Phosphorus compounds in the dissolved and particulate phases in urban rivers and a downstream eutrophic lake as analyzed using 31P NMR.

Phosphorus (P) discharges from human activities result in eutrophication of lakes. We investigated whether the forms of phosphorus (P) in rivers with high effluent loads flowing through urban areas of Sapporo, Japan, were transformed when transported downstream into a eutrophic lake, namely Lake Barato. We hypothesized that the inorganic P supplied from the rivers might be transformed to organic forms in the lake. The results showed that soluble reactive phosphorus (SRP) and particulate inorganic phosphorus (PIP) dominated in the river discharge to the lake. Suspended solids in the rivers were rich in iron (Fe) so PIP was associated with Fe. A comparison of the concentrations at the river mouth and 4.5 km downstream showed that the concentrations of SRP and PIP were lower at 4.5 km downstream than at the river mouth, whereas the concentrations of organic P (i.e., dissolved organic phosphorus and particulate organic phosphorus) were similar. The results from solution 31P nuclear magnetic resonance spectroscopy of lake water showed that pyrophosphate was only present in the particulate fraction, while orthophosphate diesters (DNA-P) were only present in the dissolved fraction. Riverine samples contained orthophosphate (ortho-P) only, while lake samples contained ortho-P, orthophosphate monoesters, and DNA-P. The results suggest that the P forms, particularly those of dissolved P, shifted from inorganic to organic forms as the water was discharged from the river to the lake.

Agronomic efficiency and profitability of cotton on integrated use of phosphorus and plant microbes / Eficiência e rentabilidade agronômica do algodão no uso integrado de fósforo e micróbios vegetais

Cotton crop, plays a significant role in Pakistan's economy by ruling a prominent place in edible oil and local textile industry. Phosphorus (P) inaccessibility and deficiency of soil organic matter are the key restraints for low crop productivity in cotton. Therefore, a two years field study was designed during 2014-15, to explore the influence of phosphate solubilizing bacteria (PSB), farmyard manure (FYM), poultry manure (PM) and inanimate sources of P on various physiological, growth, yield and quality parameters of cotton crop at CCRI Multan. Field responses of seeds inoculated with two distinctive phosphate solubilizing bacteria (PSB) strains viz. S0 = control, S1 =strain-1, S2 = strain-2 and eight organic, inorganic P sources viz., P0= control, P1 = 80 kg ha-1 P from inorganic source, P2 = 80 kg ha-1 P from FYM, P3 = 80 kg ha-1 P from PM, P4 = 40 kg ha-1 P from FYM + 40 kg ha-1 P from inorganic source, P5 = 40 kg ha-1 P from PM + 40 kg ha-1 P from inorganic source, P6 = 80 kg ha-1 P from FYM + 40 kg ha-1 P from inorganic source, P7 = 80 kg ha-1 P from PM + 40 kg ha-1 P from inorganic source and P8 = 40 kg ha-1 P from FYM + 40 kg ha-1 P from PM were evaluated. Results revealed that inoculation of seeds with PSB and collective use of inorganic and organic sources of P had considerably increased the yield contributing attributes in cotton. However, the treatment P7 (80 kg P ha-1 from PM + 40 kg P ha-1 from inorganic source) in coincidence with seeds inoculated with PSB (S1) produced taller plant, maximum boll weight, significantly higher LAI and CGR. Significantly higher seed cotton yield, lint yield, fiber length and maximum BCR of 1.95 and 1.81 was also obtained from the P7 treatment during both crop-growing seasons. In conclusion, combined use of 80 kg P ha-1 from PM + 40 kg P ha-1 from inorganic source and cotton seeds inoculated with strain-1 improved phosphorus uptake ensuing in greater consumption of photo-assimilates for maximum growth and yield.

