The effect of cyanobacterial bloom decay on water quality and the complete degradation of cyanobacterial blooms in a short period were examined by an enclosure experiment in Gonghu Bay of Lake Taihu,China.Water quality parameters as well as taste and odor compounds during the breakdown of cyanobacterial blooms were measured.Results showed that the decay of cyanobacterial blooms caused anoxic water conditions,decreased pH,and increased nutrient loading to the lake water.The highest concentrations of dimethyl sulfide (DMS),dimethyl trisulfide (DMTS),and β-cyclocitral were observed in the anoxic water,at 62331.8,12413.3,and 1374.9 ng/L,respectively.2-Methylisoborneol was dominant during the live growth phase of cyanobacterial blooms,whereas DMS and DMTS were dominant during the decomposition phase.Dissolved oxygen,pH,and chlorophyll a were negatively correlated with DMS,DMTS,and β-cyclocitral,whereas total phosphorus,total nitrogen,and ammonium (NH4+-N) were positively correlated with DMS,DMTS,β-cyclocitral,and β-ionone.The experimental results suggested that preventing the anaerobic decomposition of cyanobacterial blooms is an important strategy against the recurrence of a malodor crisis in Lake Taihu. 相似文献
Environmental Science and Pollution Research - A coal fire is one of the most serious disasters in coal mining. To improve the efficiency of an inert gas for extinguishing the fire, the adsorption... 相似文献
In this work, hexadecyltrimethylammonium-bromide (HTAB)-modified polythiophene (PTh)/TiO2 nanocomposite (HTAB/PTh/TiO2) was applied to remove uranyl ions (UO22+). FT-IR, XRD, ζ potential, TGA, SEM, and XPS were utilized to obtain the chemical and physical properties of HTAB/PTh/TiO2. The effects of HTAB content, preparation temperature, and adsorption conditions on UO22+ removal were investigated comprehensively. And the UO22+ adsorption process on HTAB/PTh/TiO2 was fitted to the Sips model with a saturated adsorption capacity of 234.74 mg/g, which was 6 times over TiO2. The results suggested that the surfactant of HTAB can significantly improve the adsorption ability of TiO2 for UO22+ ions. This work provides a strategy of surfactant modification for enhancing the separation and recovery ability of adsorbent toward UO22+ in the radioactive wastewater.
Environmental Science and Pollution Research - The hazards of particulate matter (PM2.5) on human respiratory health have been previously reported. However, the molecular mechanisms underlying... 相似文献
In plant configuration of landscaping, herbaceous plant is often inter-planted with ornamental tree species. But unreasonable plant collocation may reduce the effectiveness of afforestation for the inhibition effect of tree on the growth of understory, and further more affect the greening effect. Camphor (Cinnamomum camphora) is widely planted in landscaping accompanying herbaceous plants including morning glory (Pharbitis nil). But camphor was reported to have allelopathic effect on its adjacent plant, therefore correct selection and collocation of plants has important significance to obtain good greening effect. This research aimed to study by a pot experiment the effects of decomposing leaf litter of Cinnamomum camphora on the growth, phenological traits of Pharbitis nil, as well as modification of these effects by nitrogen application. Three application rates of C. camphora leaf litter including 25, 50 and 100 g/pot (denoted by L25, L50 and L100, respectively) and a control (CK) were implemented. Nitrogen application began on the 34th d of decomposition, with 0.39 g urea being divided into three equal portions and added continuously to each pot. The results showed that (1) The height, basal diameter, leaf area and biomass production of Pharbitis nil were all inhibited sharply by exposure to the leaf litter, being decreased by 32.85%-83.78%, 5.23%-23.00%, 30.31%-58.47%, and 40.34%-84.54%, respectively, with the inhibition effect increasing both in intensity and stability with the increase of leaf litter. Such inhibition effect was obviously alleviated by exogenous nitrogen application. (2) The flowering dynamics of Pharbitis nil was greatly impacted by the leaf litter, with the flower initiation 2.5-10.0 d later and the flowering duration 6.3-11.4 d longer compared to the control. Although the leaf litter-treated plants exhibited more (0.5-3.3) flowers than the control, their quality decreased, and the hundred-grain weight of the seed decreased with the increase of leaf litter. However, the differences among treatments in the reproductive parameters mentioned above reduced after nitrogen fertilization. The results indicated that leaf litter of C. Camphora has a great allelopathic effect on morphological and reproductive growth of Pharbitis nil, which may be attributed to the release of phototoxic substances during the decomposition process. 相似文献
A new method was proposed to determine pyrene in mucus, which combined the synchronous fluorimetry with the multiple standard addition method (SFMSA). The method was used to determine pyrene in mucus directly without pretreatment. The method detection limit (MDL) for pyrene in mucus was measured as 0.47 ng/ml with a relative standard deviation of 12.7% (n = 7). The standard addition graph was linear in the range 0.05-50.00 ng/ml (r(2) = 0.9989). SFMSA was validated using a GC/MS method as a reference method, and nice agreement was found. The pyrene in mucus can be directly monitored by SFMSA without solvent extraction of samples. This indicates that SFMSA is more timesaving, less laborious and cheaper than the GC/MS method with solvent extraction. SFMSA has lower MDL and higher average recovery than the GC/MS method. 相似文献