环境•农林最新文献

The synthesis of a covalent triazine framework polymer (CTF-P) from the polymerization of piperazine and cyanuric chloride is reported in this study. The prepared CTF-P was used as photocatalyst to evaluate its activity for the degradation of ofloxacin (OFL), an emerging concern in water. The material was characterized using N₂ isotherms, XRD, FTIR, TEM, SEM, EDX and DRS-UV–Vis analyses. FESEM and TEM images confirmed that CTF-P exhibits a nanosheet-like structure. The findings showed that 98.6% of OFL would degrade under pseudo-first-order kinetics in 120 min of exposure to 50 W LED light. Quenching tests showed that holes, superoxide, and exited electrons play crucial roles in the degradation of OFL. The recyclable nature of CTF-P was demonstrated over five cycles, maintaining an impressive 88.9% removal efficiency, which showcases the feasibility of the proposed photocatalyst for reuse. The strategic design of photocatalysts based on the CTF framework offers a novel approach to enhancing the degradation of organic pollutants.

Over the past few decades, numerous researchers have focused on creating novel, practical, affordable, and easy-to-use techniques for determining and estimating organic pollutants in aquatic environments. This study aims to determine ADP drug using KMnO₄ as reagent by spectrofluorometric method. At pH 4, the fluorescence spectrum of the produced complex ion association [Mn (II)-ADP] was obtained at 420 nm with high intensity. The quantification and detection limits were 0.56 and 0.18 µg mL⁻¹, respectively. The Stern–Volmer and the apparent binding constant were calculated to be 158.6 and 159.95 L mol⁻¹, respectively. Also, different variables were investigated such as KMnO₄ concentration, and the optimized conditions were pH 4, and 0.1 µg mL⁻¹, respectively. In studied samples, adapalene recovery percentages ranged from (90–95%), and (90–93%) in wastewater, and sea water, respectively. These results represent an exceptional and a perfect recovery percentage.

In this paper, the pollen morphology characteristics, chromosome karyotype characteristics, floral pigments, and scents components of 15 species and hybrids of Syringa L. were obtained by means of scanning electron microscopy, root tips quash method, HPLC–MS, and GC–MS, and the 15 species and hybrids of Syringa L. were clustered separately with each index. Results show that the 15 species and hybrids of Syringa L. are clustered into four different groups separately by each index. In morphological taxonomy, S. microphylla Diels and S. microphylla ‘ShuangJi’, which belong to the Ser. Pubescentes family, original and hybrid species, most varieties of Ser. Syraega are basically cluster into the same group, which is consistent with morphological taxonomy. The findings indicate that the aforementioned four indicators are significantly related to the morphological classification of Syringa L. Among them, the clustering results of pollen morphology were the most consistent with morphological classification. The relationship between the above four aspects and the morphological classification of Syringa L. groups has not been reported in previous related researches, especially indicating the relationship between microscopic morphological indicators, specific physiological components and Syringa morphological classification. The research results have novelty, scientificity and comprehensiveness.

In this present study, initially, activated carbon is derived from eucalyptus wood utilizing a single-stage activation method. Then, the developed sample is characterized by different characterization and analytical techniques such as (i) proximate analysis, (ii) ultimate analysis, (iii) Brunauer–Emmett–Teller (BET) surface area analysis, (iv) Barrett-Joyner-Halenda (BJH) pore size analysis, (v) Scanning Electron Microscopy (SEM) surface morphology analysis, (vi) Fourier transform infrared spectroscopy (FTIR) surface chemistry analysis, and (vii) Thermogravimetric Analysis (TGA) thermal stability analysis to evaluate its surface features and ensure suitability as an adsorbent for carbon capture. After that, the characterized adsorbent is filled inside the capture unit and coupled to a test engine. This study uses a computerized diesel engine, and the test engine is operated by employing two distinct test fuels: (i) petro-diesel (D100) and (ii) 80% Jatropha methyl ester (JME) + 20% D100 (JME20). The adsorbent performance is examined in terms of CO₂ adsorption, and the adsorbent sample’s adsorption parameter is discussed. The results obtained from experimental findings are compared with the adsorbent performance and fuels used in a test engine. The experimental test results showed that about 44% and 38% of CO₂ emissions are captured for D100 and JME20 fuel operations, respectively.