A safra de algodão, desempenha um papel significativo na economia do Paquistão, ao ocupar um lugar de destaque no óleo comestível e na indústria têxtil local. A inacessibilidade e a deficiência de fósforo (P) da matéria orgânica do solo são as principais restrições para a baixa produtividade das culturas em algodão. Portanto, um estudo de campo de dois anos foi desenvolvido durante 2014-15, para explorar a influência de bactérias solubilizantes de fosfato (PSB), esterco de capoeira (FYM), esterco de aves (PM) e fontes inanimadas de P sobre vários fatores fisiológicos, crescimento, rendimento e parâmetros de qualidade da cultura do algodão no CCRI Multan. Respostas de campo de sementes inoculadas com duas cepas distintas de bactérias solubilizantes de fosfato (PSB) viz. S0 = controle, S1 = cepa-1, S2 = cepa-2 e oito fontes orgânicas de P inorgânicas viz., P0 = controle, P1 = 80 kg ha-1 P de fonte inorgânica, P2 = 80 kg ha-1 P de FYM, P3 = 80 kg ha-1 P de PM, P4 = 40 kg ha-1 P de FYM + 40 kg ha-1 P de fonte inorgânica, P5 = 40 kg ha-1 P de PM + 40 kg ha-1 P de fonte inorgânica, P6 = 80 kg ha-1 P de FYM + 40 kg ha-1 P de fonte inorgânica, P7 = 80 kg ha-1 P de PM + 40 kg ha-1 P de fonte inorgânica e P8 = 40 Foram avaliados kg ha-1 P da FYM + 40 kg ha-1 P da PM. Os resultados revelaram que a inoculação de sementes com PSB e o uso coletivo de fontes inorgânicas e orgânicas de P aumentaram consideravelmente os atributos que contribuem para a produtividade no algodão. No entanto, o tratamento P7 (80 kg P ha-1 da PM + 40 kg P ha-1 da fonte inorgânica) em coincidência com sementes inoculadas com PSB (S1) produziu planta mais alta, peso máximo de cápsula, IAF e CGR significativamente maiores. Produtividade significativamente maior do algodão, rendimento de fiapos, comprimento da fibra e BCR máximo de 1,95 e 1,81 também foi obtida a partir do tratamento P7 durante as duas épocas de cultivo. Em conclusão, o uso combinado de 80 kg P ha-1 de PM + 40 kg P ha-1 de fonte inorgânica e sementes de algodão inoculadas com a cepa-1 melhoraram a captação de fósforo, resultando em maior consumo de foto assimilados para obter crescimento e produtividade máximos.

Reactive and Additive Modifications of Styrenic Polymers with Phosphorus-Containing Compounds and Their Effects on Fire Retardance.

Polystyrene, despite its high flammability, is widely used as a thermal insulation material for buildings, for food packaging, in electrical and automotive industries, etc. A number of modification routes have been explored to improve the fire retardance and boost the thermal stability of commercially important styrene-based polymeric products. The earlier strategies mostly involved the use of halogenated fire retardants. Nowadays, these compounds are considered to be persistent pollutants that are hazardous to public and environmental health. Many well-known halogen-based fire retardants, regardless of their chemical structures and modes of action, have been withdrawn from built environments in the European Union, USA, and Canada. This had triggered a growing research interest in, and an industrial demand for, halogen-free alternatives, which not only will reduce the flammability but also address toxicity and bioaccumulation issues. Among the possible options, phosphorus-containing compounds have received greater attention due to their excellent fire-retarding efficiencies and environmentally friendly attributes. Numerous reports were also published on reactive and additive modifications of polystyrene in different forms, particularly in the last decade; hence, the current article aims to provide a critical review of these publications. The authors mainly intend to focus on the chemistries of phosphorous compounds, with the P atom being in different chemical environments, used either as reactive, or additive, fire retardants in styrene-based materials. The chemical pathways and possible mechanisms behind the fire retardance are discussed in this review.

Characterization of phosphorus forms in a Eutrophic Lake, China.

In this study, molecular compositions of cyanobacteria, suspended matter, and surface sediments in the Dianchi Lake, a highly eutrophic lake, were investigated by solution and solid-state 31P nuclear magnetic resonance (NMR) spectroscopy. A solution-state 31P NMR spectral analysis of NaOH-EDTA-extracted samples revealed the presence of orthophosphate (ortho-P, 48.5%-91.2% of the total extracted phosphate), orthophosphate monoester (mono-P, 7.3%-43.9%), orthophosphate diester (diester-P, 0.9%-3.9%), and pyrophosphate (pyro-P, 0.7%-5.5%). The organic phosphorus (Po) distribution in suspended matters and cyanobacteria was relatively similar but different from surface sediments. The inorganic phosphorus (Pi) distribution in suspended matters and surface sediments was slightly similar. Results of the solid-state 31P NMR spectral analysis of non-extractable residue showed that cyanobacteria and suspended matter contain a large proportion of Po and poly-P. For surface sediment, only metal-bonded pyro-P and a high proportion of ortho-P were detected. The solid-state 31P NMR spectra results of extracted residual indicated that several of the pyro-P bound to metals and other Pi or Po compounds associated with mineral phases in suspended matter and surface sediment are non-extractable. This result revealed that a high proportion of biogenic phosphorus is bioavailable. These results verify the process of biogenic poly-P regeneration in the Dianchi Lake given that Po, poly-P, and pyro-P are predominant in cyanobacteria and can be released into lake water through chemical and biological degradation, thus further worsening eutrophication.

