Assessing the efficacy and mechanisms of glycol-contaminated water treatment through floating treatment wetlands.

The growing concerns surrounding water pollution and the degradation of ecosystems worldwide have led to an increased use of nature-based solutions (NbSs). This study assessed the feasibility of using floating treatment wetlands (FTWs) as an NbS to treat propylene glycol-contaminated water and quantitatively investigated different removal pathways. With an environmentally relevant concentration of propylene glycol (1,250 mg/L), FTWs containing Acorus calamus and mixed species demonstrated the highest average glycol mass removal efficacy (99%), followed by Carex acutiformis (98%), Juncus effusus (93%), and the control group without plants (10%) after 1 week. Additional mesocosm-scale experiments with varying FTW configurations, including surface coverage to reduce evaporation and photodegradation processes, and the addition of antibiotics to inhibit microbial activity, were conducted to quantify glycol removal pathways. Mass balance analysis results revealed that microbial biodegradation (33.3-39.7%) and plant uptake (37.9-45.2%) were the primary pathways for glycol removal. Only 15.5-19.5% of the glycol removal via evaporation and photodegradation was accounted in this study, which may be attributed to the mesocosm experimental setup (static water and no wind). Aligned with the broader discussion regarding biodiversity improvements and carbon storage capacity, this study demonstrated that FTWs are an environmentally friendly and effective NbS for addressing glycol-contaminated water.

Utilization of coal fly ash waste for effective recapture of phosphorus from waters.

Reutilization of the waste by-products from industrial and agricultural activities is crucially important towards attainment of environmental sustainability and the 'circular economy'. In this study, we have developed and evaluated a sustainably-sourced adsorbent from coal fly ash, which was modified by a small amount of lanthanum (La-FA), for the recapture of phosphorous (P) from both synthetic and real natural waters. The prepared La-FA adsorbent possessed typical characteristic diffraction peaks similar to zeolite type Na-P1, and the BET surface area of La-FA was measured to be 10.9 times higher than that of the original FA. Investigation of P adsorption capability indicated that the maximum adsorption (10.8 mg P g-1) was 6.14 times higher than that (1.8 mg P g-1) of the original fly ash material. The ζ potentials measurement and P K-edge X-ray Absorption Near Edge Structure (XANES) spectra demonstrated that P was bonded on La-FA surfaces via an adsorption mechanism. After applying the proposed adsorbent to real lake water with La/P molar ratios in the range from 0.5:1 to 3:1, the La-FA adsorbent showed the highest phosphate removal ability with a La/P molar ratio 1:1, and the P adsorption was similar to that performance with the synthetic solution. Moreover, the La-FA absorbent produced a negligible effect on the concentrations of total dissolved nitrogen (TDN), NH4+-N and NO3--N in water. This study thus provides a potential material for effective P recapture and details of its operation.

Selenium migration mechanism in wet FGD slurry: Experimental and DFT analysis.

Selenium (Se) is one of the hazardous trace elements emitted from coal-fired power plants. The Se migration behavior in wet flue gas desulfurization (FGD) slurry is still unclear, and the species of Se in FGD gypsum remains controversial. In this research, the bubbling experiments using simulated slurry with/without gypsum crystallization process were conducted. The experimental results indicated that pure gypsum has poor capability to capture Se components, and only selenite could be trapped in gypsum during its crystal growth stage. Furthermore, the DFT calculation was conducted to provide the microscopic information of Se adsorption and substitution characteristics during gypsum crystallization process. The research findings of this study could help understand the mechanism of Se migration process in FGD slurry, and facilitate the development of effective Se emission control technologies in the future.

[C_(19)-diterpenoid alkaloids from Aconitum austroyunnanense].

Eight C_(19)-diterpenoid alkaloids( 1-8) were isolated from the ethyl acetate soluble fraction of 95% ethanol extract of the ground roots of Aconitum austroyunnanense through various column chromatographies on silica gel,ODS,Sephadex LH-20 and MCI gel.Their structures were elucidated as 14α-benzoyloxy-13ß,15α-dihydroxy-1α,6α,8ß,16ß,18-pentamethoxy-19-oxoaconitan( 1),N-deethylaconitine( 2),spicatine B( 3),leucanthumsine A( 4),acofamine B( 5),macrorhynine B( 6),aconitilearine( 7),and ambiguine( 8) based on their chemical and physicochemical properties and spectroscopic data. Compound 1 was a new compound and alkaloids 2-8 were isolated from this plant for the first time. Some isolated alkaloids were tested in vitro for cytotoxic potential by employing the MTT method. As a result,alkaloid 1 exhibited weak cytotoxic activity against three tested tumor cell lines( A-549,He La,and Hep G2) with IC_(50) values less than 20 µmol·L~(-1).

[Amaryllidaceae alkaloids from Lycoris radiata].

Three aporphine-type alkaloids (1-3), three lycorine-type alkaloids (4-6), two crinane type alkaloids (7, 8) and one phenanthridine-type alkaloid (9) were isolated from the chloroform soluble fraction of 70% ethanol extract of the bulbs of Lycoris radiata through various column chromatographies over silica gel, ODS, Sephadex LH-20 and MCI. Their structures were elucidated as (+)-N-methoxylcarbonyl-1,2-methylenedioxyl-isocorydione (1), isocorydione (2), 8-demethyl-dehydrocrebanine (3), (+)-3-hydroxy-anhydrolycorine N-oxide (4), vasconine (5), pancratinine D (6), yemenine A (7), 11-O-acetylhaemanthamine (8), and 5,6-dihydro-5-methyl-2-hydroxyphenanthridine (9) based on their chemical and physicochemical properlies and spectroscopic data. Compound 1 was a new compound and alkaloids 2-9 were isolated and identified from this plant for the first time.

Combating hypoxia/anoxia at sediment-water interfaces: A preliminary study of oxygen nanobubble modified clay materials.

Combating hypoxia/anoxia is an increasingly common need for restoring natural waters suffering from eutrophication. Oxygen nanobubble modified natural particles were investigated for mitigating hypoxia/anoxia at the sediment-water interface (SWI) in a simulated column experiment. By adding oxygen nanobubble modified zeolites (ONMZ) and local soils (ONMS), the oxygen nanobubble concentrations (105-107 particles/mL) were several orders of magnitude higher in the water than the original water solution (104 particles/mL) within 24 h. In the column experiment, an oxygen-locking surface sediment layer was formed after capping with ONMZ and ONMS particles. The synergy of diffusion of oxygen nanobubbles and retention of oxygen in this layer contributes to both the increase of DO and reversal of hypoxic conditions. The overlying water had significantly higher dissolved oxygen (DO) values (4-7.5 mg/L) over the experimental period of 127 days in ONMZ and ONMS compared with the control systems (around 1 mg/L). Moreover, the oxidation-reduction potential (ORP) was reversed from -200 mV to 180-210 mV and maintained positive values for 89 days in ONMZ systems. In the control systems, ORP was consistently negative and decreased from -200 mV to -350 mV. The total phosphorus (TP) flux from sediment to water across the SWI was negative in the ONMZ and ONMS treated systems, but positive in the control system, indicating the sediment could be switched from TP source to sink. The oxygen-locking capping layer was crucial in preventing oxygen consumption caused by the reduced substances released from the anoxic sediment. The study outlines a potentially promising technology for mitigating sediment anoxia and controlling nutrient release from sediments, which could contribute significantly to addressing eutrophication and ecological restoration.