treatment technology. The organic loading rate (OLR) exhibits a critical effect on the AGS formation process. The special role of OLR on AGS is rarely established, especially in a complicated environment. This work explored the influence of OLR on the AGS system under a micro-electric stimulation environment. The dynamic OLR affected the behaviors of AGS and reactor performance. AGS cultured under a dynamic OLR environment showed a more compact structure and the AGS system displayed an excellent capacity in removing pollutants. The stable texture of AGS is related to the extracellular polymeric substance (EPS). The main constitutions of EPS include tryptophan protein, tyrosine protein, humic acid-like substance, and fulvic acid-like substance. The OLR-varied environment may provide a selective condition, impacting the microbial population. The prevail bacteria were Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium (21.98%), Lactococcus (23.93%), and Chryseobacterium (5.58%) in OLR-varied AGS system. The evolution of the microbial population induced the change in bacterial community functions, such as carbohydrate metabolism, replication and repair, and membrane transport functions. This work provides valuable insights into the OLR on AGS processes, helping to the stability of AGS-based systems.
A small fraction of high-emitting vehicles make disproportionally large contributions to total fleet emissions. Therefore identifying high emitters under real driving conditions is crucial. In this study, two portable sensor platforms for high-emitter identification were used for online roadside measurements of vehicle-emitted NO, particle number (PN), and CO2 concentrations in Tangshan and Chengdu, respectively. The measured mean concentrations of vehicle-emitted NO, PN, and CO2 in Tangshan and Chengdu were 27.7–32.9 ppb, 5.4 × 103–8.2 × 103 #/cm3, and 7.3–8.2 ppm, respectively. Based on more than one month of second-by-second measured pollutant concentrations and passed vehicle information, a scheme was developed to identify high emitters. Among the 217000 and 43000 vehicles that passed the roadside sensor platforms at Tangshan and Chengdu, approximately 60% and 73% of vehicle exhaust plumes were successfully detected using the sensor platform. The NO and PN emission factors (EFs) tended to have log-normal distributions with the median values of 14.3 g/kg-fuel and 1.3 × 1015 #/kg-fuel, respectively. In general, the percentages of high-emitters identified at the Tangshan and Chengdu sites were 8.7% and 12.2% of the total identified vehicles, respectively. Among these high-emitters, 122 vehicles were randomly inspected on-site with the assistance of traffic officers, and the rate of correct identification was approximately 95%, which demonstrates that our methodology performs well in identifying real-world high-emitters. Overall, its low cost, good mobility, strong adaptability, and high correct identification rate make this roadside sensor platform a promising approach for real-world high-emitter identification.
This study promotes the integration of ecological green infrastructure with traditional gray infrastructure to tackle urban water management challenges and safety issues. Using the Storm Water Management Model (SWMM), we simulated runoff control in Beijing Tongzhou District Sponge City Pilot Area across 15 gray-green infrastructure scenarios and identified the optimal strategy through a cost-benefit analysis focusing on scenarios that meet runoff control standards. A cost-benefit evaluation framework was developed for gray-green infrastructure projects, employing payback period and net present value methods to assess cost-effectiveness. Findings revealed notable operational benefits, particularly in temperature and humidity regulation, which accounted for 88% of the total benefits. A standout scenario with a rapid payback period of 7.16 years and a net benefit of 1957.7 million yuan was highlighted. The research provides a holistic assessment, integrating environmental, ecological, and economic aspects of gray-green infrastructure, offering insights for effective green infrastructure deployment and evaluation in sponge city construction.
Clinical surveillance for respiratory pathogens has traditionally been challenging in low-resource settings, such as Western China. A low-cost wastewater monitoring network offers an alternative solution. To explore this, we first compared the sensitivity of a MeltArray-based qPCR assay, which detects 25 respiratory pathogens, with singleplex qPCR using both mock and real wastewater samples. We then employed this MeltArray assay to detect these respiratory pathogens in wastewater from a low-income region in Xi’an city from September 2023 to January 2024. Following this, qPCR and MLST were employed to quantify the dynamics of positive respiratory pathogens and confirm their genotypes. Results showed unusual surges in sewage influenza A virus (IAV) and adenovirus levels starting in October 2023, persisting until late December. Additionally, influenza B virus (IBV) outbreaks were identified beginning in late December. These findings matched the positivity rates reported by a sentinel hospital. For coronaviruses, HCoV-229E/OC43 were consistently detected in wastewater, while SARS-CoV-2 was occasionally found. The qPCR assays revealed continuous increases in sewage Mycoplasma pneumoniae and Hemophilus influenzae concentrations since September, both peaking in October. Genotyping confirmed the circulation of specific bacterial genotypes in the region. Therefore, to the best of our knowledge, this study is possibly the first to evaluate the efficacy of qPCR assays for wastewater monitoring of respiratory bacterial pathogens. Thus, these findings provide significant insights into the co-circulation of various respiratory pathogens during the autumn and winter of 2023, thereby suggesting that wastewater surveillance could be a powerful tool for the early warning of respiratory diseases.
