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It is generally thought that phosphine (PH3) concentrations exist at the low ng/m3 level during the night and at the pg/m3 level during daylight in the remote atmosphere of the lower troposphere. The first determination of gaseous PH3 on the Antarctic Millor Peninsula is reported in this paper. No PH3 was detected in the air samples around 10:00 when it was sunny. However, PH3 was found in all the 10:00 air samples when it was cloudy or light snow with the average of 75.3±28.8 ng/m3 (n=5). It was also found in nearly all the samples around 22:00 with the average of 87.2±70.9 ng/m3 (n=11). Atmospheric PH3 concentrations around 22:00 were generally higher than those around 10:00 in January and they were almost the same in February. In addition, PH3 concentrations around 22:00 showed a downtrend with the decreasing air temperature, suggesting that light intensity and air temperature had an important effect on atmospheric PH3 concentration. It is very surprising to have found that high concentrations of PH3 exist in the Antarctic atmosphere under the influence of strong UV-radiation and light intensity. The tentative analyses show that dry, cold and very clean atmosphere may be very suitable for the PH3 survival and cause the concentration to increase and accumulate in the local atmosphere. New approaches for the PH3 formation and the process of atmospheric chemistry may exist under such an extreme environment. Atmospheric PH3 may also be from the emissions of local sources.

Phosphite (H2PO3(-), HPO3(2-), +3 valence), a reduced form of phosphorus (P), has been widely detected in water environments. The role of phosphite in the P biogeochemical cycle has not been investigated systematically and quantitative results on phosphite fluxes are lacking. In this study, intact sediment core simulation was employed to measure the flux of phosphite at the sediment-water interface in northern Lake Taihu. Phosphite fluxes (μmol m(-2) d(-1)) ranged from -38.21±1.14 to 7.10±2.18, with an annual average of -4.72±10.40. On the whole, phosphite migrated from water into sediment and the sediment was primarily a sink. The highest seasonal negative phosphite fluxes (μmol m(-2) d(-1)) occurred in winter (-10.44±18.63), followed by summer (-8.04±5.61) and spring (-2.61±4.17). In autumn, phosphite flux was 2.20±4.07. Higher annual average negative fluxes of phosphite (μmol m(-2) d(-1)) appeared in site ZSB (-12.70±17.96), which contained the highest content of total soluble P. The average yearly migration of phosphite in Lake Taihu from water to sediment was estimated to be (4.04±8.88)×10(6) mol y(-1). The transfer of phosphite from water into sediment usually occurs in winter may due to the season's natural tendency to create more favorable conditions for phosphite biogeochemical reactions. Phosphite fluxes showed significant negative correlations with the original phosphite concentration in water (r=-0.840, p

This study investigated the reduction of antibiotic resistance genes (ARGs), intI1 and 16S rRNA genes, by advanced oxidation processes (AOPs), namely Fenton oxidation (Fe2 +/H2O2) and UV/H2O2 process. The ARGs include sul1, tetX, and tetG from municipal wastewater effluent. The results indicated that the Fenton oxidation and UV/H2O2 process could reduce selected ARGs effectively. Oxidation by the Fenton process was slightly better than that of the UV/H2O2 method. Particularly, for the Fenton oxidation, under the optimal condition wherein Fe2 +/H2O2 had a molar ratio of 0.1 and a H2O2 concentration of 0.01 mol L− 1 with a pH of 3.0 and reaction time of 2 h, 2.58–3.79 logs of target genes were removed. Under the initial effluent pH condition (pH = 7.0), the removal was 2.26–3.35 logs. For the UV/H2O2 process, when the pH was 3.5 with a H2O2 concentration of 0.01 mol L− 1 accompanied by 30 min of UV irradiation, all ARGs could achieve a reduction of 2.8–3.5 logs, and 1.55–2.32 logs at a pH of 7.0. The Fenton oxidation and UV/H2O2 process followed the first-order reaction kinetic model. The removal of target genes was affected by many parameters, including initial Fe2 +/H2O2 molar ratios, H2O2 concentration, solution pH, and reaction time. Among these factors, reagent concentrations and pH values are the most important factors during AOPs.

Nitrous oxide (N2O) emission during wastewater treatment can be mitigated by improving operational conditions, e.g., organic carbon supply and dissolved oxygen. To evaluate the control parameters for N2O emission in the low carbon source domestic wastewater treatment process, N2O emissions from Cyclic Activated Sludge System (CASS) under different feeding strategies and aeration rates were investigated. Results showed that continuous feeding enhanced nitrogen removal and reduced N2O emission compared to batch feeding, while a higher aeration rate led to less N2O emission. N2O was mainly produced during non-aeration phases in batch feeding CASS and the amount of N2O generated from denitrification decreased under continuous feeding, indicating that carbon source in the continuous influent relieved the electron competition between denitrification reductases during non-aeration phase. Moreover, taxonomic analysis based on high-throughput 16S rRNA gene sequencing revealed higher abundance of denitrifying bacteria, especially N2O-reducing bacteria in continuous feeding CASS.

