Photochemical degradation of environmentally persistent perfluorooctanoic acid (PFOA) in the presence of Fe(Ⅲ)

Environmentally persistent and bioaccumulative perfluorooctanic acid (PFOA) was difficult to be decomposed under the irradiation of 254 nm UV light.However,in the presence of 80μmol/L Fe(Ⅲ),80% of PFOA with initial concentration of 48μmol/L (20 rag/L) was effectively degraded and 47.8% of fluorine atoms in PFOA molecule were transformed into inorganic fluoride ion after 4 h reaction.Shorter chain perfluorocarboxylic acids bearing C_3-C_7 and fluoride ion were detected and identified by LC/MS and IC as the degradation products in the aqueous solution.It was proposed that complexes of PFOA with Fe(Ⅲ) initiated degradation of PFOA irradiated with 254 nm UV light.

Environmental Impacts of Solid Waste Landfills on Natural Ecosystems of Southern Caspian Sea Coastlines

The problem of solid waste landfills on Caspian Sea coastlines is one of the current concerns of the Iranian environmental authorities. Physical and environmental constraints as well as shortcomings in present municipal solid waste management are the main factors for environmental pollution and natural resources destruction in this geographical region. In order to reduce the above problems, this study has been carried out on the basis of a comparative assessment of the existing condition of landfill sites in natural ecosystems. In this study, 48 cities of the region have been investigated. All of them are located in Gilan and Mazandaran provinces. Total daily waste production in the study area is about 1209 tons that are dumped in open spaces and/or in aquatic and terrestrial ecosystems. Surveying of 53 physical, adaptability and constraint parameters as well as hygiene and environmental parameters in the landfills, based on “Monavari-94 Method” indicate that the main problem in all of them is a high groundwater table. In 42% of landfills, the groundwater level is between from 0.5 to 2 meters. This phenomenon may cause severe risks due to the infiltration of leachate into potable groundwater. Indeed, the results of the study show that 87.5% of the landfills are located in areas with unacceptable conditions. In spite of geographical and environmental problems and constraints and as a final alternative in this respect, the need for sanitary and technical solid waste management is the main need of the study areas.

The life of Xuan Zhou, founding father of the Gastrodia elata cultivation and industry in China

Those familiar with Gastrodia elata Blume(Tianma,天麻)in China will most certainly recognise the name of Xuan Zhou(周铉),the first postgraduate student of Professor Zheng-Yi Wu(吴征镒),widely respected professor of botany and an academician of the Chinese Academy of Sciences(Peng et al.,2013).Xuan Zhou(abbreviated S.Chow in taxonomic citations,also Chou,Hsüan in Wade-Giles transliterations)(Fig.1)was born in Xinzheng,in the central Chinese Province of Henan on 4 May 1926.He graduated from Tongji University in 1951.He took part in and successfully passed the first national post-graduate examination held by the Chinese Academy of Sciences in 1956 and became a candidate for an Associate Doctor degree(equivalent to MSc)under the tutelage of Prof.Wu.

The Influence of Alluvial Mining on the Morphology and Ecological Health of the Jhimruk River in Pyuthan, Nepal

Historically, alluvial rivers have been a desirable source of sediment for various industrial purposes. However, the demand for sand is rapidly increasing, leading to environmental concerns associated with its extraction. The extraction of sediment from riverbeds has both visible and invisible effects. This research aims to investigate the dynamics of the Jhimruk River’s morphology and its impacts by evaluating the river’s quality and studying its changing morphology. To assess morphological changes, satellite images from different years were compared using Geographic Information System (GIS). Physical assessments were conducted by calculating a Habitat score based on various parameters. Water quality assessments involved measuring factors such as pH, temperature, nitrate levels, and alkalinity. A water quality map of the river was generated using color coding to indicate different conditions. The Habitat score demonstrated variations in the data collected from all sites, with factors such as instream cover, bottom substrate stability, riparian vegetation, and aesthetic of the river stretch playing crucial roles in influencing the total score. The Water Quality Index value for the disturbed site indicated moderate pollution, falling under class II. Aquatic macroinvertebrates displayed natural responses to increasing levels of stressors across their life stages, as observed through the analysis of the GRS-BIOS/ASPT index. With the exception of the disturbed site, all other sites were classified under water quality class II, while the disturbed site belonged to class III, indicating a moderate to critically polluted state for most of the Jhimruk River. Furthermore, an increase of 180.87 meters in the river width at the disturbed site provided evidence of morphological changes occurring over the specified period. Mining activities were identified as a significant contributor to the alteration in river morphology.

