Exposure to PM10, NO2, and O3 and impacts on human health

Modeling of methane formation in gravity sewer system: the impact of microorganism and hydraulic condition

Sewer system is an important source of methane formation and emission. Although some models were developed to predict methane production in sewers, the impact of microorganism amount was indicated indirectly. Here, seven laboratory scale sewers with varied wall-shear stresses were established. The biofilm thickness, microorganism amount, DO distribution, microorganism community in the biofilms and methane production in the sewers were measured. Based on experimental data, an empirical model was developed to directly describe the relationship between methane production, microorganism amount and wall-shear stress. The results showed that DO concentration decreased significantly along the biofilm depth under varied wall-shear stress, and the DO reduction rate was positively related to the intensity of wall-shear stress. The dominant archaea species in mature biofilms were similar whereas the proportions showed remarkable differences. The abundance of Methanospirillum in biofilms cultured at 2.0 Pa wall-shear stress was 53.08% more than that at 1.29 Pa. The maximum methane production rate, 2.04 mg/L wastewater day, was obtained when the wall-shear stress kept at 1.45 Pa, which was 1.2-fold higher than the minimum in sewer at 0.5 Pa. The R² value of the established model was 0.95, the difference between the measurement and simulation was in the rage of 1.5–13.0%.

Solid fuel use for cooking and its health effects on the elderly in rural China

Indoor air pollution is mainly caused by solid fuel use for cooking in developing countries. Many previous studies focused on its health risks on the children and in specific local area. This paper investigates household energy usage and transition for cooking in rural China and the health effects on the elderly. A national large-scale dataset CHARLS (China Health and Retirement Longitudinal Study) covering 450 villages and communities is employed. Logit regressions were used to quantitatively estimate the effects, after controlling for some factors such as income, demographic, and geographical variables. The results robustly show that compared to non-solid fuels, solid fuel use significantly increases the possibility of chronic lung diseases (30%), exacerbation of chronic lung diseases (95%), seizure of heart disease (1.80 times), and decreases self-evaluated health status of the elderly (1.38 times). Thus, it is urgent to improve clean energy access for cooking in rural China.

High lithium tolerance of Apocynum venetum seeds during germination

Identification and use of lithium (Li) accumulator plants is a promising strategy to remediate Li-contaminated soil. Apocynum venetum is reported as a Li accumulator. However, its tolerance to Li salt during germination is still unknown. The primary aim of this study was to investigate the effects of two Li salts on seed germination of A. venetum. At the same concentrations, germination percentages in LiCl solution were higher than that in Li₂CO₃ solution. At 25 °C, seeds germinated to 4-90% at 0-400 mmol L^-1 LiCl and 3-91% at 0-150 mmol L^-1 Li₂CO₃. Low concentration (0-50 mmol L^-1) of LiCl did not significantly affect germination percentage. The simulated critical value (when germination percentage is 50%) in LiCl solution is 196 mmol L^-1, and 36 mmol L^-1 for Li₂CO₃. Activity of α-amylase, contents of MDA, soluble sugar, and proline were dramatically affected by Li salts, especially at medium and late germination stages. When compared with control, α-amylase activity of seeds under 25 mmol L^-1 LiCl and 10 mmol L^-1 Li₂CO₃ did not show significant difference. Germination percentage and index, radicle length, and physiological parameters indicate A. venetum seeds are highly tolerant to Li salts during germination, especially LiCl.

Preparation of high-yield N-doped biochar from nitrogen-containing phosphate and its effective adsorption for toluene

Novel biochar was prepared from plant-based biomass by the addition of nitrogen-containing phosphates (NCPs), including ammonia phosphate (AP), ammonia polyphosphate (APP) and urea phosphate (UP). The results demonstrated that with the addition of NCPs, the yield of biochar could be significantly increased from about 30% to up to about 60%. The pore structure of the biochar was significantly improved, and the AP-prepared biochar obtained a higher S_BET and V_tot of 798 m² g⁻¹ and 0.464 cm³ g⁻¹, respectively. Moreover, the surface chemistry of the NCP-prepared biochar was affected, and N heteroatoms could be successfully doped on the surface of biochar, up to 4.16%. Furthermore, through TG-FTIR and XPS analysis, some possible interactions between plant-based biomass and NCPs during the pyrolysis process were proposed to explore the mechanisms of the preparation process, including the P route and N route, in which the H₃PO₄ and NH₃ gradually generated during the heating process played the dominant roles for the high yield N-doped biochar. All the NCP-prepared biochar presented good toluene adsorption capacities from 175.9 to 496.2 mg g⁻¹, which were significantly higher than that of blank char (6.5 mg g⁻¹).

Novel biochar was prepared from plant-based biomass by the addition of nitrogen-containing phosphates (NCPs), including ammonia phosphate (AP), ammonia polyphosphate (APP) and urea phosphate (UP).

One-step synthesis of S,B co-doped carbon dots and their application for selective and sensitive fluorescence detection of diethylstilbestrol

S,B co-doped carbon dots were synthesized, and their application in the detection of diethylstilbestrol.