Dermal exposure to plasticizers in nail polishes: An alternative major exposure pathway of phosphorus-based compounds.

Phosphorus-based compounds are used as plasticizers in the manufacture of many products found in the indoor environment. Here we quantitatively investigated dermal exposure to phosphorus-based compounds contained in 45 nail polishes purchased in Japan. The alternative plasticizer triphenyl phosphate (TPhP) was detected in some samples of the nail polishes made in the USA (concentration, 1.1-1.8 wt%). The potential dermal exposure rates for TPhP, estimated using ConsExpo (version 5.0; Dutch National Institute for Public Health and the Environment), were in the range 200 (5%ile)-1700 (50%ile)-5000 (95%ile) ng kg-bw-1 day-1, which is more than 1400 times the reported values for exposure via dust ingestion and inhalation. Thus, dermal exposure via nail polish may be a major route of exposure to TPhP. The margin of exposure range for TPhP was 3.6 × 105-4.1 × 104-1.4 × 104. For comparison, the potential dermal exposure rate range for the conventional plasticizer dibutyl phthalate and the alternative plasticizer acetyl tributyl citrate was 360-3500-14,000 and 430-4100-17,000 ng kg-bw-1 day-1, respectively, and the margin of exposure range was 4.1 × 103-4.2 × 102-1.1 × 102 and 2.3 × 105-2.4 × 104-5.9 × 103, respectively.

Effect of supplementation of phytase to diets low in inorganic phosphorus on growth performance and mineralization of broilers.

There has been discussion regarding microbial phytase replacing inorganic phosphorus (P) supplementation in broiler diets. Therefore, an experiment was conducted to examine the effect of phytase supplementation on diets low in inorganic P. Ross 308 broilers (n = 288) were fed one of 6 experimental diets in 4 phases. The control diet had 16.20, 10.90, 9.40, and 6.10 g/kg inorganic P in the Starter, Grower 1, Grower 2 and Finisher phase respectively. The remaining diets had 10.50 g/kg inorganic P in the Starter phase. Two of the diets had graded reductions in inorganic P of 5.10, 3.60, and 0.60 g/kg or 2.00, 0.50, and 0.60 g/kg for the Grower 1, Grower 2 and Finisher phase respectively, plus 500 FTU phytase. Three of the diets had inorganic P levels of 0.40, 0.50, and 0.60 g/kg for the Grower 1, Grower 2 and Finisher diets respectively and either 500, 750, or 1,000 FTU phytase. Broiler performance was analyzed at d 10, 20, 26, and 35. On d 35, ileal calcium (Ca) and P digestibility and tibia bone strength, mineralization, and mineral content were analyzed. There were no significant differences between the control diet and diet containing 1,000 FTU phytase and low inorganic P in the grower or finisher diets based on bird performance, tibia strength, and Ca and P digestibility. Birds fed the control diet had significantly higher BWG (P = 0.001), bone strength (P < 0.001) and ash content (P < 0.001) compared to birds fed the diets with 500 FTU or 750 FTU phytase and low inorganic P in the grower and finisher stages. This may be due to incomplete dephosphorylation of the inositol ring of phytate with these doses of phytase, but with 1,000 FTU phytase there was almost complete phosphate hydrolysis of each phytate. This study showed that relying on phytase alone to ensure full supply of P in broiler diets is viable in finisher diets but is not recommended in grower diets unless phytase is supplied at doses of 1,000 FTU or greater.

Spatially resolved chemical analysis of cicada wings using laser-ablation electrospray ionization (LAESI) imaging mass spectrometry (IMS).