A Spectral Index for Estimating Soil Salinity in the Yellow River Delta Region of China Using EO-1 Hyperion Data

Soil salinization is one of the most common land degradation processes. In this study, spectral measurements of saline soil samples collected from the Yellow River Delta region of China were conducted in laboratory and hyperspectral data were acquired from an EO-1 Hyperion sensor to quantitatively map soil salinity in the region. A soil salinity spectral index (SSI) was constructed from continuum-removed reflectance (CR-reflectance) at 2052 and 2203 nm, to analyze the spectral absorption features of the salt-affected soils. There existed a strong correlation (r = 0.91) between the SSI and soil salt content (SSC). Then, a model for estimation of SSC with SSI was established using univariate regression and validation of the model yielded a root mean square error (RMSE) of 0.986 and an R2 of 0.873. The model was applied to a Hyperion reflectance image on a pixel-by-pixel basis and the resulting quantitative salinity map was validated successfully with RMSE = 1.921 and R2 = 0.627. These suggested that the satellite hyperspectral data had the potential for predicting SSC in a large area.

Chemical Composition of PM_(2.5) at an Urban Site of Chengdu in Southwestern China

PM2.5 aerosols were sampled in urban Chengdu from April 2009 to January 2010, and their chemical compositions were characterized in detail for elements, water soluble inorganic ions, and carbonaceous matter. The annual average of PM2.5 was 165 μg m-3 , which is generally higher than measurements in other Chinese cities, suggesting serious particulate pollution issues in the city. Water soluble ions contributed 43.5% to the annual total PM2.5 mass, carbonaceous aerosols including elemental carbon and organic carbon contributed 32.0%, and trace elements contributed 13.8%. Distinct daily and seasonal variations were observed in the mass concentrations of PM2.5 and its components, reflecting the seasonal variations of different anthropogenic and natural sources. Weakly acidic to neutral particles were found for PM2.5 . Major sources of PM2.5 identified from source apportionment analysis included coal combustion, traffic exhaust, biomass burning, soil dust, and construction dust emissions. The low nitrate: sulfate ratio suggested that stationary emissions were more important than vehicle emissions. The reconstructed masses of ammonium sulfate, ammonium nitrate, particulate carbonaceous matter, and fine soil accounted for 79% of the total measured PM2.5 mass; they also accounted for 92% of the total measured particle scattering.

Identification and Metabolic Mechanism of Non-fermentative Short-cut Denitrifying Phosphorus-removing Bacteria

To investigate the characteristics and metabolic mechanism of short-cut denitrifying phosphorus-removing bacteria (SDPB) that are capable of enhanced biological phosphorus removal (EBPR) using nitrite as an electron acceptor, an aerobic/anoxic sequencing batch reactor was operated under three phases. An SDPB-strain YC was screened after the sludge enrichment and was identified by morphological, physiological, biochemical properties and 16S rDNA gene sequence analysis. Denitrifying phosphorus-removing experiments were conducted to study anaerobic and anoxic metabolic mechanisms by analyzing the changes of chemical oxygen demand (COD), phosphate, nitrite, poly-β-hydroxybutyrate (PHB), and glycogen. The results show that strain YC is a non-fermentative SDPB similar to Paracoccus denitrificans. As a kind of non-fermentative bacteria, the energy of strain YC was mainly generated from phosphorus release (96.2%) under anaerobic conditions with 0.32 mg P per mg synthesized PHB. Under anoxic conditions, strain YC accumulated 0.45 mg P per mg degraded PHB, which produced most of energy for phosphate accumulation (91.3%) and a little for glycogen synthesis (8.7%). This metabolic mechanism of strain YC is different from that of traditional phosphorus-accumulating organisms (PAOs). It is also found that PHB, a kind of intracellular polymer, plays a very important role in denitrifying and accumulating phosphorus by supplying sufficient energy for phosphorous accumulation and carbon sources for denitrification. Therefore, monitoring ΔP/ΔPHB and ΔNO2--N/ΔPHB is more necessary than monitoring ΔP/ΔCOD,ΔNO2--N/ΔCOD, or ΔP/ΔNO2--N.