Phosphine (PH3) was monitored in the Taihu Lake in China by a GC/NPD method, coupled with cryo-trapping enrichment technology. Results showed that PH3 was universally de- tected in sediments, lake water and atmosphere of the Taihu Lake area. Total phosphorus (TPs) and fractions of different phosphorus species in lake sediments were separately measured as dis- solved phosphate (DP), phosphorus bound to aluminum (Al-P), iron (Fe-P) and calcium (Ca-P), occluded phosphorus (OP), and organic phosphorus (Org-P) by sequential chemical extraction. High PH3 levels were correlated with high TPs values in sediments and with eutrophication at different sites. In addition, a positive linear correlation equation was obtained between the con- centrations of PH3 in lake sediments and of the phosphorus fractions. The resulting multiple linear regression equation is PH3 = � 165 + 63.3 DP + 0.736 Al-P + 2.33 Ca-P + 2.29 Org-P. The flux of PH3 across the sediment-water interface was estimated from sediment core incubation in May and October 2002. The annual average sediment-water flux of PH3 was estimated at ca. 0.0138±0.005 pg dm � 2 h � 1 , the average yearly emission value of PH3 from Taihu Lake sedi- ments to water was calculated to be 28.3±10.2 g year � 1 , which causes a water PH3 concentration of up to 0.178±0.064 pmol dm � 3 . The real importance of PH3 could be higher, because PH3 could be consumed in the oxic sediment-water boundary layer and in the water column. Spatial and temporal distributions of total phosphorus (TPw) and chlorophyll a (Chl-a) in the water column of Taihu Lake were measured over the study period. Higher water PH3 has also been found where the TPw content was high. Similarly, high Chl-a was consistent with higher water PH3. Positive rela- tionships between PH3 and TPw (average R 2 = 0.47±0.26) and Chl-a (average R 2 = 0.23±0.31)

A mixed culture containing nitrifying bacteria and denitrifying bacteria was investigated for aerobic simultaneous nitrification and denitrification. A mixture of NaHCO3 and CH3COONa was selected as the appropriate carbon source for cell growth and nitrogen removal, the concentrations of carbon and nitrogen sources were also examined. Ammonia could be oxidized aerobically to nitrite by the mixed culture, and the intermediate nitrite was then reduced to dinitrogen gas. No nitrite was detected during the process. 0.212 g of ammonia/l could be removed in 30 h and nitrate could not be utilized aerobically by the mixed culture. Nitrite could be degraded aerobically as well as anaerobically. Very little ammonia was degraded anaerobically, but the ability to degrade ammonia could be recovered even after oxygen had been supplied for 42 h.

This study aimed to investigate biofilm properties evolution coupled with different ages during the start-up period in a moving bed biofilm reactor system. Physicochemical characteristics including adhesion force, extracellular polymeric substances (EPS), morphology as well as volatile solid and microbial community were studied. Results showed that the formation and development of biofilms exhibited four stages, including (I) initial attachment and young biofilm formation, (II) biofilms accumulation, (III) biofilm sloughing and updating, and (IV) biofilm maturation. During the whole start-up period, adhesion force was positively and significantly correlated with the contents of EPS, especially the content of polysaccharide. In addition, increased adhesion force and EPS were beneficial for biofilm retention. Gram-negative bacteria mainly including Sphaerotilus, Zoogloea and Haliscomenobacter were predominant in the initial stage. Actinobacteria was beneficial to resist sloughing. Furthermore, filamentous bacteria were dominant in maturation biofilm.

Phosphine is a part of an atmospheric link of phosphorus cycle on earth, which could be an important pathway for phosphorus transport in environment. Wetland ecosystems are important locations for global biogeochemical phosphorus cycle. In this study, production and emission fluxes of free phosphine from four wetlands types in southern China were observed in different seasons. The results showed that the concentration of phosphine liberated from wetlands was at pg/m3-ng/m3 level. The emission concentrations of different wetlands followed the sequence: paddy field (51.83 +/- 3.06) ng/m3or = marsh (46.54 +/- 20.55) ng/m3lake (37.05 +/- 22.74) ng/m3coastal wetland (1.71 +/- 0.73) ng/m3, the positive phosphine emission flux occurred in rice paddy field (6.67 +/- 5.18) ng/(m2 x hr) and marsh (6.23 +/- 26.9) ng/(m2 x hr), while a negative phosphine flux of (-13.11 +/- 35.04) ng/(m2 x hr) was observed on the water-air interface of Lake Taihu, suggesting that paddy field and marsh may be important sources for phosphine gas in atmosphere, while lake may be a sink of atmospheric phosphine gas during the sampling period. Atmospheric phosphine levels and emission flux from Yancheng marsh and rice paddy field varied in different seasons and vegetational zones. Both diffusion resistance in aqueous phase and temperature were dominating factors for the production and transportation of phosphine to atmosphere.