Laser-ablation electrospray ionization (LAESI) imaging mass spectrometry (IMS) is an emerging bioanalytical tool for direct imaging and analysis of biological tissues. Performing ionization in an ambient environment, this technique requires little sample preparation and no additional matrix, and can be performed on natural, uneven surfaces. When combined with optical microscopy, the investigation of biological samples by LAESI allows for spatially resolved compositional analysis. We demonstrate here the applicability of LAESI-IMS for the chemical analysis of thin, desiccated biological samples, specifically Neotibicen pruinosus cicada wings. Positive-ion LAESI-IMS accurate ion-map data was acquired from several wing cells and superimposed onto optical images allowing for compositional comparisons across areas of the wing. Various putative chemical identifications were made indicating the presence of hydrocarbons, lipids/esters, amines/amides, and sulfonated/phosphorylated compounds. With the spatial resolution capability, surprising chemical distribution patterns were observed across the cicada wing, which may assist in correlating trends in surface properties with chemical distribution. Observed ions were either (1) equally dispersed across the wing, (2) more concentrated closer to the body of the insect (proximal end), or (3) more concentrated toward the tip of the wing (distal end). These findings demonstrate LAESI-IMS as a tool for the acquisition of spatially resolved chemical information from fragile, dried insect wings. This LAESI-IMS technique has important implications for the study of functional biomaterials, where understanding the correlation between chemical composition, physical structure, and biological function is critical. Graphical abstract Positive-ion laser-ablation electrospray ionization mass spectrometry coupled with optical imaging provides a powerful tool for the spatially resolved chemical analysis of cicada wings.

Internal phosphorus loading across a cascade of three eutrophic basins: A synthesis of short- and long-term studies.

Ascertaining the phosphorus (P) release processes in polymictic lakes is one of the methodologically most complex questions in limnology. In the current study, we combined short- and long-term investigations to elucidate the role of sediments in the P budget in a chain of eutrophic lake basins. We quantified the internal loading of P in three basins of Lake Peipsi (Estonia/Russia) for two periods characterized by different external P loadings using radiometrically dated sediment cores (long-term studies). The relationships between different water quality variables and the internal P loading, and the external P loading were studied. Our short-term studies aimed at elucidating the possible mechanisms behind variations in internal P loading included examination of the surficial sediments, i.e., seasonal measurements of redox potential, sediment pore water P concentrations and diffusive fluxes. Our results provided evidence for a potentially high importance of internal P loading in regulating water quality. The sediment core analyses revealed an increase in the internal P loading during the period of lower external P loading coinciding with the general deterioration in the lake water quality (i.e, higher concentrations of soluble reactive phosphorus, total phosphorus and biomass of cyanobacteria). Increase in wave action between the two studied periods appeared to cause more frequent sediment resuspension, and thus be the most likely reason for the variations in internal P loading. Our short-term measurements indicated that resuspension events can be followed by a considerable increase in the diffusive fluxes.

Determination of Phosphorus and Potassium in Commercial Inorganic Fertilizers by Inductively Coupled Plasma-Optical Emission Spectrometry: Single-Laboratory Validation, First Action 2015.18.

A previously validated method for the determination of both citrate-EDTA-soluble P and K and acid-soluble P and K in commercial inorganic fertilizers by inductively coupled plasma-optical emission spectrometry was submitted to the expert review panel (ERP) for fertilizers for consideration of First Action Official Method(SM) status. The ERP evaluated the single-laboratory validation results and recommended the method for First Action Official Method status and provided recommendations for achieving Final Action. Validation materials ranging from 4.4 to 52.4% P2O5 (1.7-22.7% P) and 3-62% K2O (2.5-51.1% K) were used for the validation. Recoveries from validation materials for citrate-soluble P and K ranged from 99.3 to 124.9% P and from 98.4 to 100.7% K. Recoveries from validation materials for acid-soluble "total" P and K ranged from 95.53 to 99.40% P and from 98.36 to 107.28% K. Values of r for citrate-soluble P and K, expressed as RSD, ranged from 0.28 to 1.30% for P and from 0.41 to 1.52% for K. Values of r for total P and K, expressed as RSD, ranged from 0.71 to 1.13% for P and from 0.39 to 1.18% for K. Based on the validation data, the ERP recommended the method (with alternatives for the citrate-soluble and the acid-soluble extractions) for First Action Official Method status and provided recommendations for achieving Final Action status.

Dynamics of particulate phosphorus in a shallow eutrophic lake.