Nitrogen nutrition in cotton and control strategies for greenhouse gas emissions: a review

Cotton (Gossypium hirustum L.) is grown globally as a major source of natural fiber. Nitrogen (N) management is cumbersome in cotton production systems; it has more impacts on yield, maturity, and lint quality of a cotton crop than other primary plant nutrient. Application and production of N fertilizers consume large amounts of energy, and excess application can cause environmental concerns, i.e., nitrate in ground water, and the production of nitrous oxide a highly potent greenhouse gas (GHG) to the atmosphere, which is a global concern. Therefore, improving nitrogen use efficiency (NUE) of cotton plant is critical in this context. Slow-release fertilizers (e.g., polymer-coated urea) have the potential to increase cotton yield and reduce environmental pollution due to more efficient use of nutrients. Limited literature is available on the mitigation of GHG emissions for cotton production. Therefore, this review focuses on the role of N fertilization, in cotton growth and GHG emission management strategies, and will assess, justify, and organize the researchable priorities. Nitrate and ammonium nitrogen are essential nutrients for successful crop production. Ammonia (NH₃) is a central intermediate in plant N metabolism. NH₃ is assimilated in cotton by the mediation of glutamine synthetase, glutamine (z-) oxoglutarate amino-transferase enzyme systems in two steps: the first step requires adenosine triphosphate (ATP) to add NH₃ to glutamate to form glutamine (Gln), and the second step transfers the NH₃ from glutamine (Gln) to α-ketoglutarate to form two glutamates. Once NH₃ has been incorporated into glutamate, it can be transferred to other carbon skeletons by various transaminases to form additional amino acids. The glutamate and glutamine formed can rapidly be used for the synthesis of low-molecular-weight organic N compounds (LMWONCs) such as amides, amino acids, ureides, amines, and peptides that are further synthesized into high-molecular-weight organic N compounds (HMWONCs) such as proteins and nucleic acids.

Substrate-independent luminescent phage-based biosensor to specifically detect enteric bacteria such as E. coli

Water quality is a major safety consideration in environments that are impacted by human activity. The key challenge of the COMBITOX project is to develop a unique instrument that can accommodate several biodetector systems (see the accompanying COMBITOX papers) able to detect different pollutants such as bacteria, toxins, and heavy metals. The output signal chosen by our consortium is based on luminescence detection. Our group recently developed phage-based biosensors using gfp as a reporter gene to detect enteric bacteria in complex environments such as sea water, and the main challenge we faced was to adapt our biodetector to a luminescent signal that could fit the COMBITOX project requirements. Another key point was to use a substrate-independent reporter system in order to avoid substrate addition in the detection prototype. This paper describes the development of a phage-based biodetector using a luminescent and substrate-independent output to detect some enteric bacteria, such as Escherichia coli, in water samples. We have successfully engineered various prototypes using the HK620 and HK97 bacteriophages that use different packaging systems, and both proved functional for the integration of the full luxCDABE operon controlled by two different bacterial promoters. We show that the luxCDABE operon controlled by the PrplU bacterial promoter is the most efficient in terms of signal emission. The emission of luminescence is specific and allows the detection of 10⁴ bacteria per milliliter in 1.5 h post-infection with neither a concentration nor enrichment step.

Semi-autonomous inline water analyzer: design of a common light detector for bacterial, phage, and immunological biosensors

The use of biosensors as sensitive and rapid alert systems is a promising perspective to monitor accidental or intentional environmental pollution, but their implementation in the field is limited by the lack of adapted inline water monitoring devices. We describe here the design and initial qualification of an analyzer prototype able to accommodate three types of biosensors based on entirely different methodologies (immunological, whole-cell, and bacteriophage biosensors), but whose responses rely on the emission of light. We developed a custom light detector and a reaction chamber compatible with the specificities of the three systems and resulting in statutory detection limits. The water analyzer prototype resulting from the COMBITOX project can be situated at level 4 on the Technology Readiness Level (TRL) scale and this technical advance paves the way to the use of biosensors on-site.

Bacterial host and reporter gene optimization for genetically encoded whole cell biosensors

Whole-cell biosensors based on reporter genes allow detection of toxic metals in water with high selectivity and sensitivity under laboratory conditions; nevertheless, their transfer to a commercial inline water analyzer requires specific adaptation and optimization to field conditions as well as economical considerations. We focused here on both the influence of the bacterial host and the choice of the reporter gene by following the responses of global toxicity biosensors based on constitutive bacterial promoters as well as arsenite biosensors based on the arsenite-inducible P_ars promoter. We observed important variations of the bioluminescence emission levels in five different Escherichia coli strains harboring two different lux-based biosensors, suggesting that the best host strain has to be empirically selected for each new biosensor under construction. We also investigated the bioluminescence reporter gene system transferred into Deinococcus deserti, an environmental, desiccation- and radiation-tolerant bacterium that would reduce the manufacturing costs of bacterial biosensors for commercial water analyzers and open the field of biodetection in radioactive environments. We thus successfully obtained a cell survival biosensor and a metal biosensor able to detect a concentration as low as 100 nM of arsenite in D. deserti. We demonstrated that the arsenite biosensor resisted desiccation and remained functional after 7 days stored in air-dried D. deserti cells. We also report here the use of a new near-infrared (NIR) fluorescent reporter candidate, a bacteriophytochrome from the magnetotactic bacterium Magnetospirillum magneticum AMB-1, which showed a NIR fluorescent signal that remained optimal despite increasing sample turbidity, while in similar conditions, a drastic loss of the lux-based biosensors signal was observed.

Preparation of cationic polymeric nanoparticles as an effective adsorbent for removing diclofenac sodium from water

New cationic polymeric nanoparticles were synthesised with high adsorption capacities for diclofenac sodium and showed fast adsorption and desorption.