Effects of different static magnetic field (MF) intensities (10–50 mT) on the activity of activated sludge were compared at low temperature (5 °C). The TTC dehydrogenase activity (TTC-DHA) achieved the maximum of 8.12 mgTF/gSS at the MF intensity of 40 mT. MF intensity enhanced from 20 mT to 40 mT could promote microorganisms to produce more unsaturated fatty acids (UFAs) to stimulate the TTC-DHA and adapt to low temperature. At 30 mT, the Gram-negative bacteria with better cold adaptability were greatly enriched, which ensured the cold resistance of low-temperature reactor. The PLFA diversity strengthened by MF was higher than that of control when MF intensities changed from 20 mT to 50 mT and reached the maximum of 1.31 at 20 mT. Optimal MF intensity is supposed to be a potential pathway to strengthen the activity and cold resistance of activated sludge microorganisms in biological wastewater treatment under low temperature.

To understand the transport and fate of antibiotic resistance genes in wastewater treatment plants, 12 resistance genes (ten tetracycline resistance genes, two sulfonamides genes) and class 1 integron gene (intI1) were studied in five wastewater treatment plants with different treatment processes and different sewage sources. Among these resistance genes, sulfonamides genes (sul1 and sul2) were of the most prevalent genes with detection frequency of 100 %. The effluent water contained fewer types of resistance genes than the influent in most selected plants. The abundance of five quantified resistance genes (tetG, tetW, tetX, sul1, and intI1) decreased in effluent of plants treating domestic or industrial wastewater with anaerobic/aerobic or membrane bioreactor (MBR) technologies, but tetG, tetX, sul1, and intI1 increased along the treatment units of plants treating vitamin C production wastewater by anaerobic/aerobic technology. In plant treating cephalosporins production wastewater by UASB/aerobic process, the quantities of tetG, tetX, and sul1 first decreased in anaerobic effluent water but then increased in aerobic effluent water.

Effective removal of aging biofilm deserves to receive more attention. This study aimed to characterized aging biofilm from a full-scale moving bed biofilm reactor treating pharmaceutical wastewater and evaluate the hydrolysis effects of biofilm by different enzymatic treatments. Results from FTIR and biochemical composition analyses showed that it was a predominately organic-based biofilm with the ratio of total protein (PN) to polysaccharide (PS) of 20.17. A reticular structure of extracellular polymeric matrix (EPM) with filamentous bacteria as the skeleton was observed on the basal layer through SEM-EDS test. Among the four commercial proteases and amylases from Genencor®, proteases were shown to have better performances than amylases either on the removal of MLSS and PN/MLSS or on DOC (i.e., dissolved organic carbon)/MLSS raising of biofilm pellets. Difference of dynamic fluorescence characteristics of dissolved organic matters after treated by the two proteases indicated distinguishing mechanisms of the treating process.

The strengthening effects of static (homopolar and heteropolar) magnetic fields (MF) on microorganisms were compared in activated sludge degrading organic matter at low temperature. The TTC dehydrogenase activity improved substantially through external heteropolar MF intensification, and led to the highest COD removal rate of 94.9% at 5 °C. Phospholipid fatty acid analysis showed that C16:1ω7c, C18:1ω7c and C18:1ω9c were the essential unsaturated fatty acids in cell membrane at low temperature (4–15 °C), accounting for the majority of the whole unsaturated fatty acids. The MF effect increased the Gram-negative bacteria content to improve the cold adaptability. Shannon–Wiener diversity analysis demonstrated the samples with heteropolar MF had a higher PLFA diversity index (1.17–1.25) than that with homopolar MF (0.89–1.13). AFM observation showed MF smoothed part of the microbial cell surface, with some remaining distinct protuberances. Heteropolar MF enhancement performance is much more effective than that of the homopolar MF with identical plate distance.