We tested the hypothesis that in shallow, eutrophic Lake Kasumigaura, the concentration of particulate phosphorus (PP) is controlled by biogenic P (P in living or dead phytoplankton and bacterial cells), rather than by resuspension of inorganic P in sediment. Increases in wind velocity and turbidity were associated with bottom shear stress exceeding the critical value for the lake (τc=0.15Nm(-2)); this increased turbidity was due to sediment resuspension. However, concentrations of PP; HCl-extractable, reactive P in PP (P-rP); and HCl-extractable, non-reactive P in PP (P-nrP) were not correlated with wind velocity (PP vs. wind velocity: r=0.40, p>0.05). Rather, the P-nrP concentration accounted for approximately 79% of PP, and the concentrations of PP, P-rP, and P-nrP were correlated with the particulate organic carbon (POC) concentration (POC vs. PP: r=0.90, p<0.01; POC vs. P-rP: r=0.82, p<0.01; POC vs. P-nrP: r=0.86, p<0.01). In our (31)P nuclear magnetic resonance spectroscopy results, mononucleotides accounted for the largest proportion among the detected P compound classes. In addition, concentrations of mononucleotides, orthophosphate, and pyrophosphate were significantly higher in samples with high POC concentrations, whereas the DNA-P concentration was not. These results suggest that biogenic P affects PP concentrations more strongly than does sediment resuspension, and the production of biogenic P creates a pool of mononucleotides, a class of easily degradable P, even in shallow, eutrophic Lake Kasumigaura.

Phosphorous fractionation in mangrove sediments of Kerala, south west coast of India: the relative importance of inorganic and organic phosphorous fractions.

The study of phosphorous dynamics in mangrove ecosystems of the northern Kerala coast aims to delineate its relationships with other biogeochemical parameters. Our intension is to check the validity of the hypothesis that these mangrove ecosystems act as an efficient trap of organic phosphorous by acting as P sink. The dissolved inorganic phosphate displayed higher concentration in monsoon that could be correlated with higher P leaching from mangrove litter as well as terrigenous input during wet season. Fe(OOH)≈P was much higher in monsoon (235.23 to 557.70 µg g(-1)) and lower in pre-monsoon (36.50 to 154.97 µg g(-1)), and displayed significant contribution towards the inorganic sedimentary P fractions. In monsoon, adsorption of P on iron hydroxides is enhanced by fresh water conditions, but pre-monsoon is characterised by the reductive dissolution of iron oxy hydroxides and the subsequent efflux of P to water column. CaCO3≈Pinorg may be present as an inert fraction in the sediment matrix, and did not display any interrelationship with other geochemical parameters. The abundant total organic P (25 to 73 %) fractions, largely derived from P bound with humic/fulvic acid, played a major role in immobilising P and regulating its dynamics in the nearby estuarine and coastal environment.

The phosphorus speciations in the sediments up- and down-stream of cascade dams along the middle Lancang River.

We detected the longitudinal variability of phosphorus speciations and its relation to metals and grain size distribution of sediments in three cascade canyon reservoirs (Xiaowan, Manwan and Dachaoshan) along Lancang River, China. Five phosphorus speciations including loosely bound P (ex-P), reductant soluble P (BD-P), metal oxide-bound P (NaOH-P) calcium-bound P (HCl-P) and residual-P were extracted and quantified. Results showed that in Manwan Reservoir HCl-P accounted for the largest part of total phosphorus (TP) (49.69%), while in Xiaowan and Dachaoshan reservoirs, NaOH-P was the most abundant speciation which accounted for 57.21% and 55.19% of total phosphorus respectively. Higher contents of bio-available phosphorus in Xiaowan and Dachaoshan reservoirs suggested a high rate of P releasing from sediments. Results also showed ex-P and HCl-P had positive correlation with Ca. Total phosphorus was positively correlated with Fe. The silt/clay contents of the sediments had close relationship with ex-P (r=0.413, p<0.05), NaOH-P (r=0.428, p<0.05) and BAP (r=0.458, p<0.05). The concentration of Ca, Mn and silt/clay speciation in the sediments explained 40%, 10% and 4% of the spatial variation of phosphorus speciations, respectively.

Nitrogen and phosphorus distribution in a constructed wetland fed with treated swine slurry from an anaerobic lagoon.