Analysis of Atmospheric Boundary Layer Height Characteristics over the Arctic Ocean Using the Aircraft and GPS Soundings

Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating against the'true'ABL height from aircraft sounding profiles, where ABL height is defined as the top of the layer with significant turbulence. Furthermore, the best performing method was used to estimate ABL height from the one-year GPS soundings obtained during SHEBA (October 1997-October 1998). It was found that the temperature gradient method produces a reliable estimate of ABL height. Additionally, the authors determined optimal threshold values of temperature gradient for stable boundary layer (SBL) and convective boundary layer (CBL) to be 6.5 K/100 m and 1.0 K/100 m, respectively. The maximum ABL height during the year was 1150 m occurred in May. Median values of Arctic ABL height in May, June, July, and August were 400 m, 430 m, 180 m, and 320 m, respectively. Arctic ABL heights are clearly higher in the spring than in the summer.

The Characteristics and Parameterization of Aerodynamic Roughness Length over Heterogeneous Surfaces

Aerodynamic roughness length(z0m) is a key factor in surface flux estimations with remote sensing algorithms and/or land surface models.This paper calculates z0m over several land surfaces,with 3 years of experimental data from Xiaotangshan.The results show that z0m is direction-dependent,mainly due to the heterogeneity of the size and spatial distribution of the roughness elements inside the source area along different wind directions.Furthermore,a heuristic parameterization of the aerodynamic roughness length for heterogeneous surfaces is proposed.Individual z0m over each surface component(patch) is calculated firstly with the characteristic parameters of the roughness elements(vegetation height,leaf area index,etc.),then z0m over the whole experimental field is aggregated,using the footprint weighting method.

Biogeochemical cyclic activity of bacterial arsB in arsenic-contaminated mines

Biogeochemical cyclic activity of the ars (arsenic resistance system) operon is arsB influx/effux encoded by the ecological of Pseudomonas putida.This suggests that studying arsenite-oxidizing bacteria may lead to a better understanding of molecular geomicrobiology,which can be applied to the bioremediation of arsenic-contaminated mines.This is the first report in which multiple arsB-binding mechanisms have been used on indigenous bacteria.In ArsB (strains OS-5; ABB83931; OS-19; ABB04282 and RW-28; ABB88574),there are ten putative enzyme,Histidine (His) 131,His 133,His 137,Arginine (Arg) 135,Arg 137,Arg 161,Trptohan (Trp) 142,Trp 164,Trp 166,and Trp 171,which are each located in different regions of the partial sequence.The adenosine triphosphate (ATP)-binding cassette transports,binding affinities and associating ratable constants show that As-binding is comparatively insensitive to the location of the residues within the moderately stable α-helical structure.The α-helical structures in ArsB-permease and anion permease arsB have been shown to import/export arsenic in P.putida.We proposed that arsB residues,His 131,His 133,His 137,Arg 135,Arg 137,Arg 161,Trp 142,Trp 164,Trp 166,and Trp 171 are required for arsenic binding and activation of arsA/arsB or arsAB.This arsB influx/efflux pum-ping is important,and the effect in arsenic species change and mobility in mine soil has got a significantly ecological role because it allows arsenic oxidizing/reducing bacteria to control biogeochemical cycle of abandoned mines.