Secondary-treated municipal wastewater (MWW) could supply a viable alternative water resource for cooling water systems. Inorganic salts in the concentrated cooling water pose a great challenge to corrosion control chemicals. In this study, the inhibition effect of 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), trimethylene phosphonic acid (ATMP) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) on corrosion of carbon steel in secondary-treated MWW was investigated by the means of potentiodynamic polarization and electrochemical impedance spectroscopy. The inhibition effect increased with increasing concentration of inhibitors. The corrosion rates of carbon steel were 1.5, 0.8, 0.2 and 0.5 mm a–1 for blank, HEDP, ATMP and PBTCA samples at 50 mg L–1, respectively. The phosphorus-based chemicals could adsorb onto the surface of the carbon steel electrode, form a coat of protective film and then protect the carbon steel from corrosion in the test solution.

The seasonal occurrence and distribution of phosphite (HPO3(2-), P) in sedimentary interstitial water from Lake Taihu was monitored from 2011 to 2012 to better understand its possible link to P cycle in the eutrophic shallow lake. Phosphite concentrations ranged fromMDL to 14.32 ± 0.19 μg P/kg with a mean concentration of 1.58 ± 0.33 μg P/kg, which accounts for 5.51% total soluble P (TSP(s)) in surficial sediments (0-20 cm). Spatially, the concentrations of sedimentary phosphite in the lake's northern areas were relatively higher than those in the southern areas. Higher phosphite concentrations were always observed in seriously polluted sites. Generally, phosphite in the deeper layers (20-40 cm and 40-60 cm) showed minor fluctuations compared to that in the surficial sediments, which may be associated with the frequent exchange at the sediment-water interface. Phosphite concentrations in surficial or core sediments decreased as springautumnsummerwinter. Higher phosphite levels occurred in the areas with lower redox (Eh), higher P contents, and particularly when metal bonded with P to form Al-P(s) and Ca-P(s). Phosphite may be an important media in the P biogeochemical cycle in Lake Taihu and contribute to its internal P transportation.

Glyphosate may have dual effect on bloom algae as a phosphorus source or pesticide. The physiological and biochemical responses of Microcystis aeruginosa ( M. aeruginosa ) to glyphosate and its formulation in the common herbicide, Roundup ® , were compared. The result suggested that both the cell numbers and Chl- a content of M. aeruginosa increased when the glyphosate concentration increased from 0.01 to 5 mg P L −1 . However, Roundup ® showed low-dose (below 1 mg P L −1 ) stimulation and high-dose (above 1 mg P L −1 ) inhibition on M. aeruginosa cell density and Chl- a content (hormesis effect). Phosphate was more available than glyphosate or Roundup ® , and Roundup ® was more toxic than glyphosate itself at 3 mg P L −1 . Analysis of the maximum yield of PSII indicated that glyphosate stimulated the photosynthesis process while Roundup ® inhibited the photosynthesis of M. aeruginosa . The photosynthesis process was enhanced on the 21st day compared with that on the 14th day in all P mediums. The extracellular alkaline phosphatase activity (APA) decreased with the increasing glyphosate or Roundup ® concentration. The change pattern of APA was similar in both the glyphosate and Roundup ® mediums.

The dry pyrolysis of magnesium ammonium phosphate (MAP) with NaOH powder for ammonium release was investigated, as well as the utility of MAP pyrolysate recycling. The identities of the MAP pyrolysate and its derivatives were experimentally validated. The results showed that the pyrolysate was amorphous magnesium hydrogen phosphate (MgHPO4) and magnesium pyrophosphate (Mg2P2O7). The best molar ratio of sodium hydroxide (NaOH) powder to ammonium was 1:1, at 110°C for 3h. The optimum pH for pyrolysate recycling was 9.5. The ammonia removal ratio could be maintained above 80% with MAP pyrolysate recycling. Seed crystal inoculation increased the rate of MAP crystallization by 20.86%, as well as the MAP grain size (2.08nm with seeding versus 1.72nm without). MAP particle size with NaOH treatment decreased: d(0.5)=19.34μm versus d(0.5)=30.35μm for direct pyrolysis. The results demonstrated that crystal growth was controlled by adding NaOH during MAP pyrolysis.

The establishment of a sensitive and specific method for the detection of reduced phosphorus (P) is crucial for understanding P cycle. This paper presents the quantitative evidence of phosphite (P, +3) from the freshwater matrix correspondent to the typically eutrophic Lake Taihu in China. By ion chromatography coupled with gradient elution procedure, efficient separation of micromolar levels of phosphite is possible in the presence of millimolar levels of interfering ions, such as chloride, sulfate, and hydrogen carbonate in freshwater lakes. Optimal suppressed ion chromatography conditions include the use of 500 μL injection volumes and an AS11 HC analytical column heated to 30 °C. The method detection limit of 0.002 μM for phosphite was successfully applied for phosphite determination in natural water samples with recoveries ranging from 90.7 ± 3.2% to 108 ± 1.5%. Phosphite in the freshwater matrix was also verified using a two-dimensional capillary ion chromatography and ion chromatography coupled with mass spectrometry. Results confirmed the presence of phosphite in Lake Taihu ranging from 0.01 ± 0.01 to 0.17 ± 0.01 μM, which correlated to 1-10% of the phosphate. Phosphite is an important component of P and may influence biogeochemical P cycle in lakes.