Nitrogen and phosphorus distribution in a constructed wetland fed with treated swine slurry from an anaerobic lagoon were studied. The methodology considered a daily meteorological monitoring site. During 2011 to 2012, water, soil and plants (Schoenoplectus californicus (C.A. Méyer) Sójak, Typha angustifolia (L.)) were seasonally sampled (spring and fall) into the constructed wetland. During study period, results showed that rainfall was the main factor of maintenance hydraulic conditions, while evapotranspiration was driver of variations in water storage level. Nitrogen and phosphorus removal from the water phase were up to 54% and 37%, respectively. Onto soil were adsorbed over 70% nitrogen and 65% phosphorus. Phosphorus was less mobile than nitrogen, since it was bound to oxides Fe-Mn. Inorganic nitrogen species were affected by level water and seasonal vegetable maturation. During spring, N-NH4(+) was the predominant soil species, while in the fall, N-NO3(-) was dominant near the belowground part of Sc and NH4(+) near to the belowground zone of Ta. In addition, nutrients uptake was less than 30% with 64% aboveground-spring and 85% belowground-fall for both plants. Findings showed nitrification process evidences when water levels are below 0.1 m.

Preliminary investigation on the potential use of two C4 turfgrass species to reduce nutrient release in a Mediterranean drained peatland.

This study compared dry matter production, nutrient uptake and tissue nutrient concentration of two C4 turfgrass species (Cynodon dactylon × Cynodon transvaalensis Burtt Davy and Paspalum vaginatum Swartz) supplied with three different nutrient solutions in a sand and peat culture. The 8-week experiment was performed in mesocosms and simulated the conditions of an open-field phyto-treatment system located in a Mediterranean drained peatland (Tuscany, Italy). Peat was collected on the site, and one of the solutions mimicked drainage water flowing into it. Three hypotheses were tested: (i) the species chosen efficiently removed nutrients from both the solution and the substrate; (ii) peat contributed to the nutrient load; and (iii) the species chosen were suitable in the open-field system. Both species adapted well to the experimental conditions and demonstrated considerable ability to remove nutrients. P. vaginatum took up nitrogen more efficiently, mainly in conditions of high nutrient availability. We observed supplementary nutrient uptake by plants in the peat treatment. Performances of the two C4 turfgrasses extrapolated to the field scale seemed effective from a phyto-treatment perspective.

Utilisation of gas-phase ion-molecule reactions for differentiation between phospho- and sulfocarbohydrates.

Gas-phase ion-molecule reactions of four boron-containing neutrals were explored as a means for differentiation between isobaric phospho- and sulfocarbohydrates. Phosphorylation and sulfation impose an addition of 80 Da to the molecular mass, so for low-resolution mass spectrometers compounds that have such modifications will appear at the same nominal mass-to-charge (m/z) ratio. However, the ions of these isobaric species behave differently in ion-molecule reactions. All four evaluated neutral molecules [trimethyl borate (TMB), triethyl borate (TEB), diethylmethoxyborane (DEMB) and diisopropoxymethylborane (DIPMB)] proved to be reactive towards phosphorylated sugars and unreactive towards sulfated carbohydrates. In addition, TMB and TEB were found suitable for distinguishing positional isomers of phosphorylated carbohydrates, while reactions with DEMB and DIPMB were successful in differentiating phosphorylated, sulfated and unmodified deprotonated sugars. Similar reactions in the positive ion mode (alkali cationised) were found to be less conclusive.

Geochemical characteristics of phosphorus in surface sediments of two major Chinese mariculture areas: the Laizhou Bay and the coastal waters of the Zhangzi Island.

Phosphorus (P) in surface sediments of the Laizhou Bay (LB) and the coastal waters around the Zhangzi Island (ZI) was analyzed. Six forms of P were separated - exchangeable or loosely sorbed P (Ads-P), aluminum-bound P (Al-P), iron-bound P (Fe-P), authigenic apatite plus CaCO3-bound P plus biogenic apatite (Ca-P), detrital apatite plus other inorganic P (De-P) and organic P (OP). The average contents of P in the LB were in the order: De-P>OP>Ca-P>Fe-P>Ads-P>Al-P; in the ZI, the corresponding order was De-P>OP>Fe-P>Ca-P>Ads-P>Al-P. Due to the high nutrient loadings from the surrounding rivers, TP contents in sediments of the LB were higher than in those of the ZI. The potential bio-available P (Ads-P and OP) accounted for 14.7% and 24.2% of TP in sediments of the LB and the ZI, respectively.