Graphical Abstract

In this study, polyethyleneimine-mesoporous silica composite materials were prepared and the effectiveness of the promising sorbents in adsorbing CO₂ was evaluated, along with the impacts of the silica support types (Mesoporous Silica Nanoparticles (MSN) and Mobil Composition of Matter No.48 (MCM-48)), polyethyleneimine (PEI) loading percentages (50 and 70 wt.%), calcination, surface functionalization by alkyl chains (CTMABr), and adsorption temperature (75 and 100 °C). The analysis’s results revealed that the pores of the sorbents were mostly covered with PEI molecules following PEI-functionalization, and the specific surface area and pore volume were also reduced with rising amine content. The highest CO₂ adsorption capacities were achieved for UC-MCM-48–50 and UC-MSN–50 at 2.26 mmol/g and 3.31 mmol/g, respectively. The CO₂ uptake capacities of CC-MSN–50 and CC-MCM-48–50, composed by dispersing CTMABr surfactant with the calcined materials before incorporating PEI, were remarkably similar to those of non-surfactant functionalized adsorbents. When the temperature’s influence on CO₂ adsorption capacity was evaluated, the maximum holding capability adsorbent UC-MSN–50 had a slight increase in adsorption capacity (~ 3.6%), whereas UC-MCM-48–50 had a considerable drop (~ 23.9%) as the temperature elevated to 100 °C. Besides, Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherms were used to model pure CO₂ adsorption data, and a thermodynamic study was applied. In conclusion, a low-cost and more beneficial approach, which included less PEI handling and eliminating the calcination step, was implemented to enhance the CO₂ sorption capacity of composites of PEI with the long alkyl chain template MCM-48 or MSN silica support materials.

Air pollution is widespread and poses significant health risks, including respiratory and cardiovascular diseases, cancer, and even lead to death. Among the strategies to mitigate exhaust gases, biological treatment technology has gained significant attention due to its high treatment efficiency, cost-effectiveness, and environmental friendliness. This technology has become a key area of research. This paper discusses the principles, scope, advantages, and cons of various biological treatment methods, including biofiltration, biotrickling filtration, bioscrubbing, and membrane bioreactors. Noteworthy advantages of current biological treatment for exhaust gases include cost savings, reduced energy consumption, and lower secondary pollution risks. However, limitations exist, such as the treatment of treating low concentration and high flow rate of exhaust gases, and the dependence on specific microbial species and fillers. Combining biological treatments with other technologies could significantly improve effectiveness. The review also explores challenges and future directions, aiming to enhance the application of biological treatments in exhaust gas management towards sustainable development.

Graphical Abstract

This study investigates aerobic landfill stabilization using three bioreactors with different operational modes: R1 with oxygenated (~ 90% pure oxygen) leachate recirculation and waste mass aeration, R2 with conventional leachate recirculation (without oxygenation) and waste mass aeration, and R3 as an anaerobic control. The waste stabilization was assessed by reductions in COD, ammonia nitrogen, NOx (nitrate and nitrite nitrogen), and total phosphorus removal, as well as reductions in volatile solids and subsidence of waste height. Among the three reactors, R1 exhibited the best performance, with ~ 85% COD removal efficiency likely due to the high DO content during leachate recirculation. Additionally, R1 achieved ~ 99% removal efficiency of ammonia nitrogen through rapid aerobic nitrification. An exponential attenuation model was applied to describe the degradation of organic substances, with degradation rates of COD and NH₃-N increasing from 0.005 and 0.007 d⁻¹ to 0.01 and 0.021 d⁻¹, respectively, when leachate recirculation and oxygenation were applied. Reactor R1 could meet the COD emission limit of 150 mg/L, as specified by WHO surface water regulations, by day 478, while reactors R2 and R3 are expected to achieve this level by days 567 and 742, respectively. The results indicated that the aerobic conditions in R1, supplemented with pure oxygen (~ 90%) aeration, elicited rapid stabilization of the simulated landfill waste, reflected by a high waste settlement of ~ 63.5%. The findings suggest that this strategy can improve landfill stabilization in practice, optimize landfill space reuse, and enhance MSW management by reducing the load on existing leachate treatment facilities.