Microcystins (MCs) are hepatotoxic heptapeptides produced by cyanobacteria in aquatic environment and have potential risk to aquatic organisms. Different histopathological alterations in fish liver, gill, or other organs under MCs exposure have be extensively studied, but most studies were based on relatively high concentrations. In this study, the dose-related histopathological alterations in fish livers and gills were assessed by light and electron microscopy after 14 d immersion of Cyprinus carpio L. (C carpio) in 1.0 and 10.0 μg L-1 MC-LR. Damages in liver and respiration efficiency of fish were evidenced by the appearance of a series of histopathological alterations in microstructure and morphology of liver and gill tissues. Although the symptoms were relatively mild, these histopathological alterations suggest that the C. carpio coexisting with cyanobacterial blooms in hypereutrophied ponds or lakes may suffer a negative ecological impact.

Contamination of environmental matrixes by human and animal wastes containing antibiotics is a growing health concern. Because tetracycline is one of the most widely-used antibiotics in the world, it is important to understand the factors that influence its mobility in soils. This study investigated the effects of pH, background electrolyte cations (Li(+), Na(+), K(+), Ca(2+) and Mg(2+)), heavy metal Cu(2+) and humic acid (HA) on tetracycline adsorption onto kaolinite. Results showed that tetracycline was greatly adsorbed by kaolinite over pH 3-6, then decreased with the increase of pH, indicating that tetracycline adsorption mainly through ion exchange of cations species and complexation of zwitterions species. In the presence of five types of cations (Li(+), Na(+), K(+), Ca(2+) and Mg(2+)), tetracycline adsorption decreased in accordance with the increasing of atomic radius and valence of metal cations, which suggested that outer-sphere complexes formed between tetracycline and kaolinite, and the existence of competitor ions lead to the decreasing adsorption. The presence of Cu(2+) greatly enhanced the adsorption probably by acting as a bridge ion between tetracycline species and the edge sites of kaolinite. HA also showed a major effect on the adsorption: at pH6, the presence of HA increased the adsorption, while the addition of HA showed little effect on tetracycline adsorption at higher pH. The soil environmental conditions, like pH, metal cations and soil organic matter, strongly influence the adsorption behavior of tetracycline onto kaolinite and need to be considered when assessing the environmental toxicity of tetracycline.

Microcystins (MCs) are produced by cyanobacteria in aquatic environments and are a potential risk to aquatic organisms. Increasing evidence suggests that oxidative stress may play an important role in the toxicity mechanism of MCs on fish, but most studies were based on relatively high concentrations. In this study, the effect of time-dependent oxidative stress in livers of Cyprinus carpio L. (C. carpio) exposed to 10 μg l(-1) of microcystin-LR (MC-LR) for 0-14 days was investigated. MC-LR induced histopathological changes in liver and gills were also assessed after 14 days exposure. Electron paramagnetic resonance (EPR) spectrum was used to directly investigate the reactive oxygen species (ROS) in fish liver and results showed that hydroxyl radical ((∙)OH) was significantly induced at 0.5 day and then tended to decline with an increase of exposure period. As a response of antioxidant, catalase (CAT) activity increased slightly at first and then decreased with exposure period. A pronounced promotion of glutathione-S-transferase (GST) indicated that the conjugation reaction of MC-LR and GSH occurred. A time-dependent decrease of reduced glutathione (GSH) with an increase of oxidized glutathione (GSSG) level suggested GSH was involved in detoxification of MC-LR in the liver. Oxidative damage was evidenced by the significant increase of malondialdehyde (MDA) level at 2-6 days. After 14 days exposure, a series of pathological changes, like partially dissolved parenchymal architecture, vacuolar degeneration, necrosis, hemorrhage and slight inflammatory cells infiltration in fish liver tissues could be observed. Scanning electron microscopic (SEM) studies showed that dissolved MC-LR could also result in pathological changes like partial broken epithelial cells, deformed taste buds and loose gill filament and lamella in gill tissues. These results suggest that although a restoring response occurred, C. carpio could still be adversely affected by MC-LR at 10 μg l(-1).