Effect of Preparation Methods of Bi_(2)O_(3) Nanoparticles on their Photocatalytic Activity

Bi_(2)O_(3) nanoparticles were prepared by means of ammonia precipitation, polyol mediated methods and microemulsion chemical method. The structure and properties of the as-prepared nanoparticles, having been submitted to a heat-treatment test at 750 ℃, were characterized by means of XRD, BET, XPS and UV-Vis absorption techniques. The photocatalytic oxidation reactions of benzene, toluene and xylene were used as the model reaction to measure the photocatalytic activity of Bi_(2)O_(3) nanoparticles, respectively. The results show that the crystallite size of Bi_(2)O_(3) prepared with different methods and calcined at 750 ℃ were 50.6, 38.5 and 31.5 nm, respectively. The photocatalytic activity of Bi_(2)O_(3) nanoparticles prepared with the microemulsion chemical method was higher than that of the particles prepared with the polyol mediated method; and that of the particles prepared with the micromulsion chemical method was the highest among the three. The degradation rates of the three pollutants xylene, toluene and benzene decreased in sequence.

Formation and structure of composite coating of HDA and micro-plasma oxidation on A3 steel

Composite coatings were obtained on A3 steel by hot dipping aluminum(HDA) at 720 ℃ for 6 min and micro-plasma oxidation(MPO) in alkali electrolyte. The surface morphology, element distribution and interface structure of composite coatings were studied by means of XRD, SEM and EDS. The results show that the composite coatings obtained through HDA/MPO on A3 steel consist of four layers. From the surface to the substrate, the layer is loose Al2O3 ceramic, compact Al2O3 ceramic, Al and FeAl intermetallic compound layer in turn. The adhesions among all the layers are strengthened because the ceramic layer formed at the Al surface originally, FeAl intermetallic compound layer and substrate are combined in metallurgical form through mutual diffusion during HDA process.Initial experiment results disclose that the anti-corrosion performance and wear resistance of composite coating are obviously improved through HDA/MPO treatment.

Decolorization of reactive brilliant red K-2BP by white rot fungus under sterile and non-sterile conditions

Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. How ever, it is obviously unpractical that wastewater with dyes is treated under ste rile conditions. A feasible study was made for using white rot fungus Phanerocha ete chrysosporium to degrade reactive brilliant red K-2BP dye under non-sterile conditions. The results showed that there was no decolorizing effect under non-s terile condition if white rot fungus was incubated under non-sterile condition, and the decolorization was always near to 0% during decolorizing test for 3 d; i n the meantime, a lot of yeast funguses were found in liquid medium when white r ot fungus was incubated under non-sterile conditions; however, if white rot fung us was incubated under sterile condition firstly, its decolorization was above 9 0% under non-sterile condition, which was similar to that of sterile condition. So we point out that the treating process for wastewater with dyes should be div ided into two stages. The first stage is that white rot fungus should be incubat ed under sterile conditions, and the second stage is that reactive brilliant red K-2BP is decolorized under non-sterile conditions. The method not only save the operation cost which decolorizing reactive brilliant red K-2BP under sterile co ndition, but also provide the feasibility for using white rot fungus to degrade wastewater with dyes under non-sterile conditions.

Iron stability in drinking water distribution systems in a city of China

A field study on the estimation and analysis of iron stability in drinking water distribution system was carried out in a city of China. The stability of iron ion was estimated by pC-pH figure. It was found that iron ion was unstable, with a high Fe(OH)3 precipitation tendency and obvious increase in turbidity. The outer layer of the corrosion scale was compact, while the inner core was porous. The main composition of the scale was iron, and the possible compound constitutes of the outer scale were ?琢-FeOOH, ?酌-FeOOH, ?琢-Fe2O3, ?酌-Fe2O3, FeCl3, while the inner were Fe3O4, FeCl2, FeCO3. According to the characteristics of the corrosion scale, it was thought that the main reason for iron instability was iron release from corrosion scale. Many factors such as pipe materials, dissolved oxygen and chlorine residual affect iron release. Generally, higher iron release occurred with lower dissolved oxygen or chlorine residual concentration, while lower iron release occurred with higher dissolved oxygen or chlorine residual concentration. The reason was considered that the passivated out layer of scale of ferric oxide was broken down by reductive reaction in a condition of low oxidants concentration, which would result more rapid corrosion of the pipe and red water phenomenon.