Pathogenic microorganisms pose a significant threat to water safety. Emerging disinfection processes that combine far-ultraviolet radiation with oxidants offer promising strategies for controlling these pathogens. This study investigated advanced disinfection processes (ADPs) that use 222 and 254 nm far-ultraviolet radiation in conjunction with hydrogen peroxide (H2O2), sodium percarbonate (SPC), and persulfate (PDS) to inactivate E. coli in water. The inactivation efficiencies of E. coli were measured as 6.50-log for UV222 alone and 2.50-log for UV254 alone at 0.0014 Einstein/L. When using UV222-ADPs, the inactivation ranged from 5.20-log to 6.50-log, while UV254-ADPs achieved inactivation levels of 2.55-log to 2.95-log. The inactivation occurred in the order of UV222 ≥ UV222-ADPs > UV254-ADPs > UV254, which was related to photon competition between E. coli and the oxidants, superiority of UV222 radiation compared with UV254 radiation, and the yields of radicals. When UV222 was combined with H2O2, SPC and PDS, the absorption fractions of 222 nm photons by E. coli reduced from 13.7% to 13.1%, 12.4%, and 12.2%, respectively, and the actual inactivation also decreased. This reduction was attributed to the light shielding effect of the oxidants. In addition, intracellular organic matter released from ruptured bacterial cell membranes during UV222-ADPs could be further damaged by UV222 photons and radicals. The effectiveness of UV222-ADPs was also demonstrated in real water samples. Moreover, it was shown that UV222-ADPs are less susceptible to dissolved organic matter (DOM) than UV222 alone. This study provides novel insights into disinfection by UV222-ADPs in water.
This narrative review evaluates the impacts of climate change, referring to the long-term shifting of temperature that could have wide-ranging impacts on societies across the globe. Moreover, changes in climatic factors could induce changes in environmental factors and/or the related health status in several ways, especially in tropical countries where both infectious and noninfectious diseases are prevalent. This review explores the relationships between diseases in tropical regions and climate change. An examination of the overall impacts of environmental factors in these countries highlights changes in health status and disease patterns related to food-borne and water-borne diseases, vector-borne diseases and remarkable noncommunicable diseases. Adaptation and mitigation measures, such as bolstering health systems and disease surveillance, are needed to address these findings. Resilience and public awareness are key components of effective policies, and cross-sector cooperation and sustainable financial practices are essential for improving health outcomes and combating diseases connected to climate change.
Efficient and environmentally sound treatment of soybean processing wastewater sludge is importance for industrial sustainability. Bioconversion by black soldier fly larvae (BSFL) has been extensively applied in biowaste recycling because of its efficacy and production of high-value outputs. However, the performance and underlying bacterial drivers of the BSFL-mediated sludge bioconversion require further investigation. This study investigated the larval bioconversion of the sludge, emphasizing waste reduction, larval quality, and the relationship between these aspects and bacterial communities. The inoculation with BSFL remarkably enhanced the reduction in the initial substrate (i.e., sludge plus wheat bran as the bulking material). This intervention also yielded a high larval bioconversion rate of approximately 22% along with a higher larval crude protein content ranging from 45%–48% and a 17 amino acid to protein ratio of 86%–92%. Higher dissolved organic carbon concentrations (15–22 g/kg), coupled with lower germination indices (< 5%), indicated that the residues retained biological instability after the bioconversion and required further composting. The potential risk of heavy metal pollution from mature larvae may not be a concern when used as aquaculture feed. The larval gut exhibited a higher bacterial diversity than the residues. Ammonium concentration increased with wheat bran and was positively correlated with the genera Lysinibacillus and Castellanella. Diverse gut bacteria (Olivibacter, Paracoccus) primarily facilitated notable sludge reduction. Sphingobacteria, Acinetobacter and Glutamicbacter played key roles in larval growth traits (biomass, protein, and amino acids). This study indicated that the valorization of soybean-processing-sourced sludge was achieved via functionally important BSFL intestinal microbiota, providing an efficient recycling approach for similar waste streams.