Phosphine (PH3) is a natural gaseous carrier of phosphorus (P) in its geochemical cycles, and it might be important to the P balance of natural ecosystems. Paddy fields are thought to be one of the main sources responsible for the production and emission of PH3 in to the environment. The relationships between matrix-bound PH3 (MBP) and different P fractions, as well as selected metals were investigated to explore the possible production of MBP and its link to P cycle in the paddy soils. MBP range from 20.8 −1 to 502 ng kg−1 with an average of 145 ng kg−1. Concentrations at the milk stage are significantly higher than at the jointing stage. The total P range from 333 mg kg−1 to 592 mg kg−1. Average P fractions decrease in the order: Ca–P (69.9%) > Organic P (16.5%) > occluded P (6.50%) > Fe–P (5.93%) > dissolved P (0.80%) > exchangeable P (0.32%) > Al–P (0.02%). Different levels of nitrogen fertilizer have little effect on the contents of MBP, P fractions and metals. A significant positive correlation between MBP and Ca–P (p = 0.002), as well as between MBP and Ca (p = 0.008) could be observed, suggesting that Ca–P mainly affects the production of MBP in the paddy soils. It is suggested that soil MBP is strongly linked to Ca–P fertilizer use because soil spiked with P-fertilizer produced an additional 758 ± 142 ng of MBP per kg of soil, compared to only 81.7 ± 12.3 ng of MBP per kg of unspiked soil. No correlations are found between MBP and other P fractions, or between MBP and Al, Fe and Mn.

The diurnal atmospheric phosphine (PH 3 ) concentrations and fluxes at the water–air interface in Lake Taihu were reported. The results showed that the PH 3 flux at the water–air interface ranged from −69.9 ± 29.7 to 121 ± 42 ng m −2 h −1 , with a mean flux of 14.4 ± 22.5 ng m −2 h −1 . The fluxes were both negative and positive during the diurnal period, indicating that the lake can act as a sink and a source of PH 3 . In addition, the PH 3 fluxes were positively correlated with water temperature, total soluble phosphorus and soluble reactive phosphorus, while they were negatively correlated with water redox potential. A similar diurnal variation curve of atmospheric PH 3 concentrations was observed during all four seasons, with the maximum level occurring in early morning and the minimum appearing around midday. These findings suggest that light plays an important role in the elimination of atmospheric PH 3 . A significant positive correlation was also found between air temperature and atmospheric PH 3 concentration. The mean flux of PH 3 in Lake Taihu was higher than in other reported wetlands, with an estimated annual emission of PH 3 to the atmosphere of 2.94 × 10 5 g y −1 .

Phosphine (PH3) is a natural gaseous carrier of phosphorus in its biogeochemical cycles, has been found ubiquitously present in the environment. The origin of phosphine in various environmental sites is still under debated, although phosphine evolution used to be reported from microbial habitats. The tentative experiments show that phosphine gas could be produced by aqueous or acid corrosion from phosphorus-containing impurities in iron. The concentration of phosphine liberated by aqueous corrosion was of the same order of magnitude (ng/kg) as those detected in natural environment. Acid could accelerate corrosion and promote the production of phosphine. The quantity of phosphine liberated by 0.5 mol/L sulfuric acid corrosion was three magnitude orders (ug/kg) higher than that in aqueous corrosion, which may provide a convincing explanation for the significant occurrence of phosphine in strong acidic condition (landfill gas, anaerobic fermentation gas, etc). It was shown that phosphine emission in air as headspace gas was higher than in nitrogen gas under aqueous corrosion, while different headspace gas (air or nitrogen gas) showed little effect on phosphine liberation by acid corrosion. Phosphine produced by reduced type iron powder (analytical reagent) was lower than by technical iron filings. Iron filings after grinding could enhance the emission of phosphine. Under acid corrosion, an exponential positive correlation between the weight of iron filings(x, g) and phosphine production concentration (y, ng/m3) has been established (y＝58.49lnx+343, R2=0.9561，n=18). A positive correlation between the concentrations of acid and phosphine production could also be observed. Results suggested that chemical corrosion of phosphorus-containing in iron filings could be considered as a source of phosphine emission in the environment. Further studies should examine the phosphorus species existing in iron and evaluate the chemical process responsible for the production of phosphine by iron corrosion.