Effects of adsorption interferents on removal of Reactive Red 195 dye in wastewater by chitosan

Reactive Red 195, which is an azoic anionic dye characterized by the presence of five sulfonic groups and one azoic group, is efficiently removed using chitosan. The increasing chitosan dose had a dramatic positive impact on the achieved color removal, there was approximately a linear relationship between chitosan dose and color removal of dye before color removal reach maximum. Also, the increase of dye concentration led to the increase of chitosan dosage in order to get the same color removal. 92 mg/L of chitosan dosage was sufficient to achieve complete remove of dye at initial concentration of dye at 200 mg/L. For the higher concentrations of dye, high dosages were necessary to reach complete color removal. On the other hand, the use of adsorption interferents（Fe 2+, Na+, HCO-3 and others） can be interesting, addition of ions had effect on the color removal of Reactive Red 195. Comparing with blank, addition of chemical species approximately decreased the color removal except Na+ and combination of Fe 2++HCO-3. However, comparing with Fe 2+ alone and HCO-3 alone, combination of Fe 2++HCO-3 increased the color removal.

Photooxidation of Furfural with Phthalocyanine-sensitized TiO_2 Particle Under Xenon Lamp

Copper phthalocyanine was selected as the photosensitizer to sensitize TiO2 in this experiment with furfural as the target pollutant. The composite catalysts(TiO2/CuPC) obtained showed a great activity under a xenon lamp. By experiments, the optimal preparation conditions of the composite catalysts were set as follows: the CuPC loading mass fraction was 1.5%, the mass fraction of acetylacetone was 0.3%, and the stirring time was 10 h. UV-Vis diffuse reflectance spectra, XRD, and BET were used to characterize the properties of the composite catalysts, which showed that after loading CuPC on TiO2, the composite catalyst retained the same crystal structure as pure TiO2 and the wavelength range of its absorption spectrum was broadened to 600—700 nm while its surface area was smaller than that of the pure TiO2. Under the optimal conditions, 20 mg/L furfural solution was degraded by nearly 90% and TOC by about 70%. When the catalyst was reused 6 times, the activity of the catalyst was still retained by about 75%.

A new perspective of ecosystem health

Ecosystem health has attracted considerable attention from different disciplines in recent years. However, it still remains a disputed issue whether to focus on its general concept or on operational practice. As a result, these disputations have caused confusion and limited further research in the field of ecosystem health. In this paper, we attempt to introduce a new perspective to the concept of ecosystem health. With the aid of modern statistical methodology, such as factor analysis and normal distribution theory, we provide a conceptual approach to the quantitative assessment of ecosystem health and our method could be applied to various categories of ecosystems.

Study on the Interaction of Mitomycin C with ct-DNA by Pd-Porphin Room Temperature Phosphorescence Probe

Anticancer drug Mitomycin C (MMC) quenches remarkably phosphorescence and reduces lifetime of phosphorescence probe, Pd-meso-tetrakis-(4-trimethylaminophenyl)porphin (Pd-TAPP), in the presence of calf thymus DNA. These results may be attributed to the site competition of MMC with the probe and electron transfer between MMC and probe. MMC also increases polarization degree of the probe by covalent drug-DNA or DNA-drug-DNA crosslinking.

Adsorption and Transport of Ciprofloxacin in Quartz Sand at Different pH and Ionic Strength

Effects of pH and ionic strength on ciprofloxacin adsorption in quartz sand were studied through a batch equilibrium adsorption experiment in this paper. The experimental data were fitted by empirical formulas from Langmuir and Freundlich adsorption isothermal curves, and the transport experiments in quartz sand at different pH and ionic strength were conducted to investigate the transport characteristics of ciprofloxacin. It was found that with the increase of pH value or ionic strength, adsorption capacity of ciprofloxacin decreased, so that it could move easier. The results indicated that low pH or ionic strength was conductive to the adsorption of ciprofloxacin in quartz sand. Meanwhile, a higher initial concentration or stronger ionic strength could result in a smaller linear distribution coefficient of ciprofloxacin, which meant a low adsorption capacity. According to the fitting results, the adsorption of ciprofloxacin in quartz sand could be described well by both Langmuir and Freundlich equations, of which Freundlich equation had a better efficacy.