Occurrence of surfactants in wastewater: hourly and seasonal variations in urban and industrial wastewaters from Seville (Southern Spain).

Surfactants are daily discharged to the environment from urban and industrial activities. The assessment of the risk derived from the presence of these compounds in the environment requires a deep knowledge about their sources and their distribution in wastewater treatment plants (WWTPs). However, in spite of several studies reporting their presence in WWTPs, only a small number is focused on their different sources. In this work, the distribution of anionic (linear alkylbenzene sulfonates) and non-ionic (nonylphenol ethoxylates) surfactants in WWTPs and in urban and industrial wastewater collection systems has been investigated. Seasonal and daily variability was also assessed. Concentrations of linear alkylbenzene sulfonates in influent and effluent wastewaters ranged from 1155 to 9200 µg L(-1), and from below limit of detection to 770 µg L(-1), respectively, whereas the concentrations of nonylphenol ethoxylates were significantly lower. Linear alkylbenzene sulfonates were efficiently removed (>96%), while mean removal rates of nonylphenol ethoxylates were significantly lower (<20%). Studies carried out in different seasons revealed seasonal discharge patterns from both urban and industrial activities. The analysis of wastewater collection systems showed a major contribution of linear alkylbenzene sulfonates from urban areas while, in the case of nonylphenol ethoxylates, their major contribution came from industrial activities. In all cases the discharge patterns of surfactants were related with the water consumption.

[Characteristics of phosphorus fractions in sediments of constructed wetlands].

In order to better understand phosphorus (P) cycle in wetland ecosystem, the characteristics of phosphorus fractions in sediments of Heituwa constructed wetland system were investigated using soil organic phosphorus (Po) fractionation scheme and 31P-NMR technology. The concentrations of TP, Pi, Po and soil organic matter were all increased along the flow direction. Four kinds of P-compounds (orthophosphate, orthophosphate monoesters, orthophosphate diesters, and pyrophosphate) were detected in the NMR spectrum. Orthophosphate and phosphate monoester accounted for the dominants position in sediment phosphorus. This study indicates that the Po in sediment plays an importance role in wetland ecosystem and suggested that more attention should be paid to Po, especially to DNA-P and pyrophosphate in further research and management of constructed wetlands. Compared with the traditional chemical analysis method, 31P-NMR method has sample preparation relatively simple and is less destructive, with components analyzed completely. Using 31P-NMR technology, the cognition of wetland phosphorus cycle, especially organophosphate, will be expected to get new breakthrough.

Phosphorus-31 nuclear magnetic resonance assignments of biogenic phosphorus compounds in sediment of an artificial Fuyangxin River, China.

River eutrophication could drastically influence the phosphorus (P) in the water and sediment. To understand the biogenic-P species, distribution and bioconversion, five sediment samples were collected from an artificial river, and analyzed by phosphorus-31 nuclear magnetic resonance ((31)P-NMR). The P pollution in the water and sediment were both severe. The average concentrations of total P (TP) and solution reactive phosphorus in the water were 3.0 and 2.6 mg L(-1), respectively, which surpass grade V of the national quality standard (China) and should not be used for any purpose. The river sediments accumulated significant inorganic phosphorus (Pi) and organic phosphorus (Po); in the P fractionation, the rank order of the P fractions was as follows: Ca-P > NaOH-Pi > Res-P > KCl-P > NaOH-Po, with average relative proportions of 25.1:16.8:6.6:1.7:1:0. Six P compounds were detected in the NaOH-EDTA extract by (31)P-NMR. Mono-P (8.96-29.58 %) was the dominant forms of biogenic-P, and other smaller fractions of biogenic-P were also observed, including pyro-P (0.22-0.86 %), DNA-P (0.75-2.03 %), phon-P (0-1.57 %), and lipids-P (0-2.66 %). The TP and biogenic-P decreased along the direction of flows, with their average relative proportions 7.97:1.20:1.49:1.00:1.00 and 40.87:2.34:3.46:1.60:1 from the upstream to downstream, respectively. The concentration and species of Po in NaOH-Po were lower than found in (31)P-NMR analysis in this research. Thus, the use of 0.25 M NaOH and 50 mM EDTA extracts and solution (31)P-NMR analysis was a more accurate method for quantifying biogenic-P in the river sediments than P fractionation.