Seeds of Vicia faba. L were grown in increasing concentrations of lead (Pb)-added soils (0–2,000 mg/kg). After germination of 25 days, roots were harvested to investigate oxidative stress, defense response and indicative biomarkers based upon chemical analyses and biological measurements. The results showed that higher concentrations of Pb-polluted soils led to seedling growth inhibition, indicative of phytotoxicity. O 2 •− and lipid peroxidation were increased with the increase of available Pb in soils and Pb contents in roots, displaying a “J”-shaped dose response curve, whereas H2O2 showed a biphasic dose response curve (a consecutive “J”-shaped and inverted “U”-shaped curve). Superoxide dismutase (SOD), guaiacol peroxidase (POD) and ascorbate peroxidase (APX) enzymes were activated by soil Pb, displaying biphasic curves. The upregulated POD and APX enzymes might be major scavengers of excessive H2O2 when CAT activities were drastically reduced with the increasing soil Pb. The enhanced glutathione (GSH) and APX activities suggested that GSH-ascorbate cycle also participated in eliminating H2O2. Moreover, obvious changes were observed in SOD, CAT and POD isoenzyme patterns, but not in APX except increasing intensities of bands. HSP70 synthesis was significantly induced by extraneous Pb from 125 to 1,000 mg/kg and showed a biphasic curve in this experiment. Comparatively, HSP70 and lipid peroxidation might be more sensitive than other parameters in response to Pb stress, suggesting that these two parameters in the roots might be potential biomarkers for early bioassay of Pb-contaminated soils.

Atmospheric phosphine (PH 3 ) fluxes from typical types of wetlands and PH 3 concentrations in adjacent atmospheric air were measured. The seasonal distribution of PH 3 in marsh and paddy fields were observed. Positive PH 3 fluxes are significantly related to high air temperature (summer season) and increased vegetation. It is concluded that vegetation speeds up the liberation of PH 3 from soils, while water coverage might function as a diffusion barrier from soils or sediments to the atmosphere. The concentrations of atmospheric PH 3 (ng m −3 ) above different wetlands decrease in the order of paddy fields (51.8 ± 3.1) > marsh (46.5 ± 20.5) > lake (37.0 ± 22.7) > coastal wetland (1.71 ± 0.73). Highest atmospheric PH 3 levels in marsh are found in summer. In paddy fields, atmospheric PH 3 concentrations in flourishing stages are higher than those in slowly growing stages.

This paper characterizes the distribution of phosphorus fractions and matrix-bound phosphine (MBP) in coastal surface sediments of the Southwest Yellow Sea from 2006 to 2007. Total phosphorus (TP), inorganic phosphorus (IP) and organic phosphorus (OP) concentrations (mg kg(-1)) range from 278 +/- 3 to 768 +/- 15, 160 +/- 1 to 653 +/- 27, and 3.42+/- 0.05 to 267 +/- 22, respectively. MBP is a small portion of TP with values of 0.69 +/- 0.06 to 179 +/- 29 ng kg(-1). Phosphorus fractions and MBP are influenced strongly by riverine input and hydrodynamic conditions. High TP and MBP are found in the old Yellow River mouth and the Yangtze River mouth. OP and MBP are strongly negatively correlated to mean particle size. Significant positive correlations are found between MBP and IP and OM, suggesting that MBP production may be the microbially intermediated transformation of IP.

Earlier reports show very low concentrations of phosphine in remote air of the lower troposphere of nonpolar regions, in the low ng m(-3) range during the night and in the pg m(-3) range during daylight around noon. In this study, abnormally and unexpectedly high phosphine concentrations (30.0-407.8 ng m(-3), 11 locations) were found in polar air samples collected on Millor Peninsula, eastern Antarctica and Fildes Peninsula, western Antarctica. The maximum concentration was measured in the atmosphere of penguin colonies. Field phosphine emission rates from four colonies were 8.99 ng m(-2) h(-1) (skua colony), 9.56 ng m(-2) h(-1) (gentoo penguin colony), 39.96 ng m-2 h-' (seal colony) and 63.58 ng m(-2) h(-1) (empire penguin colony), respectively. Our air sampling sites are located downwind of two large penguin colonies, indicating that penguin colony emission is the predominant source for atmospheric PH3 on Millor Peninsula. Laboratory scale incubation of ornithogenic soils amended by penguin guanos yielded a maximum PH3 production rate of 0.58 ng kg(-1) d(-1) specifically at low temperature (4 degrees C). Significant concentrations of phosphine occur in the atmosphere of coastal Antarctica and confirm the existence of a small gaseous link in the phosphorus cycle of the Antarctic tundra ecosystem.

Phosphine (PH(3)) is a natural gaseous carrier of phosphorus in its geochemical cycles, and it might be of importance to the phosphorus balance of natural ecosystem. For the first time phosphine levels were investigated in the Earth's coldest, driest, and most southerly Antarctic biosphere. Matrix-bound phosphine (MBP) was found in sea animal guanos, ornithogenic sediments and soils. Phosphine concentrations varied with different sea animal guanos. Average phosphine concentrations in empire penguin, gentoo penguin, sea lion, skua and gull guanos were 2.54+/-1.28 ng kg(-1), 6.21+/-2.15 ng kg(-1), 9.12+/-4.66 ng kg(-1), 11.90+/-1.29 ng kg(-1) and 14.55+/-6.74 ng kg(-1), respectively. The contents of phosphorus in these various matrixes have an important effect on MBP concentrations. The levels of phosphine appeared an increasing tendency with the content of TP, IP and OP in sea animal guanos, ornithogenic sediments or soils. The correlation between PH(3) and Fe, Mn, Al in these matrixes was also analyzed and discussed. Phosphine showed an obviously positive correlation with Fe in sea animal guanos. However, excessively high Fe, Al and Mn may inhibit the formation of PH(3) in the ornithogenic soils or sediments in the Antarctic biosphere.

Closed anaerobic batch-fermentation of eutrophic lake sediment samples was performed under variation of four environmental fermentation factors (pH, temperature, water/sediment ratio and disturbance) to learn how the quantity of phosphine will change and if the quantity of phosphine can increase. The fermentation conditions where matrix bound phosphine (MBP) increased (doubled from 3193+/-520 to about 7982+/-1003 ng/kg) were: a pH of 8 and of 10 (as compared to 1, 2, 4, 6, 12), a temperature of 20 and 30 degrees C (as compared to 4 and 40 degrees C), a water/sediment ratio of 3:1 (as compared to 1:1, 2:1, 5:1) and a disturbance of 100 r/min (as compared to 0 r/min), respectively. Although, over the full time course of fermentation, the balance of phosphine production became negative again or did remain almost unchanged under most conditions. A pH of 1 or disturbance of 150 r/min was significant factors to decrease phosphine over the long term. Free phosphine had been detected but was of minor importance (in the order of 60.9+/-10.1 ng/m(3)). Overall, the fermentation conditions which had been most favorable for microbial life (moderate temperature (20 and 30 degrees C) and pH 8) were also most favorable for a positive phosphine balance. This is an indication, but no biochemical proof that a natural (biogenic, microbial, biochemical) NET PRODUCTION of phosphine or DE NOVO PRODUCTION of phosphine has occurred. MBP concentrations in lake sediments were discussed as to be strongly dependent on a balance of natural generation and depletion processes, dependent of the simulated parameters.

Phosphine is a natural gaseous carrier of phosphorus in its geochemical cycles, and it might be of importance to the phosphorus balance of eutrophic lakes. Phosphine concentration levels in Taihu Lake, a typical shallow eutrophic lake in China, were intensely investigated in this work. Results show that in the period of 2002 the variation of phosphine concentration in the atmosphere near Taihu Lake is significant, with a maximum value 2.85 pg/l. Concurrent sampling of phosphine in surface and bottom water of the lake had no distinct change. The mean concentration of phosphine in the water ranged from 1.92 to 3.01 pg/l. Approximately 84–90% of the phosphine was removed from lake water during passage of the sample through a 0.45 μm pore size filter, i.e. the average phosphine concentrations of filtered lake water in all sampling locations were from 0.37 to 0.40 pg/l with the highest value 0.73 pg/l and the lowest 0.08 pg/l, whereas phosphine concentrations in unfiltered samples were 5–9 times higher. Phosphine levels in lake sediments were positively correlated with different contamination of the samples. The concentration levels of phosphine were also higher in severe polluted sites. The local average values of the phosphine concentrations were from 21 550 to 563 100 pg/kg. Its highest value was 919 238 pg/kg at 6# site (Zhihu harbor), a severely polluted sampling site.

Environmental context. Although phosphine (PH3) is an important gaseous carrier in the phosphorus cycle, its production and environmental behaviour remain unclear. Paddy fields are thought to be one of the main sources responsible for the production and emission of PH3. Understanding the behaviour of PH3 in paddy fields under elevated CO2 concentration is crucial in understanding the phosphorus cycle and its response to rising global atmospheric CO2 concentration. Abstract. The behaviour of matrix-bound phosphine (MBP) in paddy fields under elevated [CO2] (ambient + 200 μmol mol–1) is investigated to understand the soil phosphorus cycle and its link to increasing global atmospheric [CO2]. MBP concentrations range from 17.0 ± 5.8 to 1035 ± 331 ng kg–1. Concentrations at the transplanting and harvest stages are significantly higher than during the growing stages. The MBP level (212 ± 61 ng kg–1) under elevated [CO2] is slightly higher than under ambient [CO2] (189 ± 44 ng kg–1). Root exudates and addition of inorganic phosphate fertiliser speed up the production of MBP, whereas fast paddy growth and increasing air temperature accelerate the emission of MBP into the atmosphere. Significant positive correlations are found between MBP and inorganic phosphorus and organic matter, indicating that MBP may be produced from the microbial reduction of inorganic phosphorus in paddy fields.